Energy for Development
The Beijer Institute The Scandinavian Institute Thc Royat Swedish of A-ffican Studies Arrtdemy of Sciences UppsaEa, Sweden Stockholm, Sweden ENERGY, ENVIRONMENT AND DEVELOPMENT IN AFRICA 11
ENERGY FOR DEVELOPMENT IN ZIMBABWE
Edited by Richard H. Hosier
Published by THE BEUER INSTITUTE and THE SCANDINAVIAN INSTITUTE The Royal Swedish OF AFRICAN STUDIES Academy of Sciences Uppsala, Sweden Stockholm, Sweden The series "Energy, Environment and Development in Africa" is published jointly by the Beijer Institute and the Scandinavian Institute of African Studies, with financial support from the Swedish International Development Authority (SIDA).
ENERGY, ENVIRONMENT AND DEVELOPMENT IN AFRICA Other titles in this series: 1. Energy and Development in Kenya: Opportunities and Constraints. P. 0' Keefe, P. Raskin and S. Bernow (Eds). 2. SADCC: Energy and Development to the Year 2000. J.T.C Simoes (Ed). 3. Energy and Development in Southern Africa: SADCC Country Studies, Part I. P. 0' Keefe and B. Munslow (Eds). 4. Energy and Development in Southern Africa: SADCC Country Studies, Part 11. P. 0' Keefe and B. Munslow (Eds). 5. Manufacturing Industry and Economic Development in the SADCC Countries. R. Peet. 6. Wood, Energy and Households: Perspectives on Rural Kenya. C. Barnes, J. Ensminger and P. 0' Keefe (Eds). 7. Energy Use in Rural Kenya: Household Demands and Rural Transformation. R.H. Hosier. 8. LEAP: A Description of the LDC Energy Alternatives Planning System. Paul D. Raskin. 9. Zimbabwe: Energy Planning for National Development. R.H. Hosier (Ed). 10. Zimbabwe: Industrial and Commercial Energy Use. R.H. Hosier (Ed). 11. Energy for Rural Development in Zimbabwe. R.H. Hosier (Ed).
ISSN 0281-8515 ISBN 91-7106-278-5 0 The Beijer Institute and the Scandinavian Institute of African Studies 1988 Printed in Sweden by Bohuslaningens AB, Uddevalla 1988 FOREWORD
The studies presented in thi S Volume were originally carried out as part of the Zimbabwe Energy Accounting Project (ZEAP). The ZEAP was a joint undertaking between the Beijer Institute of the Royal Swedish Academy of Sciences and the Ministry of Water and Energy Resources and Development of the Republic of Zimbabwe. The objectives of the Project were fourfold, namely:
(1) To establish a detailed end-use energy accounting system for Zimbabwe;
(2) To examine rural energy problems in general , and the woodfuel problem in particular;
(3) To examine, in detail, industrial energy consumption and the commercial fuel supply sectors;
and
(4) To develop a set of projects consistent with the Government-S overall policy directions to address the energy problems identified.
The materials in this Volume, which concentrate on the second objective above, are published for two reasons: First, there is generally very little information available on Zimbabwe energy issues. Second, the overall conclusions of the ZEAP project, summarized in Volume 9 of this series, was only able to reflect the "tip of the iceberg" of work that went into the ZEAP effort.
I am most grateful to all our Zimbabwean and other colleagues who contributed to this volume (see page 243). I am particularly indebted to Dr Richard Hosier who has taken responsibility for up-dating and editing of the ZEAP material that went into this Volume.
Gordon T. Goodman Executive Director Bei jer Institute PREFACE
The papers published in this book represent the collec- tive and individual thoughts of the working group on rural energy development of the Zimbabwe Energy Accounting Project (ZEAP). The project was a joint undertaking between the Beijer Institute of the Royal Swedish Academy of Sciences and the Ministry of Water and Energy Resources and Development of the Government of Zimbabwe. The first paper was formulated by the entire rural energy working group. Originally written in late 1383, it was intended to formulate the major concepts and issues to inform the remainder of the work on rural energy. The papers then progressively focus on agriculture, households, and energy technology and the environment. The second paper provides a thorough look at energy use ~n Zimbabwe's agricultural sector. This is complemented by the third paper on land-use patterns and ecological potential. From the agricultural sector, the papers then turn to the household sector. The fourth paper analyses household energy consumption and uses a multinomial logit framework to analyze the determinants of fuel choice throughout Zimbabwe. The fifth paper focuses on the role of women in Zimbabwe's rural energy economy. The final four papers address issues of energy technology and the environment in rural Zimbabwe. The sixth paper focuses on the efficiency of domestic cookstoves and presents the results of a comprehensive stove-testing program carried out as part of the ZEAP. The seventh paper examines current tree-planting, and agroforestry practices in Zimbabwe. The eighth paper looks at the impact of fuelwood harvesting on soil erosion in Zimbabwe's communal areas. The final paper assesses the potential of renewable energy technologies for making a significant impact on the major problems in Zimbabwe's rural energy system. I am greatly indebted to all the contributors to this volume, and I hope that the final product is worthy of their efforts. A special vote of thanks goes to Bonnie Ram who was the project administrator responsible for organizing most of the work. I would like to thank Lars Kristoferson and Gordon Goodman for their encouragement to organize and publlsh this material. Keith Adams spent endless hours deciphering notes, tracing references, editing drafts, and finally putting all of this into acceptable form. Priscilla Chinyangara, Solveig Nilsson, and Lori Cole all deserve thanks for having entered different versions of these papers onto word processors and then revised them. Any errors of omission or commission remaining at this point are solely the respons~bilityof the editor.
Richard B. Hosier
August 1987 Philadelphia, Pennsylvania CONTENTS
I. Energy for Rural Development in Zimbabwe: Concepts 1 and Issues for Growth with Equity
1. Introduction 1 2. Energy for Rural Development in Zimbabwe 1 3. Approaches to Energy Planning in Developing 3 Countries 4. Zimbabwe's Rural Structure and Energy System 10 5. Zeap Rural Energy Studies 14 6. Rural Energy Policy Issues 16
11. Energy Use in Zimbabwe's Agricultural Sector 20
Introduction 20 Energy Use in Agriculture 2 1 Zimbabwe's Natural Resource Base 2 3 Zimbabwe's Agrarian Structure 25 Energy Use in Zimbabwe's Agricultural Sector 3 2 The Energetics of Agriculture in Zimbabwe 3 5 Key Issues for Agricultural Energy Development 45 Summary and Recommendations 5 2
111. Methodology for the Assessment of Land-Use in Zimbabwe
1. Introduction 60 2. Land Areas and Ecological Zones 60 3. Distribution of Cultivation 6 7 4. Indigenous Forest and Grazing Land and Non- 7 1 Utilizable land 5. Agricultural Productivity 73 Appendices: The distribution of Land by Natural 75 Region, 1982 Appendix 111-1: Communal Land 75 Appendix 111-2: LSCF and State Farms 77 Appendix 111-3: Resettled Areas 79 Appendix 111-4: SSCF
IV. Household Energy Use in Zimbabwe: An Analysis of Consumption Patterns and Fuel Choice
1. Introduction 2. Physical and Conceptual Background 3. Residential Energy Consumption in Zimbabwe 4. Household Fuel Choice 5. Conclusions V. Women and the Rural Energy Economy of Zimbabwe: 110 Research Findings and Policy Issues 1. Introduction 2. Women and Rural Energy 3. Towards a 17omen-Oriented Rural Energy Development Policy
VI. Performance Testing Domestic Cookstoves for Zimbabwe 142 1. Introduction 2. The Program 3. The Stoves 4. Results and Discussion 5. Conclusions
VII. Fuelwood Consumption and Supply Patterns, Tree- 160 Planting Practices, and Farm Forestry in Rural Zimbabwe 1. Introduction Part I. Fuelwood Consumption Patterns and Supply in Rural Zimbabwe 2. Background 3. Fuel Types, Appliances and Preferred Fuelwood Species 4. \?ood Storage 5. How Fuel is Obtained 6. Source of Fuelwood 7. Transport 8. Demand and Supply 9. Wood Resource Adequacy Part 11. Tree-Planting Practices and the Potential Role of Farm Forestry in Zimbabwe's Rural Areas 10. Introduction 11. Results of the Tree-Planting Survey 12. Discussion 13. Farm Forestry 14. General Discussion 15. Conclusions
VIII.Woodfuel Harvesting and Soil Erosion in Zimbabwe 185 1. Introduction 185 2. Factors Influencing Soil Erosion and Erosion 186 Rates in Zimbabwe 3. Soil Erosion Hazard 190 4. Soil Erosion Observations 191 5. Erosion Classification Scheme 193 6. General Conclusions from Field Observations 194 IX. The Prospect for Application of Renewable Energy Technologies in Zimbabwe's Rural, Domestic and Agricultural Sectors Introduction Demand Renewable Energy Resources Review of Applications and Technology Cooking and Heating Water Heating Traction and Transport Irrigation, Stock Watering and Domestic \later Pumping Conclusions
List of Contributors Index
LIST OF TABLES
Chapter I 1-1 Classification Matrix for Rural Energy Studies 8 1-2 Zeap Project Studies 15
Chapter I1 Land Areas by Natural Region 25 Distribution of Agricultural Land 26 Energy Consumption in the Agricultural Sector 3 2 Energy Consumption in the LSCF Sector 3 3 Energy Consumption in the LSCF Sector by Crop 34 Energy Consumption for the Major LSCF Crops 35 Energetic Efficiency of Maize Production in 36 Zimbabwe's LSCF Sector and the United States Energetic Efficiency of Wheat Production in 37 Zimbabwe's LSCF Sector and the United States Energetic Efficiency of Wheat Production on Two 38 Lowveld State Farms in Zimbabwe Energy Intensity of Irrigated Cotton Production 39 Production Statistics: Communal Areas 40 Energy Inputs and Outputs: Communal Areas 4 1 Production Statistics: Resettlement Schemes (A) 43 Energy Inputs and 0utputs:Resettlement Schemes (A) 43 Chapter I11
Related Farming Systems Provincial Land-Use Totals by Natural Region 6 3 Land-Use Categories and Agro-Ecological Regions 65 Land-Use Categories in Zimbabwe 6 6 Forest Lands 6 7 Projection of Cropped Land 69 Projected Increases in Agricultural Production 70 Non-Utilizable Land in Zimbabwe 7 1 Indigenous ~orest/~razingLand in Zimbabwe 72 Distribution of Non-Utilizable Land 72
Chapter IV
IV-1 Fuel Consumption by Residential Subsector 88 IV-2 Fuel Consumption by Income Category 89 IV-3 Fuel Consumption by Natural Region 9 1 IV-4 Definition of MNL Variables: National Level 9 5 IV-5 Analysis of Individual Parameters: National Level 97 IV-6 Sign Effects of Variables: National Level 98 IV-7 Definition of MNL Variables: Urban Areas 100 IV-8 Analysis of Individual Parameters: Urban Areas 101 TV-9 Sign Effects of Variables: Urban Areas 102 IV-10 Definition of MNL Variables: Rural Areas 103 IV-11 Analysis of Individual Parameters 104 IV-12 Sign Effects of Variables: Rural Areas 105
Chapter V v- l Population Pressures and Timber Shortages v- 2 Heads of Households by Age and Sex v- 3 Women's Labor Contribution per Task v-4 Karange TTL Labor Input in Agriculture v- 5 Major Food Crop Cycles and Labor Input by Sex V-6 Labor Input In Rural Zimbabwe by Task v- 7 Age and Gender Composition of Labor V-8 Tasks: Timing and Labor Input for Maize v-9 Labor Input by Task: Percentage of Working Hours v-10 Seasonal Schedule of Daily Activities for Women v-l l Length of Day for Men and Women v- 12 Labor Intensity by Age and Gender V-13 Household Labor Times for Fuelwood Collection V-14 Family Decision-Making in Rural Zimbabwe V-15 Age and Gender Composition: Crop Production V-16 Peasant Crops Grown for Food or Cash Chapter V11
Tree-Part Use as Fuel Distance to Fuel Source Forms of Transport National Fuelwood Supply and Demand Relationships Provincial Fuelwood Supply and Demand Fuelwood Supply and Demand for Three Provinces ~ype/Frequencyof Trees Planted in Communal Areas Percentages of Seedling Sources Percentages of Tree-Planting Initiatives Percentages of Tree-Planting Purposes
Chapter V111
VIII-1 Soil Loss from Crops Having Varying Cover Values 188 V11I-2 The Categories of Erosion in Zimbabwe 189 VIII-3 Soil Erosion Hazard in Communal Areas 190 VIII-4 Erosion Observations in Makoni District 192 VIII-5 Erosion Observations in Marange District 193
Chapter IX
IX-1 Final Consumption by Sector IX-2 Fuel Consumption by End-Use IX-3 Fuel Consumption by End-Use IX-4 Fuel Consumption by Epd-Use IX-5 Average Monthly Rainfall by Catchment Area IX-6 Technical Characteristics: Selected Applications IX-7 Technical Characteristics: Selected Technologies IX-8 Selected ~pplication/Technology Matches
LIST OF MAPS Map 11-1 Distribution of Natural Regions by Province 2 4 Map 11-2 Distribution of Large-scale Commercial and 27 Communal Farm Areas by Natural Region Map 11-3 Distribution of Resettlement Schemes 30 by Natural Region Map 11-4 Tillage Zone Map of Mechanical Tillage Program 51
LIST OF FIGURES
Figure 11-1 Effect of Fertilizer on Maize Yields 48 Figure V-l Age-Gender Pyramid in Communal Areas 113 Figure VI-1 Constant Power Tests: Efficiency v Output 155 Figure VII-1 Fuelwood Supply Balance: Base-Case Scenario 168 Figure IX-1 Typical Daily Rural CookingIHeating Schedule 220
I. ENERGY FOR RURAL DEVELOPMENT IN ZIMBABiJE: COMCEPTS AND ISSUES FOR GROWTH WITH EQUITY D. Q. Chandiwana, T. Harris , R. Hosier, K. Johnson, S. Moyo and D. Tleiner
1. INTRODUCTION
This paper serves to set out the conceptual foundation of the rural energy studies carried out as part of the Zimbabwe Energy Accounting Project (ZEAP). This foundation was drawn from an understanding of energy planning models, the social-economic context of rural development in Zimbabwe, and a critical attitude towards much of the rural energy planning which had taken place to date. Our concern - hence the focus of this paper - was the cursory attention given to rural energy problems, in particular, the lack of an integrated conception of rural development and energy issues in most planning exercises. This paper also outlines ZEAP in broad strokes, and in more specific terms, details the issues to be addressed in the following chapters and the methodologies that should be used in any study dealing with energy for rural development in Zimbabwe. It is important to stress that this paper is not a summary of the rural studies actually carried out in ZEAP, but rather a presentation of the background, aims, methods and concepts of the issue, leaving discussion of the actual results obtained in the studies to the other chapters in this volume. We begin with a brief discussion of the goals of rural development in Zimbabwe and the energy implications of these goals. We stress the need to supply energy for subsistence and development purposes. A presentation and critique of common energy planning approaches £01 lows. This sets the stage for a discussion of our approach to energy planning. The final section addresses several of the most relevant policy issues in rural energy.
2. ENERGY FOR RURAL DEVELOPMENT IN ZIMBABWE
The only major document to address both the energy and rural development questions, albeit in isolation, is the Transitional National Development Plan (Republic of Zimbabwe, 1982). The primary objective of the plan for rural development is to achieve growth and equity simultaneously. Central to the plan is the enhancement of rural incomes, level of education, agricultural productivity, and job creation. This strategy of spatial economic integration involves a land reform program (in the form of resettlement), the establishment of rural growth and service centers, as well as a general improvement in access to social and physical infrastructures. If this rural development strategy is to succeed, the increase of rural energy supplies is crucial. Along with increased energy used for rural infrastructure and other large scale projects, equitable growth necessitates an increased flow of energy to the poorest of rural households. Presently there is a real danger that access to energy supplies for development purposes will be limited to the upper income groups in rural areas. This would intensify the process of agrarian differentiation and directly counter the growth with equity objective. Any attempt, therefore, to address this question requires a clear understanding of the energy processes within the Zimbabwean agrarian structure. In successful l y providing energy for rural development, there must also be provision of sufficient energy for purposes of subsistence. Rural development requires rural surplus generation with local reinvestment. This cannot occur if people are struggling to maintain a subsistence standard of living. Unfortunately, in many areas of Zimbabwe, the initial hurdle of providing energy for the acquisition of basic needs has not yet been completed. Therefore, certain subsectors within the Zimbabwean agrarian structure require special attention before their development needs for energy can be considered. It is therefore the task of the Department of Energy to ensure that the broad policy objective of growth with equity in the energy sector is implemented. To this end, the Department's central guiding principles are as follows:-
(1) To ensure a balanced and equitable development and expansion of energy supplies to meet the energy needs of all sectors of the economy, paying particular attention to the energy needs of communal areas, and seeking tobring this sector into the mainstream of economic development.
(2) To conserve the country's scarce foreign exchange by developing to the fullest extent the indigenous energy resources, particularly new and renewable energy sources.
(3) To achieve security of local energy supplies and thus reduce dependence on imported energy resources.
The Government's emphasis on the provision of energy for rural areas is evident in the variety of projects undertaken towards research and development of new and renewable energy resources; particularly in the fields of biogas, solar energy and rural afforestation. These efforts are complemented by energy conservation measures geared towards the household. Rural electrification is also being considered at the national level, focusing initially on growth and service centers. With respect to biogas, seventeen demonstration plants have been set up at various schools and business centers in the country to promote public awareness of biogas as an alternative source of energy. In the area of solar energy, water heaters, pumps and solar clinics have been installed at various locations on an experimental basis. A rural afforestation project is also underway to improve woodfuel supplies in communal areas. This is complemented by a woodstove demonstration project which is aimed at promoting woodfuel conservation. At the time the project began, about eight such fuel-efficient woodstoves had been constructed at various district service centers in the country. Although rural energy projects have been undertaken to alleviate the so-called "energy crisis", such projects do not alone constitute an energy policy. The program has often lacked coherence due to an inadequate understanding of the socio-economic realities in rural Zimbabwe, and the subsequent role of energy for rural subsistence and development. As a result, projects have been often piecemeal and have focused solely on one technical dimension of a problem while ignoring the larger social context in which that problem has occured. Furthermore, certain major energy needs have often been neglected, while other minor ones received a great deal of attention. In order to reconcile the Government's energy and rural development goals, a comprehensive understanding of the rural socio-economic system was required to direct and prioritize planning efforts. Unfortunately, the problem was exacerbated by the planning approaches commonly utilized in developing countries. Here, we will briefly examine these before presenting our alternative approach for rural energy analysis in Zimbabwe.
3. APPROACHES TO ENERGY PLANNING IN DEVELOPING COUNTRIES
In recent years, several approaches to energy planning in developing countries have emerged. There are two common types of models which are applied to energy planning at the national level: reduced-form model S and end-use models. Each of these has its strengths and weaknesses when applied to developing countries. In addition to these two generic models, a large number of studies have been undertaken of the rural energy problem. Initially, these arose sole1y with reference to fuelwood requirements, but have recently become more complex and involved. These approaches are frequently linked to energy policy initiatives. In this section, we briefly describe these approaches to the energy question in developing countries. IJe will move from a discussion of reduced form models to a consideration ofend-use models, paying particular attention to the end-use model used in the ZEAP project. However, it is our argument that no matter how refined one of these models is, it still fa11s short of providing sufficient information to outline a set of policies and projects that can adequately address crucial rural energy problems. Therefore, we shall briefly review some of the better studies of the rural energy question, with an emphasis on the link between these studies and policy interventions. This will set the stage for a presentation of the comprehensive approach used by the ZEAP team to tackle the rural energy problem in Zimbabwe.
ENERGY PLANNING MODELS
Most energy planning in developing countries has been based on models directly transplanted from those used in L7estern industrialized countries. L7hile this seems understandable to a point, it has tended to focus planning efforts almost entirely on defining strategies to synchronize the growth of commercial fuel supplies to growth in consumption requirements. Planning for commercial fuel supplies in most developing countries is far more advanced than even planning for agriculture, let alone overall rural energy requirements. Since data for these studies is easily accessible, they are relatively simple to undertake and usually focus on the supply of a single fuel, say electricity or coal. There are few if any attempts, however, to examine the technical substitution possibilities between fuel sources, so that the picture obtained is often static and simplistic. Planning and research tend to focus on large capital-intensive projects, as it is much simpler to deal with projects having a financial l y recoverable output than with projects addressing the broad and complex questions raised by an examination of rural energy development and subsistence requirements. When rural development is seen, as it is in the Zimbabwean case, in the context of growth with equity, the level and scope of analysis must focus on the local or micro-level. So far, Zimbabwe has planned for energy at the more macro level suggested above. For example, studies have been undertaken for coal (Montan Consultants, 1983), liquid fuels (Snamprogetti, 1983), and electricity supply re-quirements (Merz-McClellan, 1981). Each has been undertaken in isolation not only from the other, but also from any coherent development context. In general, energy planning makes use of one of types of models: reduced-form models and end-use models h37 While the Zimbabwean coal, liquid fuel, and electricity studies a1l make use of rudimentary reduced-form models in the projections of fuel consumption, no end-use models had been applied (prior to 1982) in Zimbabwe. Both approaches have strengths and weaknesses, particularly when applied to rural energy issues. Here, we shall briefly discuss each as a backdrop to the outline of the work undertaken by the ZEAP team.
REDUCED FORPI MODELS
Reduced-form models are designed to forecast the demand for a specific energy source. The demand forecast Is then compared with existing energy supplies to determine future supply requirements. The reduced-form approach, which has been promulgated by the World Bank, is essentially a supply- focused planning methodology. As such, the models contain few details of the structural determinants of energy use. They are based on economic principles and utilize econometric hods to explain the growth in demand for a particular fuel Income and price elasticities play a central role, as historically observed trends are used as independent variables to explain consumption by making use of regression analysis. As a result, growth in fuel consumption is seen to be a function of the growth in income, price, or possibly both. Growth parameters remain constant or change according to historically observed patterns. The advantage of this approach is its simplicity: it is possible to obtain a forecast of future energy supply requirements by applying simple statistics to readily available data. For certain purposes, this form of analysis is sufficient. However, two major limitations to gaining a thorough understanding of a national energy system can be identified. First, although reduced-form model S can provide adequate forecasts in cases of discontinuities or weak historical trends, they can seriously over- or underestimate future energy consumption because they fail to allow for structural change. Sensitivity analysis of key parameters has been applied to go part way towards solving this problem, but the fundamental flaw remains. Second, reduced-form models, as applied by most consultants, do not account for the substitution of alternative fuels. Substitution possibilities can be included using regression analysis, but the ability to refine the sophisticated trans-log models required is not found in most consultancy groups. Frequently, weak historical trends are used to project demand for a single fuel. An example of these shortcomings can be found in the Zimbabwe Power Sector Development Plan (Merz- McClellan, 1981). The lowest of the electricity consumption scenarios provided overestimated by nearly one hundred percent the actual consumption from 1980 to 1983. The techniques used did not account for both the severity of the world recession and the level of interfuel substitution and conservation that has occurred.
END-USE DEMAND MODELS
End-use model S, in contrast with reduced-form models, derive from an engineering approach to energy issues. In the specification of the models, an attempt is made to explicitly incorporate a11 the major structural and physical determinants of energy use. Energy users are aggregated into sectors which are then subdivided into those employing a specific end-use, that is a qualitatively discreet category of energy utilization, such as cooking, heating or lighting. Technical coefficients, frequently derived from laboratory experiments, then represent the quantity of energy consumed for a specific purpose within each sector and subsector. Projections are made based on assumptions about end-use or appliance dissemination, technical efficiencies, economic or demographic growth, and fuel substitutions. Different scenarios incorporating these assumptions are used to project future supply requirements and thus to examine the impact of different policy interventions. The real strength of the end-use approach is its ability to marshal together the detailed technical dimensions of the energy problem into a projection of supply requirements which allows planners to probe deeply into the operation of the energy system. It is able to account for substitution of different fuels as well as changes in the consumption of any particular fuel. The model, therefore, is not as likely to be used to examine trends within the market for one particular commercial fuel. It is also capable of including non-commercial fuels such as wood-fuels, which may not be bought and sold in a formal market. By adopting a comprehensive approach to fuel consumption, the end-use approach is better able to deal with the complexities of the energy system in developing countries. The ZEAP team used an end-use model for the projection of future energy needs in Zimbabwe. It is called the LDC Energy Alternative Planning Program (LEAP) and was developed specifically for use as an energy planning tool for developing countries. At the core of the LEAP system is an end-use based program designed to keep account of all the energy used in the economy. The economy is first broken down into sectors and subsectors (e.g. rural household, low income). Then the energy used in the subsectors is divided into specific end-uses (e.g. cooking) and end-use devices (e.g. wood stoves or paraffin stoves). Using this system, it is possibleto follownotonlyhow energyis used,butalso, who within the economy uses it. The demand module, driven by demographic, economic, and agricultural models, then provides a forecast of future consumption requirements. These estimates are then routed through programs tracing fuel supplies back to their initial source: hydro-electricity or barrels of crude oil in the case of commercial fuels, or wood and biomass resources in the case of traditional fuels. For the latter, LEAP contains a detailed land-use model designed to keep track of the basic resources necessary to meet woodfuel requirements. Both of the programs are then tied into a costing subprogram designed to keep track of the costs and benefits of meeting future energy requirements in local and foreign exchange terms. The result is a detailed projection of future energy requirements which takes into account different supply options and policy alternatives and calculates their costs. LEAP is an end-use model designed specifically to fit the unique energy problems encountered in developing countries. As such, it has several advantages. First, it can trace requirements for all fuels, both commercial and non-commercial. In countries like Zimbabwe where nearly forty percent of all energy comes from wood, this is crucial. Second, its disaggregated approach makes it able to trace specific target groups of particular interest for equitable development. It is possible to identify not only who uses the energy in the economy but also what they use it for. This is especially important for working within a growth- with-equity framework. Third, since it is an end-use model, it can be used to identify specific energy needs for rural development. The user can test the impact of new energy sources and identify the level of fuel shortages in critical sectors. Finally, the LEAP system provides a clear forum for investigation of the impacts of different energy policy interventions. For any fuel substitution, conservation, or supply-enhancement program, LEAP can trace its likely impacts on the national energy balance, measured in both energy and monetary terms. The LEAP system's real strength lies in the fact that because it is a specialized end-use model, it places the emphasis squarely on understanding the workings of the demand-side of the energy system. It forces the question of why energy-use patterns are the way they are. The ZEAP team adopted this approach for the work in Zimbabwe. To understand what present and future energy requirements are, it is necessary to understand energy demand, since demand, not supply, is the driving force. However, having said this, we must acknowledge that at this stage we encounter the major weakness of the LEAP system, or rather the weakness of all broad modelling approaches to energy planning. Energy models built to represent a national energy system cannot contain sufficient detail to sufficiently explain all of the problems in a national energy system. No national-level model, for instance, can explain the reproduction of the rural economy and the rural household. The LEAP system also assumes that all energy demand is currently being met. This is an assumption which has to be scrutinized. There are likely to be certain basic energy needs which are, at present, going unsatisfied. For this reason, we attempted to distinguish between "unmet" demand, current "effective" demand, and "desirable" demand. Furthermore, while LEAP can describe the impact of a rural energy program such as a stove-dissemination project, it cannot indicate either which stove conforms to the preferences of the fuel user or what is the best way to disseminate those stoves. To plan successfully for this and other rural energy interventions requires a detailed understanding of labor budgets, household preferences, access to capital and other important aspects of rural life. While LEAP can provide an analysis of the national implications of rural energy-use patterns, it must be complemented by a comprehensive investigation into the rural household and its decision-making framework. For this reason, we now turn to a discussion of rural energy studies that have been undertaken to date. RURAL ENERGY STUDIES
At their best, rural energy studies seek tounderstand the underlying processes determining rural energy consumption patterns. At their worst, they represent a half-hearted attempt to begin doing something about the oft-neglected rural energy system. Clearly, in order to understand the workings of the rural energy system well enough to make energy plans for growth with equity, a detailed, comprehensive study of energy use in rural Zimbabwe was necessary. In this section, we briefly review a few of the rural energy studies which have been undertaken to date. We will be paying special attention to the link between these studies and the formulation of plans, projects, and policies, since this is the aim of ZEAP: to gain sufficient understanding of Zimbabwe's energy system to be able to plan effectively for energy initiatives. This leads to a more detailed presentation of the efforts undertaken by the ZEAP team in coming to grips with Zimbabwe's rural energy problems. Most rural energy studies can be classified according to the matrix in Table I-l. The three most commonly used substantive frameworks are portrayed along the horizontal axis. Rural energy studies have tended to evolve from one of these three perspectives: wood/supply demand studies; energy supply/demand studies: and energy ecosystem studies. Simply stated, wood supply/demand studies focus on the supply of and demand for fuelwood and poles. These are the most limited of the studies as they concentrate on a single fuel. Energy supply/demand studies enlarge the scope of investigation to include all other fuels used in the rural sector but usually fall short of including animate sources of energy. Energy ecosystem studies view the rural energy from an ecosystem approach, attempting to quantify all energy flows (including animate energy) and to establish an energy equilibrium.
TABLE 1-1 CLASSIFICATION MATRIX FOR RURAL ENERGY STUDIES
Wood Energy Energy ~upply/~emand Supply/ ema and Ecosystem ...... Household/ Fleuretet a1 Beijer (Oleche) Briscoe Village Tanzania, 1978 Kenya, 1982 Bangladesh, 1979
Multiple Brokenshaet a1 Beijer (Johnson) Astra (Reddy et al) Village Kenya, 1980 Kenya, 1982 India, 1980
~egional/ FAO (Openshaw) Beijer (Hosier) Revelle National Tanzania, 1978 Kenya, 1985 India, 1976 ~egional/ Whitsun National Zimbabwe, 1981 ...... Each of these approaches has been applied at a single household or village, multi-village or regional or national level during the past few years. Each has been used as the basis for energy projects and policy planning on numerous occasions. In the appropriate location on the matrix is written the name of an organization, country, and reference detailing some of the formative work done in the substantive areas. Each will be discussed in turn to give a feel for the state of rural energy planning research as it has been undertaken to date. The first category of studies focuses solely on one rural energy resource - wood. The use of reduced-form models provides a projection, which may or may not be based on valid assumptions. Supply targets and plantation projects are planned for, but little attention is paid to precisely how to utilize or distribute the wood that is produced. In other words, wood requirements are estimated, but the workings of the rural system remain a mystery. As far as energy supply/demand studies are concerned, perhaps the most effective work to date has been undertaken by the Beijer Institute in Kenya. As part of the Kenyan Fuelwood Project, the staff of the Institute supervised a national rural household energy survey which estimated household consumption of all fuels (Hosier, 1985). These survey results helped both to build a national end-use accounting model and to stratify a set of detailed single and multiple village-level household energy-use studies (Oleche, 1982; Johnson 1982). On the basis of these studies, Beijer proposed to establish a set of rural energy centers adopting a decentralized, participatory approach to the dissemination of agroforestry techniques and fuel-efficient stoves in high potential regions of the country. The research results indicated that the energy problem was most severe in the high potential regions and that to be effective any effort must incorporate the knowledge, opinions and perceptions of the rural people. The study appears to have worked we1 l. By coupling national surveys with local studies, the Beijer Institute team was able to identify both the location of the most severe problem, as well as the inner workings of the rural energy system. Both the technical and social sides of the problem were analyzed with the exception that animate power was not included. In the first year of operation, the energy centers appeared to be having an impact on the rural energy problems in Kakamega District, The formative work done within the energy-ecosystem paradigm has been pursued by A.K.N. Reddy and his colleagues at ASTRA in Bangalore, India (Reddy et al., 1980). The ASTRA research team performed a series of careful surveys and observations to establish an energy flow balance for all activities in five villages in Karnataka. The study team then identified shortages and bottlenecks in the energy supply system. The project team eventually adopted a participatory approa.ch to the design of the energy centers to meet the supply requirements of the study communities. Residents were asked to identify their most pressing energy needs, and fuel supply options were identified to fulfil these needs. The ecosystem approach adopted by the ASTRA team has proved to be very useful. High quality data was derived and used in the ecosystem model to identify critical energy supply areas. The obvious shortcomings of their approach are twofold. First, while the technical aspects of the energy system were very strong, very little attention was paid to the socio-economic aspects of the energy problem. A more detailed overlay of socio-economic data is needed to lend a thorough understanding of energy-use patterns to the study results. Critical household decisions cannot be understood without a better understanding of intra-household processes than can be achieved with an ecosystem model. Second, the energy center solutions proposed by the team were mostly technological fixes requiring capital investment and substitution of alternative fuels for traditional ones. These solutions provided energy for development with insufficient attention being paid to the constraints impinging on household energy decisions. In this respect, the ASTRA energy centers were designed to provide development-oriented energy supplies, forsaking the tradi- tional, subsistence energy resources. As part of the ZEAP effort, a thorough study of the rural energy system from the energy demand/supply perspective was undertaken. The aim was to analyze the use of all fuels using methodologies suitable for household or village-level, multiple-site, and national studies. Of crucial importance to this analysis was the subsectoral disaggregation of the agrarian structure in order to pinpoint differences in resources, constraints, and opportunities influencing energy demand and supply patterns and subsectoral changes. We therefore, turn to a discussion of Zimbabwe's agrarian system before presenting in a more detailed manner the methodological approaches used in the work.
4. ZIMBABWE'S RURAL STRUCTURE AND ENERGY SYSTEM The analysis of the rural energy system in Zimbabwe by the ZEAP team involved the application of the energy accounting system at the national level, and the micro-level study of the structure and processes affecting energy supply and demand. The latter entailed clearlyidentifying the subsectors of the agrarian structure and characterizing these in terms of their economic, environmental, demographic, and production features. The units of investigationhad to be identified, as these vary by production units fromhouseholds to estates. Appropriate methods and approaches to the investigation had to be given special attention in order to fit the methodology to both the scale of observation and the level of detailed information required. At present, rural Zimbabwe reflects an historical process of uneven development: a labor-reserve economy was created to provide a constant source of cheap labor to mines, industries, and large-scale commercial farms. The State acted to limit access to capital and new technologies to the white minority. As a result, patterns of energy utilization vary tremendously between different rural subsectors. the Government's growth-with-equity strategy is an attempt to reverse this historical trend. In attempting to conceptualize Zimbabwe's rural energy system, we identified six subsectors. Each subsector plays a particular role in the rural economy, exhibits markedly different energy supply and demand characteristics, and presents a different set of potential energy policy initiatives. These subsectors are: (1) Large-Scale Commercial Farms (LCSF); (2) State Farms; (3) Small-scale Commercial Farms (SSCF); (4) Communal Areas; (5) Resettlement Areas; and (6) Rural Growth Points and Service Centers. For the ZEAP analysis, the first two subsectorswere treated as purely agricultural production units. Their domestic energy requirements were handled separately. The three remaining agricultural subsectors were considered as individual household units for domestic, agricultural, and non-agricultural activities within the context of the overal l household economy. Growth points and service centerswere examined as small urban entities servicing the other rural subsectors.
LARGE-SCALE COMMERCIAL FARMS The large-scale commercial farm sector constitutes approximately 4,500 highly mechanized and relatively energy intensive farms. Because of the large input of energy onto these farms, outputs are also high. The LCSF subsector has an energy profile similar to farming in the more industrialized countries of the world, with a very important difference in its reliance on large amounts of cheap labor. (There are presently over 250,000 LSCF workers). Future energy utilization in this subsector is uncertain for a number of reasons. Firstly, as workers' wages rise, farmers will attempt to displace labor with machines, creating a substitution of human for fossil fuel energy. Secondly, political pressures to reduce the size of this subsector are high due to its virtual monopolization of the country's most productive land. So, although long-term predictions regarding this subsector can be no more than speculation, in the short term it does seem likely that the LSCF subsector will remain a major destination for the flow of rural energy resources, primarily in the form of diesel, coal, agro- chemicals and electricity.
STATE FARMS
State farms have a similar energy profile to the LSCF subsector. Although on a national scale the importance of this subsector is currently minimal, the state farm subsector is expected to grow rapidly. All state farms are irrigated and use large quantities of diesel, agro-chemicals and electricity. In the future, it seems reasonable to assume that an increased amount of energy will have to flow to this subsector.
SMALL-SCALE COMMERCIAL FARMS
The small scale commercial farm subsector (SSCF) represents an attempt by former governments to create a small African agrarian capitalist class. The plan failed as many SSCF remained undercapitalized and absentee landlords became common. Although these farms primarily rely on human energy, there has been some diffusion of tractors and agro-chemicals. Nationally, the SSCF subsector is not an important consumer of energy.
COMMUNAL AREAS
The communal areas, where the bulk of the population live, face numerous energy problems. Firstly, because of the historical role as a labor reserve, these areas are increasingly reliant on off-farm sources of income simply to survive. Access to agro-chemicals - which are very important due to the poor quality land in many communal areas - is limited by monetary constraints, and the droughts have severely reduced access to draught power for agricultural work and manure for fertilization. An insufficient on-farm production capability for many communal farmers, exacerbated by difficulties in obtaining work in the towns, means that many communal area families are now facing a crisis of reproduction. Clearly there must be adequate energy for agricultural subsistence before overall economic development in the communal areas can occur. In many communal areas, obtaining adequate quantities of wood for cooking has also become a problem. Along with increasing the labor time for wood gathering, money is now sometimes required to obtain this critical household energy source. The commodification of wood could direct the flow of this resource to the wealthier communal area households. This could directly counter the Government's growth-with-equity strategy. On the other hand, the commodification of wood could increase the incentive to grow trees. The full implications of this transition, which is in the formative stages in Zimbabwe, must be clearly thought through by policy makers. Overall, the communal areas will remain a major chal lenge to planners adhering to a growth-with-equity strategy. The combination of a poor resource base and increasingly limited off-farm income opportunities will mean that communal area families will have trouble obtaining new technologies and securing even the most essential energy resources.
RESETTLEMENT AREAS
To date, approximately 35,000-40,000 families have been resettled. Most families have been resettled on an individual basis (model A), where each family is given five hectares of arable land and a designated grazing area. Because many of the resettled families were landless, poor, or refugees, the overall access to draught power and capital in this sector is low. Also, because the government acquires land on a willing-seller, willing -buyer basis, most of the schemes are located on lands which are marginal for dry-land maize production. Hence, many of these areas will require large inputs of agro-chemicals in order to achieve high yields. Some resettlement schemes have been organized on a co-operative basis (model B). Because of their ability to pool scarce family resources, model B farms have a greater ability to mechanize particular components of the production process. Furthermore, where tractors substitute for draught power, a much higher intensity of land use is possible. In the future, there is the likelihood that model B farms will become more energy and land-intensive. This will require additional flows of energy to the co-operative farms while helping to save land. Expansion of model A schemes will require more land but less energy. Presently, there does not appear to be a fuelwood shortage on resettlement schemes. However, early reports suggest that massive tree cutting is occurring without replanting. If this pattern is allowed to continue unabated, severe wood scarcities in these areas will develop rapidly.
RURAL GROWTH POINTS AND SERVICE CENTERS
The rural growth points and service centers are a major component of the Government's growth-with-equity strategy. The areas designated for development are likely to become centers for rural population migration as well as centers of demand for both rural-based energy sources and supplies of commercial energy. However, there is the danger that if the planning of these rural towns does not adequately address future energy requirements, competition between the town and adjacent farming communities will develop. There is already some indication that scarce wood from the communal subsector is being sent to local towns where a more lucrative market exists. There is also the danger that these rural growth points and service centers will serve only the wealthier rural inhabitants, as has been the case in other developing countries with plans for spatial economic integration (e.g. Kenya, Venezuela). This would intensify the historical process of uneven development at a local level, for example, within communal areas. These six subsectors serve as the structural basis for the ZEAP rural energy analysis. We feel that it is important to understand the flows of energy between and within these subsectors. Furthermore, we stress the need to understand that within each subsector are individual families, farming operations, commercial and industrial enterprises which exhibit varying capabilities for utilizing new energy sources as well as larger quantities of existing types of energy. We also believe that although conservation and increased efficiency are important, in the underdeveloped areas of Zimbabwe the emphasis must be on increasing the supply of energy to these areas. If the growth-with-equity strategy is to be successful, it is imperative that energy be supplied to the poorest of rural households, first for subsistence and then for developmental purposes.
5. ZEAP RURAL ENERGY STUDIES Having presented the original conception of Zimbabwe's rural structure held by the ZEAP team, we now turn to the studies and methodologies that the ZEAP team utilized in addressing the rural energy system in Zimbabwe. Returning to the classification matrix presented in Table I-l, the ZEAP team undertook an energy supply-demand study at the household or vil lage, multiple-vil lage and national level S. These studies focused on a detailed specification of end-use energy consumption as well as the socio-economic determinants of overall resource utilization. Energy consumption was defined broadly to include human energy, in the form of labor budgets, and animal energy, in the form of draught power. The layout of these studies is presented in Table 1-2 by producing the energy supply/demand column of Table I-l. At the village level, the ZEAP team conducted a series of household observation studies. For these studies, the labor budget, appliance utilization, wood consumption, and agricultural practices of fifteen household in different parts of the country were observed and detailed for one week at four times during the course of a year. The four site visits corresponded to the planting ,weeding,harvesting and dry seasons. The primary objective of these household observations was to compile detailed labor budgets of households facing varying physical and economic resource constraints. This study had the aim of allowing us to better understand the seasonal dimensions of labor utilization, important at the project formulation stage. These observations also provided us with information on cooking practices, eff iciencies, and consumption of wood for other uses such as construction. The relationships between agricultural practices, agricultural inputs, and overall productivity were also examined. Table 1-2 ZEAP PROJECT STUDIES
Scale of Energy ~upply/~emand Observation Studies
Household/Village Observation Studies Multi-Village Comprehensive Rural Survey National National Household Energy Survey
At the multiple-village level, we conducted a comprehensive survey of approximately 800 households in different parts of the country. The stratification was designed to include communal area farms, small-scale commercial farms, and resettlement area farms in the various natural regions. Through this it was hoped that information would be obtained on the relationship between the socio- economic status of households and their utilization and access to various energy resources. Variations by ecological zone were also assessed. The primary objective of the survey was to get an idea of the constraints that people in the rural areas face in their attempt to secure adequate levels of food, clothing, water, energy, health and shelter. For those families who manage to fulfil their basic needs and are able to accumulate some capital, we were interested in finding out what enables them to generate a surplus. Ultimately, it is local surplus-generation and local reinvestment which leads to rural development. Finally, at the national level, the ZEAP team worked with the Central Statistical Office (CSO) to administer a national energy survey in rural and urban areas alike. The aim of the survey was to provide national estimates of household energy consumption to be used in the LEAP end-use demand model for the urban and rural household subsectors. Through the overlapping coverage of survey results we expected to gather information ranging from the very detailed, but inferentially weak, to the less detailed, but inferentially strong. Each set of results, it was hoped, would serve to substantiate the others. These studies provide relatively complete coverage of those subsectors examined as household production units. But for the Large-Scale Commercial Farms, State Farms and Growth/Service Centers, additional research was required. For the first two, existing data sources were used to examine energy requirements of the farming units. The National Household Energy Survey included farm workers from both of these subsectors. For the Growth and Service Centers, existing data, survey results and plans were used to provide a first impression of energy requirements. Then a more detailed examination was made of the supply options available for supplying these needs for rural or small-scale urban industrial growth. Using this inter-related set of analyses, we expected to obtain a complete picture of the energy requirements of the rural subsectors identified in Table 1-2. Due to our adopted end-use approach, we have focused this discussion on our studies of the demand-side of the energy equation. However, the ZEAP team also examined supply. A major challenge was the estimation of supplies of woody biomass throughout the country. This entailed mapping vegetation types and estimating standing volume through an extensive review of previous ecological work and mensuration exercises of existing tree cover. In addition to this, of course, available information on commercial fuel supplies was assembled and summarized, but since this was perhaps the simplest part of the exercise to undertake and is relevant not only to the rural system but to the entire economy, further discussion of this subject will be left to other papers in the volume.
6. RURAL ENERGY POLICY ISSUES Through these exercises a large body of information was assembled which should lead to a more complete understanding of Zimbabwe's rural energy system. In the pages of the papers that follow, we attempt to pinpoint particular problems within the system which demand action as well as identifying which approaches to these problems stand the greatest chance of success. This understanding of the rural energy system can then be used to forge a set of unified programs for rural energy development in Zimbabwe. Our assessment of the rural energy system in this introductory paper is already sufficient to indicate at least four critical areas which require policy attention. These are: SHORTAGE OF FUEL FOR DOMESTIC ENERGY This is the problem area which demonstrates perhaps most clearly the problem of energy for basic human needs. Without satisfactory wood supplies, rural households cannot fulfil their cooking requirements. The problem is further exacerbated by the diffusion of inefficient stoves and the indiscriminate cutting of wood to meet the demands of the urban market. Both the Energy Department and Forestry Commission have begun work in this area, but the severity of the problem requires a redoubling of efforts. ENERGY INPUTS INTO AGRICULTURAL PRODUCTION Due both to the drought and to the low level of capital accumulation in most communal farming areas there is a need to increase energy-related inputs into agriculture. Draught power is in particularly short supply following the drought of recent years. Fertilizers and pesticides are too expensive to experience broad dissemination throughout many conmunal areas. If small-scale farming in Zimbabwe is to remain viable, development energy for agriculture is required to raise production, output and incomes. ENERGY FOR RESETTLEMENT To date, the resettlement effort has been primarily Model A (individual farming). However, Model B (co-operative farming) offers poor peasants opportunities to utilize more sophisticated energy resources and agricultural inputs to obtain higher yields. Co-operative farming also allows for a more intensive use of land. If the present pattern of individual farming on marginal land continues, the potential for significant changes in agricultural inputs and practices will be reduced. ENERGY SUPPLIES FOR RURAL INDUSTRIES If growth and service centers are to pose viable, attractive alternatives to the major urban areas, energy supplies are required to spur economic growth and increase employment opportunities. Energy is desperately needed for the development of these areas. If the electricity grid cannot be extended to them, other supply sources will have to be made available or else the whole decentralization p01 icy will doubtless fall flat. This presentation of perceived problems in the rural energy system is meant to be neither exhaustive nor exclusive. Other energy needs will be addressed in the following papers which detail our comprehensive study of the rural energy system. However, the adoption of such a comprehensive approach is the only way to circumvent the pursuit of more piecemeal efforts. We would maintain that this approach is the singularly most appropriate one to adopt in planning for rural energy needs for growth-with-equity.
FOOTNOTES (1) This discussion draws implicitly upon a similar presentation in UNIDO (1982). (2) In economic jargon, the reduced form of model is the simplest, most easily verifiable form of a series of simultaneous equations. REFERENCES Briscoe, J., 1979 "The Political Economy of Energy Use in Rural Bangladesh", Harvard University Environmental System Program. Cambridge: Harvard University. Brokensha, D. and Riley, B., 1980 "Fuelwood in Rural Kenya: Responses to a Dwindling Resource," (mimeo). Proposal to U.S. National Science Foundation. Washington, D.C. Fleuret, P.C. and Fleuret, A.K., 1978 "Fuelwood Use in a Peasant Community: A Tanzanian Case Study." The Journal of Developing Areas 12: 315-322. Hosier, R., 1982 " " Somethingto Buy Paraffin With': An Investigation into Domestic Energy Consumption in Rural Kenya," Ph.D. dissertation. Worcester, Mass.: Clark University. Johnson, J., 1982 "A Comparative Study of Fuelwood Acquisition and Consumption in Two Rural Kenyan Households," Beijer Institute Kenyan Fuelwood Project Working Paper. Stockholm: Beijer Institute. Merz-McClel lan, 1981 "Power Sector Development Plan for Zimbabwe," Newcastle-Upon-Tyne, England: Merz-McClel lan Ass. Montan Consultants, GMBH., 1982 "Zimbabwe Coal Utilization Study," (draft) Essen: Montan Consultants. Oleche, F., 1982 "Report on Kombewa Location," Beijer Institute Kenya Fuelwood Project Working Paper. Stockholm: Beijer Institute. O~enshaw.K.. 1978 "~obdfuel- A Time for Reassessment." Natural Resources Forum 3: 35-51. Reddy, A.K.N., et al, 1980 "Rural ~nergy~onsum~tionPatterns: A Field Study," ( mimeo). Bangalore: ASTRA. Reaublic of Zimbabwe. 1982 Transitional ~ationalDevelopment Plan 1982/83-1984/85. Harare: Amalgamated Press (Pvt) L-
Revelle, R., 1976 "Energy Use in Rural India." Science 192: 969-975. Snamprogetti, Ltd., 1983 "Petroleum Fuels Supply Engineering Project Report," (draft) Milan: Snamprogetti. UNIDO, 1982. "A Conceptual Model for Projecting Industrial Energy Use in Developing Countries," IS.278, V.82-20426. Geneva: UNIDO, Global and Conceptual Studies Branch, Division for Industrial Studies. Whitsun Foundation, 1981 Rural Afforestation Study. Salisbury: Whitsun Foundation. 11. ENERGY USE IN ZIMBABFTE'S AGRICULTURAL SECTOR
Dan Weiner, Sam Moyo, and Charles Chidiya
I. INTRODUCTION
In Zimbabwe, a1though agriculture contributes on1y 15 percent towards gross domestic product, It accounts for over a quarter of formal wage employment, and 70 percent ofthe population are directly dependent on the land. Agriculture earns 40 percent of foreign exchange and supplies 40 percent of the inputs to the manufacturing sector (Agricultural Marketing Authority, 1983; Mumbengegwi, 1983). Maintaining the viability of the agricultural sector is essential for the overall health of the economy. Since Independence there has been a rapid increase in the production and marketing of maize and cotton from African producers. Zimbabwe's agricultural success story, however, is sobered by the reality that over one-third of its population lives under quite marginal conditions for dryland agriculture. This coexistence of agricultural vitality and stagnation is reflected in the various systems of agricultural land-use in the country. The challenge to Government will be to help create the conditions whereby agriculture can maintain its historical role as generator of economic growth while providing a more reliable source of subsistence for the bulk of Zimbabwe's people. Agricultural development is the key to overall rural development in Zimbabwe. Because the majority of Zimbabweans rely on the land for their livelihood, and due to their relative impoverishment, agriculture must provide a more lucrative base for income generation if the Government's "growth-with-equity" strategy is to succeed. To date, information on energy use in the agricultural sector has estimated the total quantity of specific fuels supplied. This has masked the large diversity of energy usage within Zimbabwean agriculture. It is necessary to disaggregate the agricultural sector according to system of production (e.g., subsector) in order to assess where energy is flowing, as well as the associated impacts on agricultural productivity. Too often, research on Zimbabwe's agriculture systems has focused on agricultural outputs without examining the full mix of inputs utilized. Because agriculture is both a producer and a consumer of energy, efficiency of use can be determined by calculating the ratio of outputs to inputs using a common denominator (such as Kcal or GJ). The assessment of agricultural energetics is one method of evaluating the relationship between energy use, agricultural productivity, labor utilization and land-use. It is the method used here. It is important to point out, however, that energetic analysis is, by nomeans, a replacement for economic analysis or other valuation systems. It is simply a complement to the more standard approaches, which helps highlight the role ofenergy in the production process. In this report we discuss the current and possible future role of energy use in agriculture for growth and equity in the economy. Using output from the LDC Energy Alternative Planning Program (LEAP - a model developed specifically for use as a planning tool in developing countries), energy consumption is disaggregated by agricultural subsector. Because of the dominance of large scale farms in consuming commercial forms of energy, the discussion focuses mainly on this subsector. We then present the results of an energetic analysis of four subsectors, namely: large-scale commercial, state, communal, and model A resettlement. For the two high-input subsectors a comparison is made with U.S. farming. The implications of our findings for policies concerned with agricultural development are then outlined.
2. ENERGY USE IN AGRICULTURE
The ability to feed an increasingly non-agricultural population has been made possible by the infusion of energy into the agricultural system. For example, only two percent of America's population of 230 million farm the land. For each day worked, the U.S. agricultural worker produces enough food for sixty people and a considerable amount for export (Green, 1978). In 1976, there were only 0.5 hectares cropped per person (Dickenson, 1978). This high level of land and labor productivity has been made possible by energy used directly in the form of liquid fuels, and indirectly in the form of electricity, machines, hybrid seed, fertilizer and pesticides. The importance of fossil fuel energy inputs into the U.S. agricultural economy is demonstrated by the fact that if 1930 levels of fossil fuel energy (direct and indirect) were presently utilized, sixty percent more land and 500 percent more labor would be required to maintain current production levels (Green, 1978). This poses a dilemma in that high-productivity agriculture tends to be less efficient in terms of energy use when compared with low-productivity agricultural systems. Where labor is the primary energy input, yields tend to be low and energetic efficiencies high. For example, for every kilocalorie put into sorghum/millet/groundnut farming in Malawi, eight kilocalories are produced (Haswell, 1981). Rappaport (1971) calculates an energetic efficiency ratio of 16:l for tar0 yam farming in New Guinea. In agricultural systems where animal and human energy are utilized in the production process, efficiency ratios of 6.4:l for Nigerian maize (Akinwume, 1971), 4.3:l for Mexican maize (Lewis, 1951), and 5:l for Phillippine maize (AED, 1960) have been calculated. In fully mechanized agricultural systems with high levels of fossil fuel consumption, energetic efficiencies for maize production have been estimated as 3.13:l for the United States and 2.3:l in Great Britain ((Pimental and Pimental, 1979). The entire U.S. agricultural system has an efficiency ratio of 1:10 (Perelman, 1980), when energy used in food processing and transportation are considered. These figures suggest that agricultural development has required large expenditures of energy, particularly commercial forms. Returns of food energy per unit of energy input into the system have tended to decline. If efficiency is measured in terms of land, labor, or on economic criteria, however, the picture reverses. For example, a day's work for a Khoisan farmer in Botswana provides food for himself and three other people. Using only muscle power, his energy 0utput:input ratio is 7.8:1, but he needs 1,040 ha. to do it. In North America, Prairie Indians required 2,500 ha. of land per person to meet their food needs. This contrasts dramatically with the American worker, who produces for 60 people each day, using an average of 0.5 cropped ha. per capita. The economic efficiency of increased energy inputs is evident in the 6.2 billion expenditure that U.S. farmers made on fertilizer and pesticides in 1971 alone. This was a 600% increase from 1966. It has been estimated that a one dollar expenditure for fertilizer in U.S. maize production in 1976 yielded eleven dollars in the field (Green, 1978), suggesting that farmers make decisions based on economic, not energetic criteria. In a recent study, the FAO (1979) predicted that the developing countries' share of energy consumption would soon rise threefold. The bulk of the increase, it was suggested, would be in the form of fertilizer. Based on historical trends, this study indicates that the use of commercial energy is increasing rapidly in the Third World. There is still, however, considerable controversy regarding the appropriateness of high-input farming for developing countries. Proponents of a transition to high-input farming cite the shortage of land and increasing population as necessitating more energy-intensive farming. More commercial energy inputs, it is argued, are needed in agriculture to enhance yields and prevent a Malthusian type disaster (Green, 1978; FAO, 1979). The small percentage of total commercial energy consumed in agriculture (3.5 percent), is cited in support of this argument. Few would disagree that Third World farming needs more energy. There is, however, disagreement over the types and quantities of energyto be used in the agricultural energy transition. Opponents of a major shift towards high-input farming argue that most rural households cannot afford commercial energy. Citing some of the failures of the green revolution, it is suggested that too often only the wealthier households reapthe benefits of new energy inputs, further dichotomizing rural class structures (Yapa, 1981). It has also been argued that more "modern" farming methods can increase the farmer's vulnerability to drought, and exacerbate existing relationships of dependency (Wisner, 1977; Griffin, 1974). Others cite the inefficiency of energy conversion in high input energy farming (Pimentel and Pimentel, 1979), and the negative environmental impacts (Perelman, 1977), while still others cite the significant productivity changes that can be achieved through better farm management and the use of renewable energy resources (O'Keefe et a1., 1984). This debate is very relevant to the current situation in Zimbabwe. Large scale commercial and state farms utilize large quantities of commercial energy and have energy profiles similar to farms in the more industrialized countries. On the other hand many of the peasants still rely primarily on human and animal power and have only recently begun utilizing commercial forms. However, £'arming in Zimbabwe is currently in a transition towards increased use of commercial energy inputs. The pace and form of the transition will depend on relative factor prices, the role of the Government in helping to develop the small farmer, and the types of farming systems developed. Regardless of the precise form that this transition takes, in order to create a more equitable agrarian landscape, energy will be required to enhance and maintain current levels of productivity. However, if sufficient energy is not available to the majority of the population, the Government's strategy of growth with equity through agricultural and rural development will fail. Gaining control of the means of production is only part of the problem. The peasantry also need means of production that can produce. This requires energy. Before presenting our findings, we briefly discuss Zimbabwe's natural resource base and agrarian structure.
3. ZIMBABWE'S NATURAL RESOURCE BASE
Zimbabwe has been subdivided into five agro-ecological zones (Map 11-1). Based primarily on average quantities of rainfall and its variability, these natural regions provide a broad framework for evaluating potential land-use. Natural Region I, con£ ined to the Eastern Highlands Districts, has annual rainfall amounts of over 900 mm, with some areas receiving over 1500 mm annually. Because of high elevation (about 1700 m) and lack of frost, the area is well suited to tea, coffee and forest crops, as well as intensive livestock production. Natural region I1 is the primary intensive farming area in Zimbabwe. Situated in the highveld region around Harare, the summer rainfall of 750-1000 mm tends to be reliable. Hence maize, the country's staple crop, is well suited to this region as is tobacco, cotton, wheat, other grain crops and intensive livestock production. Natural Region 11, therefore is the key farming area of Zimbabwe. Subregion II- B, although still suitable for intensive production, experiences higher levels of rainfall variability and risk. a Semi-Extensive Farming Region
0/ Extensive Farming Region
Survoyor-General Rararo Zimbabwe. 1984
MAP 11-1 DISTRIBUTION -OF NATURAL REGIONS -BY PROVINCE Natural Region I11 is best suited for semi-intensive crop and livestock production. In this zone, the annual rainfall amounts decline to 650-800 mm. Cropping is therefore risky, particularly for maize which requires large quantities of moisture at specific periods of plant development. Natural Region IV receives 450-650 mm of rainfall annually, which means that drought-resistant crops should be grown, and that livestock should be the basis of the farming system. Mid-season dry spells are common, making any form of dry land cropping risky. Natural Region V receives rainfall that is both low and erratic. This land has sound use only in extensive livestock production. The region includes the hot and dry lowveld areas of the Zambezi and Sabi-Limpopo valleys. In Table 11-1, the total area in each Natural Region is shown. Only 16.8 percent of the total area of Zimbabwe falls into zones where there is the potential for intensive crop and livestock production. Well over half the country is best suited for livestock rearing only. Turning back to Map 11-1, it can be seen that most of Zimbabwe's prime agricultural land is located in the three Mashonaland provinces.
TABLE 11-1 LAND AREAS BY NATURAL REGION ...... Natural Suitable Intensity Land Area Percent of ...... Region of Land-Use (1000 ha) Total I Specialized and 0,705 1.8 Diversified Crops I I Intensive 5,857 15 .O I11 Semi-Intensive 7,290 18.7 IV Semi-Extensive 14,770 37.8 ...... V Extensive 10,450 26.7 Total 39,072 100 .O
The relationship between the natural region and the agricultural production system (subsector) is the key to determining appropriate types and levels of energy inputs into agriculture. Planning must be done within this context. This is a general theme throughout this chapter.
4. ZIMBABWE'S AGRARIAN STRUCTURE
In Zimbabwe, six primary agricultural subsectors can be identified:
(1) Large Scale Commercial Farms (LSCF),
(2) State Farms, (3) Communal Areas (CA),
(4) Model A (individual) Resettlement Schemes,
(5) Model B (cooperative) Resettlement Schemes,
(6) Small Scale Commercial Farms (SSCF).
Recently, the Government has initiated a model C outgrower scheme and a model D semi-arid land-grazing scheme under the resettlement schemes. These developments are not included in this study. LARGE-SCALE COMMERCIAL FARM SUB-SECTORS
The large-scale commercial farm sector consists of approximately 4000 privately owned farming units. As indicated in Table 11-2 and Map 11-2, the sector is fairly evenly distributed between the various natural regions. However, in contrast to the communal areas, very little dryland cropping takes place in the marginal rainfall areas. The bulk of LSCF cultivation is done in Natural Region I1 where over three-quarters of the land is occupied by approximate1 y 2,600 large-scale commercial farms (C.S.O., 1983).
TABLE 11-2 DISTRIBUTION AGRICULTURAL LAND BY NATURAL REGION AN0 AGRICULTURAL SUBSECTOR
Natural Resettlement Resettlement Region LSCF (1) % State (3) % Communal (l) % Model A (2) % Model 8 (2) % SSCF (1) %
Total 13,943,446 100 78,702 100 16,355,580 100 1,669,233 100 66,775 100 1,416,100 100
Sources : (1) Agritex Planning Branch, Ministry of Agriculture: LSCF figures adjusted for resettlement for period up to August 1983.
(2) Ministry of Lands, Resettlement and Rural Development (MLRRD). For period up to August 1983.
(3) Agricultural and Rural Development Authority (ARDA). For period up to July 1984. Large Scale Commerc~al Farm Area
Communal Areas
yor-Gsnsral Barars ZLmbabrro, 1979
MAP 11-2 DISTRIBUTION OF LARGE-SCALE COMMERCIAL AND COMMUNAL FARM ATEASBY NATURAL REGION -p- The LSCF sub-sector produced 78 percent of the total agricultural output in 1984 and over 90 percent of the total marketed output (AMA, 1986). Of a total output of Z$ 598 million, approximately 90% was produced on large-scale commercial farms. The subsector provided permanent employment for 165,000 people and seasonal employment for another 56,000 in 1982, (C.S.O., 1983), and had strong linkages with the service and industrial sectors of the economy. In the 1981-82 crop year the LSCF subsector consumed 90 percent of the total commercial energy in agriculture. Nationally, the entire subsector averages one tractor for every 6.5 tractors/farm in the more favorable Mashonaland region (Ministry of Agriculture, 1984). Besides diesel, the sector is also a large consumer .of coal and wood for tobacco curing and crop drying, electricity for irrigation, and agrochemicals.
STATE FARMS
State farms are the only other subsector utilizing high- input methods. The Agricultural and Rural Development Authority (ARDA) operates over 20 farms on 67,000 ha. of land (Table 11-2). Because of the role of state farms in maintaining high input farming in Zimbabwe, we compare their energetic efficiency with the LSCF subsector in this chapter. Most state farms are located in the drier natural regions Hence, the opening up of marginal lands through irrigation is one of the main objectives.
COMMUNAL AREAS
The communal areas' (CAs) are where the bulk (57 percent) of Zimbabwe's population live. As indicated in Table 11-2 and Map 11-2, almost three-quarters of communal land area is in Natural Regions IV and V, where dry-land cropping is risky. According to 1982 census results, 2.65 million people live in these marginal areas. This represents 62 percent of the communal area populat+.on and 35 percent of the national population (C.S.O., 1984) Human and bullock power, fertilizers, agrochemicals and hybrid seed are the primary energy inputs into communal area agriculture. With regard to bullock power, however, it has been estimated that 27-52 percent of communal area households do not have their own draught animals (Whitsun Foundation, 1983), and hiring and borrowing is common. In addition, draught animals are often at their weakest when their energy is in most demand. These factors constrain the development of communal area agriculture. Since their demarcation around the turn of the century, the communal areas have served as a labor reserve for local mines, large farms and industries (Arrighi, 1973; Palmer, 1977). This had led to a permanent population of womeq, children and the elderly in the communal areas while many young and middle-aged men are migrants. Furthermore, because of an excessive human and livestock population, the resource base is under severe stress. Hence, household wealth and subsistence is increasingly dependent on off-farm sources of income. Recently, the deterioration of employment prospects combined with drought has created a crisis situation for many communal area households. This crisis, we believe, is not a short term problem caused by a temporary environmental fluctuation. It is a result of a long term deterioration in the viability of the labor reserve economy as a whole. This is particularly true for the 2.65 million people living in areas where even a year with a subsistence crop is considered a good one. There is also a small portion of communal area households who live in quite favorable environmental zones. Because of higher yields many farmers in these areas have been able to successfully reinvest capital back into their farms. The recent success of many communal area farmers, particularly in more favorable natural regions, underscores the ability of the peasantry to produce for subsistence and the market. The high variability in farming viability between and within natural regions indicates that generalizations about communal area agriculture (which are very common in all sorts of reports on Zimbabwe's agriculture sector) must be interpreted cautiously.
RESETTLEMENT MODEL A The model A resettlement program allocates land on an individual family basis. Throughout the country each family is provided with 5 ha. of arable land and 5-15 livestock units for grazing, depending on the natural region. The figures in Table 11-2 indicate that most model A schemes have been in natural regions I11 and IV. There is some slight improvement in the ecological location of the peasantry under resettlement, when compared to the communal areas. However, as indicated in Map 11-3, the best land (Region I1 A) has had limited resettlement. The large area of natural region I1 B under resettlement in the area to the east and north of Harare is primarily former white farming land abandoned during the war. The Lancaster House requirement that Government can only purchase land on a willing-sel ler/wil ling-buyer basis has effectively prevented peasant-access to Zimbabwe's best land. The energy profile of model A schemes is similar to that in communal areas. However, access to the Government's mechanical tillage unit has meant a higher percentage of tractor usage. A few schemes are also experimenting with an internal mechanical tillage unit. This is an important experiment in the provision of tractors to small farmers who cannot afford to buy their own. AFRICA
Intensive Resettlement F7 ,,he,
Source: Ministry of Lands, Resettlement and nural Development, June, 1983
MAP 11-3 DISTRIBUTION OF RESETTLEMENT SCHEMES
-U=- -U=- - P REGION Farmers on model A schemes are not permitted to have formal employment off the farm. The purpose of this rule is to create a viable on-farm income base for resettled families. Furthermore, credit-access for the purchase of fertilizer, pesticide and seed (and in some cases, to hire a tractor) has given settler farmers access to commercialized energy inputs. However, because of their location in marginal areas it is unclear whether the returns to higher inputs (in the form of higher outputs) will be realized. It should not be forgotten that poor environmental conditions helped create the labor reserve economy in the first place.
RESETTLEMENT MODEL B Model B resettlement schemes are producer cooperatives. There are approximately 35 model B schemes in Zimbabwe, on just over 66,000 ha. of land. It is interesting to note that the model B resettlement schemes are, in general, being allocated good land. This is primarily because the Ministry of Agriculture (MOA) and the former Ministry of Lands, Resettlement and Rural Development (MLRRD) opted for model B schemes where viable large-scale farms could potentially be maintained. To date, the cooperatives have been faced with serious shortages of capital and managerial experience. However, with the late rains of the 1983-84 crop season some impressive yield levels have been achieved. About 75 percent of model B farms have at least one tractor, although few have more than two. A few have none. We could not obtain any specific information on levels of energy consumption in the subsector. However, monitoring inputs and outputs on cooperatives is very important because of their potential to pool scarce family resources in order to harness greater quantities of energy in agricultural production as well as their greater access to the country's prime arable land. Producer cooperatives represent a potential form of production organization that could help the peasantry move up the energy ladder. SMALL-SCALE COMMERCIAL FARMS The SSCF subsector was created by the former Government in an attempt to create a small, elite, African farming class with freehold title. The proposed theory suggested that private ownership would create the conditions for high investment on the farm, hence, higher productivity. The plan failed because of under-utilization of land, and the farms simply became sources of income for investment in town. A further factor, as indicated in Table 11-2, is the poor resource base of the subsector. The subsector consumes a very small proportion of the nation's energy and is not a major contributor to overall marketed surplus. 5. ENERGY USE IN ZIMBABWE'S AGRICULTURAL SECTOR
In the agricultural component of LEAP, four energy types were accounted for: petroleum products, coal, electricity and fuelwood. Fertilizer, a major energy input, was not accounted for here because of its inclusion in the industrial sector. Furthermore, gasoline consumed in agriculture was accounted for in the transportation sector, as most gasoline use in the farming sector is not directly for production. Hence, the category of petroleum products refers to diesel fuel only. Besides energy used for drying and curing, this is an account of energy used in production only. In the 1981-82 crop year agriculture accounted for 8.7 percent of the total commercial and fuelwood energy consumed nationally. In Table 11-3, the breakdown by fuel type is presented. It can be seen that coal and fuelwood (for drying and curing) were the major fuels used. Petroleum products, accounting for less than 15 percent of the sectoral total, accounted for 10.3 percent of the national total. This represented almost 20 percent of total diesel consumed in the country. Electricity, primarily for irrigation purposes (with some used for drying), accounted for 9.3 percent of agricultural consumption and 7.3 percent of national consumption that year.
TABLE 11-3 ENERGY CONSUMPTION IN THE AGRICULTURAL SECTOR 1981-82 --CROPSEASON
% of Total % of Total Fuel Million Agricultural National ...... TYPe G J Usage Usage Petroleum Products 2.78 13.4 10.3 Coal 8.80 42.2 18.3 Electricity 1.94 9.3 7.3 ...... Fue lwood 7.31 35.1 6.5 Total 20.83 100 8.7
Draught Animal Power 3.6 Human Energy 2.S
The total human energy and animal draught power expended in agriculture was estimated exogenously from LEAP. As can be seen, animal draught power accounted for more energy than petroleum products. The human energy component is also quite significant. If we went further and included the energy consumed in the form of fertilizer (approximately 7.5 million GJ) we could estimate that, as a whole, the agricultural sector utilized 35 million GJ. If we included hybrid seed and pesticides the figure would be closer to 40 million GJ. This amounts to approximately 15 GJ per hectare cropped. When only commercial energy inputs are accounted for, energy consumption per hectare (GJ) has been estimated to be 0.8 for Africa, 2.2 for all developing countries, 2.4 for China, 9.3 for the Soviet Union, 20.2 for North America and 27.9 for Western Europe (FAO, 1979). Although these figures are a bit outdated (1972173) and do not include human and animal energy they clearly demonstrate the intensity of energy use in Zimbabwean agriculture, particularly relative to other African countries. These aggregate figures must be treated with caution because of the large level of variation within Zimbabwe's agricultural sector. In Table 11-4, energy consumption in the large-scale commercial subsector is presented. It can be seen that the subsector accounted for 90 percent of the commercial and fuelwood energy consumed in the entire sector that year. This amounts to 32 ha. which is higher than any of the regional averages of ten years earlier. Again, tobacco curing and crop drying consumed the bulk of commercial energy. The subsector accounted for 9.6 percent of the petroleum products (18 percent of the diesel), 17 percent of the coal, 6.7 percent of the electricity and 5.6 percent of the fuelwood consumed nationally.
TABLE 11-4 ENERGY CONSUMPTION IN THE LSCF SUBSECTOR --p ...... % of Total % of Agricultural National Fuel...... Type Million GJ (end-use) Consumption Consumption Petrol.Prod. 2.59 (Tractor) 93.2 9.6 Coal 8.20 (Drying,Curing) 93.2 17.1 Electricity 1.78 (Irrigation,Drying) 91.8 6.7 ...... Fuelwood 6.21 (Curing,Drying) 85 .O 5.6 Total 18.78 90.2 7 -9
To get a more precise estimate of energy consumed in the LSCF subsector we disaggregated by the four major crops grown and a residual category called "Other." This is presented in Table 11-5. The table shows the importance of tobacco, which accounted for 57.5 percent of the total energy consumed in the subsector. In that year tobacco accounted for 7.8 percent of total cropped hectares. Again, the high energy costs of the curing process are indicated. However, although the absolute diesel consumption doesn't appear to be high, on a per hectare basis, tobacco utilizes more than double the amount of diesel (194 liters per hectare) than all the crops grown, with the exception of cotton (MOA, 1978). Even though maize used forty-six percent of the total cropped hectarage that year, it accounted for a relatively small proportion ( 16.2%) of total LSCF energy consumption. Drying was a large component of this. Wheat, although accounting for a small proportion of total consumption (3.9%), required a lot of electricity. This was primarily for irrigation.
TABLE 11-5 ENERGY CONSUMPTION IN THE LSCF SUBSECTOR BY CROP --p -- ...... Million % of LCSF Crop Fuel Type GJ Consumption ...... Maize Diesel 1.03 39.8 Coal 1.86 22.7 Electricity .l7 9.6 Total 3.06 16.2 ...... Cotton Diesel .25 9.6 Electricity .l4 7.9 ...... Total .39 2.0 Tobacco Diesel .45 17.4 Coal 6.13 74.8 Electricity .04 2.3 Fuelwood 4.18 67.3 Total 10.80 57.5 ...... Wheat Diesel .l2 4.6 Coal .l3 1.6 Electricity .49 27.5 Total .74 3.9 ...... Other Diesel .74 28.6 Coal .08 0.9 Electricity .94 52.8 Fuelwood 2.04 32.9 Total 3.80 20.2 ......
The large expenditure on electricity for the residual crop category (other), was primarily for lowveld irrigation. Fuelwood for tea and coffee drying also was a major energy consumer. Coal consumption was of minor importance and diesel use was roughly proportional to the number of other crops grown. The intensity of energy required to produce the major crops is indicated in Table 11-6. It can be seen that for 3 of the 5 crops, curing and drying consumed the largest quantities of energy. Tobacco, the most intensive, consumed over 25 times more energy than cotton, the least intensive, on a per hectare basis. On average, one LSCF cropped hectare required 33 GJ. Curing was the single largest end-use in the subsector. TABLE 11-6 PERHECTAREENERGY CONSUMPTION FOR THEMAJORLSC F CROPS ...... Crop GJ/ha. Major End-Use ...... Tobacco 210.9 Curing Wheat 26.1 Irrigation Other 21.5 Drying Maize 11.7 Drying Cotton 7.4 Landpreparation and Maintenance
Mean 33.01 Curing ......
These figures demonstrate the dominance of the LSCF subsector in the consumption of commercial energy inputs within agriculture. State farms accounted for most of the remaining commercial energy consumption. Combined with the communal areas, model A resettlement schemes and small-scale commercial farn areas used less than 1 percent of the total energy consumed in the sector. However, if animal draught power and human energy were included, the figure would be closer to 25 percent.
6. THE ENERGETICS OF AGRICULTURE IN ZIMBABWE
In agriculture, energetics is the study of the flow and conversion of energy in food production. Because energy in food production is both a producer and consumer of energy, energy inputs can be evaluated in the context of energy outputs by converting both into common energy units. If the ratio of the outputs to inputs is greater than 1, the agricultural system is a net provider of energy. An output:input ratio less than 1 indicates that there is a net loss of energy. Before we proceed to evaluate the energetics of agriculture in Zimbabwe, a few words about this method are necessary. First, energetic analysis should not be viewed as a substitutefor economic analysis. As we have discussed, farmers make decisions on economic not energetic criteria. Energetic analysis, therefore, is a way to evaluate the energy implications of the economics of agriculture. Secondly, energetic analysis can disguise the importance of particular fuels by combining all energy types together. This is avoided here by maintaining the disaggregation of particular energy types after conversion into standardized units. Finally, 0utput:input ratios are very dependent on yield levels (per unit of land). Although energy inputs play a pivotal role in determining outputs, factors such as weather, soil and management skills are also important. Hence, energetic analysis should be limited to broad statements about averages. When evaluating energy use in the production of industrial crops (tobacco, cotton, etc.), converting outputs into their energy equivalents would be meaningless. In such cases, we evaluate the intensity of energy use measured as the energy input required per unit of physical output (tons). This should not be confused with the concept of intensity as unit energy input per cropped hectare, also in use in this chapter.
LSCF AND STATE FARM SUBSECTORS
In Table 11-7 we compare the energetic efficiency of maize production in Zimbabwe's LSCF subsector and the United States on a per hectare basis. It can be seen that in Zimbabwe, inputs are slightly higher while outputs are slightly lower when compared with the U.S. Energetic efficiencies were calculated as 2.67 and 3.13 respectively. The figures indicate that, in Zimbabwe, the bulk of the energy used in maize production is for fertilizer (50.3%), drying (20.4%), and diesel (12.2%). Although fertilizer is also the major use of energy in U.S. maize production (36.9%), diesel (20.9%) and irrigation (12.7%) play a more important role. Energy used for drying (7.0%) is mucli less in the U.S., and labor inputs (0.1%) are virtually nil.
TABLE 11-7 ENERGETIC EFFICIENCY OF MAIZE PRODUCTION -IN ZIMBABWE'SL ARGE-SCALE COMMEEIALREI--SECTO R AND THE UNITED STATES ...... Zimbabwe United States
Input Kcal. GJ/ha % kcal. GJ/ha % ...... Labor 259,560 1.09 4.0 5,580 .02 0.1 Machinery 348,000 1.46 5.3 558,000 2.34 9.1 Diesel 797,898 13.34 12.2 1,278,368 5.35 20.9 Fertilizer 3,301,481 3.82 50.3 2,257,100 9.45 36.9 Pesticides 255,614 1.07 3.9 286,730 1.20 4.7 Seed 161,250 .67 2.4 525,000 2.20 8.6 Irrigation 100,334 .42 1.5 780,000 3.26 12.7 Drying 1,337,792 5.60 20.4 426,341 1.78 7.0 ...... Total Inputs 6,561,929 27.47 6,117,119 25.60 Output 17,497,950 73.24 19,148,700 80.16 Output/ Input 2.67 3.13 ......
Sources:CFU (1983); MOA (1978); de Jong (1983); CS0 (1983); Pimental & Pimental, 1979.
These figures demonstrate the relative intensity of both commercial energy and labor use in Zimbabwean maize production. There is a slight skew towards labor saving inputs (tractors) versus yield enhancing inputs (fertilizer) in U.S. production. This, however, is partially due to higher levels of soil fertility in the U.S. midwest in comparison to Zimbabwe's highveld region. What these figures suggest is that despite the relative labor intensity of Zimbabwe's LSCF maize production, inputs of commercial energy are also quite high. It can be seen that in order to become high yielding, the LSCF maize grower has required a very large energy subsidy. In Table 11-8, a similar analysis is performed for wheat. The figures are interesting, Zimbabwe utilizes almost 4 times the inputs, and gets almost 2.5 times more yield than the U.S. Hence, Zimbabwe's energetic efficiency (1.65) is again lower than in the U.S. (2.65). The comparison is a bit inconsistent, however, because cropping is mostly non-irrigated in the U.S.
TABLE 11-8 ENERGETIC EFFICIENCY OF WHEAT PRODUCTION -IN ZIMBABWE ' S LARGE-SCALE COMME~I~FARMSECTOR AND THE UNITED STATES ...... Zimbabwe (Irrigated) United States (Dryland) ...... Input Kcal. ~~/ha% kcal. G~/ha % ...... Labor 139,050 .58 1.4 3,255 0.014 0.1 Machinery 360,000 1.51 3.7 360,000 1.51 14.0 Diesel 848,065 3.55 8.8 604,942 2.53 23.5 Fertilizer 4,505,494 18.86 46.5 852,025 3.56 33.1 Pesticides 95,557 .4 1.0 49,955 0.21 2.0 Seed 264,000 1.11 2.7 699,600 2.93 27.3 Irrigation 3,468,705 14.52 35.9 ------...... Total Inputs 9,680,871 40.53 2,569,777 10.75 Output 16,005,000 67.0 6,798,000 28.46 ~utput/~nput 1.65 2.65
Sources: CFU (1983b); Mangombe (1983); CFU (1983b); CS0 (1983); Pimental & Pimental (1979);
The energetics of wheat production in Middle-Sabi and Chisumbanje state farms is presented in Table 11-9. On the Middle-Sabi scheme, input levels are very similar to the average for large-scale commercial farms. However, because of lower yields, the output:input ratio of 1.32 is lower. On Chisumban je, however, the combination of significantly lower inputs and slightly lower outputs combines to make for a more efficient conversion of energy (1.56). Although the energy demand profile is similar on the two farms, the higher rate of labor utilization on the Middle-Sabi scheme is noticeable. However, when compared with the LSCF average, both schemes appear quite labor intensive. The lower demand for fertilizer and irrigation at Chisumbanje is due to their more fertile soils and system of flood irrigation (soils at Middle-Sabi are sandier and they use a sprinkler system).
TABLE 11-9 ENERGETIC EFFICIENCY OF \?HEAT PRODUCTION ON-- TWO LOWVELD STATE FARMSINTBZAB\JE ...... Middle-Sabi Chisumbanje ...... Input Kcal. GJ/ha % Kcal. GJ/ha % Labor 306,744 1.28 3.2 173,813 0.73 2.3 Machinery 360,000 1.51 3.6 360,000 1.51 4.7 Diesel 857,620 3.59 8.9 721,452 3.02 9.3 Fertilizer 3,932,154 16.46 40.9 3,203,535 13.41 41.4 Pesticides 119,466 0.50 1.2 110,295 0.5 1.5 Seed 1,247,400 5.22 13.0 1,005,000 4.21 13.0 ...... Irrigation 2,795,031 11.70 29.1 2,150,024 9.0 27.8 Total Inputs 9,618,415 40.26 7,724,119 32.38 Output 12,658,800 52.99 12,078,000 50.56 Output/ Input 1.32 1.56 ......
High input farming in Zimbabwe is only slightly less efficient than in the U.S. However, both systems achieve very high levels of output. When comparing the two countries, it is important to consider the lower levels of soil fertility and higher levels of rainfall variability in Zimbabwe. Our comparison of LSCF and state-farm wheat production, although limited, suggests that the two subsectors exhibit similar energy use patterns. The LSCF subsector is more productive and slightly more energy efficient. However, absolute quantities of energy use are higher. The state farm subsector utilizes more labor while levels of diesel use are quite similar. To complete the comparison of the two subsectors, we focus on a major industrial crop: cotton. In Table 11-10, the energy intensity of cotton production in the LSCF subsector and on the Chisumbanje scheme are assessed. It can be seen that the state farm utilizes more energy per hectare. However, the Chisumbanje yields are also higher than the LSCF average. The Chisumbanje scheme requires slightly more energy (9.22 GJ) to produce 1 ton of cotton than the LSCF sector (8.76 GJ). Furthermore, labor use is substantially higher on the state farm, as is fertilizer use. These figures suggest a similar pattern as that seen in the energetic analysis: higher quantities of energy lead to higher yields but less efficient conversion of energy. FABLE 11-10 ENERGY INTENSITY OF IRRIGATED COTTON PRODUCTION I-N ZIMBZ~Z~LARGE-SCALECOMMERCIAL FARMSECTOR AND CHISUMBANJE -STATE ---FARM (PER=)-
LSCF Chisumbanje ...... Input Kcal. ~~/ha % Kcal. ~~/ha% ...... Labor 644,265 2.70 12.0 1,056,780 4.42 15.4 Yachinery 417,150 1.75 7.8 413,030 1.73 6.0 Diesel 967,511 4.05 18.0 957,955 4.01 14.0 Fertilizer 1,471,572 6.16 27.3 1,958,910 8.2 28.6 Pesticides 288,570 1.21 5.4 495,150 2.07 7.2 Seed 100,000 0.42 1.8 250,000 1.05 3.7 Irrigation 1,488,294 6.23 27.7 1,720,019 7.20 25.1 ...... Total Inputs 5,377,362 22.52 6,851,844 28.68 Iutput (tonsjha) 2.57 3.11 Energy required ?er Ton 2,096,000 8.76 2,200,000 9.22
Sources: MOA (1976): Pimentel & Pimentel (1979); FIOA (1983); Browne (1983); CS0 (1983);
COMMUNAL AREAS
In this section the energy efficiency of maize production is calculated for farmers in six communal areas. The sites are stratified by natural region because of the strong influence of environment on both inputs and outputs. Data on inputs was collected from a comprehensive survey >f communal area households, administered during February and March of 1984. Secondary data sources were also used where necessary. The data thus pertains to the 1983-84 crop season. 3ur estimate of outputs is based on a review of the available statistics and literature for particular regions of the zountry. The output estimates, therefore, are averages, and 3re not meant to pertain to the 1983-84 crop season. Another problem faced was the calculation of the ~uantityof inputs utilized for specific crops and fields. Farmers appeared to have a very clear idea of the total quantity of inputs used and area cropped. However, many could not be much more specific than that. Hence we simply averaged the total quantities of inputs used by the total area cropped to obtain an estimate of per-hectare energy usage. Although this method underestimates input levels for crops like maize and cotton, and overestimates them for crops like millet and sorghum, the average is still useful for our purposes here. In Table 11-11, some basic production and input information is presented for six sites. Although the sample size used is small the geographical range is large, and all five natural regions are covered. Guruve, the site in the most favorable natural region had the highest household average cropped area, 3.17 ha. Chibi, the site in the least favorable natural region averaged only 1.76 ha. cropped per family. Along with Mhondoro, and Sabi-Lqorth, this represented the lower averages. The fact that cropped areas were highest in the two sites located in the most favorable natural regions is important, for this suggests that households in these areas are producing (through higher yields and larger cropped areas) substantially more per household than the majority of households living in more semi-arid regions. The high level of variability within sites, however, does diminish the significance of the site averages. The large range of cropped areas (not show below) suggests that variations between households in the same site could be as important in formulating an explanation as variations between sites.
TABLE 11-71 SOME BASIC PRODUCTION AN0 INPUT STATISTICS FOR SIX COMMUNAL AREAS, 1983-84
Mean Land Preparation and Maintenance Fertilizer Pestlclde Hybrid SE Planted Bullock Use(kg) Use(kg) Use (kg:
Communal Sample Natural Area 5 W 5 Tlmes Hrs. HH Per 5 HH Per E HH Per Area Size Region (Ha) Manur. Harrow. Cult. Plough.(Per Ha) Ave. HA Use Ave. HA Use Ave. HA L
Guruve 9 IIA 3.17 7.8 29.8 62.4 2.0 93.7 Mangwende 6 IIA/IIB 2.29 3.7 0 32.4 1.5 65.1 bondoro 8 IIB/III1.73 29.9 8.0 53.3 1.1 55.4 Sabi North 7 I11 1.79 40.3 41.9 66.1 2.0 96.7 Nyajena 7 IV 2.14 54.1 0 10.8 3.0 120.9 Chibi 7 V 1.76 8.2 18.0 9.8 1.3 54.7
Total/Mean 44 IIA-V 2.18 21.9 17.8 42.5 1.8 81.1 567 260 77 0.8 0.3 18 56.8 26.0
The table also gives the percentage of total cropped area which is manured, harrowed, and cultivated. These percentages, along with the average number of times each acre was ploughed that season, give an estimate of bullock hours expended per hectare. This later calculation (as we will discuss below) is important for the analysis of the energetics of communal area agriculture. With the exception of Chibi, there appears to be a substantially larger area manured in more marginal areas. Percentages harrowed and cultivated were high in Guruve, while almost none of the six households surveyed in Mangwende used a harrow. Although no pattern of harrowin g is evident, there does seem to be greater use of cultivator for weeding in higher rainfall areas. Fertilizer use is directly correlated with natural regionwhenmeasuredboth as ahousehold average and on a per hectare basis. Farmers in Guruve used very large quantities of fertilizer, whereas only one farmer in Chibi used any at
Overall, fertilizer was the primary source of energy consumption at 44.5 percent but varied from approximately 65 percent in the higher rainfall areas to only 1.5 and 8.7 percent in the drier areas of Nyajena and Chibi respectively. Pesticide use was negligible and hybrid seed was an important source of consumption throughout the country averaging between 5.6 and 18.1 percent of total energy use. In the column indicating total inputs it can be seen that for the site with highest potential, Guruve, average energy consumption was almost four times greater than in Chibi, the site with lowest potential. Given certain assumptions on output, derived from a survey of available communal area research literature, Mangwende had the highest energetic efficiency with an 0utput:input ratio of 6.96. In Guruve, the figure was 5.10. Thus in these two sites, efficiencies of agricultural energy use were greater than in LSCF or United States maize production. However, the figures are comparable to estimated efficiencies for peasant maize production utilizing draught animal power in other parts of the world (see section 2 in this chapter). Energetic efficiencies in the other four sites were much lower, with only Mhondoro receiving over 3 units of energy for each unit put into the system. We can see that energetic efficiency and natural region are highly correlated. In other words, adequate moisture levels are necessary to reap the benefits of enhanced energy utilization. There is nothing new in this statement; evaluations of green revolution innovations throughout the world have shown this quite clearly. However, this conclusion is quite important in the Zimbabwean context because it severely limits the prospects for significant agricultural change for the one-third of Zimbabwe's total population who live in natural regions 1V and V.
MODEL A RESETTLEMENT SCHEMES
Five Model A resettlement schemes were also surveyed during the ZEAP rural household energy survey. The results are presented in Table 11-13. It can be seen that farmers on Model A resettlement schemes cropped, on average, approximately one more hectare than farmers in communal areas.As all farmers are allocated 5 hectares of land, there is an upper limit to the cropped area as indicated in the range. With the exception of the Mukosi scheme, all households cropped at least 2 hectares. Access to draught animal power varied by scheme, but, overall, was less than in the communal areas. However, the area ploughed by tractor was greater, due to the settlers' greater access to the services of the Government tillage unit. In the sample, use of manure, harrows and cultivators was lower than in communal areas. However, household fertilizer use was higher, although per hectare use was not. Pesticide use was limited to a few farmers in two schemes, and, as in the communal areas, all of the surveyed households used hybrid seed. In Table 11-14, the energy equivalent of the physical inputs to production are shown. The figures indicate that resettled farmers utilized 75 percent of the total energy inputs (on average), when compared to the communal area average. Significant1y less manure and draught animal power was used on these schemes, than in communal areas. Only diesel had higher rates of use.
TABLE 11-73 SOME BASIC PRODUCTION AN0 INPUT STATISTICS FOR 5 MOOEL A RESETTLEMENT SCHEMES 1983-84.
Land Preparation and Maintenance Fertilizer Pesticide Hybrid Seed Area Planted Average Bullock Use (kg) Use (kg) Use (kg)
Sample Natural (HA) C,a v,m % Times Hrs. HH Per % HH Per E HH Per % Area S1ze Region Mean Range Manur.Harrow.Cult~v.Plough.(Per Ha) Ave. HA Use Ave HA Use Ave HA Use ...... Hoyuyu 10 IIB/III 3.03 2-5 0.0 0.0 12.0 1.0 12.8 1,052 347 100 - - - 43 14 100 Mayo 8 113-IV 2.98 2-4 5.9 0.0 20.3 1.8 63.7 803 269 100 1.6 0.5 37 57 19 100 Tugwl 9 III/IV 4.05 2-5 8.8 18.8 30.0 1.7 74.5 744 184 100 4.8 1.2 56 81 20 100 Kotanal 9 III/IV 3.15 2-5 10.0 47.1 68.6 1.2 65.6 414 131 89 - - - 65 21 100 Mukosi 7 IV 2.56 1-4 4.5 0.0 0.0 1.1 43.1 171 67 71 - - - 43 17 100
Tot/Mean 43 IIB-IV 3.18 1-5 6.1 14.8 28.4 1.3 51.9 665 209 93 1.3 0.4 19 58 18 100
TABLEII-14 ENERGY INPUTS AN0 ESTIMATED OUTPUTS IN FIVE MOOEL A RESETTLEMENT SMMES ...... Per Ha. Energy Inputs (1983/84) Estimated (GJ) Output ...... Sample Natural Hybrld Total Maize Output/ Scheme Size Region Hman Bullock Tractor Manure Fertilizer Pesticide Seed Inputs Kg. GJ Input ...... byuyu 10 IIB/III .70 0.28 0.69 - 5.75 - 0.38 7.8 3,000 44.6 5.72 Mayo 8 IIB-IV .70 1.41 0.16 0.31 4.76 - 0.51 7.9 2,250 33.4 4.23 Tugwl 9 III/IV .70 1.65 - 0.47 2.67 0.25 0.54 6.3 1,500 22.3 3.54 Kotanai 9 III/IV .70 1.45 - 0.53 1.90 0.60 0.57 5.8 1,50022.3 3.84 Mukosi 7 IV .70 0.96 - 0.24 1.02 - 0.46 3.4 1,000 14.9 4.38
Given our assumptions on yield levels, the highest energetic efficiency (5.72) is in a region of higher potential (Hoyuyu). However, unlike in the communal areas, there is no rapid reduction in rates of efficiency in marginal areas. This is partially due to the small range of environmental extremes between resettlement schemes, unlike in communal areas. The figures suggest that, on resettlement schemes, farmers in natural regions 111 and IV practise less energy intensive agriculture than those in communal areas. SUMMARY
This analysis of the energetics of agriculture production in Zimbabwe clearly illustrates the role of energy in a highly differentiated agricultural sector. The hlgh yields of the LSCF subsector, even when compared with U.S. farming, is evident, as is the large energy subsidy needed to produce such high yields. This analysis of state farm energetics is limited to two lowveld farms. However, even in such a small sample, similarities with LSCF production are evident, particularly in the unusual pattern of high labor and energy intensity. Comparison of the two high input subsectors has l imitations, principally because of the limited state farm production in the Mashonaland region. The analysis of communal and Model A resettlement farming quite clearly indicates that small-scale farming in Zimbabwe is in a state of transition. Use of fertilizer and hybrid seed is now widespread, and pesticide use is rapidly on the increase. In lower potential environmental zones, energetic analysis suggests that returns to lnputs are much lower (and probably quite variable on an annual basis). In natural region I1 and the better parts of 111, the use of hybrld seed and fertilizer has greatly increased yields. The high productivity of conununal area farmers under more favorable environmental conditions was recently highlighted by the Director of Agritex, Mr. J. Hayword. In an interview with the "Financial Gazette" (iday 18, 1984) he described communal area yields of cotton and maize in natural region I1 as "remarkable" and a "breakthrough" and suggested that they were comparable with yield levels of adjacent large-scale farmers. Our figures indicate that in energy terms they are also twice as efficient. Manure use is highly varied and access to draught power is constrained, particularly in communal areas. So while, on the one hand, the small-scale, African farm is moving rapidly towards yield enhancing commercial energy inputs, the transition to more labor saving inputs (e.g., animal and mechanical draught power) has been l i~nlted. Furthermore, in some regions a backward transition is occurring, as drought- related cattle deaths have forced people to plough some of their land by hand. These trends, we believe, are contradlctory. Desprte characterizations of Zimbabwe as a labor surplus economy, there is substantial evidence suggestrng that, at the household level, labor shortage is a key constraint on development (de Jong, 1983) This is particularly true durlng periods of peak labor use: planting, weeding and harvestrng. There is also evldence that money earned off tile farm 1s a major source of income for investment on the farm. In this labor migrant economy, the draught power shortage puts additional strains on women's labor. There is increasing evidence that agricultural development in the communal areas is highly uneven. For those fortunate enough to be located in the more favorable natural regions, a transition to higher input and higher output farming is taking place. But for the majority of communal area households, situated, as they are, in areas that are normally dry, the agricultural crisis has deepened. With sources of off-farm income drying up, the prospects for development in these regions is presently bleak.
7. KEY ISSUES FOR AGRICULTURAL ENERGY DEVELOPMENT
In this section we move from a general overview of energy use in Zimbabwe's agricultural sector to a discussion of what we consider to be the major issues, particularly regarding the Government's objective of growth-with-equity. Three key issues emerge as being of paramount importance in this respect. These are:
(l)Resettlement and agricultural land-use;
(2) Kraal compost and fertilizer use in semi-arid areas;
(3) The crisis of draught power.
RESETTLEMENT AND AGRICULTURAL LAND-USE
Because of the large disparity in land potential in the country, the geographical location of the major agricultural subsectors is critical to the evaluation of energy inputs and agricultural outputs. Current1y, the nation's prime arable land is, for the most part, monopolized by large-scale commercial farms. As we have shown, the subsector achieves very high yields at the expense of a very high energy cost. There is a tendency towards increased foreign exchange-using inputs on large-scale commercial farms. The unusual pattern 2f high labor and energy-intensive farming appears to be changing as the subsector replaces labor with capital. The increased capital intensity of farm production will reduce efficiency levels further. In regions of higher potential, communal and resettlement scheme farmers appear to be making a partial transition to more energy-intensive farming. Outputs have responded remarkably, leading to much more efficient conversions of energy. Energy analysis points favorably in the direction of resettlement for the natural region I1 and 111 areas. The relationship between energy and land-use in the Xashonaland region is highlighted by the question of cropping intensity and arable land availability. Work done at the Zimbabwe Institute of Development Studies (ZIDS), suggests that less than one third of the potentially arable land of the LSCF Mashonaland region was cropped or fallowed in the 1981-1982 agricultural season (see Weiner et al, 1985). Furthermore, regional stocking rates were over 5 ha/livestock unit. Interesting1y, Model A schemes exhibited similar intensities of land-use while Model B schemes utilized less of the potentially arable land for cropping. Meanwhile, communal areas were shown to have the highest percentage of arable land under crops or fallow (Whitlow, 1979). Due to increased capitalization of LSCF production, more effective use of the nation's prime arable land, given existing allocations of natural region IIA land, would require a transition to more capital- and energy-intensive farming. This would require a greater flow of foreign exchange into the subsector while demanding less labor. Planners must seriously evaluate the costs and benefits of this scenario for Zimbabwe. Although there has been limited Model A resettlement in natural region I1 (particularly IIA), the study suggests that the intensive resettlement model is really extensive. This is prirnarily due to the generous allocations of land given to draught animals in this region (5 hectares per livestock unit). So while the use of fertilizers and hybrid seed has helped the small settler farmer achieve high yields, reliance on draught power has substantially reduced the amount of potentially arable land in a crop rotation, which ultimately limits the number of households which can be resettled. Although most model B farms are tractorized, the ZIDS study indicates that gross underutilization of potentially arable land existshere too. Model B farms, in an attempt to maintain former LSCF production, have often been given whole LSCF farmsteads. This has led to greater underutilization of the nation's prime arable land. There has been limited state-farm development in the Mashonaland region. Although state farms appear to have the potential for a more intensive use of the country's prime farming region, similar constraints on capital and managerial availability apply here as in the LSCF and model B subsectors. Land-use planning in Mashonaland must find a middleground between the high capital- and energy-intensity associated with LSCF areas, the overutilization of land in many communal areas and the underutilization of land on resettlement schemes. In natural regions 111, IV, and V draught power allocations to settler farmers are more consistent with environmental conditions where extensive forms of land-use are necessary. This is quite evident in the communal areas where the land is being farmed and grazed too intensively. At present, there is a conflict between land-use potential and land-use planning in Zimbabwe's highveld region because much of the area with potential for intensive land- use is being used extensively whereas land that should only be used extensively is being farmed and grazed intensively. Energy has a potentially key role to play in helping to resolve this problem, by enhancing peasant access to mechanical tillage in natural region 11, and to yield enhancing energy inputs in all natural regions.
KRAAL COIbIPOST AND FERTILIZER USE IN SEMI-ARID AREAS
High rates of fertilizer utilization are already in evidence in communal areas and resettlement schemes in the highveld region, as are low rates of use of kraal manure and compost. Application rates of fertilizer are lower and kraal compost higher in natural regions 111, IV and V. Because fertilization (particularly with nitrogen) is highly correlated with yield, the potential use of organic and inorganic fertilizers in Zimbabwe's dry regions is quite important. A major problem associated with fertilizer use in semi- arid areas is illustrated in Figure 11-1. Prepared by the Department of Research and Specialist Services of the MOA, the flgure presents results of research carried out during the 1981-1982 crop season. The effects of nitrogen fertilizer on maize yields were analyzed in nine communal area sites with sandy soils. It was found that, on average, there was a 46 percent increase in yield when fertilizer was used. However, as indicated in Figure 11-1, two sites in the Berenjena cluster of Chibi south experienced very slight increases whereas one site actually calculated a yield decline. This was caused by poor rainfall in Chibi south that year. In the remaining sites where rainfall was better, the positive response on yields is quite striking. The dilemma here is the level of risk associated with fertilizer use in semi-arid areas. With adequate moisture, yields respond well, but fertilizer can increase vulnerability to drought. Data presented here indicates that farmers in natural regions I11 and IV feel the risk is worth taking whereas farmers in region V are reluctant to use fertilizer (or can't afford to). Research on the relationship between fertilizer, kraal compost and anthill use show similar results. For example, Theisan (1979) concludes that "it has been consistently shown that in a dry season, as after a dry spell, maize yields with low rates of ammonium nitrate applied with low rates of anthill or compost will invariably out-yield maize plots with high rates of compound fertilizer and anthill or kraal compost." These conclusions are partially based on field trials in the Chiwundura communal area in the 197611977 drought year. In that year, applications of 200 kg. of ammonium nitrate (AN) and 8,000 kg. of an anthill compost mixture yielded 3,124 kg./ha. Adding an additional 2,500 kg. of compound D and doubling the anthill compost rate to 16,000 kg.,/ha. only increased yields to 3,429 kq./ha. llhen an additional 8,000 kg. of anthil l kraal compost was applied, wilting occurred and yields declined to 2,819 kg./ha. Grain Yield t/ha
Not fertilized
------.Fertilized
FIGURE 11-1 EFFECT OF FERTILIZER ON MAIZE YIELDS AT VARIOUS COMM~~SITES, 1981q9820SEAS0~
Source: Department of Research and Specialist Services (1983) In research geared towards communal area farming in the poor granite soils of natural region 11, Rode1 et a1 (1980) found dramatic effects of kraal compost and fertilizer use on levels of productivity. Maize yields with no kraal compost increased from 490 kg./ha., to 972 kg./ha. when 4.5 tons was applied and to 1,593 kg./ha. with 9.0 tons application. An application of 180 kg. nitrogen yielded 2,808 kg./ha., and as much as 4,896 kg./ha. was yielded with an additional 9 tons of kraal manure. The implications of this research for the development of communal area agriculture are complex. There is little doubt that the use of fertilizer and kraal compost can have a dramatic impact on yields. Before the rapid increase of fertilizer use in the LSCF subsector in the 19601s, maize yields averaged only 2,000-2,500 kg./ha. (Muir, 1981). In the early 19501s, LSCF maize yields averaged only 1,421 kg./ha. (Tattersfield, 1982), whereas yields on granite sandveld were only 700 kg./ha. in the early 1960s (Grant, 1976). As in the LSCF subsector, the breakthrough into high output farming in the communal areas located in natural region 11, can be attributed to the diffusion of fertilizers with hybrid seed, along with institutional and financial support. Technical packages developed historically for LSCF highveld use are being successfully transferred to the peasantry. However, these inputs are expensive, and can have little or even negative impacts on yields when rainfall is low. Furthermore, the environmental impacts on the community are uncertain, and can also be problematic. Because the majority of communal and resettlement areas are located in semi-arid regions the level of risk associated with fertilizer use is high. With regard to kraal manure, our research suggests that fertilizer is replacing manure in many areas, with the transition occurring at the rapidest pace on the highveld. A11 5 of the surveyed resettlement schemes applied manure to no more than 10 percent of the total cropped area. However, in the communal areas located in natural regions 111 and IV, 30-55 percent of the total cropped area was under manure. Other studies indicate that current rates of manure application are insufficient to have a dramatic impact on yields. Furthermore, rates are declining as access to livestock in general declines.
DRAUGHT POWER CRISIS
The crisis of draught power in the communal areas is one of the more well documented aspects of communal area agriculture. Analysis of these studies suggests that 27-52 percent of households do not have access to this critical energy source (Whitsun Foundation, 1983). Furthermore, for households with draught animals, the ability of the animals to work is lowest at the point where their work is needed the most. For households hiring and borrowing draught power, ploughing is often done too late, further reducing yields. Although the problem is universally recognized, workable solutions often seem elusive. Some optimistic words and programs have emerged. For example, Sanford (1982), in a controversial report, concluded that there is no evidence of long-term environmental degradation due to overgrazing in the communal areas. He went against conventional wisdom by suggesting that there are too few, not too many livestock. Arguing that livestock are the key to small farm development, he proposed a system of intensification of livestock production through supplementary feeding combined with better management practices. The importance of Sandford's study is that the problem has been redefined from simply a Malthusian dilemma of population outgrowing the resource base, towards a realization that the capital availability and the organization of the production system are also critical. In other words, carrying capacity is a relative concept. Critics of more intense livestock production argue that peasants do not have the available biomass (for direct feed) or cash (to buy feed). While this is indeed the case for many households we question why some of the critics of developing commercial feed for the communal areas do not have the same objections to the rapid diffusion of fertilizers, pesticides and hybrid seed. Recently, the people of Mwenezi (Victoria Province) have spontaneously developed their own livestock development program. In short, all members of the community have been allocated an area of grazing land with a corresponding number of livestock units. Households with large herds are obliged to sell off some of their livestock or buy more land if they want access to more land. Presumably, they will buy from households with little (or no) livestock, giving this poorer family an opportunity to purchase livestock. The system is devised to reduce community pressure on a common resource, while helping to create greater opportunities for livestock production for the poorer households. It is too early to evaluate whether the program will be successful, but it is a very important experiment that could provide guidelines for a Government livestock policy, particularly in the semi-arid areas. One important lesson of the Mwenezi experiment is the decision by the local population that changing the way that production is organized is the key to overcoming the interrelated crises of environment and livestock production. A third possible means of helping to alleviate the draught power crisis is a transition to mechanical tillage. Because individual households cannot afford tractors, cooperative production is one mechanism to help farmers make this transition. For this reason, model B farms are being allocated better land where more contiguous tracts of arable land exist. Presently, most cooperative farms have only one tractor and a few have none. Furthermore, the combination of very large allocations of land (an average of 1,740 ha./farm) and a shortage of managerial expertise, has led to an underutilization of prime arable land. Model B farms have Mechanical Tillage Head Office Central Mechanical Equipment Department SOUTH Base for Major, Repairs AFRICA 1:1,000.000 Sub Base for Servicing, Maintenance and Fuelc a 50 LOO 150 xi low^== Tsetse .Belt: Free or Subsldlzed Servlce Viable Cropping Zone: Economlc Service f--? Water Conservation Zone and Reclamati0n:~c~nomicand Free Subsidlzed Servlce Water Conservation and Food Deficit ( z0ne:Free or Subsidlzed Service source: ninlstq of Iands, Resettlement and Rural Development, 1983
MAP 11-4 TILLAGE ZONE MAP OF MECHANICAL TILLAGE PROGRAM been designed to replace large-scale commercial farms. Clearly, it is unreasonable to expect these cooperative producers to crop the 400-500 hectares of potentially net arable area available to them. Large-scale farmers who average 6.5 tractors per farm, in the Mashonaland region, crop less than half of this (on average). The fact that Model B farms averaged 61 cropped ha./farm (73 ha./farm in Mashonaland) in the 1983-1984 crop season (MOA estimate) indicates that this method of organizing production does have the potential to bring significantly larger tracts of land under production than in individual farms. Furthermore, the cooperative model can play an important role in providing peasant-access to mechanical tillage and other forms of commercial energy while putting more of the nation's prime arable land into production. This latter goal will require that land-use planning (particularly in natural region 11) be more in tune with the capital and managerial availability of particular forms of production organization. In the case of individual smal l-scale production, any transition to mechanical tillage will have to come through private hire, government hire or service. In the 1983-1984 crop year, the Government's mechanical tillage unit ploughed 6,094 ha. on contract and 5,136 ha. as a free service. Ninety-four percent of the 11,230 total hectares ploughed by the mechanical tillage unit that year were in resettlement schemes. A major dilemma in developing mechanical til lage for small-scale individual producers is graphically displayed in Map 11-4. The map indicates that economic service is possible in natural regions I and 11, the better part of I11 and a small area of IV around Gokwe. To the south, in Masvingo and the Sabi-valley region, economic and subsidized service is possible. For much of the midlands and all of Natabeleland, no economic service is possible at all. The Ministry of Lands, Resettlement and Rural Development estimates that yield levels of 3,000 kg./ha. for maize are necessary to justify the ploughing charge to the farmer ($62 per ha. in 1983-1984) for a hectare of maize. Again, the possibilities for harnessing new energy sources in agriculture are in the areas of higher potential. An economically viable mechanical tillage unit servicing individual producers appears unviable in the regions where the majority of the cornmunal area population live.
8. SUMMARY AND RECOMMENDATIONS
The LSCF subsector is the dominant consumer of commercial energy and fuelwood. The skewed flow of energy into this subsector is indicative of the historical process of uneven development that has occurred in Zimbabwean agriculture. Since independence, there has been some redirection of energy flows towards communal areas and resettlement schemes, a1though primarily in the form of fertilizer, agrochemicals and hybrid seed. Furthermore, this change has occurred primarily in the more favorable natural regions. With the exception of producer cooperatives and tractor hiring, there has been limited diffusion of agricultural machinery and liquid fuels into peasant production. The post-independence pattern of energy-use suggests that, although differentiation between subsectors may be diminishing somewhat, there is heightened differentiation within the communal areas. This process threatens the Government's strategy of growth-with-equity. The following observations and opinions are made regarding post- independence land and energy-use patterns. At present, the nation's prime arable land in Mashonaland is being underutilized. Given existing farm sizes in the LSCF subsector (which are growing), fuller utilization of the land will require an intensification of energy and capital utilization, at the expense of labor. This process has already begun to happen. In Mashonaland, Model B farms also underutilize land because they have been allocated whole LSCF farmsteads. Model A schemes in natural region I1 underutilize land because of a generous allocation for draught power. A comparison of state farm and LSCF production suggests that, while their level of capital and energy intensity are similar, the state farm sector utilizes more labor and potentially arable land. There are no significant differences in levels of productivity and energetic efficiency. Given the right environmental, infrastructural and economic conditions, Zimbabwe's small-holders can achieve levels of productivity comparable to the LSCF and state subsectors, utilizing substantially less energy inputs. There must be a re-evaluation of land-use planning in the LSCF area of Mashonaland in order to maximize the use of the country's best land. Model B producer cooperatives are we1 l-suited to the higher rainfall areas; however, allocations of land must be smaller and Government support greater. The schemes need better access to credit for the purchase of machinery and more assistance from Agritex on issues of management and agronomy. In natural region 11, Model A schemes must be allocated less land for grazing and must increase the area cropped. Cooperative livestock and tractor schemes, and the mechanical tillage unit offer potential here. Where large tracts of arable land are available, the state farm model appears to be attractive. More research on the viability of fertilizer use in semi-arid regions (natural regions 111 and IV primarily) needs to be done. Also, the feasibility of diffusing crop packages of hybrid seed, fertilizer and agrochemicals in these areas should be evaluated. Research on the environmental impacts of the transition to high-input farming is necessary. Models for livestock development in natural regions IV and V need to be tested and evaluated, In this context, planners can learn a lot from spontaneous projects such as the Mwenezi scheme.
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D.K. Munasirei
1. INTRODUCTION
The purpose of this report is to outline the methodology behind the development of the land-use data base for the Zimbabwe Energy Accounting Project. There are two stages to consider: the specification of a classification of ecological zones (i.e. natural regions) and how these are distributed by administrative province; and the specification of land-use categories within the natural regions. The data for the 1982 base year were collected from secondary sources. Sources included publications from government departments (especially the Central Statistical Office and Agritex), foundations and institutions, and articles from journals. Official sources were not always available for this study and some were not in a form suitable for the study. The sources of information which were valuable regarding land-use did not, unfortunate1y, consider communal land-use. Therefore, estimates of cultivation of communal areas are subject to large errors (iThitlow, 1979b) for different land-use categories at the provincial level. The 1982 Population Census (CSO, 1984) gives a more comprehensive but incomplete coverage of communal land areas. The sources which satisfy the requirement that there be complete area coverage of the area, are official reports for non-agricultural land-use, and topographic maps which provide a wealth of data on land-use at the national level. A graticule was used to measure land areas by natural region, and these measurements were compared with official control totals (CSO, 1984), and adjusted where necessary.
2. LAND AREAS AND ECOLOGICAL ZONES
The original agro-ecological survey of Zlmbabwe classifies the country into five natural regions (Vincent and Thomas, 1960) These natural regions (NR) indicate the potential use of land in relation to the amount and variability of rainfall, soil characteristics, and relief. However, a considerable amount of additional information has made modifications to the system inevitable (Ivy, no date). The modified natural regions and a brief description of each are highlighted in Table 111-1. The natural regions were remodified for ZEAP by combining regions IIb and I11 into just region 111. Before dividing the land area by natural region, the control totals were obtained for each province. On a national basis, the distribution of land by natural region is 1.6 percent in region I, 11 percent in region 11, 25.4 percent in region I11 and 62 percent in region IV (Table III- 2). The national total and the proportions by natural region are quite comparable with data from other sources. The diversity in the ecological character of Zimbabwe is greatest in Manicaland province because of a wide range of altitude, rainfall and soil characteristics. The distribution of land by natural region in the province is 17 percent in region I, 5.3 percent in region 11, 42.2 percent in region 111, and 35.3 percent in region IV. While the land areas of other provinces fall in at least two ecological zones, Matebeleland South is ecologically homogeneous (Table 111-2). The full list of the land-use categories used in this report are:
(1) Commercial land: comprising all privately owned commercial land referred to as Large Scale-Commercial Farms (LSCF), Smal l-Scale Commercial Farms (SSCF), and some small areas of state land (State Farms);
(2) Communal land (formerly, Tribal Trust Land): comprising 171 defined areas of state land which are occupied on a traditional pattern of land tenure;
(3) Resettlement land: comprising land bought or acquired by the state from commercial farmers, and used either for intensive village settlements with individual arable locations and communal grazing areas (i.e. Model A), or for intensive settlement with communal living and co- operative farming (Model B);
(4) Parks and wild life land: comprising areas of state land that are currently used as national or recreational parks, safari areas, botanical gardens and reserves;
(5) Forest land: comprising areas of state land that have been reserved for forests, and natural reserves for the protection of trees and forest produce;
(6) Urban-built environment: comprising urban areas located mainly in LSCF areas with a population of 10 000 people or more, and
(7) Rural-built environment: comprising towns, mission and mining centers with less than 10 000 people. TABLE 111-1 RELATED FARMING SYSTEMS ...... NR I Specialized and Diversified Farming Region: Rainfall in this region is hlgh (more than 1 000 mm per annum in areas lying below 1 700 m altitude, and more than 900 mm per annum at greater altitudes), normally with some precipitation in all months of the year. Temperatures are normally comparatively low and the rainfall 1s consequently highly effective, enabling afforestation, frult and Intensive livestock production to be practiced. In frost-free areas, plantation crops such as tea, coffee and macadamia nuts can be grown. Where the mean annual rainfall is below 1,400 mm, supplementary irrigation of these plantation crops 1s requlred for top yields.
NR IIa Intensive Farmlng Region: Rainfall is confined to the Simmer and is moderately high (750- 1,000 mm). Two sub-regions have been defined. Sub-region IIa receives an average of at least 18 ralny pentads per season and normally enjoys reliable conditions, rarely experiencing severe dry spells in Sunmer. The region is sultable for Intensive systems of farming baaed on crops and/or livestock production...... NR IIb Sub-region IIb receives an average of 16-18 rainy pentads per season and is subject either to rather more severe dry spells during the rainy season, or to the occurrence of relatively short rainy seasons. In either event, crop ylelds in certaln years will be affected, but not sufficiently frequently to change the overall utilization of Intensive systems of farming.
NR 111 Seml-Intensive Farming Region: Rainfall in this region is moderate In total amount (650-800 mm), but, because much of ~t is accounted for by infrequent heavy falls, and temperatures are generally hlgh, its effectiveness is reduced. This region will receive an average of 14-16 rainy pentads per season. The region 1s also subject to falrly severe mld-season dry spells and therefore 1s marginal for malze, tobacco and cotton productlon, or for enterprises baaed on crop productlon alone. The farming systems, in conformity with the natural conditioning factors, should therefore be based on both livestock production (assisted by the productlon of fodder crops) and cash crops under good management on solls of high available moisture potential.
NR IV Seml-Intensive Farmrng Region: This reglon experiences falrly low total rainfall (450-650 mm) and is subject to periodic seasonal droughts and severe dry spells during the rainy season. The ralnfall is too low and uncertain for cash cropplng except in certain very favorable localities, where limited drought-resistant crops can afford a sideline. The farming system, In accord with natural factors, should be based on livestock production, but it can be ~ntensifledto some extent by the growlng of drought-resistant fodder crops.
NR V Extensive Farming Reglon: The ralnfall in this region is too low and erratic for the reliable production of even drought-resistant fodder and grain crops, and farming has to be based on the utlllzation of the veld alone. The extensive form of cattle ranching or game ranching 1s the only sound farmlng systems for this reglon. Included ln thls region are areas of less than 900 m altitude, where the mean rainfall is below 650 mm In the Zambezl Valley and below 600 mm In the Sabi-Llmpopo valleys......
Note: A rainy pentad SI deflned as the center one of three five-day ~eriods(pentads) which together recelve more than 40 mm ralnfall and two of which recelve at least 8 mm of rainfall. TABLE 111-2 PROVINCIAL TOTALS BY NATURAL REGION ( gooo- ...... I II I11 IV Total ...... Manicaland 611.24 190.77 1522.71 1270.23 3594.95 17 % 5.3% 42.4% 35.3% Mashonaland Central 1145.14 496.54 1079.31 2721.00 42.1% 18.2% 39.7% Mashonaland East 728.53 946.88 637.03 2312.45 31.5% 40.9% 27.6% Mashonaland \Jest 2262.55 2078.49 1777.77 6118.80 36.9% 34% 29.1% Matebeleland North 439.40 6697.50 7136.90 6.2% 93.8% Matebeleland South 6647.00 6647.00 100% Midlands 3723.26 2073.74 5797.00 64.2% 35.8% Masvingo 708.14 4051.76 4759.90 14.9% 85.1% ...... National Total 611.24 4326.99 9915.42 24234.35 39088.00 1.6% 11% 25.4% 62% ...... Note: Top figures represent area in ha. Bottom figures denote percentages of provincial total.
Communal land-use data were obtained from the 1982 Population Census report (CSO, 1984). The communal areas are also well-demarcated on the official Map of Natural Regions and Farming Areas of Zimbabwe (DCE, 1984) For the LSCF and SSCF sectors, the ICA supplement for 1982 (CSO, 1982a) proved invaluable. However, these two categories were grouped into the old 5 provinces so it was necessary to rearrange the farming types to fit the currently used administrative provinces, taking note of their ecological location. The data for resettled areas were obtained from lists produced by the Ministry of Lands Resettlement, Rural Development (MLRRD) and the Agritex Planning Branch, a 1982 map prepared by the MLRRD, and the 1982 Census report. Only those resettled areas that appeared in the Census report and the map were considered for the 1982 base year. The data for state farms were obtained primarily from detailed 1982 returns of the Agricultural and Rural Development Authority (ARDA, 1984) which administers all the farms in the country. For non-agricultural land-use categories various sources were used. The data for parks and wild life areas were obtained from a pamphlet published by the Ministry of Natural Resources and Tourism (MNRT, 1982). For forest Lands, the 1982 report of the Forestry Commission was helpful. Data of the urban and rural built-environments were obtained from measurements and calculations made on 1:5000 government maps (Surveyor General, 1982). These maps show the plans of urban areas, towns, missions and mining centers of Zimbabwe. The calculations for the built areas of the big municipalities were treated individually. The calculated proportions of the built area of these urban centers are as follows: Harare and Chitungwiza (70%), Gweru (57%), Kwekwe (54%), Bulawayo (50%), Kadoma (40%), Mutare (20%), and Redcliff (13%). A fifty percent sample of 12 towns was selected on the criterium that all the towns selected were smaller than the municipalities. For these centers the average proportions of built-up area used is 37 percent. For the remaining 32 small towns, missions and mining centers, the 25 percent sample yielded an average built-up proportion of 33 percent. The shortcoming of the proportions used from the sampled centers is that they are not representative of the actual built-up areas. It is important to note that most of the centers except Kariba, Victoria Fa1 ls, Chimanimani, Zimunya Town and Kamative are located in the LSCF sector. The distribution of land at provincial and national levels is shown for each of the land-use categories by natural region in tables 111-2 and 111-3. These figures are quite comparable to official figures and those from other sources. On a national basis, 41.8 percent of the land area is under communal land-use. Of this area about 70.9 percent lies in natural region IV. Another source (Ilhitlow, 1980a) estimates this to be 74 percent. In contrast, LSCF areas, which occupy 34.4 percent of the nation, have more than half of their area (53.3 percent) in more favorable natural regions (i.e. NR I, I1 and 111). Parks and Wild Life areas are the third major land-use type, occupying 13.5 percent of the country. About 81.4 percent of this area occurs in NR IV. The ecological distribution of land at the national level of other land-use types is shown in Table 111-3. TABLE 111-3 LAND-- USE CATEGORIES AND AGRO-ECOLOGICAL REGIONS ( '000 HTA
Agro-Ecological Regions Land-Use Category I I I I11 IV Total
Communal lands 106.52 958.06 3702.16 11595.45 16362.20 (c) 0.6% 5.9% 22.6% 70.9% Resettlement 13.46 80.32 844.78 630.25 1568.80 (R) 0.9% 53.8% 40.2% SSCF 7.89 155.77 569.62 539.73 1273.00 0.6% 12.3% 44.7% 42.4% State Farms 1.90 1.04 17.64 58.82 79.40 (SF) 2.4% 1.3% 22.2% 74.1% Parks and Wild Life 39.50 16.66 922.85 4281.10 5260.11 (PRES) 0.8% 0.3% 17.5% 81.4% Forest Lands 86.25 16.29 42.25 808.58 953.37 9.1% 1.7% 4.4% 84.8% Urban Built Env. 49.57 24.61 32.52 106.70 (STR) 46.4% 23.1% 30.5% Rural Built Env. 2.19 5.1 11.13 12.55 30.97 (STR) 7.1% 16.7% 35.8% 40.4% LSCF 353.54 3044.10 3780.39 6274.45 13452.48 2.6% 22.6% 28.1% ...... Note: Top figures denote area in ha. and bottom figures represent percentage of Land-use category total.
Provincially, communal land occupies over 50 percent of land in Manicaland, Mashonaland East and Mashonaland Central. LSCF areas occupy a greater portion of land only in Mashonaland West and Matebeleland South (Table 111-4). Over 45 percent of the communal area in each of the eight provinces, except Mashonaland West (35.6 percent), occurs in NR IV. In contrast, Manicaland has 40.6 percent of its LSCF area in NR I, Mashonaland East 53.1 percent in NR 11, Mashonaland Central 86.7 percent in NR I1 and Mashonaland West 64.9 percent in NR 11. The provincial distribution of parks and wild life areas is uneven. The highest concentration of this category occurs in Matebeleland North. Important areas in this province include Hwange National Park, the biggest in Zimbabwe, and Matetsi and Deka Safari areas. About 35 percent of the total area reserved for this category in the country occurs in this province (Table 111-4). This is followed by Mashonaland West (27.3 percent) and Masvingo (15.4 percent). Most of this land occurs in NR IV. Small-scale commercial farming areas occupy about 3.3 percent of the country, which is quite comparable with the 3 percent estimated for the 1972-1977 period given in another source (Whitlow, 197933) The 0.3 percent difference might be accounted for by a slight increase in SSCF areas between 1977 and 1982. Even though the ecological distribution of the SSCF sector is uneven, over 50 percent of this land-use category occurs in NR I11 in Manicaland, Mashonaland East, Mashonaland Central, and Midlands provinces. This ecological concentration in NR I11 is similar to, but even higher than resettlement areas, where for each of the provinces (except the Matebeleland provinces) the proportion is over 70 percent. The expected change by the year 2002 is a doubling of resettled areas, with expansion into NR I11 where land is being acquired by the state from LSCF areas. In contrast, the LSCF sector will contract andbe consolidatedinNRI1 of the Mashonaland Provinces. State farms are concentrated in the marginal areas (NR IV) in most provinces. Like resettled areas, state farms are expected to more than double in the marginal areas by the year 2002.
TABLE 111-4 LAND-USE CATEGORIES IN ZIMBABWE ( ' 000 HA)
Prov lnce Resettlement SCFA Parks, Reserves Towns, Townships LSCF and Communal Total (Oct. 1982) & Ssfarl Areas Munlcipalities Forest Lands Mines, Missions Lands
Manlcaland
Msshonal and East
Mashonaland West
Mashonaland Central
Midlands
Masvingo
Matebeleland North
Matebeleland South ...... Totals 1568.80 1274.00 5261.OO 300 .OO 14323.00 16362.20 39089.00 ...... Note: Top figures denote area in ha. and bottom figures represent percentages of provincial total.
The category of forest lands includes managed forest (FMG), unmanaged forest (FUN), large scale exotic forest (LEXF) and communal exotic forest (CEXF) (Forestry Commission, 1982). Forest lands, which occupy about 2.4 percent of the country, have about 84.8 percent of their total in NR IV (Table 111-4 and 111-5). The highest concentration of forest lands occurs in Matebeleland North where Gwaai, Ngomo, and Mafungabusi managed forests are found. About 88 percent of all the forest lands in Zimbabwe occurs in this province. TABLE 111-5 FOREST LANDS ( '000HA) - EMG FUN LEXF/ Total CEXF ...... Manicaland 83.45 0.95 2.30 Mashonaland Central 2.78 - 2.89 Mashonaland East 5.19 - 4.54 Matebeleland North 14.25 824.12 0.91 Matebeleland South 0.01 - 0.17 Midlands 4.12 - 3.33 Masvingo 0.10 1.29 0.88 ...... Total 109.90 826.36 15.02 951.28 ......
Urban-built environment occupies about 0.3 percent of the country. About 46.4 percent of this environment occurs in NR 11. The largest area occurs in Mashonaland East where Harare and Chitungwiza municipalities are located. About 23.1 percent of this land-use category occurs in NR I11 in which are found mostly Midlands municipalities. The ecological distribution for rural-built environment on the other hand shows a heavy concentration in natural regions I11 and IV.
3. DISTRIBUTION OF CULTIVATION
The data presented in this section may be taken as a close approximation to the present distribution of cultivation in Zimbabwe. The only exception is the distribution of cultivation and intensity of cropping in communal lands. The data obtained for the intensity and distribution of cultivation in communal lands (Appendix III- 1) is based on aerial photographs (at 1:25 000 scale) taken over the period 1972 to 1977 (Whitlow, 1979b). Cover types analyzed on the photographs included cultivation and fallow in communal lands. It was not possible to distinguish cultivation and fallow on the photographs. The figures of "actual cropped" area shown on Appendix 111-1 include fallow. On average, 40 percent of the "actual cropped" area is fallow. To understand how the figures were obtained it is important to note how the 1972-77 data were presented. For analytical and mapping purposes the data were expressed in categories (classes) giving the proportion of cultivation and fallow per unit area as follows: less than 10 percent; 10-25 percent; 26-50 percent; 51-75 percent; and over 75 percent. An estimate of the actual area under cultivation was calculated as the product of the percentage of land in a given class and the median value of the cultivation class, divided by 100. For example, if 25% of Mutasa South Communal Area is in the 51-758 cultivated land class, then the actual cropped area is:
(25 X 63)/100 = 15.75% of Mutasa South.
The area of Mutasa South is 19 700 hectares and 15.75% of this yields a cropped area of 3102.8 hectares. The actual cropped area of all the 171 communal lands was derived using the method outlined above. It is important to note the shortcomings of using the 1972-1977 data for the 1982 base year. The 1972-77 data were used mainly because they represent the only data base covering the whole country. It is also assumed that there have been only slight changes in the intensity of cropping in communal lands between 1977 and 1982. Therefore, the data shown in Appendix 111-1 may be taken as a close approximation to the 1982 distribution of cultivation in communal lands. Appendix 111-1 reveals that 29.5 percent ofall comlnunal lands is cropped (40 percent of this is fallow). This is an extremely high proportion in view of the fact that about 70 percent of the land occurs in NR IV. The proportion under cultivation by ecological region is 50.4 percent in NR I, 45.2 percent in NR 11, 39.6 percent in NR I11 and 24.7 percent in NR IV. The most intensively cropped province 1s Mashonaland East with 41.1 percent of its area cropped. Cropped proportions for Manicaland, Masvingo and Midlands range from 34 to 37 percent of their areas. The situation in which about 25 percent of the marginal areas is cropped is exacerbated by the occurrence of rock domes. These non- utilizable land areas form an arc in the communal areas which extends from Mberengwa through Buhera and Sabi North to Mutoko (\;hitlow, 1980a). These areas provlde woodfuel and poor grazing and are of extremely marginal value. They greatly limit the availability of arable land. In these communal areas, it is important to note that population is increasing at the very high rate of over 3 percent per annum. In the light of such estimates, ~t is obvious that there is a critical situation regarding the availability of land In communal areas. In terms of the absolute slze of communal lands, no change is expected by 2002. The expected changes by 2002 include the intensification of crop cultivation, the reduction of fallow and a slight expansion in the ~ndlgenous forest and grazing areas. Through these changes, the cropped area is expected to increase by 26.2 percent by 2002 (Table 111-6). From the 1982 ICA Supplement the calculated proportion of cropped area in the LSCF sector is 4 percent. Sixty five percent of the cropped area occurred in NR I1 in 1982. Provincially about 78.5 percent of LSCF cropped area occurred in the three Plashonaland provinces (Appendix 111-2). In other provinces, less than 4 percent of the LSCF land in the provinces was cropped. For example, the Matebeleland provinces, with over 90 percent of thelr LSCF land In NR lV, are used primarily for livestock rearing. The malor changes expected in the cultivated area are in the LSCF and resettled areas. The LSCF cropped area is expected to decrease by 14.2 percent by the year 2002 (Table 111-6). This decrease will affect mainly the Mashonaland provinces where the Government is acquiring land for the resettlement program. Resettled areas will more than double their cropped area (Table 111-6). The bulk of the resettled land will be in NR 111. This assumption is based on the pattern that emerged in the first two years of the program (1981-82). The changes expected by 2002 are the expansion of resettled areas in NR I11 and the contraction and consolidation of the LSCF land in NR 11. The exclusion of NR I and I1 in the Resettlement Program can be seen as a need to allow for the intensification of crop cultivation in the LSCF sector. This intensification is expected to be concentrated on tobacco, cotton, and other industrial crops. The production of these crops is expected to increase by 40 percent (tobacco), 20 percent (cotton) and 20 percent (other industrial crops) by 2002 (Table 111-7). The apparent loss in food production in this sector is expected to be compensated for by a net gain from small holder farming in resettled areas.
TABLE 111-6 PROJECTION OF CROPPED LAND ( ' 000 HA)- ...... 1982 2002 % of Change ...... LSCF 588.9 505.4 -14% Resettlement 107 .O 246.0 +129% Communal 2892.6 3650.5 +26% SSCF 67 .l 73.0 +9% State Farms 16.1 40.0 +148% ...... Total 3671.7 4514.9 +23%
Note: The cropped area in communal lands includes about 40 percent fa1low.
The cropped area and area under different crops in resettled land was derived from the preliminary reports of resettled areas produced by the Agritex Planning Branch (MOA, 1984). The actual area under cultivation was estimated to be 6.8 percent of the total. The most intensive cultivation occurred in NR 111, where 53.7 percent of all cropped area lies. Appendix 111-3 highlights the area cropped by natural region. Of all the resettled land in Manicaland, Mashonaland East, Mashonaland Central, Mashonaland West and Midlands provinces over 60% of the cultivated land occurred in NR 111. Other than the expected changes by 2002 mentioned earlier, expected changes in productivity are high1ighted in Table 111-7. TABLEIII-7 PERCENTAGEINCREASEINAGRICULTURAL -.--pPRODUCTION BY FARI~~INGSYSTEM~~~~~) ...... 1982 2002 % Increase ...... LSCF Area Maize 1223 1223 - Tobacco 8 6 120 40% Cotton 123 147 20% Other Food Crops 8 0 80 - ...... Other Industrial Crops 3716 4458 20% Total 5228 6028 15% ...... Resettlement Areas Maize 122 384 15% Other Food Crops 36 125 247% Other Industrial Crops 60 17 2 187% ...... Total 218 681 212% ...... Communal Areas Maize 1215 3571 194% Other Food Crops 72 3 2096 190% Other Industrial Crops 600 1193 99% ...... Total 25 38 6860 170% ...... Note: Projections on increased agricultural productivity are on the basis of increased intensity of cropping, and not expansion of cultivation into new areas.
State farms, despite their marginal location (74.1 percent in NR IV and 22.2 percent in NR 111) are more intensively cropped than are LSCF farms. Approximately one state farm out of every five is cropped, and 82.3 percent of the cropped area lies in NR IV. By the year 2002, the number of state farms is expected to more than double. This is reflected in the expected change in the cropped area, as shown in Table 111-6. Unlike LSCF farms, state farms will take up marginal land (NR I11 and IV). Small-scale commercial farming areas are less intensively cropped than state farms. The actual proportion of SSCF area under cultivation is 5.3 percent, with over 50 percent of the cultivation occurring in NR 111. Details of the distribution cultivation in the SSCF sector are shown in Appendix 111-4. Small-scale commercial farms are expected to change slightly in number by 2002 (Table 111-6). This change is expected to come from expansion of the cropped area into indigenous forest and grazing land. 4. INDIGENOUS FOREST AND GRAZING LAND AND NON- UTILIZABLE LAND
About 3.7 million hectares (14.2 percent) of Zimbabwe is cropped. The remaining land area within agricultural land- use categories is taken up by non-utilizable land (NUT) and indigenous forest and grazing land (IFG). These categories occupy 3.9 and 65.7 percent of the country respectively (Tables 111-8 and 111-9). Non-utilizable land (NUT) is defined for this report as land dominated by bare domed-inselbergs which preclude cultivation and limit plant growth. The bare rock domes may occupy between 20-35 percent of the land lying in the domed- inselberg terrain (Whitlow, 1980~).A map (Whitlow, 1980a), showing the occurrence and distribution of the domed- inselberg terrain, was used to measure the extent of NUT by land-use type and natural region for each province. The area under this terrain was measured for different land-use categories. The area obtained was then multiplied by the median of the range (the range is 20 to 35 percent, so the median is 27.5 percent) to give the NUT area. For example, the area in the communal lands of NR IV in Manicaland province under this terrain is 399 753 hectares. The actual NUT area of this province is obtained by multiplying this area by 27.5 and dividing by 100, to give 109 932 hectares. On a national basis, the occurrence of NUT land according to land-use categories is shown in Table 111-8. Sixty percent of all NUT land occurs in communal areas and the lowest proportion of 1.5 percent in Parks and Wild Life Areas. Of a1l the NUT land in communal areas, 59.3 percent is in Masvingo and 20 percent in Manicaland. For NUT land in the LSCF and SSCF sectors, 31.6 percent is in Manicaland and 21.4 percent in Mashonaland Central. In other provinces, the proportion ranges from 7.9 percent in Midlands to 15.2 percent in Masvingo. It is important to note that for all land-use categories, about 88 percent of all NUT land occurs in NR I11 and IV (Table 111-10).
TABLE 111-8 NON-UTILIZABLE LAND IN ZIMBABWE
Abbreviation Land-Use Category Area ('000 ha) % of Total
CNUT Communal Non-Utilizable Land 921.27 60.0% LNUT Large Scale Commercial Farm Non-Utilizable Land 323.25 20.9% RNUT Resettlerpent Non-Utilizable Land 169.59 I1 .C% SNUT %all Scale Commercial Farming Non-Utilizable 102.19 6.6% PNUT Parks and Wild Life Non-Utilizable Land 24.19 1.5%
National Total 1540.49 100.0% TABLE 111-9 INDIGENOUS FOREST/GRAZING LAND IN ZIMBABWE ( '000 HA) ...... Land-Use Category I I1 111 IV ...... Total LSCF/State Farms/SSCF (LIFG) 332.44 2724.92 4065.49 6673.69 13796.54 (53.8%) Communal Lands (CIFG) 50.90 49881 1961.67 8067.03 10578A2 (41.2%) Resettlement )RIFG) 6-46 68.05 677.83 538.85 1293.19 (5%) ...... Totals 391.80 3291.78 6704.99 ...... 15279.57 25668.15 Note: Figures give the area in ha. The percentages in the last colmn denote the proportion of the total IFG in Zimbabwe.
Indigenous forest/grazing (IFG) land is considered, in this paper, as the residual land area after the subtraction of cropped area and NUT from the total area of each agricultural land-use category. Of the total IFG area (65.7 percent of the country), about 53.8 percent is LIFG (see Table 111-9 for an explanation of abbreviations). The highest proportion of LIFG land is in Matebeleland provinces which account for 33.1 percent of the total IFG area. Almost all of the LIFG land in these provinces occurs in NR IV. In the Mashonaland provinces, over 60 percent of the LIFG land occurs in NR I1 and 111. Communal indigenous f~rest/~razing(CIFG) land accounts for about 40 percent of IFG area (Table 111-9). The largest extent of CIFG land (39.5%) is in the Matebeleland provinces. Like LIFG land, CIFG land in these provinces is in NR IV. Resettlement indigenous forest/grazing areas (RIFG) occupy about 5 percent of the IFG land. Unlike the LIFG and CIFG areas, the highest proportion of RIFG land (20.2 percent) occurs in Manicaland, with about 73.3 percent of it lying in NR 111.
TABLE 111-10 DISTRIBUTION Of NON-UTILIZABLE LAND BY PROVINCE AND NATURAL REGION ( '000 HA)
I I1 111 IV Total ...... Manical and 52.90 23.71 215.05 143.80 435.46 Mashonal and Central 90.57 22.67 12.63 125.87 Mashonaland East 18.04 55.56 61.31 134.91 Matebeleland South 89.67 89.67 Midlands 51.32 36.34 87.66 Mssvingo 159.43 507.48 666.91 ...... Total 52.90 132.32 504.03 851.23 1540.48 (3%) (9%) (33%) (55%) 5 . AGRICULTURAL PRODUCTIVITY The agricultural productivity of commercial farms is much higher than that of communal or resettled farms. It is suggested that "the commercial producer averages a yield of marginally over 5 tonnes per hectare (5 000 kg), while the non-commercial producer averages less than 1 tonne per hectare." (Zimbabwe Agricultural and Economic Review, 1982) For this chapter, the overall yield estimates used are 5 tons per hectare for commercial producers, 2 tons per hectare for resettlement producers, and 1 ton per hectare for the communal producers. The higher productivity figure for the commercial producer reflects high-input farming on favorable land, while the figures for non-commercial producers result from low-input farmlng on marginal lands.
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Saunders, C.R., 1977 "The use of Land for Parks and Wild Life" The Rhodesia -- -p- Science News Volume 11, PJo. 6, 190-196. Surveyor General, 1982 "Section 6 - 1:5 000 Street Maps of cities and towns of Zimbabwe" Harare: Surveyor General.
Vincent, V., and Thomas, R.G., 1960 "An Agricultural Survey of Southern Rhodesia: Part 1 Agro-Ecological Survey." Harare: Government Printers.
Whitlow, J.R., 1979a "A Scenario of Changes in Subsistence Land-Use and its Relevance to the Tribal Trust Areas of Zimbabwe" Zambezia, Volume V11 171-190.
Whitlow, 1979b "An Assessment of Cultivated Lands in Zimbabwe Rhodesia, 1972 to 1977," The Zimbabwe Rhodesia Science News, XIII, 233-238.
Whitlow, 1979c "An Assessment of Cultivated Lands In Zimbabwe Rhodesia, 1963 to 1977" The Zimbabwe Rhodesia Science News, XIII, 286-290.
Whitlow, 1980a "Environmental Constraints and Population Pressures in the Tribal Trust Areas of Zimbabwe" Zimbabwe Agricultural Journal, Volume 77, No. 4, 173-181.
Whitlow, 1980b "Agricultural Potential in Zimbabwe: a Factorised Survey" Zimbabwe Agricultural Journal, Volume 77, 97- 106. p-p-P -
Whitlow, 1980c "Land Use, Population Pressure and Rock Outcrops in the Tribal Areas of Zimbabwe Rhodesia," Zimbabwe Rhodesia Agricultural- Journal Volume 77, 3-11. IJlltshire, J.E.B., 1977 "Forest and Timber Resources." The Rhodesia Science News Volume 11, No. 8, 196-200.
Zlmbabwe Agricultural and Economic Review, 1982 Harare: Modern Farming Publication. APPENOIXIII-1 THE DISTRIBUTION OF LAND AND CULTIVATION BY NATURAL REGION IN COMMUNAL LAND 1982
Province I II 111 IV Total
Manicaland Malze 22529 6526 148704 122699 300458 OFC 13410 3885 88514 73053 178862 OIC 17701 5127 116838 96407 236073
Total Cultivated53640 15538 354056 292159 715393 Total Land Area 106522 52400 737670 1064808 1961400
Mashonaland East Malze OFC OIC
Total Cultivated Total Land Area
Mashonaland Central Malze OFC OIC
Total Cultlvated Total Land Area
Maahonaland West Maize OFC OIC
Total Cultivated 147764 166898 90974 405636 Total Land Area 310457 595123 499620 1405200 ...... Mtdlands Maize 185388 182740 368128 OFC 110350 108774 219124 OIC 145662 143581 289243
Total Cultivated Total Land Area ...... Masvlngo Maize 51964 268776 320740 OFC 30931 159986 190917 OIC 40828 211181 252009
Total Cultivated Total Land Area Appendix 111-1 Continued
Province Crop/Land I II I11 IV Tot a1
Matebeleland North Maize OFC OIC
Total Cultivated Total Land Area
Matebeleland South Maize OFC OIC
Total Cultivated Total Land Area
Total Cultivated Area Total Communal Area
Note: OFCr Other Food Crops OIC- Other Industrial Crops All cropped areas lnclude fallow. On average 40 percent of the cropped land is fallow.
APPENDIX 111-2 THE DISTRIBUTION OF LAND AN0 CULTIVATION BY NATURAL REGION LSCF AND STATE FARMS ...... Province I II I11 IV Total
Maize 1295 2453 6241 260 10249 (Wheat) (746) (2200) (2946) Tobacco 385 4228 4613 Cotton 5417 5804 11221 OFC 169 7945 8114 OIC 5552 7970 6679 20201
Total Cultivated 6847 3007 31801 12743 54398 Total Land Area 437379 122511 408738 107372 1076000 ...... Mashonaland East Maize 42398 8893 51291 (Wheat) (5544) (401) (5945) Tobacco 8655 1385 10040 Cotton 851 519 1370 OFC 3935 41 0 4345 OIC 25272 5866 31138
Total Cultivated 81111 17073 98184 Total Land Area 376260 326369 6371 709000 Appendix 111-2 Continued ...... Province Crop/Land I I1 111 IV Tot a1
Mashonaland Central Maize (Wheat) Tobacco Cotton OFC OIC
Total Cultivated Total Land Area
Mashonaland West Maize (Wheat) Tobacco Cotton OFC OIC
Total Cultivated 166608 43331 209939 Total Land Area 1789293 967707 2757000 ...... Midlands Maize 10705 2810 13515 (Wheat) (482) (200) (682) Tobacco 1052 1052 Cotton 2493 280 2773 OFC 612 612 OIC 4872 2625 7497
Total Cultivated Total Land Area ...... Masvingo Maize 3175 3312 6487 (Wheat) (657) (338) (995) Cokton 225 225 OFC 95 95 OIC 3298 31827 35125
Total Cultivated Total Land Area ...... Matabeleland North Maize 1908 1908 (Wheat) (500) (500) Cotton 250 250 OFC 390 390 OIC 2792 2792
Total Cultivated Total Land Area Appendix 111-2 Continued
Province Crop/Land I II 111 IV Total ...... Matabeleland South Maize 1462 1462 IWheat) (1617) (1617) Cotton 1542 1542 OFC 30 30 OIC 610 610
Total Cultivated Total Land Area
Total Cultivated Area 6847 352746 132969 64615 557177 Total LSCF and State Farm Area 437379 3024080 3783007 7078534 14323000
Note: As wheat 1s nearly always a second crop grown on irrigated land, it has been excluded from totals. Its inclusion would result in significant double-counting.
APPENDIX 111-3 THE DISTRIBUTION OF LAND AN0 CULTIVATION BY NATURAL REGION IN RESETTLED AREAS 1982
Province I II I11 I V Total
Manicaland Maize OFC OIC
Total Cultivated 1295 1529 29159 4337 36320 Total Land Area 13458 15859 292375 74858 396550
Mashonaland East Maize OFC OIC
Total Cultivated 680 11339 Total Land Area 23553 121797
Mashonaland Central Maize OFC OIC
Total Cultivated 1870 3906 Total Land Area 14380 60420
Mashonaland West Maize OFC OIC
Total Cultivated 1716 2643 4359 Total Land Area 26526 67074 93600 ...... Appendix 111-3 Continued
Province Crop/Land I I1 I11 IV Tot a1 ...... hdlands Malze 14962 780 15742 OFC 5204 5204 OIC 6908 390 7298
Total Cultivated 27074 1170 28244 Total Land Area 2442 261906 16652 281000 ...... Masvingo Maize 1220 6516 7736 OFC 80 2601 2681 OIC 610 3167 3777
Total Cultivated Total Land Area
Metebeleland North Malze OFC OIC
Total Cultivated Total Land Area
Matebeleland South Maize OFC OIC
Total Cultivated Total Lend Area ------Total Cultivated Area 1295 5795 76031 22908 106029 Total Resettled Area 13458 82760 842337 630245 1568800
APPENDIX 111-4 THE DISTRIBUTION OF LAND AND CULTIVATION BY NATURAL REGION IN SMALL SCALE COMMERCIAL FARMS 1982 ...... Province Crop/Land I I1 111 IV Total
Manical and Maize 812 Tobacco Cotton OFC 107 OIC 86
Total Cultivated 1005 Total Land Area 7886 Appendlx 111-4 Continued
Province Crop/Land I I1 I11 IV Tot a1 ...... Mashonaland East Malze 3694 2858 471 7023 Cotton 75 83 158 OFC 377 29 1 48 716 OIC 1079 835 137 2051
Total Cultivated 5225 4067 656 9948 Total Land Area 7259 57345 44396 109000
MashonalandCentral Maize Tobacco Cotton OFC OIC
Total Cultivated 1929 4435 891 7255 Total Land Area 33594 67364 9042 110000
Mashonal and West Maize Tobacco Cotton OFC OIC
Total Cultivated 10601 2692 2216 15509 Total Land Area 114912 24024 29064 168000 ...... EZldlande Malze 7425 596 8021 Cotton 1545 307 1852 OFC 701 139 840 OIC 1063 212 1275
Total Cultivated Total Land Area
Masvingo Malze (Wheat) Tobacco Cotton OFC OIC
Total Cultivated 11352 2509 13861 Total Land Area 34031 210969 245000 ------Appendix 111-4 Continued ...... Province Crop/Land I I1 111 IV Total
Matebeleland North Maize (Wheat) OFC OIC
Total Cultivated 402 402 Total Land Area 41000 41000 ...... MatebelelandSouth Maize 2225 2225 Cotton 1 1 OFC 504 504 OIC 309 309
Total Cultivated Total Land Area
Total Cultivated Area Total SSCFA Area
Note: As wheat is nearly always a second crop grown on irrigated land, it has been excluded from totals. Its inclusion would result in algnificant double-counting. IV. HOUSEHOLD ENERGY USE IN ZIMBABWE: AN ANALYSIS OF CONSUMPTION PATTERNS AND FUEL CHOICE
Richard H. Hosier and Jeffrey Dowd
1. INTRODUCTION
Ever since international attention began to focus on the importance of energy for continued economic growth, a body of literature has centered on comparisons of energy use for countries at different levels of development. This literature has shown that as development proceeds, not only does energy consumption increase but also the mix of fuels relied upon changes. In its cross-sectional form, this work shows that wealthier countries rely more heavily on petroleum and electricity than poorer countries. Poorer countries rely more heavily on biomass fuels. In its longitudinal form, this work shows that as a country progresses through the industrialization process, its reliance on petroleum and electricity increases and the importance of biomass decreases. This literature has been enlightening, but has had limited policy relevance for energy work in developing countries. A household-level corollary of this macro-tenet focuses on the concept of the "energy ladder" within the energy systems of developing countries. The underlying assumption is that households are faced with an array of energy supply choices which can be arranged in order of increasing technological sophistication. At the top of the list is electricity and LP gas while the low end of the range includes fuelwood, dung, and crop wastes. As a household's economic well-being increases, it is assumed to move "up" the energy ladder to more sophisticated energy carriers. If the economic status decreases, through either a decrease in income or an increase in fuel price, the household is expected to move "down" the energy ladder to less- sophisticated energy carriers. Thus, the energy ladder serves as a stylized extension of the economic theory of the consumer: as income rises, households consume not only more of the same goods, but they also shift to consuming higher quality goods. A dissenting view on the above concept would hold that while the energy ladder exists as a conceptual construct, it is not a reality for the households in developing countries. The economic status of most of these households is so constrained that they have little or no choice about which fuels to use. While it is possible to hypothesize the existence of such a ladder, it serves no functional purpose to do so since most households in developing countries are too constrained to make any movements on that ladder. For a number of developing countries, particularly those in Africa, these issues are of crucial importance. Rural households in these countries face serious to severe fuelwood shortages. The question about how free households are to make fuel substitutions is important. Much of the policy work undertaken to date has assumed that an energy ladder exists but. that most households are so constrained by the physical and economic environment that they have no choice but to remain dependent upon woodfuel for the foreseeable future. As a result, all policy efforts will focus on rural afforestation and ignore any possibilities of interfuel substitution, particularly those which involve movements up the energy ladder. From a policy perspective, there has appeared to be no way to encourage households to move away from traditional to the more sophisticated energy carriers. This paper examines household energy-use patterns as identified in the Zimbabwe National Household Energy Survey and presents a preliminary empirical test of the energy ladder hypothesis. In order to fulfil the latter objective, it applies a multinomial logit model to the data on residential fuel choice in Zimbabwe. The purpose of this analysis is to verify whether or not households do operate on an "energy ladder" and, if they do, can certain policies elicit desired movements or substitutions away from scarce or expensive fuels to plentiful or inexpensive ones.
2. PHYSICAL AND CONCEPTUAL BACKGROUND HOUSEHOLD ENERGY USE AND THE ENERGY LADDER
The energy ladder concept takes as its starting polnt the differences in energy-use patterns between households with differing economic status. Households are assumed to behave in a manner consistent with the neo-classical consumer, moving to more sophisticated energy carriers as their incomes increase. As opposed to wood and crop-wastes burned by the poor, wealthier households will choose to utilize electricity and petroleum products. While a large number of household energy surveys have been undertaken in recent years, none of them has explicitly addressed the validity of this assumption. The energy ladder always hovers in the background without ever being put to the test. i7hile not explicitly addressing the question of the energy ladder, a number of these recent empirical studies do address the question of the energy consumption patterns of different socio-economic groups. Bajracharya (1983) notes that energy-use patterns in the village he studied in Nepal differed according to the social class of the household. Kennes, et al. (1984) note that the energy consumption patterns different socio-economic groups in Bangladesh are radically different. In particular, households with earnings from formal employment rely much more heavily on commercial fuels than do landless or smallholder households. For the Indian city of Hyderabad, Alam ~1.(1985) found that household fuel-choice decisions vary directly with income level. The higher the income level, the greater the tendency for households to choose petroleum-based commercial fuels over biomass fuels. Reddy (1981) notes that for the Indian villages studied, there is a strong correlation between the size of landholding and household energy use. The essays in Barnes, et al. (1985) note that household fuel-mixes in Kenya vary accordrng to the household's level of involvement with the monetary economy. In general, the literature on household energy use in developing countries supports the concept that household energy-use patterns are differentiated with respect to economic status. A related question is not so frequently addressed in the literaure. How free are households to choose between different energy carriers? Are they actually able to exercise choice between different fuels or is their movement along the energy ladder heavily restricted by their physical or economic environment? While these questions border on the rhetorical, they have been alluded to in the literature. O'Keefe, et al., (1984) argue that in the case of Kenya, economic c?ndytions dictate that the bulk of rural households will be dependent upon wood for the foreseeable future. French (1985) notes that rural households in Malawi have such limited incomes that they cannot possibly opt to utilize commercial fuels. Continuing to rely on fuelwood is their only alternative: decisionmaking is the process of selecting from an opportunity set having a single feasible alternative. Despite these negations of the existence of decision- making in household energy consumption, other authors have suggested that decisionmaking does occur. Briscoe (1979) notes that in rural Bangladesh, households do move along the energy ladder. However, the most visible movements are those of the poorer households switching either toward less- sophisticated energy carriers or towards purchased fuels. Hosier (1985) argues that in rural Kenya, the household decisionmaker must make a two-stage decision in the energy arena. In the first stage, he or she decides which fuels to use. The second stage consists of the decision about how much of each fuel to use. The options in each case will depend upon the household's specific resource endowment--the higher the economic status or the more integrated the household is into the monetary economy, the greater will be the options available to it. The modelling of these decisions and energy-use patterns is complicated by a number of factors. Biomass fuels are usually not purchased but are gathered. Where markets do exist for them (Hymen, 1983), they are usually fragmented and chaotic, capitalizing on the common-property nature of wood resources. As a result, households which do purchase these fuels rarely pay prices commensurate with their full opportunity cost. Pri.ces are not easy to monitor and are rarely accurate measures of the fuel's true value. The non- commoditized nature of biomass energy resources poses both an opportunity and a constraint. From the household's perspective, it is an advantage as it enables the household to obtain its energy requirements without spending any of its scarce financial resources. From a policy perspective, however, movements up the energy ladder are difficult to encourage as long as biomass resources can be obtained at no financial cost. For this reason, policy efforts and programs to encourage interfuel substitution are more appropriately aimed at urban households where markets are operative and households more frequently have a non-neglible disposable income.
THE ZIMBABLIEAN CONTEXT
In April of 1980, Zimbabwe became the newest African nation to gain its independence. With a strong agricultural sector and a manufacturing sector which consistently contributes 20% of total GDP, it has one of the strongest economies in Sub-Saharan Africa (Stoneman, 1982). Historically, the electricity system was based on the cheap power from the Kariba dam complex. However, since Independence, the coal-fired generation plant at Hwange has added nearly 400 megawatts (MW) to a system which already had a capacity of over 1000 MW. Although all petroleum fuels are imported, Zimbabwe has developed possibly the cheapest ethanol program in the world (Juma, 1985). Despite these strengths, Zimbabwe, like other African countries, depends largely on woodfuel to supply the energy needs of the residential sector. In 1982, wood used as fuel and in rural construction accounted for over 45% of the national end-use energy consumption (Hosier, 1986). The residential sector in Zimbabwe can be divided into a number of subsectors which were originally created through legislation. While this legislation dates largely from the pre-independence period, the systems which were created are still in place. The urban areas consist of high and low density residential suburbs. Although they were originally established on racial lines, the suburbs have been thus titled in order to provide non-racist categories. The low- density areas house the more affluent households and their domestic workers (who frequently outnumber their employers). The high-density areas, previously called townships, contain the working classes and the less affluent households. The rural subsectors reflect categories created through the Land Apportionment Act. The largest category consists of communal farming areas, original l y called Tribal Trust Lands, In these areas, which provide homes for the bulk of the African population, the land is held under communal tenure arrangements. Large-scale Commercial Farming Areas (LSCFA) are the next largest category. These consist of large farms making use of capital-intensive techniques. Like the case of the low-density suburbs, the farm workers outnumber the landowners. Small-scale Commercial Farming Areas (SSCFA) were created in the 1950's to allow a limited number of successful black farmers to own their own land. The farms are larger than in the communal areas, and the residents tend to be wealthier. Finally, resettled areas have been created since Independence to alleviate the political and ecological pressure brought about by the inequitable distribution of land resources. Although the resettlement program has been relatively successful to date, its future hangs in the balance for both political and financial reasons (Weiner -et --al., 1985). Zimbabwe is both similar to and different from its African neighbors. As in other African countries, the bulk of Zimbabwe's population relies on wood to meet its domestic energy needs. The country is facing an increasingly severe shortage of fuelwood for household use (Hosier, 1986). At the same time, Zimbabwe has plentiful coal and hydropower resources. Unlike its neighbors, Zimbabwe's industrial base is sufficiently diversified to produce domestic appliances at affordable prices. In these respects, Zimbabwe possesses unique advantages which bring policy options like urban or rural electrification into the realm of feasibility. The diversity shown within the residential sector, the sophistication of the national energy system, and the country's relative economic strength make it an ideal case in which to examine the energy ladder hypothesis.
3. RESIDENTIAL ENERGY CONSUMPTION IN ZIMBABWE The data-base to be used for analyzing household energy decisions in Zimbabwe is taken from a national household energy survey. Implemented by the Central Statistical Office (CSO) from March to May of 1984 as part of the Zimbabwe Energy Accounting Project, the National Household Energy Survey was a comprehensive residential energy survey. Drawn from the permanent household sampling frame of CSO, the sample was stratified according to the population in each of the residential subsectors discussed in the previous section. The survey instrument itself included questions about appliance ownership and utilization, fuel use, fuel procurement, demographics, perceived scarcity of fuelwood, income, and landholding. While the details of the survey itself are discussed elsewhere (Hosier, 1984), the survey data serve as the basis for the analysis which follows. This section serves as an introduction to the survey by presenting the results in summary form. This serves two purposes. First, it is intended to acquaint the reader with the data and the results of the survey in its simplest form. Second, it is intended to serve as an analytical foundation for the logit work which is presented in section 4. The variables and categories used in the logit analysis were developed on the basis of the conceptually simpler analysis of variance results in this section. The survey results are examined first by stratum, then by income categories, and finally by natural region (ecological zone) for the rural households only. FUEL USE PATTERNS BY STRATUM
Table IV-1 presents the results of the survey broken down by residential subsector. The table contains both the consumption of each fuel by those using it and the percentage of households actually using each fuel. The first four subsectors are rural while the remaining two are urban. The importance of this subsectoral breakdown can be seen in the fact that all of the quantities and percentages demonstrate statistically significant differences.
TABLE IV-1 ECONSUMPTION& UTILIZATION 5 RESIDENTIAL SUBSECTOR ...... Subsector Fuel wood Coal Kerosene Electricity Load Limited Metered n kg/day 5 Using kg/day L Using lt/week 5 Uslng E Uslng kwh/rnonth % Usir
Communal 1230 15.6 94.3% 0.4 0.2% 0.63 76.45 0.22 SSCFA 74 14.8 98.6% - 0.45 94.6; Resettled 88 17.8 97.7% - 0.58 69.3% LSCFA 227 14.0 83.3% 10.0 11.4% 0.46 489% 4.8% High Density 322 5.6 19.25 6.5 2.5% 2.45 28.3% 60.9L 267.3 10.1 Low Density 20 6.4 10.7% 2.0 0.5% 2.75 30.2% 30.7% 531.4 45.1
Total 2146 15.0 74.2% 8.5 1.7% 0.84 62.2% 12.7% 461 .2 6.1
Note: Analysis of variance shows the above quantities and percentages to be signlflc: different from zero at the p:0.001 level.
The fuelwood figures are somewhat predictable as urban households utilize wood less commonly and in smaller quantities than do rural households. This may well be attributed to the fact that urban households normally purchase wood while rural households normally gather it. Although there is some variation in the quantities utilized by the different rural subsectors, a 95% simultaneous confidence level shows that there is, in fact, no difference between wood consumption in these different groups. Only a few households utilize coal as a domestic energy carrier due both to expense and relative uncleanliness. Kerosene is used in small quantities by a large percentage of rural households for lighting. A smaller quantity of urban households use paraffin, but they use it mostly for cooking. As a result, the quantity used is much larger. While being relatively scarce in rural Zimbabwe, residential electrical connections are common in the urban areas. Load-limited connections, where the consumption is limited by the amperage rating of the system's fuse, are more common in high-density residential areas. Metered connections are more frequently encountered in low-density areas. In Table IV-1, a number of subsectors demonstrate major differences in both the penetrations and the level of consumption of each fuel. The major differences are between the rural and the urban areas. Within the rural areas, the most significant differences are between the LSCF areas and the remaining groups, all of which consist of private smallholders. The high and low density areas show differences in the levels of wood, kerosene, and electricity use. In summary, households in the different Zimbabwean residential subsectors demonstrate different energy-use patterns.
FUEL-USE PATTEWS BY INCOME CATEGORY Household energy consumption is normally assumed to vary according to the level of household income. In fact, some might argue that the differences in energy consumption behavior by residential subsector are solely a reflection of the differences in monetary income. This differentiation by income class lies at the basis of the energy-ladder hypothesis: as income increases, the quality of the energy carriers are supposed to increase. Table IV-2 summarizes the survey results by four income categories, based on monthly income in Zimbabwean dollars. Although another category was originally included for incomes of more than Z$ 500, this extra category was omitted as it added no additional insight.
TABLE IV-2 FUEL CONSUMPTION AND UTILIZATION BY INCOME CATEGORY ...... ome Fuel wood Coal Kerosene Electricity egory Load Limited Metered t per month) n kg/day % Using* kg/day* 5 Using* lt/week* 5 using* % usingX kwh/month * b Using* ...... s than 50 1173 15.09 86.6% 4.45 0.3% 0.614 68.5% 5.2% 541.5 3.4% s than 150 589 14.62 68.9% 9.68 4.2% 1.081 63.7% 17.6% 352.0 l .9% S than 250 166 15.34 51.8% 8.26 3.0% 1.498 42.8% 27.1% 255.8 1 1.4% ater than 250 218 15.64 38.5% 4.63 1.4% 1.372 39.0% 28.9% 493.8 26.6%
Analysis of variance results are significantly different from zero at the pz0.1 level.
Analysis of variance results are significantly different from zero at the p:0.001 level. According to the results in the above table, fuelwood consumption --per --se does not appear to change with income. )That does decrease significantly is the proportion of households relying on fuelwood. As incomes rise, the importance of fuelwood as a domestic fuel declines. Although differences in coal consumption do appear to be statistically significant, the pattern is not clearcut. This may be due to the fact that coal is used by so few households. The quantity of kerosene consumed by households using it increases with income. This is accompanied by a decline in the percentage of households actually using the fuel. Kerosene can perhaps best be characterized as a transitional fuel for those with enough income to purchase a fuel. Kerosene must be considered as inferior to electricity. The quantity of electricity utilized by those with metered connections shows no staightforward pattern, although the figures do suggest a general increase. However, both the proportion of households with load-limited and metered connections increases across income categories. This becomes particularly apparent if the two figures are added to provide the percentage of households having access to electricity: this estimate increases steadily from 8.6% for the poorest group to 55.5% for the richest group. These results do tend to support the existence of a crude energy ladder. Households with higher incomes have access to and tend to utilize more effective or sophisticated energy carriers. The overall tendency appears to be a move toward electricity and away from wood. However, these findings are cross-sectional for all households. Although there is no way to be sure that any individual household will follow this pattern as its income rises, the overall trend appears to be in this direction.
FUEL-USE PATTERNS BY NATURAL REGION
Combining the estimates of both the rural and urban households in the preceding two sections is useful to provide a quick overview of the survey data. However, it can obscure some information which is important to the interpretation of the survey results. In Table IV-3, the survey results for rural households only are grouped according to the natural region or agroecological zone of the household. According to the classification of land potential, rainfall and agricultural potential both decrease from natural region I to natural region IV (Munasirei, 1984). Although several factors do demonstrate statistically significant differences, the most striking pattern is that of the fuelwood and kerosene estimates for zones I1 and 111. In both cases, the quantity of wood consumed is noticeably lower than for zones I and IV. In zone 11, only 83% of the households surveyed made use of fuelwood. Although the quantity of kerosene consumed does not appear to vary, the percentage of households using kerosene is higher for zones I1 and 111. Three factors should be considered when attempting to explain these patterns. First, the areas with the highest population density and the greatest shortage of woodfuel are the communal areas of natural region I1 (Hosier, 1986). The rural wood shortage in these regions is, perhaps, exacerbated by their proximity to Harare, itself a rather large center for wood demand. Second, the rural areas of zone I1 have the best road network in the country. This has the dual effect of both increasing the availability and decreasing the price of kerosene to rural dwellers. It also improves the ability of wood traders to export wood to Harare. Finally, while incomes do vary by natural region, they do not do so Sn a nonotonical ly-decreasing fashion. In fact, among the louseholds surveyed, the differences are statistically significant only at the 10% level. Income cannot be ~nterpretedas the major determinant of the observed 2atterns.
TABLE IV-3 CONSUMPTION AND UTILIZATION BY NATURAL REGION: RURAL HOUSEHOLDS !lNLJ ...... Natural Fuel wood Coal Kerosene Electrlclty Region Load Limited x n kg/day Z ~slng* kg/dayx % usin; lt/week % o sing* % using*
Total 1619 15.5 93.1% 9.3 1.7% 0.62 73.0% 0.9% ...... * Analysis of variance results are significantly different from zero at the 0.001 level.
In short, the rural energy consumption patterns do vary >y natural region, but the patterns are relatively complex. L11 of the above-mentioned factors may play a role in influencing these patterns, but the causes are subtle, and 2erhaps masked by viewing the problem at the national level.
. HOUSEHOLD FUEL CHOICE The preceding sections demonstrate that household energy :onsumption patterns vary according to residential subsector, income, and natural region. The subsectoral analysis shows :hat the major consumption differences are between rural ;mal lholders, commercial farmworkers, and urban dwellers. rhe income analysis shows that at first glance, the energy Ladder appears to hold. That is to say, households at higher income levels show a greater tendency to utilize higher luality energy carriers. Among rural households, natural region or ecological zone appears to be a significant factor ietermining consumption patterns. However, natural region ilone does not go a long way toward explaining the observed >atternS. IJhi le these findings imp1 icitly support the :oncept of an energy ladder, they are not an adequate test ?or it. In this section, a set of multinomial logit models ire constructed to address more directly the factors ~nfluencinghousehold fuel choice in Zimbabwe.
?ORMULATION OF THE MODEL
The real question surrounding the energy ladder has to lo with the household's choice among a number of domestic mergy a1ternatives. For example, under what conditions will a household in Zimbabwe decide to cook with kerosene instead of wood? In order to more precisely formulate this question, it is necessary to both limit the end-uses being discussed and invoke a number of assumptions about both household's decisionmaking environment and its preferences. While the former is necessary in order to ensure that the options being examined are true alternatives, the latter is also required in order to adequately characterize the decisionmaking process. Since cooking is the most important end-use in Zimbabwe, the following discussion focuses on the choice of household cooking fuels. The assumption that households are free to exercise some basic choice about which fuels they will use underlies all of the following analysis. This is a relatively weak assumption, for, although the choice set may be limited by unreasonably high transactions costs in many cases, energy authorities cannot force households to use or not to use a specific fuel. For example, electricity is not a realistic option for the bulk of Zimbabwe's rural households. However, even these households do decide among a reduced set of alternatives. Therefore, the question facing the Zimbabwean energy authorities hinges upon the identification of those factors which can be influenced in order to encourage households to utilize the desired fuel. The model is intended to identify those factors which will most directly influence that choice. A household faces a choice between a finite number of different cooking-fuel options. Each fuel is distinguished by a range of attributes, such as price, efficiency, and convenience. The modelling approach assumes that any particular household will make a given choice because it reflects the preferences inherent in its decisionmaking environment. This environment plays two roles in the choice process. First, it influences the preference structure of the household, and second, it imposes retrictions on the structure of the choice set. Therefore, the household energy decision is best determined by both a relevant choice set and the socio-economic context of the household. If the choice about whether or not to use a particular fuel is viewed as a discrete decision (even when fuels are used in combination), then the househoid fuel choice problem reduces to one of choice among a set of discrete fuel alternatives. It is not the quantity of a particular fuel to be used which is to be modellec, but rather the decision about whether or not to use a particular fuel at all. Multinomial logit models have been developed to deal with situations in which a decision must be made between a number of discrete or distinct alternatives (McFadden, 1974; Luce, 1959). In the US, they have been used with increasing frequency tc analyze household fuel-choice and appliance- purchase decisions (Brownstone, 1979; Goett, 1979; and Dubin and McFadden, 1984). The formulation of the multinomial logit model (MNL) begins with the assumption that a household is seeking to maximize its utility. Under the conventional neoclassical choice framework, a utility function is prescribed and then maximized with respect to a "bundle" of choice alternatives. The resulting solution is therefore somewhat deterministic. In contrast, the MNL framework is probabilistic in nature. It is stochastic, being comprised of both a deterministic and a random component, Hence, utility is not fixed but is random1y determined. In this probabil istic framework, the choice decision can be algebraically determined from a given utility function by defining a choice probability such that household i will select alternative j over alternative k if and only if:
where Ui and Ui represent the utility to individual i of alternatjve j an8 k, respectively. In the case of numerous alternatives, the probability (P) of individual i choosing alternative j over alternative k will depend upon the utility associated with each alternative, such that
where Zi. is a function of both the attribute vector associate& with each alternative and the vector describing the household's decision-making environment: B represents an unknown taste parameter common to all households: and Eij represents an error term. McFadden (1974) has shown that if certain assumptions are made about the nature of the error terms, the utility function assumes a logit form having an associated choice probability of the form:
By taking the logarithm of the ratio of any two choice probabilities, the model can be expressed in a convenient regression form with the unknown B coefficients estimated using maximum likelihood estimation. For example, assume that there is a choice situation with J possible alternatives, with probabilities: Pil, Pi2, ... PiJ. Also assume that there is a set of explanatory variables that describe the context of the choice situation. Then the explanatory variables can be regressed onto the log odds ratio Ln(Pi j/~ik), so that:
where CO represents tkie intercept and B and Z represent the vectors of coefficients and independent variables, respectively. The independent variables included in the different formulations are household income, household size, ecological potential, relative fuel prices, and the perception of fuel accessibility. Maximum-l ikelihood non1 inear estimation is used to calibrate the logit model to the data. Maximum likelihood estimates of only the first tier logistic odds ratios (i.e., comparisons to the first option, Ln(p2!pI), Ln(P3/pl), etc.) are obtained directly. The remaining estimates are obtained from coefficient constraints which result from the requirement that the choice probabilities sum to one. Thus:
for m > 3 and k > 1 and m # k. In the following sections, we apply the logit model to the data from the Zimbabwe National Household Energy Survey to predict the type of fuel a household selects for cooking. The attributes of the alternative fuels and the characteristics of the household decisionmaking environment combine to determine the likelihood of any one fuel being chosen in preference to another. The results from three different models are presented: one for the entire sample, one for urban areas only, and one for the rural areas only. The alternative choice sets are different for each case as are the independent variables describing the household decision environment and the characteristics of the fuel alternatives.
NATIONAL-LEVEL RESIDENTIAL FUEL CHOICE
Viewing the household fuel decision from the national level provides a useful first cut at the question of the energy ladder and interfuel substitution. However, this is complicated by one important factor. Not all households face the same alternative set. Although rural households could conceivably pay the connection fee to obtain electricity, this is an unlikely alternative. For purposes of the national analysis, two implicit assumptions are necessary to use the same alternative set for all households. First, the user fees are assumed to be prohibitively expensive in those cases where a particular fuel, electricity for example, is not really an option. Second, these costs are represented, not by explicit cost factors, but are folded into the effects of a household being in a different stratum or coming from a different area. The response set and the independent variables used in the national-level analysis are summarized in Table IV-4. The cooking fuel alternatives are gathered firewood, purchased f irewood, kerosene (paraffin), electricity, and a transition alternative, This last category is comprised of households using more than one fuel to cook with, The most common examples of this are wood and kerosene, or wood and electricity, being used in combination. The last column in the table gives the number of households using each alternative. The independent variables used in the national analysis fall into three clusters. The first cluster corresponds to household characteristics, such as household size and income class. The second category includes measures of stratum or location. Two dummy variables were included to distinguish households in the large-scale commercial farming areas and urban households. Two other dummies were used to represent households in Natural Regions I1 and 111. The third cluster includes the characteristics of the different fuel alternatives, such as price ratios and fuelwood availability. For the sake of computational efficiency, all independent variables are entered as dummies, with the exception of household size.
TABLE IV-4 DEFINITION OF VARIABLES USED IN THE MNL MODEL: NATZNALLEVEL
Variable VariableDef inition Frequency ...... Response Variables: Households Using Particular Fuel-type
Gathered Fuelwood Purchased Fuelwood Transition Fuels Kerosene Electricity
Total Sample Size N = 1965 ...... Explanatory Variables: ...... HHSIZE Household Size (continuous) 1965 STLSCFA Dummy Variable Indicating Commercial Farming Areas 186 STURBAN Dummy Indicating Urban Household 463 NRDUM2 Dummy Indicating Natural Region I1 539 NRDUM3 Dummy Indicating Natural Region I11 453 RPRCAT Ratio of Per Energy Unit Price of Kerosene to Electricity > 0.5 1011 YCATl Monthly Income Dummy for Z$ 50-150 528 YCAT2 Monthly Income Dummy for Z$ 150-250 146 YCAT3 Monthly Income Dummy for > Z$ 250 198 FWNDIFF Woodfuel User's subjective Assessment of the Ease of Collecting Fuelwood 835 ...... The coefficients and the T-statistics from the maximum- likelihood estimation procedure are listed in Table IV-5. Tab1e IV-6 summarizes the direction and significance of each independent variable for each fuel choice. In each case, the dependent variables or log-odds ratios are portrayed across the top of the table. They are arranged in such a way that a positive sign represents a movement up the energy ladder. The effects of income on fuel choice are summarized by the coefficients of the income variables. The four income categories used are represented by three dummy variables, with the default case being the lowest category. The income category variables have a positive influence on choosing kerosene, purchased wood, and the transition alternative over gathered wood. Only in the highest income category do households demonstrate a higher probability of choosing electricity over gathered fuelwood. Being in the Z$50-250 monthly income range actually appears to have a negative influence on the probability of a household choosing electricity over kerosene, purchased wood, or the transition alternative. For most fuels, income does have a positive influence on movements to more sophisticated fuels. The exceptions to this rule, as demonstrated by the negative signs in Table IV-6, are largely for groups where there are few cases. It is as likely as not that they are statistical artifacts with no reasonable underlying explanation. Of the variables describing a household's location, the urban dummy turns out to be significant and positive in every case. This means that urban households always show a higher probability of choosing a higher quality energy carrier than rural households, other things being equal. The coefficient for the commercial farming area dummy is insignificant in every case, in spite of the significant findings from the results presented in previous sections. This lack of any significant effect can be traced to the limitation of this analysis to the cooking end-use. It is apparent that many farm workers have the equivalent of load-limited connections: they are supplied with sufficient electricity for lighting, but not for cooking. Natural region does appear to play a role in household fuel choice. Being in Natural Region I1 increases the probability of a l~ouseholdchoosing kerosene over any other option. This may be attributed to the greater accessibility of kerosene brought on by the superior road network. Households in Natural Region I1 are also less llkely to choose electricity over purchased wood as a cooking fuel. Households in Natural Region 111 show a greater tendency to move away from gathered wood to purchased wood or a transition-fuel combination but not moving on to electricity or kerosene. Unfortunate1 y, the reason for this preference pattern is not altogether clear. It is likely that the households in this region would display patterns slmilar to those of Natural Region 11 if they had both the household resources and the infrastructural capacity. Increases in household size increase the likelihood of a household choosing kerosene over any other alternative. It is not clear why this should be the case, but the effect of household size is to encourage positive movements up the energy ladder toward kerosene and negative movements beyond kerosene toward electricity.
TABLE IV-5 ANALYSIS OF INDIVIDUAL PARAMETERS NATIONAL RESULTS
Dependent Variables (Natural Log of Odds Ratio)
(PS/PI) (P4/P1) (P3/P1) (P2/P1) (P5/P4) (P4/P3) (P4/P2) (P3/P2) (P5/P3) (P5/P2) cplanatory Elec: Kero: Tran PWD: Elec: Kero: Kero: TRAN: Elec: Elec: arlables Wood Wood Wood Wood Kero Tran PWD PWO Tran PWO .------VTERCEPT Istlmate 9.1 977 8.0769 1.7272 -0.93516 1.1208 6.3497 9.01206 2.66236 7.4705 10.13286 I-Stat (0.038) (0.011) (1.963) (-2.483) (0.001) (0.008) (0.012) (2.781) (0.030) (0.042) {SIZE lstlmate 0.03015 0.35956 -0.05601 0.04237 -0.32941 0.41557 0.31719 -0.09838 0.08616 -0.01222 T-Stat (0.485) (4.990) (-0.796) (1.090) (-3.462) (4.128) (3.876) (-1.224) (0.917) (-0.167) TLSCFA Istimate 0.82874 -8.47992 -0.26989 0.13174 9.30866 -8.21002 -8.61166 -0.40163 1.09863 0.69699 r-Stat (1.301) (-0.011) (-0.485) (0.763) (0.012) (-0.011) (-0.011) (-0.689) (1.299) (1.055) TURBAN Estlmate 4.4101 2.4022 1.7572 1.2649 2.0079 0.645 1.1373 0.4923 2.6529 3.1452 T-Stat (10.605) (9.987) (5.379) (6.818) (4.179) (1.589) (3.744) (1.310) (5.016) (6.907) ROUMZ 'skimate -0.19027 0.68155 -0.17247 0.21555 -0.87182 0.85402 0.46600 -0.38801 -0.01779 -0.40581 T-Stet (-0.958) (3.297) (-0.417) (1.416) (-3.042) (1.850) (1.816) (-0.882) (-0.039) (-1.622) ROUM3 Estimate -0.03469 0.18098 1 .l264 0.76473 -0.21567 -0.94542 -0.58375 0.36167 -1.16109 -0.79942 T-Stat (-0.148) (0.703) (3.740) (5.801) (-0.619) (-2.386) (-2.018) (1.100) (-3.041) (-2.969) PRCAT Estimate 0.44102 0.14015 -0.38025 0.00770 0.30087 0.52040 0.13245 -0.38794 0.82127 0.43332 T-Stat (2.208) (0.682) (-1.336) (0.059) (1.050) (1.482) (0.546) (-1.242) (2.362) (1.825) CAT1 Estlmate -0.36442 0.58798 0.37966 0.53697 -0.95240 0.20833 0.05102 -0.15731 -0.74407 -0.90138 T-Stat -1715 (2.655) (1.123) (3.912) (-3.104) (0.516) (0.195) (-0.431) (-1.864) (-3.564) CAT2 Estimate 0.21491 1.0856 1.1 218 1.2616 -0.87068 -0.0362 -0.176 -0.1398 -0.90688 -1.04668 T-Stat (0.824) (3.934) (3.023) (7.310) (-2.294) (-0.078) (-0.540) (-0.342) (-2.000) (-3.349) CAT3 Estimate 0.93405 1.2632 1.1998 0.89280 -0.32915 0.0634 0.37040 0.30700 -0.26575 0.04125 T-Stat (3.397) (4.361) (3.154) (4.310) (-0.824) (0.132) (1.040) (0.709) (-0.566) (0.119) WNDIFF Estlmate -9.43819 -2.17023 -0.26719 -0.59370 -7.26796 -1.90303 -1.57652 0.32651 -9.17099 -8.84448 T-Stat (-0.039) (-5.411) (-1.023) (-4.734) (-0.030) (-3.975) (-3.751) (1.126) (-0.038) (-0.037) ...... ote: -2 Log Llkellhood Rat10 = L790.47; rho2 = 0.7574. Finally, fuel cost and availability do appear to have an effect on household fuel choice; however, few of the estimated effects are those that would be expected. When fuelwood is considered to be relatively easy to collect, households are discouraged from choosing kerosene and purchased wood over gathered wood. This is much as would be expected. In addition, a supply of easily gatherable fuelwood decreases the probability of a household using kerosene instead of a transition alternative or purchased fuelwood. This finding is not one which would be either readily anticipated or easily explained.
TABLE IV-6 SIGN EFFECTS OF EXPLANATORY VAR1ABLES:NATIONAL RESULTS ...... Dependent Variables (Natural Log of Odds Ratio) ...... ( P5/P1) (P4/P1) (P3/P1) (P2/P1) (P5/P4) (P4/P3) (P4/PZ) (P3/P2) (P5/P3) (P5/PZ)
Explanatory ELEC: KERO: TRAN: PWO: ELEC: KERO: KERO: TRAN: ELEC: ELEC: Variables WOOD WOOD WOOD WOOD KERO TRAN PWD PWD TRAN PWD
INTERCEPT 0 HHSIZE 0 STLSCFA 0 STURBAN + NROUMZ 0 NRDUM3 0 RPRCAT + YCATI YCATZ 0 YCAT3 + FWNDIFF 0
"+" denotes significant positive effects (t > 1.5). "0" denotes no significant effects (ABS(t) < 1.5). 11 - 11 denotes significant negative effects (t < -1.5)
Even more enigmatic to interpret is the variable indicating that the price of kerosene is high relative to the price of electricity on an energy unit basis. It shows no significant effects on the choice between electricity and kerosene, but has a positive effect on the choice of electricity over gathered wood, the transition alternative, and purchased wood. Presumably, if electricity is cheap relative to kerosene, it will also be cheap relative to other alternatives, thereby increasing its attractiveness. Either the effects of price on fuel-choice decisions is relatively weak over the range of prices and decisions captured in the survey, or the variable is a poor one for summarizing its effects. In summary, the analysis of household fuel choice at the national-level shows that there are consistent patterns to household choice of domestic fuels in Zimbabwe. In most cases, increases in income will lead to a higher probability of a household choosing a higher quality fuel. Larger household size encourages the use of kerosene over the range of values examined. Abundance of fuelwood tends to encourage its use. However, the most striking finding from the above two tables centers on the importance of the urban dummy variable. Urban households demonstrate a far higher probability of using a higher quality energy carrier than do their rural counterparts. If policy efforts are going to focus on encouraging households to substitute fuels, such efforts should focus their attention on the urban areas in order to be effective. This finding so dominates the others that it justifies breaking the national-level data down into urban and rural subsamples.
URBAN RESIDENTIAL FUEL CHOICE
Breaking the sample into its separate urban and rural components necessitates a reformulation of both the independent variables and the choice set facing the households. Since all of the cooking-fuel options found in the national sample are found in the urban areas, no reformulation of the response set is necessary. With respect to the independent variables, a1l of the strata variables from the national analysis have been deleted due either to their redundancy or their insignificance. The remaining independent variables deal with income, price or availability, and household size. The variables included in the analysis are summarized in Table IV-7 below. The results from the maximum-likelihood estimation are presented in Table IV-8 and the sign effects of each coefficient are summarized in Table IV-9. For the urban areas, the effects of income increases are mixed, but generally tend to be positive. Having an income higher than the default limit of 2$50 per month tends to increase the probability of choosing kerosene over wood. Only for the highest income group is there a tendency to move toward electricity away from wood. For households in the two highest income categories, there is a significant tendency to choose purchased wood over gathered wood. These are all positive energy-ladder effects of income in the urban areas. However, there are also some negative effects of income on movements up the energy ladder. For example, households in the Z$50-150 category (YCATl) tend not to use electricity instead of either kerosene or purchased wood. In these cases, they actually choose the lower quality energy carrier. In the highest income categories, households might be expected to choose the higher quality energy carrier in this instance. This is not the case, clearly reflecting the fact that the step toward electricity away from kerosene is not one over which the household exercises total control. The extension of supply lines to households is paramount in determining a household's ability to cook with electricity. A large number of Zimbabwean urban households have load- limited connections with insufficient capacity to allow electric cooking. This factor makes kerosene's role a pivotal one in the household energy ladder in Zimbabwe. Increases in income above Z$50 per month encourage households to use kerosene instead of gathered fuelwood. However, if continued, these same income forces are insufficient to encourage households to move away from kerosene towards electricity as a cooking fuel. This last step would appear to depend upon access to the electrical grid via higher amperage household connections, not the household's economic well-being.
TABLE IV-7 DEFINITION OF VARIABLES USED IN THE MNL MODEL:
URBAN AREAS ONLY- p - p
Variable Variable Definition Frequency
Response Variables: Households Using Particular Fuel-type
Gathered Fuelwood Purchased Fuelwood Transition Fuels Kerosene Electricity
Total Sample Size N = 463 ...... Explanatory Variables: ...... HHSI ZE Household Size (continuous) 463 RP RCAT Ratio of Price of Kerosene to Electricity 115 (Greater than 0.5 per equivalent MJ) YCATl Monthly Income Dummy for Z$ 50-150 160 YCAT2 Monthly Income Dummy for Z$ 150-250 81 YCAT3 Monthly Income Dummy for Z$ 250 123 FWNDIFF Woodfuel User's Subjective Assessment of the Ease of Collecting Fuelwood 24
The effects of household size on urban fuel choice are more complex than for the national sample. For most of the cases involving gathered wood, an increase in household size increases the probability that a household will continue to use gathered wood. The exception to this is the kerosene:wood decision, wherein the coefficient is positive, but insignificant. For the e1ectricity:kerosene choice, increases in household size lead to a decreased tendency to choose electricity. In general, the effect of larger household sizes is to decrease the likelihood of moving up the energy ladder. Additionally, increasing household size encourages the use of kerosene. This is evidenced by the e1ectricity:kerosene coefficients, as we11 as the kerosene vs. transition or purchased wood coefficents. These latter two are the only cases in which the coefficients are positive. TABLE IV-8 ANALYSIS OF INDIVIDUAL PARAMETERS: URBAN AREAS ONLY
Dependent Variable (Natural Log of Odds Ratio)
(P5/P1) (P4/P1) (P3/P1) (P2/P1) (P5/P4) (P5/P3) (P5/P2) (P4/P3) (P4/P2) (P3/P2) ...... xplanatory ELEC: KERO: TRAN: PWD: ELEC: ELEC: ELEC: KERO: KERO: TRAN: ariables WOOD WOO0 WOOD WOO0 KERO TRAN PWO TRAN PWD PWO ...... NTERCEPT Parameter 7.5071 -1.59171 -6.14927 0.84447 9.09881 13.65637 6.66264 4.55756 -2.43617 -6.99373 T-Stat (0.017) (-2.120) (-0.015) (0.912) (0.020) (0.023) (0.015) (0.011) (-2.044) (-0.017) HSIZE Parameter -0.20093 0.11742 -0.23001 -0.29748 -0.31836 0.02908 0.09655 0.34744 0.41491 0.06748 T-Stat (-1.939) (1.069) (-1.463) (-2.601) (-2.11) (0.154) (0.626) (1.811) (2.616) (0.347) PRCAT Parameter 0.42727 0.20995 0.12320 -1 .l1843 0.21732 0.30407 1.54570 0.08675 1.32838 1.24163 T-Stat (1.332) (0.635) (0.239) (-1.812) (0.472) (0.501) (2.222) (0.142) (1.897) (1.544) CAT1 Parameter -0.28326 0.43452 7.692 0.41852 -0.71778 -7.97526 -0.70178 -7.25748 0.01601 7.27349 T-Stat (-1 .D221 (1.456) (0.019) (1.140) (-1.763) (-0.020) (-1.526) (-0.018) (0.034) (0.018) CAT2 Parameter 0.11583 0.75104 8.1364 0.89315 -0.63521 -8.02056 -0.77732 -7.38535 -0.14210 7.24325 T-Stat (0.301) (1.863) (0.020) (1.903) (-1.140) (-0.020) (-1.281) (-0.018) (-0.230) (0.018) CAT3 Parameter 0.77589 0.73365 8.3037 0.75387 0.04225 -7.52780 0.02203 -7.57005 -0.02021 7.54983 T-Stat (1.902) (1.690) (0.021) (1.533) (0.071) (-0.019) (0.034) (-0.019) (-0.030) (0.019) WNDIFF Parameter -10.0595 -1.83329 -0.95740 -0.05228 -8.22621 -9.10209 -10.0072 0.87588 -1.78101 -0.90512 T-Stat (-0.023) (-4.422) (-1.541) (-0.172) (-0.019) (-0.021) (-0.023) (-1.172) (-3.465) (-1.308)
3te: -2 Log Likelihood Ratio = 652.64; rho2 = 0.4379.
Turning to the effects of availability and price, the coefficients are again somewhat difficult to interpret. The effect of a readily available supply of fuelwood on movements away from gathered wood to kerosene or a transitional package are negative, as would be expected. However, the negative effect of fuelwood availability on the move from purchased wood to kerosene would again suggest that there is a correlation between readily gatherable fuelwood supplies and a low purchase price of wood. The variable describing the relative price ratios of wood and electricity yields unusual results. None of these results seem sensible. What is clear is that the price of kerosene relative to electricity has no significant impact on the choice of electricity vs. kerosene over the range of values examined. Other factors, such as electricity availability, would seem to dominate.
TABLE IV-9 SIGN EFFECTS OF EXPLANATORY VARIABLES: URBAN AREAS ONLY ...... Dependent Variable (Natural Log of Wds Ratio)
...... Explanatory ELEC: KERO: TRAN: PWO: ELEC: ELEC: ELEC: KERO: KERO: TRAN: Variables WOOD WOOD WOOD WOOD KERO TRAN PWD TRAN PWD PWD ...... INTERCEPT 0 - 0 0 0 0 0 0 0 HHSIZE 0 0 0 + + 0 RPRCAT 0 0 0 - 0 0 + 0 + + YCATI 0 + 0 0 - 0 - 0 0 0 YCATZ 0 + 0 + 0 0 0 0 0 0 YCAT3 + + 0 + 0 0 0 0 0 0 FWNDIFF 0 0 0 0 0 0 0
"+" denotes significant positive effects (t > 1.5). "0" denotes no significant effects (ABS(t) < 1.5). 11-11 denotes significant negative effects (t < -1.5). Households in the urban areas are more likely than their counterparts in the rural areas to make use of higher-quality energy carriers. This can be attributed both to the proximity of fuel supplies or supply facilities, such as the electrical grid, as well as to the higher incomes. Deliberate attempts to encourage fuel substitution are more likely to gain a foothold in the urban areas. Unfortunately, the factors determining household fuel choices in the model, such as income and household size, are not easy to control. At the same time, it does appear that more households would readily cook with electricity if the availability of metered connections were increased. This supply-side bottleneck, rather than the household decisionmaking environment, appears to be the greatest obstacle to the increased use of electricity for cooking in urban Zimbabwe.
RURAL RESIDENTIAL FUEL CHOICE Because of the striking differences between rural and urban life in Zimbabwe, the set of fuel alternatives being examined in the rural case are necessarily more limited than for the urban case. The choice alternatives, independent variables and the frequencies for each are summarized in Table IV-10. The gathered and purchased wood options have remained the same. The main change involves the treatment of commercial fuel options. Since there were so few rural households who cooked with either kerosene or electricity, these were combined into one option, called commercial fuels, While it is not strictly valid to assume that all rural households have the option of using electricity, the assumption is rationalized on the basis that the connection fees are prohibitively expensive.
TABLE IV-10 DEFINITION VARIABLES: RURAL HOUSEHOLDS ONLY ...... Variable Variable Definition Frequency
Response Variables: Households Using Particular Fuel-type ...... P1 Gathered Fuelwood 1397 P2 Purchased Fuelwood 82 P3 Commercial Or Transition 23
Total Sample Size PT = 1502 Explanatory Variables: ...... HHSIZE Household Size (continuous) 1502 RPRCAT Ratio of Price of Kerosene to Electricity 896 (Greater than 0.5 per equivalent MJ) YCATl Monthly Income Dummy for Z$ 50-150 368 YCAT2 Monthly Income Dummy for Z$ 150-250 6 5 YCAT3 Monthly Income Dummy for > Z$ 250 75 FWNDIFF Woodfuel user's subjective Assessment of the Ease of Collecting Fuelwood 811 ......
The results of the maximum-likelihood estimation are presented in Table IV-11 and the sign effects are summarized in Table IV-12. Focusing first on the coefficients of the income variables, they generally have a positive effect on a household's position on the energy ladder. Households in either of the higher two income groups demonstrate a greater propensity to choose the commercial-fuel alternative over gathered wood. Households in any but the lowest income category will show a higher probability of choosing purchased wood over gathered wood. These effects are as would be expected. At the intermediate income levels, income has a somewhat puzzling negative effect on the probability of using commercial alternatives instead of purchased wood. Again, this may be derived from the limited number of cases. Household size appears to influence significantly only the decision to utilize purchased wood over gathered wood. The larger the housek~old,the greater the probability of choosing to purchase firewood. Again, this counterintuitive finding may be attributed to the limited sample size, the existence of a few exceptional cases, or even an element of multicollinearity between household size and income. The measures of fuel availability and price have negative effects on movements along the energy ladder. The impact of the fuelwood accessibility measure is much as would be expected: when fuelwood is readily accessible, households tend not to utilize other fuels. When it is available, rural households prefer to utilize fuelwood instead of purchased fuelwood or a commercial alternative. Other things being equal, a household in a fuelwood-scarce area will be more likely than a household in a fuelwood-abundant area to utilize a purchased alternative instead of gathered fuelwood. This finding cannot be considered to be particularly startling. However, scarcity alone is not a sufficiently- strong condition to encourage the substitution of commercial fuels for gathered fuelwood. A minimum income level is another of the conditions necessary to encourage rural households to purchase fuels.
TABLE IV-11 ANALYSIS OF INDIVIDUAL PARAMETERS: RURAL HOUSEHOLDS ONLY ...... Dependent Variable (Natural Log Odds Ratio)
(~31~1) (~21~1) (p3/p2) ...... Explanatory COMM: P17OOD : COMM: Variables WOOD IJOOD Pi7OOD ...... lNTERCEPT Estimate 2.5778 0.564401 2.013399 T-Stat (3.771) (1.421) (2.547) HHSI ZE Estimate 0.025056 0.100027 -0.07497 T-Stat (0.361) (2.256) (-0.910) RP RCAT Estimate -0.45823 0.044024 -0.50225 T-Stat (-1.989) (0.355) (-1.919) YCATl Estimate 0.04435 0.541004 -0.49665 T-Stat (0.159) (3.815) (-1.585) YCAT2 Estimate 0.704534 1.4108 -0.70626 T-Stat (1.765) (7.997) (-1.618) YCAT3 Estimate 1.1807 0.748924 0.431776 T-Stat (4.306) (3.081) (1.178) FWNDIFF Estimate -0.61490 -0.80589 0.190988 T-Stat (-2.499) (-5.466) (0.666) ...... 2 Note: -2 Log Likelihood Ratio = 2564.40; rho = 0.7770. Viewed from the perspective of the results, there appear to be relatively few opportunities to encourage rural households to move away from gathered wood to other fuels. Few alternatives to wood are currently in use, reflecting the constrained decision environment. On the one hand, this might be viewed as a reflection ofthe limited data set being used for the analysis. However, this criticism must be discounted as the data set is among the most complete of its kind in the African context. On the other hand, if the limited data really do reflect both a limited choice set and a heavily constrained decision environment, then it makes little or no sense to focus efforts to promote alternative fuels on the rural areas. Such efforts would most certainly fail to achieve widespread acceptance even in the best-case scenario. In the more problematic instances, they would place unnecessary strain on rural households. The effects of the variable indicating a high price of kerosene relative to electricity are negative in the comparisons which concern commercial fuel alternatives. For households facing a high relative price of kerosene, there is less of a tendency to utilize any commercial fuel. This might have resulted becaused the cost of electricity relative to the income of many rural households approximates infinity. Therefore, if the price of kerosene is high enough to give the variable a value of one, this discourages households from using the only commercial alternative open to then.
TABLE IV-12 SIGN EFFECTS OF EXPLANATORY VARIABLES: RURAL HOUSEHOLDS ONLY ...... Dependentvariable (Natural Log OddsRatio)
Explanatory COMM: PWOOD: COMM: Variables WOOD WOOD P1700D
INTERCEPT HHSIZE RP RCAT YCATl YCAT2 YCAT3 FLrnDIFF
5. CONCLUSIONS
The preceding analysis has demonstrated several interesting points relevant to fuel decisions and household energy use in Zimbabwe. In general, the energy ladder hypothesis appears to hold for the data examined. That is to say, as household economic well-being increases, households show a higher probability of choosing a more sophisticated energy carrier. As presented here for Zimbabwe, the energy ladder moves from gathered fuelwood to purchased f uelwood, to cornbination or transitional fuel mixes, to kerosene, and finally to electricity. While the analysis presented here does go part way to demonstrate that this transition is taken, it is not complete for two reasons. First, to do so, it would have to incorporate a more direct test of these transitions as a continuum. Second, there has been no discussion of the reasons for this transition. Such a discussion lies beyond the scope of the present paper, but would have to focus on the identification of those indifference points where households value equally the resources (both time and monetary) which are expended to obtain each fuel. Future efforts will focus more closely on both of these shortcomings. Next, having said that there does exist a tendency for households with a higher economic status to move to more sophisticated energy carriers, there appear to be points at which this does not happen. For example, there appears to have been no significant impact of the higher income categories on the choice between electricity and kerosene. All of the significant impacts were incorporated into the coefficients of the first two income categories. This would appear to mean that the household's decisionmaking environment ultimately does not determine the decision in these cases, but rather the capacity of the connection to the grid. Households with load-limited connections are less likely to cook with electricity, not because they cannot afford it, but simply because their electrical wiring cannot carry the necessary current. From this perspective, the extension of non-load-limited connections to urban consumers is paramount not only to the expansion of electricity users but also to the avoidance of the proliferation of illegal connections. To date, Zimbabwe has managed to avoid heavy electricity losses due to pirated connections. However, this is more likely to emerge as a problem in cases such as that revealed in this analysis, where households can afford metered connections, but the supply-authorities have dragged their feet in supplying them. Urban electrification appears as a critical policy initiative for Zimbabwe's energy future. Thirdly, kerosene does appear to play a critical role in the household energy sector in Zimbabwe. Income increases encourage households to move away from wood to kerosene, and yet are not strong enough to encourage them to move to electricity. As a result, kerosene serves as a holding pattern, particularly for urban households. This is the case in a number of other countries where the kerosene price is heavily subsidized (Pitt, 1985). While the Zimbabwean government does not provide subsidies, it applies a only minimal excise tax to its retail price when compared to the price of other fuels. As a result, this critical fuel has remalned relatively affordable for those needing to use it. Fourth, the effects of the relative price variable used in the above analysis yielded only enigmatic results. The variable was based on the relative price ratio of kerosene to electricity, and yet it never demonstrated a significant effect on the choice between these two fuels. Two reasons can be advanced for this difficulty. First, as was argued above, the decision to utilize electricity over kerosene is based on the availability of electrical connections. The ratio of the price per energy unit of the two fuels may not have an important impact on the decision. Secondly, the measure itself may not be very good. Kerosene prices are controlled at the pump in Zimbabwe. The price markup from second-hand vendors may be enough to give the variable a value of one only in extreme cases. Not enough variation is expressed in the variable for it to be interesting. The policy implications of this last point are both good and bad. The price regulatory system appears to be working well throughout Zimbabwe. There do not appear to be many cases of extreme price inequities in the different areas surveyed. This is a positive finding for the energy authorities. On the negative side, however, it means that controlling the price of domestic fuels is insufficient to encourage the use of the desired fuel-mix. The attractivness of price regulation is that it is simple and requires a minimal l eve1 of involvement. To encourage households to move from kerosene to electricity will require a more active role for the electricity-supply authorities. Finally, the analysis has demonstrated that urban households show a consistently higher propensity to make use of commercial fuels than do their rural counterparts. While this is not surprising, it does have two significant implications. First, any efforts at policy-induced fuel substitution should focus their attention on the urban areas. In these areas, the household decisionmaking environment is more amenable to the adoption of commercial fuels. The second implication is related to this. As urban households move more toward the adoption of commercial fuels, the demand for firewood will decrease. Thus, the forces encouraging deforestation of the rural areas to supply the urban fuelwood markets will abate, lessening the extent of "parasitic" deforestation. This is not to say that trees will no longer be cut faster than they can regenerate, but rather that the forces encouraging this will be the extension of agriculture, not the supplying of fuelwood to the urban markets. The substitution component of Zimbabwe's household energy policy should focus on fuel substitution in the urban areas.
REFERENCES
Alam, M., Dunkerley, J., Gopi, K.N., Ramsay, W., and Davis, E., 1985 Fuelwood in Urban Markets: A Case Study of Hyderabad. ------p New Delhi: Concept Publishing Co. Bajracharya,D. 1983 "Fuel, Food or Forest? Dllemmas in a Nepali Village," World Development 11,12: 1057-1074. --p Barnes, C., Ensminger, J., andOIKeefe,P., 1985 -Wood, Energy, -and Households: Perspectives-- on-- ---Rural Kenya. Energy, Environment and Development in Afrlca, Volume 6. Stockholm: Beijer Institute and the Scandinavlan Institute of African Studies. Brownstone, D. , 1979 "Econometric Models of the Choice and Utilization of Energy-Using Durables," in The Choice and Utilization of --Energy-Using Durables, EPRI Report EQ-1961, prepared August 1981.
Dubin, J. A., and McFadden, D., 1984 "An Econometric Analysis of Residential Electric Appliance Holdings and Consumption," Econometrica 52: 132-148.
French, D., 1985 "The Economics of Bioenergy in Developing Countries," rn H. Egneus et ed. 1985. Bioenergy '84 Volume 5: al. - --p --- - Bioenergy 15 Developing Countries. - - -p- London: Elsevier Applied Science Publishers.
Goett, A.A. ,1979 "A Structured Logit Model of Appliance Investment and Fuel Choice," in -The- Choice - and Utilization --of -Energy-- Using Durables, EPRI Report EQ-1961, prepared August 1981. --p
Hosier, R., 1986 "Energy Planning in Zimbabwe: An Integrated Approach," Ambio 15, 2: 90-96.
Hosier.. R.. . 1985 Energy Use in Rural Kenya: Household Demand and Rural - -- p---- - Transformation. Energy, Environment and Development in Africa. Volume 7. Stockholm: Beiier Institute and the scandinavian Institute of African Studies.
Hosier, R., 1984 "Household Energy Consumption in Zimbabwe: A Preliminary Analysis," Zimbabwe Energy Accounting Project (ZEAP) Working Paper No. 18. Stockholm: Beijer Institute.
Hymen, E.L., 1983 "Analysis of the bJoodfuels Market: A Survey of Fuelwood Sellers and Charcoal Makers in the Provrnce of Ilocos Norte, Phillippines," Biomass 3: 167-197. Juma, C., 1985 "Market Restructuring and Technology Acquisition: Power Alcohol in Kenya and Zimbabwe," Development and Change 16: 39-59.
Kennes, W., Parikh, J.K., and Stolwijk, H., 1984 "Energy from Biomass by Socio-economic Groups- A Case Study of Bangladesh," Biomass 4: 209-234. Luce, R., 1959 Individual Choice Behavior: _A Theoretical Analysis. New York: Wiley. McFadden,D., 1974 "Conditional Logit Analysis of Qualitative Choice Behavior," pp. 105-142 in P. Zarembka, ed. 1974. Frontiers -in Econometrics. New York: Academic Press. Munasirei, D.K., 1984 "Methodology for the Assessment of Land-Use in Zimbabwe," This volume. O'Keefe, P., Raskin, P., and Bernow, S., ed. 1984 Energy and Development in Kenya: Opportunities and Constraints.----p Energy, ~nviironment and Development in Africa, Volume 1. Stockholm: Beijer Institute and the Scandinavian Institute of African Studies. Pitt, M., 1985 "Equity, Externalities, and Energy Subsidies: The Case of Kerosene in Indonesia," Journal of Development Economics 17: 201-217.
Reddy, A.K.N.et- -al,- 1982 "Rural Energy ;Consumption Patterns- A Field Study," Biomass 2: 255-280. Stoneman, C., ed. 1982 Zimbabwe's Inheritance. London: Macmil lan.
Weiner, D., Moyo, S., Munslow, B., and O'Keefe, P., 1985 "Land Use and Agricultural Productivity in Zimbabwe," Journal of Modern A£rican Studies 23,2: 251-285. V. WOMEN AND THE RURAL ENERGY ECONOMY OF ZIMBABWE: RESEARCH FINDINGS AND POLICY ISSUES Kirsten Johnson
1. INTRODUCTION The past decade has seen agrowing awareness ofthe role of women in rural development. This awareness has generated an expanding body of theoretical and applied analyses reflecting the experience of women in both socialist and nonsocialist countries. The Zimbabwean Government recognizes the considerable contribution of women to the transformation of production and family welfare in all sectors of society. It also recognizes the inherited conditions of inequity and vulnerability affecting many rural women and has set for itself, as a social and political priority, to redress these conditions. In principle, the broad social priorities formulated in such documents as the Transitional National Development Plan serve to guide the programs and activities of the ministries and departments responsible for implementing diverse aspects of the country's rural development. In practice, a series of intermediary steps is required before the social and political aims of the country's transitional program can be translated into the day-to-day planning procedure of specific government agencies. This translation process, frequently requiring legislative changes, institutional redirection, and a high level of ideological commitment, is itself a key element of the transition period. A modest yet necessary initial task in this process is the reformulation of the existing broad social and political objectives into specific policy guidelines directed at the activities of particular ministries and departments. These guidelines would serve to evaluate existing and new programs and projects, select among suitable energy technologies, and initiate rural development activities consonant with the country's social objectives. The present paper outlines the major issues and policy options concerning women and rural energy development in Zimbabwe. The first section provides background information highlighting the major problems affecting women and the rural energy economy in Zimbabwe. Where useful, additional information from analogous experiences in other sub-Saharan countries is included. The material in the first section draws primarily upon selected reports, articles, and monographs synthesizing the current experiences and thinking generated by women-oriented programs in agriculture, domestic water supply, and forestry which have some bearing upon the Department of Energy's current process of policy formulation for rural areas. In addition, this section includes informatior, derived from a preliminary analysis of selected data on labor budgets and gender division of labor taken from the Zimbabwe Energy Accounting Project's 1984 Rural Energy Survey. The Rural Energy Survey represents the first attempt to gather comprehensive country-wide data on all aspects of rural household energy use as well as the conditions governing its use. Central to this lies the question of women's role in the rural energy economy. The last section delineates the elements of a rural energy policy capable of mobilizing women's knowledge, concerns, and capabilities. This discussion is not presented as a formal or complete proposal, but rather as a set of guidelines framing options to be taken into account when formulating a comprehensive energy policy for rural areas.
2. WOMEN AND RURAL ENERGY
RURAL DEVELOPMENT AND RURAL ENERGY DEVELOPMENT
The most prevalent forms of energy in rural Africa are animal power for draught, water lifting and transport; and woody biomass, crop residues and dung for cooking, space heating and lighting. All these are mediated by the region's primary form of energy: human labor power. Generally speaking, this labor power is equipped with fairly rudimentary technology and is governed by social arrangements at the household or community level of organization. One of the key objectives of rural development is to induce the social and technical arrangements permitting an increase in the productivity of human labor power as well as ensuring that this increase is translated into improvements in rural livelihood and welfare. Closely attuned to this objective is a rural energy policy aimed at increasing the supplies and enhancing the efficient uses of diverse forms of existing and novel energy sources. The dual task of this policy is to satisfy both growing domestic requirements and the demands of a developing agricultural economy. These objectives seem self-evident. What is not altogether clear is how they may best be achieved. The current difficulties of many African countries in maintaining food self-sufficiency, as we1 l as the impending fuelwood crisis in many parts of the region, coupled with the widespread failure of ambitious, large-scale, expensive agricultural development schemes and forestry projects, have led a growing number of development planners to question the validity of capital-intensive, "top-down" models of rural development. Thus the mystique of the large, pre-packaged scheme has lost much of its appeal. In its place integrated resource planning, informed by local priorities and the selection of appropriate technologies, has gained a growing number of adherents. There is also much interest in approaches aimed at enhancing local self-reliance and local control over physical and technical resources. The decentralized, participatory approach would also seem to be most closely suited to Zimbabwe's espoused development goals for its communal areas and resettlement schemes. Thus, potentially at least, we have, in community- based, participatory models, an approach in which the goals of equity and effective, pragmatic planning converge. Yet critical questions remain for rural energy planners. Most rural energy development schemes tend to substitute, even on a small -scale, capital inputs (in the form of petrochemicals, fertilizers, pesticides, herbicides, and machinery) for labor. Even seemingly modest technological innovations such as small stoves or manual water pumps carry a relatively high price tag when viewed from "below." Additionally, most rural energy supply enhancement schemes tend to substitute monetized commodities (such as fuelwood and timber from plantations) for what had hitherto been a free (although increasingly scarce) good. As many studies have shown, locally based development can be costly and demanding of scarce resources, and can place undue demands on those least able or willing to bear them. Community woodlots, for example, established a£ter due consultation with local (male) leaders, have a singular record of failure when women are expected to do the maintenance (EIoskins, 1979) or they produce a product that only some groups within the community value or can afford (Skutch, 1983). The concept of "local" or "community" development can mask important intra-family and intra-community differences. Effective and equitable rural energy development is based on an understanding of the different sets of constraints and opportunities operating within and among rural households situated in particular agro-ecological settings. Some of the most important of these differences relate to gender-defined division of labor, decision-making, and access to productive resources. The following pages review some of the most important features of this phenomenon and address their possible implications for an equitable yet effective rural energy development policy. The discussion will treat the £01 lowing interrelated aspects of the problem:
(1) Col.onialism's demographic legacy;
(2) Ilomen's responsibility for providing basic household necessities;
(3) Labor time and the allocation of tasks;
(5) Sharing the rewards of labor; and
(6)Access to means of production and means of subsistence. The issues raised in the discussion provide the basis for a consideration of women-oriented energy policy options in the final section of the paper.
THE CONTEXT: COLONIALISM'S LEGACY
In much of rural Africa, women outnumber men. In some areas the overwhelming majority of permanent rural residents are women, children, and the elderly. Frequently, their lands are poor, overcrowded, and distant from all-weather roads and basic services. In the Zimbabwean case, the demographic consequences of colonial land and labor policies have compelled men to seek wage employment in mines, commercial farms, and cities. Women have thus become the de facto heads of household and the principal providers of the family's subsistence needs. According to Chavunduka (1970) the percentage of males 15-55 years of age absent from the Tribal Trust area typical of rural Zimbabwe increased from 24.13 percent in 1948 to 67.4 percent in 1968. The imbalanced demographic results of these policies are shown in Figure V-l, an age-sex pyramid for communal land population based on the 1969 Census of Powulation.
300 200 100 0 100 200 300 (IN THOUSANDS)
FIGURE V-l AGE-GENDER PYRAMID IN COMMUNAL LANDS Source: 1969 Census of Population
More recent information derived from the CSO's national household survey for the communal areas of Mashonaland Central and Manicaland Provinces indicates that this trend has not changed to any significant degree in the intervening fifteen years. Census figures for these two provinces show that children under 10, women and individuals over 60 years of age comprise 75.30 and 75.29 percent, respectively, of the communal area population of Mashonaland Central and Manicaland provinces (CSO, 1983/84a and 1983/84b). Most significantly, the male to female sex ratio for individuals in the prime working age group between 20 and 49 years of age indicates that women outnumber men roughly 2 to 1 in the communal lands of these two provinces (CSO, 1983/84a and 1983b). The colonial legacy in Africa, of which Zimbabwe is an outstanding example, is an agrarian economy characterized not only by a distorted demographic structure, but also by a peasantry with limited control over productive resources, whose fields, forests and waters are now experiencing widespread deterioration. Table V-l summarizes the results of a recent survey of deforestation in communal lands.
TABLE V-l POPULATION PRESSURES ANC CRITICAL AREAS OF TIMBER SHORTAGES IK CO~lMUl\rALAREAS - -- p ...... Degreeof Pressure Total Communal Areas Critical Areas
Balance or No Pressure 32.7% 5.6% Some Pressure 29.8% 20.7% Great to Extreme Pressure 37.5% 73.7% ...... Totals 100.0% 100.0%
Source: Whitlow. 1980
Deforestation and soil erosion directly threaten the livelihood of African farmers. Limited access to additional and improved means of production intensifies processes of environmental degradation and leads to the marginalization of peasant agriculture and to the pauperization of rural African households. As a result, many households are increasingly unable to provide for the subsistence needs of their members on the basis of on-farm activities or locally available water and biomass resources. In the case of fuelwood, two recent studies have concluded that between 20 and 30 percent of Zimbabwe's communal areas are experiencing critical shortages of fuelwood (Whitlow, 1980: Whitsun Foundation, 1981).
RURAL WOMEN AS PROVIDERS
In men's absence, women shoulder the major burden of farm labor and responsibility for family welfare. In the communal lands of Zimbabwe the overwhelming majority of household heads are either women or the elderly. The CS0 household survey results for Mashonaland Central and Manicaland indicate that somewhat over 70 percent of heads of household are female or over 50 years old (CS0 1983/84a and 1983/84b). Table V-2 summarizes the specifics of the officially recorded numbers. If -de -facto women heads of household were included in these figures it is probable that an even greater disparity between women and men would be revealed in the 20 to 49 age group.
TABLE V-2 --HEADS OF HOUSEHOLDS: ----BY AGE AND SEX
Mashonaland Group Central Manicaland ...... Female or Over 50 70% 72% Over 50 37% 33% Females in 20-49 Age Group 5 3 % 61%
Source: CS0 Household Survey, 1983/84a and 1983/84b
TABLE V-3 WOMEN'S LABOR CONTRIBUTION PER TASK PER UNIT OF PARTICIPAT~NRURAL AFRICA~O~OLGS p-- ...... ~roduction/~u~ply/~istribution ...... Responsibility Participation
Food Production Domestic Food Storage Food Processing Animal Husbandry Marketing Brewing IJater Supply Fuel Supply
~ousehold/~ommunity ...... Responsibility Participation ...... Household: Bearing, Rearing of Children 1.OO Cooking for Husband, Children, Elders 1.00 Cleaning, Washing, etc. 1.OO House Building 0.30 House Repair 0.50
Community Self-Help Projects 0.70
Source: ECA, 1974: after Muchena, 1977 Women farm, fetch water, collect firewood, cook, clean, wash, and bear and care for children. They engage in crafts production and, increasingly, perform what hitherto were considered male tasks: ploughing, livestock herding and repairs. Table V-3 provides a summary of the estimated degree of female involvement in rural tasks in an average African household. An early case study from Zimbabwe concerning rural women's role in agriculture recorded that women contributed between 32 and 40 percent of total household labor hours to farming (Weinrich, 1975). Table V-4 below shows the percentage figures derived from this study, indicating that in both peasant and Master Farrner households women's and children's labor input in crop production outweighs that of men.
TABLE V-4 KARANGE TTL LABOR INPUT IN AGRICULTURE
Percentage of Total Llorking Hours Devoted to Crop Production ...... Peasant Households Master Farmer Households
Women Men Children
Source: Tleinrich, 1975
Table V-5 provides additional case study-based information on the age and gender division of agricultural labor in Zimbabwe. It should be noted that women are involved at all stages of the crop cycle for the country's major staple crops. Table V-6 records the most recent survey-based data on the division of labor in agriculture in rural Zimbabwe, providing a useful disaggregation by task. The Zimbabwe- specific findings on the division of labor shown in Tables V- 4, V-5, and V-6 confirm women's critical role in agriculture, however the percentage figures differ somewhat from the overall averages recorded in Table V-3. Table V-6 suggests that women's contribution to many farm tasks is higher in rural Zimbabwe than elsewhere. Moreover, the Zimbabwe labor studies suggest that children play a critical role in production by performing numerous agricultural and livestock care tasks. In an effort to document the age and gender-linked aspects of rural labor, the Rural Energy Survey, sponsored by the Department of Energy and the Beijer Institute, gathered interview- and observation-based information on household labor budgets over a range of Zimbabwe's natural regions and communal, small scale commercial, and resettlement production systems. TABLE V-5 MAJOR FOOD CROP CYCLES AND LAJ3OR INPUT: BY SEX
Crop Type Crop Cycle Labor Input by Sex ...... Millets Ploughing Men and Hoeing Women Sorghum Planting Women Transplanting \iomen/\iork Parties Weeding women/ Men Harvesting \{omen/ Men Threshing women/ ~en/\iorkParties Winnowing, Transportation and Storage Women Marketing (barter) Women/Men
Maize Ploughing Men Hoeing Women Planting omen/ Men Weeding Women/Children Harvesting ~omen/~en/~hildren She l l ing Women/Children Transportation and Storage Women ...... Groundnuts Hoeing Women Planting Women Weeding Women Harvesting Women/Chi ldren Transportation and Storage Women Marketing Women ...... Beans and A1 l Cycles Women Sweet Potatoes
Sources: Alvord, 1929; Gelfand, 1971; Weinrich, 1975 Muchena, 1977
TABLE V-6 LABOR INPUT IN AGRICULTURE IN RURAL ZIMBABWE: AS PERCENTAGE OF TOTAL LABOR INPUT PER TASK ...... Performer Ploughing Planting Weeding Transport Manure Winter Gardening Cattle Handling Ploughing Herding ...... Wife 23.7 63.0 27.2 16.3 22.2 16.3 52.2 16.8 Husband 18.2 6.0 36.4 25.0 10.7 30.1 15.9 27.2 Both 16.7 11.7 13.8 27.0 9 .O 20.4 12.7 7.6 Children 10.4 5.8 10.1 11.9 6.2 14.2 4.9 17.0 Hired Labor 8.2 2.7 2.4 6.8 6.3 4.5 1.2 8.7 Worlung Party 4.4 1 .8 2.2 2.7 6.3 2.1 1 .D 5.2 Mher 13.4 1.6 1.6 1.5 1.8 1.7 1.4 2.9
Source: Ministry of Community Developnent and Women's Affairs, 1982 Table V-7 summarizes the labor budget findings of interviews conducted in 117 households. In each, data were recorded on the extent of each working member's participation in a range of farm, livestock care, and domestic tasks. Individuals were then grouped, for the purpose of analysis, into one of four gender/age categories: men (males 18 years and over), women (females 18 years and over), boys (males under 18 years), and girls (females under 18 years). As shown in Table V-7, women and children perform 73 percent of farm labor (including ploughing, planting, weeding, and harvesting), 62 percent of livestock care, 81 percent of fuel gathering and chopping, and 96 percent of routine domestic tasks (including cooking, col lecting water, and child care). In total, women and children's labor contribution to basic rural tasks equals 80 percent. When women's labor is compared to men's, analysis of the survey data indicates that women contribute significantly more labor than do men in all the task categories with the exception of livestock care, and that (at 44 percent) their average total contribution to household livelihood is over twice that of adult males (who account for a total of 20 percent of basic task labor). With the exception of the somewhat higher than average labor involvement of men in farming and livestock care on small-scale commercial holdings, the percentages recorded on Table V-7 indicate little variation in adult male contribution to task labor over the three sectors. Making due allowances for levels of aggregation, a comparison of Tables V-5, V-6, and V-7 shows that all three studies have arrived at roughly similar figures for the age/gender composition of agricultural labor.
TABLE V-7 AGE AND GENDER COMPOSITION OF LABOR
Percentage Labor Contribution ...... Routine Sector Sample Farming Livestock Fuel Domestic Total MWBG MWBG MWBG MWBG MWBG
Communal 71 26 45 15 14 35 18 36 11 11 56 14 19 3 66 9 22 19 46 19 16 Small-Scale 21 33 35 19 13 47 15 32 6 12 58 8 22 6 67 6 21 25 44 16 15 Commercial Resettlement 25 23 37 21 19 39 18 33 10 10 46 20 24 B 49 16 2 20 38 22 20 ...... Total 117 27 41 17 15 38 17 35 10 11 54 14 22 4 63 10 23 20 44 19 17
Source: Preliminary Analysis of Labor Extension Section of the ZEAP 1984 Rural Energy Survey.
Preliminary analysis of the 1984 Rural Energy Survey labor data provides previously unavailable information on the composition of labor involved in household maintenance. Here we see that women and children are overwhelmingly responsible for the provision of fuel and water, as we1 l as for cooking and child care. Perhaps the most significant findings concern the level of children's involvement over the entire range of rural activities. Table V-7 shows that children contribute roughly one-third of total labor for crop production, fuel gathering and routine domestic tasks. In addition, they are responsible for almost half of livestock care. Significantly, the Rural Energy Survey findings suggest that children's labor is even more critical in resettlement areas, where they contribute well over forty percent of both productive activities and household maintenance. Others (e.g. Kinsey, 1983: 183) have pointed out that resettlement schemes suffer from labor shortages. The figures compiled in Table V-7 indicate that, for the time being at least, this shortage is being ameliorated by the use of children's labor. However, once school S become wide1 y accessible to resettlement populations, this labor may be partially withdrawn from the households's labor budget. At this point, adult women may be forced to absorb a greater share of the tasks and the resettlement agelgender labor profile may evolve to resemble that of the more established sectors. Finally, by examining the differences between girls' and boys' labor contributions, we see that gender divisions are established relatively early in life. While boys and girls contribute equal l y to crop production and to overall household labor, boys are more responsible for livestock care while girls are more heavily involved in fuel provision and routine domestic chores. The conclusions, which can be drawn from existing studies and a preliminary analysis of the Rural Energy Survey labor data ,indicate, in unequivocable terms, that rural women, along with their children, shoulder a major share of the responsibility for production and household we1 fare in all the small-holder sectors of the agrarian economy. Moreover, current trends suggest that women shoulder these tasks under increasingly difficult conditions. While their responsibility for overall household we1 fare grows, so does their dependence on often irregular and inadequate remittances from the wage sector. Despite the large numbers of absent males, perhaps as few as 30 percent of rural remittances allow the family to subsist and stave off the consequences of a deteriorating resource base. Only occasionally do they serve as a basis for an expanding and prosperous agricultural enterprise.
WOMEN'S LABOR TIME
As we have seen, women's labor, along with that of their children, represents a major component of the tasks critical to household livelihood. This is partially a reflection of the lopsided demography of rural areas where women outnumber men, and also partially the result of the fact that women work longer hours on a greater range of tasks than do men. This section outlines the principal features of rural household labor budgets in order to highlight the stresses experienced by women who shoulder these heavy work loads. Three important aspects of household labor budgets will be treated here:
(1) Time budgeting by task;
(2) Length of the working day; and (3) Intensity of labor.
Before considering the particulars of the labor budget data from the 1984 Rural Energy Survey, it is useful to summarize the findings of earlier studies done on this topic (e.g., Callear, 1982; Muchena, 1977, 1981, 1982a, 1982b; Owen, 1982; Weinrich, 1975, 1979). These studies, done at different times and in different settings, using diverse methodologies, concur in their assessments of the following features of rural women's labor. (1) The multiple and competing demands made upon women, especially during the summer months, result in extraordinarily long work days and often in physical exhaustion.
(2) This situation is, in part, the consequence of a breakdown in the traditional gender and age division of labor resulting from male out-migration and children attending school, both of which (as argued above) have compelled women to assume new tasks and responsibilities.
(3) In addition, there has been an intensification of labor in tasks traditionally within women's domain. For example, the shift from long-term fallow rotations to short-term or no fallow has meant that more time and care must be spent weeding if yields are to be maintained. Likewise, soil depletion has increased the need for manuring and field maintenance. Additional ly, the depletion of woodlands owing to the replacement of forests by fields and a growing demand for wood and timber has added to the labor time necessarily allocated to fuelwood provision.
(4) Finally, the prevailing gender division in the use of implements and equipment makes women's labor particularly arduous. Draught animals, ploughs, cultivators are most often the province of men. Thus when men participate in agricultural activities such as groundbreaking or weeding they are more likely to use this level of technology. Likewise, when they fetch wood, they are most likely to use scotch carts. Women, on the other hand, most frequently are limited to using hoes for groundbreaking and weeding, and to carrying wood on their heads.
Time Budgeting By Task
Rural women work upwards of 12 hours a day. As described in the previous section on the age and gender composition of labor and documented further in Table V-8, women participate in practically all stages of the agricultural cycle, often providing the major labor input for both food and cash crop production. Thus during the agricultural season women spend long hours in their fields and gardens in addition to performing their routine domestic tasks. During the non-farm season women engage in craft production as a vital source of cash income.
TABLE V-8 TASKS: TIMING AND LABOR INPUT FOR FIELD AND GARDEN MAIZE
Task Month(a) Labor Input
Field Maize ...... Winter Plough March-Sept . Men Apply Manure Aug .-Oct. Men/Women/Children Plough and l arrow October Men/Women/Children Fence Sept .-Oct. Men Plant and Fertilize? End Oct .-Early Nov. Women/Children Weed (1 st) Mid-Late Nov. ~omen/~hildren/~en* Top Dress with Fertllizer Early Dec.-Late Jan. Women/Children and Apply Inecticide Weed (2nd) Late Dec.-Late Jan. ~ornen/~hildren/~en* Weed (3rd) End of February Women/Children/kn Harvest Green Malze February on Women Harvest Ripe Maize Mid April-May Fmily/Work Parties Shell August on Women/Some Men ...... Garden Maize
Plough and Harrow June-Aug. Women Fence March-Aug . Wornen/Children Plant and Fertilizer June-Aug. Women Weed (1 st) July-Sept . Women Top Dress with Fertilizer End Sept.-Oct. Women and Apply Insecticide Weed (2nd) Sept .-Oct. Women Weed (3rd) Sept .-Oct. Women Harvest Green Malze Mid December on Women ...... Source: Cal lear, 1982 X Also Work Parties The observation/measurement component of the Rural Energy Survey carefully recorded the activities of 14 households for three week-long periods corresponding to the planting, weeding, and harvesting times of the agricultural cycle. Preliminary analysis of labor data from six of these households (five communal and one small-scale commercial) provides an accurate, although statistically unrepresentative, picture of the time budgets of all their resident members. Early case study-based data suggest that men, women, and children devote somewhat different proportions of their total work hours to crop production (see Table V-4). Table V-9 summarizes the Rural Energy Survey data on task time budgeting for agriculture as well as for four other task categories. TABLE V-9 LABOR INPUT BY TASK: -AS PERCENTAGEOFOTALORKINGURS--
Group Livestock Routine* Farming Care Fuel Water Domestic ~otal** ...... Men 50.1 23.4 2.7 1.8 0 .8 78.3 Women 22.6 2.4 1.0 2.6 44.3 72.9 Boys 29.5 32.8 1.6 9.4 7.8 81.1 Girls...... 14.9 7.3 4.2 12 .O 60.7 99.1 Average (Weighted)...... 29.3 19.1 2.2 6.8 24.9 82.3 * Includes cooking, child care. * * Not included in these percentages are tasks such as food processing, crafts manufacture, repairs and construction, etc., which make up the balance of recorded productive activities. Source: Preliminary Analysis of Labor Observation Component of the ZEAP 1984 Rural Energy Survey. At first glance, these results appear to indicate a strong gender-linked emphasis on farming and livestock care for males and on routine domestic tasks for females. It is interesting to note, however, that while women budget roughly 25 percent of their labor time for crop production, women's labor overall (as shown in Table V-7) accounts for approximately 40 percent of the labor contribution to the final product. There are two possible explanations for this disparity. The first is that it is a reflection of the imbalanced demographic composition of rural labor. The second is that while women may devote as many or more hours to crop production than men, these tasks represent only a fraction of their overall responsibilities. As shown in Table V-9, fuelwood provision represents, in both relative and absolute terms, a rather small proportion of the average individual's labor budget. On the average, people expend roughly three times as much time fetching water as they do on fuelwood collection. It should be noted, however, that these figures may have been influenced by the fact that 1984 was a drought year, compelling people to walk greater distances to water sources. Another probable influence is the fact that the observations were made during the agricultural season during which time households often have stockpiles of fuelwood.
Length of the Working Day p-- Studies of time use in rural areas of the Third World indicate that women work from eight to over sixteen hours a day depending upon season and socio-economic factors. Table V-10 provides an example of a typical daily schedule for rural women in Zimbabwe during different seasons of the year. The 1984 Rural Energy Survey provides the first comparative data on women's and men's length of day in rural Zimbabwe. Table V-11 summarizes these findings indicating that women's days tend to be slightly longer than men's by between 20 and 25 minutes on the average. This seems to be the case during both farming and non-farming seasons in all three small- holder sectors. Additionally, a preliminary analysis of the labor observation data suggests that men engage in more leisure time activities than do women during this period.
TABLE V-10 SCHEDULE OF TYPICAL DAILY ACTIVITIES OF RURAL WOMEN IN DIFFERENTSEASONSINZIMBABWE --p- - ...... Summer (Farming Season) 4:OO-4:30 a.m. Get up and go to the fields (usually without breakfast) to cultivate, sow and weed.
10:OO a.m. Rest for 30 minutes. Usually have mahewu (homebrewed non-intoxicating drink). More work in the fields until after midday.
A light lunch is prepared on site, but in some instances, someone goes to bring cooked food. After lunch, more cultivating and weeding until sundown.
6:00 p.m. Gather firewood on the way home and prepare supper,
...... 9:OO-10:OO p.m. Bedtime for most families...... Dry Season
5:30-6:00 a.m. Get upand work aroundthehomestead and have a light breakfast.
7:30-8:00 a.m. Work in the garden patch (small cultivated patch -- approximately 1/2 acre, mainly for vegetables). The rest of the day is spent digging cow manure from cattle pens and carting it to the fields and spreading it around the field,
4:OO-5:00 p.m. The family goes home early and has more time for a leisurely meal and rest. Club activities, other forms of adult learning and involvement, church conferences, brief visits to husbands in towns, etc., are more possible during the dry season...... Harvest Season
The day is very much like a day in the summer except that the field chores are done with some more festive spirit as the rewards of their toil are quite obvious, and there is ...... also a lot to eat.
Source: Mujeni, 1974, after Muchena, 1977
TABLE V-11 LENGTH -OF -DAY FOR -MEN AND I7OMEN
Sector Group Farming Season Non-Farming Season ...... (hours) (hours) Communa l Men (n=59) 15.08 14.18 Women (n=72) 15.40 14.50
Smal l-Scale Men (n=24) 14.65 Commercial Women (n=14) 15.05
Resettlement Men (n=24) 14.76 14.30 ...... Women (n=26) 14.90 14.90 Totals Men (n=97) 14.93 14.26 Women (n=112) 15.24 14.67 ......
Source: Preliminary Analysis of Labor Extension Section Interview of the ZEAP 1984 Rural Energy Survey. Intensity of Labor
Preliminary analysis of the six labor observation households indicates that each devoted a weekly average of 88.6 hours to crop production, 45.5 hours to livestock care, 7.7 hours to fuel provision, and 100.6 hours to routine domestic tasks. The per capita, genderlage breakdown of these labor times is provided in Table V-12. It can be seen from these results that both women and girls bear a considerably heavier labor burden than do men and boys, respectively. If the Rural Energy Survey's preliminary findings on intensity of labor are representative of a broader rural population, than it can be concluded that, on the average, during the farming season women do approximately 50 percent more work than do men, and that girls work 30 percent longer than boys. Women put in above average labor time in crop production in addition to a range of other tasks. Girls, many of whom are school age, take on a full work week, assuming major responsibilities for household maintenance.
TABLE V-12 LABOR INTENSITY BY AGE AND GENDER (Hours per Week) ...... Group Farming Livestock Fuel ~outine* ~otal** ...... Care Domestic Men 22.8 9.7 1.2 0.7 43.1 Women 15.5 0.8 0.8 31.6 63.8 Boys 10.1 10.7 0.6 5.0 32.7 Girl...... S 6.1 2.6 2.2 30.0 42.5 Average...... 13.6 5.9 1.2 16.8 45.5
*includes water provision, childcare, and cooking. * * Includes crafts, food processing, repairs, and other miscellaneous tasks.
Source: Preliminary Analysis of Labor Observation Component of the ZEAP 1984 Rural Energy Survey.
Fuel wood gathering, a task partially shared among household members, appears to represent a very small proportion of total labor hours, even for girls who are the major providers. As discussed above, because of their timing,. the observatiops undertaken by the 1984 Rural Energy Survey may not be representative of the larger fuelwood provision situation in Zimbabwe. However, we may take these figures as indicative of labor time spent during the wet season, when agricultural tasks take precedence over others. Clearly, the time spent in collecting firewood varies considerably with local ecological conditions, season, availability, and family size. The average weekly household figure of 7.7 hours spent on fuelwood provision for the six Rural Energy Survey households falls within the range of estimates for other rural areas in Africa. Table V-13 summarizes some of these figures, including those of a preliminary household survey conducted in Zimbabwe in 1982 under the auspices of the Beijer Institute. To conclude this section, an appropriate and effective rural energy policy would be one which is sensitive to the multiple demands on women's labor time and, therefore, is directed at increasing their productivity across a range of activities without also unduly increasing their workload in any one task. TABLE V-13 HOUSEHOLD LABOR TIMES FOR FUELWOOD COLLECTION -IN SE~D~C~SITES
Area Time Spent Source ...... (Hours/~eek) Upper Volta 1 McSweeney cited in Tinker, 1981 Mbere, Kenya 2.5-10 Brokensha and Riley, 1978 Embu, Kenya 3.5-7 Haugerud, 1981 Nyakyusa, Tanzania 4-10 Bush, 1977 cited in Devres, 1980 Zambia 7 ECA in Molinyi, 1977 Bukoba, Tanzania 11 Fleuret and Fleuret, 1978 Selected Communal 16 Hosier, 1982 ...... Areas, Zimbabwe
THE SCOPE OF WOMEN'S DECISION-MAKING POWER Decision-making in peasant households is a complex matter combining both farm management and family welfare. It often has been pointed out that, unlike a commercial enterprise, the peasant family cannot declare bankruptcy; it must survive from year to year. This reality has been observed to circumscribe the range of options open to the household. While accurate, this observation fails to address important intra-household disparities in decision-making power. In many instances, these disparities are based on age, in others they are based on gender, or in the case of polygamous households, upon seniority. In rural Zimbabwe these disparities have been reported to be quite wide, and are cited, along with other hardships, as being the cause of considerable resentment among women (Ministry of Community Development and Women's Af f airs, 1982; Zimbabwe Women's Bureau, 1981). Decision-making covers a broad range of questions including the disposition of members' labor time, the timing of agricultural operations, investments in productive inputs, the selection of crops, the ratio of retentions to sales, expenditures on a variety of household necessities, the allocation of rewards and sharing of benefits. Issues concerning the sharing of benefits will be treated in a separate section to follow. The present section considers the broad determinants and consequences of unequal decision- making power within the household. Most available reports and studies concerned with this issue conclude that rural women have much less decision- making power than their male kin. This situation is rooted in patriarchal relations prevailing both within the household and in society at large. Most central to this disparity is male control over land and productive assets. As women's rights to land are mediated through husbands or male kin, and as the critical means of production (to the extent that they are available) are in men's hands, women's bargaining power within the household is seriously circumscribed. Therefore, while women may bear the major responsibility for family welfare and shoulder a disproportionate share of both farming and domestic work, they may have relatively little say in major decisions concerning household livelihood or community affairs. Two excel lent recent studies (Cal lear, 1982; Cheater, 1981) modify this general picture of women's subordination by pointing out that many women have been able to retain a decision-making role in certain important facets of agricultural production. They argue that a distinction should be made between the formal norms for male/female decision-making and the informal means whereby women exert influence upon decisions or, in fact, make decisions. This is particularly the case within households where men are absent for long periods of time. These arguments are supported by findings of the Ministry of Community Development and IJomen's Affairs survey (see Table 14).
TABLE V-14 FAMILY DECISION-MAKING --IN RURAL ZIMBABWE ...... Decision-Making What Crops How Much What Inputs to Process...... to Grow to Sell Procure Husband and Wife 28.5 25.3 38.1 Husband Dictates 17 .O 25 .O 14.8 Wife Alone 10.2 24.4 35.9 Senior Relative 5.5 7 .O 1.6 Head of Household 4.4 5.6 1.3 Other...... 1 .O 0.6 0.6
Source: Ministry of Community Development and Women's Affairs, 1982 While the arguments stressing formal vs. informal decision-making power are, without a doubt, valid, the fact remains that women overall are subordinated to male decision- making and that this subordination is based upon unequal control over- productive assets. While women have indeed been able to exert in£luence within certain spheres of household decision-making, in particular over domestic routines and those questions concerning the timing of agricultural operations, males retain crucial decision-making powers when it comes to expenditures, income-generating activities, and the allocation of the rewards to household (often female) labor. In summary of this section, there exist both practical and political reasons why rural energy planners should pay particular attention to disparities between men and women's decision-making power. Rural energy programs designed to enhance women's decision-making capabilities are more likely both to gain women's support and acceptance and to contribute to Zimbabwe's broad social goals. In the design of locally- based energy projects, care should be taken not to inadvertently replicate or build upon existing gender differences, thereby increasing women's structural vulnerabilities. SHARING BENEFITS
The material benefits of a peasant household's efforts can be grouped into four broad categories:
(1) The product of domestic and farming activities; (2) Personal services;
(3) Leisure; and (4) Savings The product of a peasant household's activities can take the form of things such as food, shelter, and clothing, directly consumed by its members. It can also take the form of commodities such as purchased food, medicine, clothing, household appliances, school fees, tools and farm equipment purchased with money obtained from the sale of crops, livestock, crafts, or labor. Personal services also take a variety of forms ranging from the care given to infants, young children, old or infirm members, to many routine domestic tasks such as cooking, washing, laundry, or ironing. A1 l available evidence points to the fact that women and older children perform the majority of these services and that men and younger children are the main recipients. Leisure, itself an important element of a healthy and fulfilled life, is a frequently overlooked benefit in the case of peasants. Leisure can be enjoyed on an individual basis or it can take a variety of social forms. In either case, substantial gender-linked differences exist in both the kinds and amounts of leisure enjoyed in rural Zimbabwe. Savings, a critical component of an agrarian economy characterized by drought and social obligations primarily take the form of livestock, usually controlled by men. Both the range and the level of benefits vary considerably among Zimbabwe's rural households. However, in all cases, benefits can be usefully distinguished in terms of the extent to which they are appropriated by individuals or by the family as a whole. Most available studies point to the fact that the sharing of benefits is a contested issue in rural society. The findings of two major surveys (Zimbabwe Women's Bureau, 1981; Ministry of Community Development and \?omen'sAffairs, 1982) concur in highlighting rural women's concerns over this issue. Women argue that they need additional reliable sources of cash income in order to cover household expenses. They also argue that men appropriate most of the money from crop sales for their personal use. TABLE V-15 AGE AND GENDER COMPOSITION OF CROP PRODUCTION --pAND MARKETING ...... Percentage Labor Contribution Farming Total** Marketing Labor MWBG MWBG MLJBG ...... Communal 26 45 15 14 19 46 19 16 40 51 5 4 labor n=71, marketing n=42 Smal l-Scale 33 351913 25441615 70 30 0 0 Commercial labor n=21* marketing n=ll Resettlement 23 37 21 19 20 38 22 20 61 35 2 2 labor n=25, marketing n=21 Total 27 41 17 15 20 44 19 17 50 44 3 3 labor n=11z marketing n=74 ...... * Data on marketing compiled on1y for households marketing crops. * * Includes farming, livestock care, fuel provision, cooking, childcare and domestic water provision.
Source: Preliminary Analysis of Labor Observation Component of the ZEAP 1984 Rural Energy Survey. These arguments are borne out, to a degree, by the preliminary results of the Rural Energy Survey. As shown in Table V-15, men control a disproportionate share of the marketing (in relation to their labor input) in all three small-holder sectors. Overall, men do about 50 percent of the marketing, while they contribute approximately 27 percent of labor to total crop production and 20 percent of labor to aggregate household tasks. It should be noted at the same time, however, that women's share of marketing control is overall roughly equivalent to their contribution to both agricultural and total labor input. The conflict between men and women may well be over the product of children's labor, who as shown, contribute significantly to household labor budget but who have negligible control over cash crop income. However, the broader issue focuses not only on control over the household's cash income, but also on the allocation of land and women's labor between food and cash crops. Generally speaking, food crops represent a shared family benefit while the proceeds from cash crop production appear to be disproportionately appropriated by men. Table V-16 provides a current breakdown of the degree to which a variety of peasant grown crops have become commercialized. One study concludes that "when a crop comes to be defined as a cash crop, men become more involved and more controlling" (Callear, 1982). This should not be interpreted to mean that women are opposed to cash crop production - per -se, but rather that they are seeking income-generating activities over which they can maintain a greater degree of control of the proceeds.
TABLE V-16 PEASANT CROPS GROWN FOR FOOD OR CASH
Crop------Food Cash Both Finger millet 35.2 16.6 13.7 Ground nuts 34.6 2.1 20.4 Beans 29-7 2.5 18.0 Pearl millet 28.4 11 .o 14.5 Maize 27.9 22.6 37.1 Rice 24.2 14.9 24.0 Vegetables 23.9 10.4 28.8 Fruits 19.9 13.3 10.6 Sweet potatoes 18.5 15.0 24.8 Sorghum 12.4 6.3 14.3 Other crops 11.9 10.4 6.9
Source: Ministry of Community Development and Women's Affairs, 1982
To conclude this section, rural energy planners may usefully build upon women's expressed interest in increased cash income in, for example, the design of commercial forestry projects. Income generating energy projects targeted st rural women must ensure that women actually receive the income resulting from their efforts. New energy-related crops, technologies, and marketing strategies, must be evaluated in terms of whether they unduly favor personal over family shared income.
ACCESS TO LAND
Along with other members of their household, women share the consequences of marginalization in the labor reserves and >f rural class differentiation which, in large measure, shape the family's access to land, productive assets, and wage mployment. In addition, patriarchal relations have largely subordinated women by making their rights to land and other 3roductive assets contingent upon attachments to husbands or nale kin. When considering women's land rights in the communal 3reas it is useful to distinguish between land such as that intended for agricultural fields, and common property resources, such as woodlands or grazing areas. In the first instance, land is a1located to individual males and women jain access to agricultural fields only by virtue of their cies to these men. Whereas women's rights to farmland are mediated by gender relationships, their access to common property resources is direct: a function of their membership in the social group. Woodland sources of household necessities such 3s woodfuel, medicines, and supplementary foodstuffs are immediately accessible to women, making available a sphere of nctivities that is relatively independent of male control. The progressive shrinking and deterioration of these :ommon property resources over time has affected women more idversely than men. As forests are replaced by fields women Eind it increasingly difficult to provide household lecessities such as woodfuel for their families. In a >erceptive analysis of the relationship between privatization )f land and the weakening of customary access rights in Cenya, Wisner (1983) argues that the latter disappear in more lr less the following sequence:
(1) Building of houses;
(2) Planting of trees;
(3) Planting of annual crops;
(4) Grazing of livestock;
(5) Cutting of firewood for sale;
(6) Cutting of firewood for domestic use; (7) Picking up fallen branches for domestic use;
(8) Placing beehives in trees;
(9) Crossing or trespassing.
Moreover, as more land is transferred from common access to the individual domain, the sphere of women's independent and unmediated activities shrinks accordingly. Conditions of land scarcity have enhanced men's individual land rights at women's expense at the same time as women's absolute and relative share of agricultural labor burden has become larger. As gender-based access to land intensifies and common property resources have less and less to offer, the situation of unattached women, such as widows or divorcees, becomes increasingly jeopardized. This situation has reached its most acute form in the former African Purchase Areas where colonial administrators attempted to create a peasant freehold class oriented to cash crop production. Although, at present, these areas are somewhat less restrictive, the male-oriented training and access to purchase area land have left a legacy. Studies of these operations (for example Cheater, 1981) reveal that the exploitation of women's labor in purchase areas reached new heights as men became petty agrarian entrepreneurs, taking on multiple wives as a strategy to increase unpaid labor, expand their production, and accumulate capital. ACCESS TO PRODUCTIVE ASSETS Along with land rights, rural women's most consistent demand has been access to new, improved productive inputs (see Ministry of Community Development and LJomen's Affairs, 1982; and Zimbabwe Women's Bureau, 1981). Historical l y, male-oriented land policies have been accompanied by agricultural extension programs and credit schemes which have largely ignored women farmers in favor of a male "head of household" who often may be only marginally involved in crop production. Yet surveys have consistently shown that women are most interested to learn modern farming techniques which are directly relevank to their current subsistence needs. They also want implements and equipment which would lighten their work-load. Women also point out that credit and financing for agricultural inputs must be made directly accessible to them, instead of through their husbands. Their new legal majority status should make this practicable. In addition to their strongly expressed interest in improved farming techniques and new crops, women voice a strong desire for training in the use and maintenance of modern equipment. Thistraining would, in any case, be a critical element in a comprehensive agricultural development program. In the case of women, this training would reduce their dependence on outside expertise, as well as reduce the probability of project failures due to prolonged equipment breakdown. This instruction and training can only be imparted if the country's agricultural extension service reorients its staff to its female constituents. In 1981, the extension service staff was overwhelmingly male (Ministry of Community Development and Women's Affairs, 1982). Prevailing cultural norms prevent women from availing themselves of extension advice given by men. This severely limits their participation in projects which might otherwise be of considerable value to them. Women argue that the male bias in agricultural extension would be reduced considerably by increasing the number of female extension workers.
3. TOWARDS A WOMAN-ORIENTED RURAL ENERGY DEVELOPMENT POLICY INTRODUCTION
Section 2 presented a review of existing studies concerning the constraints operating upon rural women in relation to an energy economy at the household level. The insights provided by the studies suggest preliminary energy policy guidelines in this area. These insights can be summarized by two general observations. First, the provision of basic household necessities is an interrelated whole encompassing all aspects of energy provision, use and demand, and is underwritten primarily by women and children's labor. Second, this labor is under severe constraints resulting in a progressive limitation of access to land, productive assets, and sources of cash income. Women are not excluded from participation in productive activities, but they are marginalized from access to productive resources, decision- making, and a fair share of the benefits of their activities. Although independence and the establishment of majority rule have led to many improvements, the principal structural limitations affecting rural women have not been significantly altered. A rural energy policy aimed at increasing women's productive potential, as well as their equitable participation in the benefits of this increase, would contribute towards the progressive weakening of these structural limitations. In order to accomplish this task, the country's rural energy policy must escape the confines assigned to it by a conventional approach to energy development. This conventional approach limits the scope of energy planning to two facets. The first involves policies and programs aimed at specific aspects of domestic energy consumption (such as dissemination of improved stoves, research on biogas and other alternative sources of domestic energy, etc.). The second facet assigns to energy planning a secondary role: supportive of development initiatives in other sectors (e.g., agriculture, service, industrial, or transport). Here the emphasis is on supply levels and pricing policies. This view limits rural energy planning to an "enabling" role in production, but grants it a fuller scope in social welfare programs aimed at fulfilling domestic fuel needs. Conventional rural energy programs identified with a female constituency often fit into this social welfare niche. Meanwhile, women and women's interests may be easily overlooked when it comes to energy planning for production and economic growth. An alternative approach would expand the role of rural energy policy goals as well as the scope of energy planning activities. It would view energy development as an integrated whole incorporating both production and reproduction, recognizing women as key actors in both these spheres. The overall objective of energy policy with regard to rural women would be to effect a transition from constrained labor-intensive forms of energy provision and use to higher technical and organizational forms. This transition would therefore encompass complementary technological and social transformations. The comprehensive approach to rural energy development would focus on two broad interrelated types of programs. The first would address existing or impending fuel scarcities by increasing supplies, introducing substitutes, and rationalizing demand. The second type of program would investigate the possibilities of anticipating latent or unmet demands for higher forms of energy for domestic uses, agriculture, rural industries, and transport in communal, small-scale commercial, and resettlement areas. In both types of programs the transition to higher forms of energy use can be accomplished by both direct or indirect means. Direct energy-related interventions include projects to increase the supply of existing or novel energy sources (e.g., woodlots, agroforestry, biogas generators) or enhance the efficiency of existing energy use (e.g., fuel efficient stoves). In addition, the communal and resettlement areas' energy-use profiles can be significantly affected by preferential pricing policies for fossil energy-based inputs for agriculture and rural industry, and by the extension of electricity grids. Additional ly, an energy transition can be accomplished by indirect means which include a broad range of technical and institutional interventions which either increase the productivity of human or animal labor power or accomplish shifts in (women's or household's) labor budgets in such a manner that labor is released for alternative productive activities. In the case of Zimbabwe's rural women, the indirect path to an energy transition can be accomplished by the production and dissemination of a wide variety of intermediate technologies (such as shellers, grinders, wire fencing, cultivators, herbicides, water pumps, small scotchcarts, etc.) along with the organizational support making their adoption practicable (such as credit cooperatives, price incentive, marketing outlets, training and maintenance facilities). GUIDELINES AND RECOMMENDATIONS Insights derived from existing studies of rural women's role in production and household welfare suggest some provisional guidelines and recommendations for program design and project identification. These studies point out that the essential reality of rural women's lives is their responsibility for household welfare, along with their heavy involvement in most facets of food and cash crop production, basic needs, provision, and domestic work. Response to Local Needs and Priorities
Numerous studies, including some concerned with women's role in social forestry (e.g., Hoskins, 1979: Skutch, 1983), emphasize the importance of basing programs and projects upon locally defined needs and priorities. One study of community forestry in Tanzania demonstrated that communal woodlots were successfully established only in areas where fuel-wood scarcity was perceived to be a serious problem (Skutch, 1983). Another study pointed out that woodlots also fail when women, who are expected to do the maintenance, are not consulted even though the project has met with the approval of local (male) authorities (Hoskins, 1979). This same study described the general unpopularity of single stand plantations in situations where forests fulfil multiple demands. The study then recommends that planners study the multiple needs fulfilled by forest resources in different settings and then introduce mixed species stands for woodlots designed to meet those needs. At a national level, Zimbabwe's rural women have left little doubt regarding their needs and priorities. Two major surveys, one sponsored by the Ministry of Community Development and Women's Affairs and the other by the Zimbabwe Women's Bureau identify inter a+ia the following perceived needs: more training and educational programs, land rights, appropriate farm implements, access to credit and extension services, child-care facilities, income-generating activities, improved health care, improved transport, and an expanded role in community decision-making. Needs and priorities can be expected to vary from area to area, and even within particular sites. Therefore planners must determine inter and intra community variation at the preliminary stages of project identification. This is best done on the basis of short surveys and of a dialogue between local women and planners in such a manner that local priorities are ultimately strongly reflected in the project design (Graham, 1979). Incorporate Local Expertise
Available studies on women's farming and fuel provisioning activities strongly suggest that rural women possess a fund of knowledge regarding resources in their local environment (Hoskins, 1979). Moreover, women have been shown to actively experiment with diverse strategies enabling them to adjust to changing circumstances and cope with scarcities. Women experiment with new crop vasieties, and plant saplings and cuttings. In the face of woodfuel scarcity, they may make a variety of cost-bearing adjustments including "switching to alternative fuels, both inferior and commercial; decreasing their household fuel consumption, perhaps with negative effects on family nutrition; improving the efficiency of their own fuel use; and exerting further pressures on the environment" (Cecelski and Loutfi, 1983). In the face of labor scarcity during critical farming periods, rural women in Zimbabwe stockpile fuel during the dry season and also use metal grate stoves which, although fuel-inefficient, have the virtue of saving labor time during cooking (Gill, 1983). The widespread failure of agricultural and woodfuel projects directed at smallholders is often blamed on the recipients' purported lack of knowledge or low level of training. However, experience suggests that people do not necessarily lack the requisite information or know-how to effect changes in their production systems, or that knowledge is an important constraining variable in many cases. For example, a comprehensive survey of Tanzania's 15-year-old community afforestation program demonstrated that there was no lack of local knowledge regarding tree planting and care. On the local level, the most important factors associated with project failure were a lack of perceived need for more trees, and, on the institutional level, poor logistics of seed1ing delivery and backup services. The most effective approaches to rural development planning tap local resource knowledge and practices and combine these with introduced techniques and innovations. Owing to their central role in the rural energy economy, women are a key source of this expertise. Projects which, in addition to responding to women's stated needs, mobilize their expertise in appropriate ways in project design and implementation, have a higher likelihood of gaining their support, of contributing to their self-esteem, and reducing structural dependence on imported techniques.
Build (Selectively) Upon Existing Groups
The female constituency for rural energy planning is likely to be clustered into diverse interest groups with different scopes, aims, and levels of organization. The task of energy planners is, wherever possible, to build uponthese existing groups in such a manner that women overall (as distinct from particular subgroups) are empowered by the process of development. Consonant with Zimbabwe's general social and political objectives, the priority will be to reinforce cooperative forms of energy management as well as common property forms of resource ownership. However, solutions aimed at the individual household level should be pursued where appropriate. The general strategy advocating the programs and/or projects built upon local groups and institutions needs to be qualified when these are male-dominated to a degree that they offer an inadequate scope for the mobilization of women's efforts. The strategy of a woman-oriented rural energy development policy is to select the groups and institutions which do offer the possibility of this mobilization. If these are found to be absent, it may then be necessary to promote new organizations suited to the task.
Emphasize Multipurpose Solutions Studies conducted to date strongly suggest that fuelwood is one component in an interrelated system of basic needs provision at the household level (see Wisner, 1983). Emphasis on the satisfaction of fuelwood needs at the expense of other basic necessities can lead to project failure. Therefore, special attention should be given to multipurpose strategies such as agroforestry designed to provide integrated fuel/food/fodder resources for household needs. Additionally, energy projects should encompass both direct and indirect means (described above) of accomplishing an energy transition for rural women. For example, income- generating projects (such as cooperative nurseries), requiring increased labor input, should be coupled with the introduction of labor-saving technologies or facilities (such as pumps for improved domestic water supply, wire fencing, or child care services), which reduce women's labor burden in other spheres of basic necessity provision. In order to identify the possibilities for multipurpose solutions, surveys of perceived needs and priorities and local resource knowledge and management practices should be conducted at the pre-feasibility stage of project design. Promote International Cooperation
Comprehensive planning for rural energy development spans the concerns and activities of numerous ministries, government agencies, and non-government organizations requiring the active, coordinated participation of these entities. The Department of Energy assumes a key role in this process by outlining a plan of action which: (1) Specifies overall needs and priorities in the rural energy sector;
(2) Translates these into long and short-term objectives;
(3) Identifies the direct and indirect means to reach these objectives in communal, smal l-sca l e commercial, and resettlement areas; and
(4) Establishes a framework for interministerial cooperation in carrying out the range of coordinated projects and tasks encompassing this integrated program. In the case of rural women, it can be expected that the Ministry of Community Development and Women's Affairs will play a key role.
Alvord. E.D.. 1929 "Agricultural Life of the Rhodesian Native," =E, No. 7, pp. 9-16. Brokensha, D. and Riley, B., 1978 Forest Foraging, Fences and Fuel in 5 Marginal Area of -- -p- - Kenya. Paper prepared for USAID Africa Bureau Firewood 1Jorkshop.
Brush.. S... 1977 Mountain, Field and Family. Pittsburgh:--p University of Pennsylvania Press. Callear, D., 1982 The Social and Cultural Factors Involved in Production -p- by- Small Farmers in Wedza CA, Zimbabwe. P~~~~:~NEsco. Cecelski, E. and Loutfi, M., 1983 "Household fuel shortages, rural women's work and family nutrition: research and action." Paper delivered at the FAO/ECA Seminar on Fuelwood and Energy for African Women in Lusaka, Zambia. Chavunduka, G.L., 1970 -----Social - -Change- - -- - in A Shona Ward. Occ. Paper No. 4. Department of Sociology, University of Rhodesia. Salisbury: Mardon Printers. Cheater, A., 1981 "Women and their participation in commercial agricultural production: the case of medium-scale freehold in Zimbabwe." Development and Change, Vo1.12, pp. 349-377. CSO, 1969 -Census of- Population. Salisbury: Government Printer.
CSO, 1983/84a ------National ------Household Survey: ------Mashonaland -Central------Province. Harare: Government Printer.
CSO, 1983/84b National Household Survey: Manicaland Province. Harare: Government Printer.
DEVRES, 1980 -The- Socio-Economic Context of Fuelwood Use in Small Rural communities.~~~Evaluation Special Study NO.~. Washington, D.C.: USAID Bureau for Program and Policy Coordination.
ECA. 1974 The Integration of Women in African Development. ------Augus tr- ----v------Abid jan, Ivory Coast.
Fleuret, P. and Fleuret, A., 1978 "Fuelwood Use in a Peasant Community: A Tanzania Case Study," Journal -of Developing Areas, July.
Gelfand, M., 1971 --Diet and Tradition --in an African Culture. Edinburgh: E. & S. Livingstone.
Gill, J., 1983 "Fuelwood and stoves: lessons from Zimbabwe," in K. K. Prasad and P. Verhaart, eds., --Wood Heat -for Cooking. Bangalore: Indian Academy of Sciences.
Hauqerud, A., 1981 Household Energy Use in Rural Embu: Socio-Economic Aspects of Wood Use, ~ookingand~ightrng ----Fuels, -ana Water Collection. --p Stockholm: Beijer Institute of The Royal Swedish Academy of Sciences.
Hosier, R., 1982 "Preliminary Report of Fuelwood Use in Zimbabwe," ms.
Hoskins, M., 1979 "Women in Forestry for Local Community Development." Tiashington, D.C.: USAID.
Kinsey, B.H., 1983 "Emerging policy issues in Zimbabwe's land resettlement programmes," Development Policy Review. Vol. 1, No. 2: 163-196, p- Mblinyi, M,, 1977 Women: Producers and Reproducers G Peasant Production. Economic Research Bureau, U. of Dar es Salaam. Occ. Paper. 77.3.
Ministry of Community Development and IJomen's Affairs, 1982 Report on the Situation of Women in Zimbabwe. Harare. p-- Muchena. O.N., 1977 Women, Subsistence Farming and Extension Services in the Tribal Trust Lands of Rhodesia. M.Sc. Thesis, Cornell University.
Muchena, O.N., 1979 "The Changing Position of African Women in Rural Zimbabwe, Rhodesia," Zimbabwe Journal of Economics. Vol. 1, No. 1: 44-61. Muchena, O.N., 1981 "Women and Work: Planning Rural Development with Women in Mind." Paper presented to Zimbabwe Economic Society Seminar. University of Zimbabwe. 22 pp.
Owen, F., 1982 biomen's Health Survey. Unpublished Manuscript cited in Bie Nio Ong "Energy accounting and the use of labour budget studies," unpublished ms. Rald, J., 1969 Land Use in 5 Bahaya Village: A Case Study from Bukoba --- p-- District, West Lake Reyion. Res. Paper No. 5. Dar es Salaam:--p BRALUP, Skutch, M., 1983 Why People Don't Plant Trees. The Socio-Economic Impacts of xis sting-%~dfu~ogr~s: Village Case Studies, Tanzania. Resources for the Future Discussion Paper D-73P, Energy in Developing Countries Series. 'Clashington, D.C.
Tinker, I., 1981 Energy ---for ------Essential ------Household Activities. CIDAT Occasional Pa~erNo. C-2. Washington, D.C.: Dames and Moore's Center for International Development and Technology.
Weinrich, A.K.H., 1975 African Farmers & Rhodesia. London: OUP.
Whitlow, J.R., 1980 Deforestation in Zimbabwe? Problems and Prospects Supplement to ~ambezia1980. --p Salisbury: university of Zimbabwe. Whitsun Foundation, 1981 Rural Afforestation Study. Salisbury: Whitsun Foundation.
Wisner, B., 1983 -Energy -and Sel £-Reliant Struggle & African Development: An Assessment for the Beijer Institute of "Basic Needs" Approaches. Stockholm: Beijer Institute of the Royal Swedish Academy of Sciences.
Zimbabwe Women'S Bureau, 1981 "We Carry a Heavy Load." Rural Women in Zimbabwe Speak Out. Harare. VI. PERFORMANCE TESTING DOMESTIC COOKSTOVES FOR ZIMBABWE Thomas N. Harris
1. INTRODUCTION There is considerable scope for the Government of Zimbabwe to take positive action in dealing with the growing f uelwood/deforestation problem of Zimbabwe's peri-urban and communal areas. Strategies for increasing wood energy supplies will be a necessary and central part of a solution, but unfortunately their benefits will become available only in the medium to long run. More immediate impact might be achieved with programs designed to encourage fuel substitution and adoption of more efficient cooking appliances. Such programs could have a major impact in a very short time if they promoted well designed deviceswhich both save fuel and are attractive to potential users. If such efforts are to be considered, it is essential that the ministries concerned should have access to some basic data on the comparative energy implications of appliance change, of fuel substitution, and on the scope for energy conservation through technical or managerial strategies. This data could enable the Government to develop an estimate of the potential impact of alternative devices and assure that its policies and extension efforts are directed to the best available technologies. It could also provide a graphic and demonstrably credible component of a media campaign on strategies for coping with the fuelwood problem. The data presented here are the result of an inexpensive short-term investigation focusing on cooking devices currently available in Zimbabwe. In the course of the investigation various hearths and stoves were put through a series of tests designed to measure operating characteristics and efficiency across their power range and to document other factors of interest, including value for space heating and lighting, ease or difficulty of use, danger of burns or asphyxiation, and the like. The goals ofthe projectwere 1imited:to gather dataon key characteristics and performance parameters of some existing stoves of particular interest, and to establish the capacity for further testing and evaluation of novel and improved devices. The test series is thus by no means comprehensive. Only a few stoves were tested and the testing done under a very limited set of conditions. However, the hearths and stoves tested are representative of the range of cooking devices available in Zimbabwe. Coal, paraffin, gas and electric cookers were included as well as those using wood and charcoal. The stoves examined were generally good examples of their type, tested under favorable conditions (Harris, 1984a). Thus the data gathered should provide a fair reflection of the performance to be expected of these stoves in tasks similar to those embodied in the tests. Beyond the development of this basic data, the test program has developed a set of well specified and documented test methods (Harris, 1984b) and trained the staff of a local technology evaluation center in their use. The capacity for further work building on this foundation is well established. In stove testing, as in many other areas of research, a bit of knowledge begets more curiosity. The fact that we have left many questions on the influence of fire management or environmental variables unanswered, and new ideas on potential stove design improvements untested for the moment, has been a source of considerable frustration. It is assuaged, however, by the anticipation that these issues will be pursued in future work facilitated by the experience and basic data gathered in these tests.
2. THE PROGRAM The Domestic Cookstove Performance Testing Project was conceived in the course of work on the Zimbabwe Energy Accounting Project, in which it was realized that rather little was known about the potential economic value or impact on fuelwood resources of alternative cooking devices. Woodburning stoves of "improved" design were being promoted by various local institutions and substitution of these stoves or others using alternative fuels was clearly a matter for government interest, in view of the high rate of deforestation evident in many areas of Zimbabwe. Obviously if government ministries or other institutions were to embark on programs of stove dissemination for fuel conservation, they had need to be well informed as to the fuel saving potential of various stoves and also as to other characteristics of the stoves which might be influential in their adoption or rejection by potential users. Although several previous investtqytions of stove efficiency had been conducted in Zimbabwe these studies covered a very limited range of stoves, or were insufficiently documented for generalization. As a result it was considered necessary to begin afresh with the development of a set of test procedures of general utility for stove evaluation, supporting full, consistent documentation. The test procedures devised are a version of a water boiling/simmering test which is rapidly becoming accepted as a world standard for comparable estimation of the performance of stoves in a simulation of the composite demands of a standard cooking task, a version of the constant power test derived from standard engineering practice for investigation of operating characteristics under steady state conditions, and a direct test of performance in preparation of a typical meal. The first test is useful for a rough screening and indexing of stove performance. The second supports a close examination of the influence of various design and management variables upon efficiency over the power range of a stove. The third test checks the relationship of standardized efficiency data to an actual application. The three tests together support controlled evaluation of performance under most conditions likely to be encountered in actual use. These tests can be used to derive estimates of fuel consumption in field use. However, such derivations are extremely tenuous, as they rely on the technical efficiency of production of a single output under highly controlled conditions. In field situations users will have many other objectives than simple maximization of the efficiency of cooking. For instance, they may wish to produce heat or light with the stove, or to attend to tasks which divert attention from the optimal management of the fire. Obviously, such interests may greatly affect fuel consumption. The tests specified also include an effort to develop a qualitative assessment of the performance of stoves with respect to some of the anci l lary characteristics common1y recognized to be important to users. However, they do not include evaluation of fuel efficiency in applications other than cooking. 17hen such applications are significant determinants of use of the stove, fieldobservations are clearly required for realistic estimates of fuel consumption in actual use. The three tests, briefly described, are as follows:
THE STANDARD WATER BOILING TEST
The objective of this combination water boiling/simmering test is to obtain an estimate of fuel consumption in a standardized simulation of common cooking practices. The test has recently become an internationally recognized standard for comparative purposes, and is being carried out on a growing number of stoves worldwide. Its components roughly approximate the predominant Zimbabwean usages. Thus, the test provides an index for assessment of the potential value of stoves tested elsewhere and an indication of the relative levels of fuel consumption likely in actual use. The test is conducted in two phases: a period of fifteen minutes at high power output followed by one of an hour at low power. The high power phase is intended to simulate relatively brief high load tasks, such as frying and water heating, while the low power phase is intended to simulate more prolonged low load tasks, such as simmering. During the high power phase, fuel is supplied freely, so that the stove yields its maximum energy output to pots of water set on top. In the low power phase, fuel is husbanded so as to yield a minimum useful output, just sufficient to maintain a simmer. The relative duration of the two phases of the test is intended to reflect an appropriate weighting of stove performance in the two types of task. In fact, the test as a whole is often taken as a generalized approximation of a common meal preparation process, in which foods are brought to the boil and then simmered for an extended period. Performance is evaluated in terms of the proportion of input energy usefully transferred to the pots, the output power capacities and range of the hearth or stove, and the time required for the standard task.
THE CONSTANT POWER TEST
The objective of the constant power test is to develop information on the available power range and on the variation of performance over the power range. This type of test is derived from standard engineering practice for process analysis. It has been applied with great effect by the L?oodburning Stove Group of the University of Eindhoven in a series of sophisticated investigations of the influence of various design and management parameters on the performance of a few prototypical stoves. The principal virtue of the test lies in the fact that it provides a relatively prolonged and steady-state environment for the evaluation of the influence of various factors on operating characteristics and the discrimination of performance under different conditions. The test is conducted as a single stage, in which fuel is provided at a steady rate for a period of somewhat more than an hour. Prior to the test, the stove, pot and water are preheated, in order to eliminate the transient demands of the initial heating. After the preheat, the fire is extinguished, any residue is removed, and the test itself is begun. Solid fueled stoves are fed with equal charges at regular intervals. Other fuels are supplied at an even flow through a fixed valve or switch setting. Any rate of fuel supply may be chosen, subject to the constraints that it is sufficient to maintain a simmer in a pot of water on the stove and that it is within the capacity of the stove. A series of tests, in which the rate of fuel supply is varied across this range, is usually conducted. Performance is evaluated in terms of the proportion of input energy usefully transferred to the pots and in terms of output and input power capacities and range. Curves describing performance over the range of power or other variables may be drawn.
THE STANDARD MEAL TEST
The objective of the standard meal test is to serve as a check on the relationship of standard measures of performance to the time and energy required for preparation of a typical meal. It thus develops a mapping of the meaning of the general physical characteristics evaluated in other tests, in reference to the specific attributes of local cooking practices, such as the temperature, time and power requirements of foods, the number of pots, and sequence of operations involved in food preparation. The standard meal test may also, to the extent that cooking is the predominant application of the appliance and to the extent that the "standard meal" is in fact a typical meal, be used for crude projections of the comparative cost of use of the stove. The test is conducted as a simple exercise in cooking a typical local meal, standardized for the test series as to types and quantities of food, cooking practices, and, preferably, the cook him/herself. The meal is prepared, with the exercise of reasonable care in fuel conservation, by a cook familiar with the use of the stove. Performance is evaluated in terms of the time and quantity of fuel required for preparation of the standard meal, and in terms of the ease of use, safety and other factors of concern to potential users of the stove.
Discussions of the potential scope and value of a cookstove performance testing program incorporating these tests were held with research officers of the Ministry of Energy and Water Resources and with various other interested individuals and institutions. It was the general consensus that an exploratory testing program would be worthwhile and that the staff of A.T.- Zim Services (Pvt) Ltd. under the direction of Mr. W.J. Ascough (an agricultural engineer and a longtime and very active alternative technology enthusiast) would be best suited to carry out such a program and to pursue further testing in the future. Mr. Ascough was highly interested in the project and an agreement was reached that the Zimbabwe Energy Accounting Project would sponsor a basic series of tests on approximately fifteen stoves, to be conducted by A.T.- Zim Services, at the facilities of the Department of Land Management, University of Zimbabwe. The program was initiated in May and concluded in August, 1984. In actuality, seventeen hearths and stoves wereselected for testing. An effort was made to include representative examples of the broad range of cooking devices available in Zimbabwe, including appliances using coal, paraffin, gas and electricity as well as those using wood or charcoal. A particular effort was made to ensure inclusion of hearths and stoves presently in widespread use, of models currently promoted by government ministries and other institutions and of designs incorporating minor modifications expected to enhance the efficiency of common hearths and stoves. By these criteria good coverage of the variety of stoves available to most Zimbabweans was attained. However, a number of highly attractive commercial stoves were neglected, principally on the basis of costs, thought to be beyond the reach of the bulk of the population.
3. THE STOVES
Tp2e) stoves chosen for testing are briefly described be low Numbers at the left margin are stove identity numbers used for reference throughout the testing and analysis. FUEL : WOOD
(1) The three stone hearth: the traditional open fire used bya large number of rural households and by some of the urban population.
(2) The open grate - high: a welded iron frame holding three pots above an open fire, Manufactured in the informal sector, it has replaced the three stove hearth in many households, largely because it provides stable support for heating several pots simultaneously and eases adjustment of the fire.
(3) The open grate - low: the open grate described above, experimentally lowered closer to the fire to increase the efficiency of heat transfer.
(4) The shielded grate: the open grate described above, experimentally shielded with galvanized iron sheeting on three sides to reduce lateral draughts and to reflect radiant heat back to the cooking area.
(5) The shielded fire 1: an experimental sheet steel tube stove incorporating an air entry door and grate in the lower portion and rods to suspend a pot in the upper portion above the fire.
(6) Metal stove (Jairos Jiri): a sheet steel stove supporting one pot above a small insulated combustion chamber, manufactured by the Jairos Jiri Association.
(7) Brick stove (Seke): a brick stove holding three pots and incorporating a grate, dumper, chimney and hot plate, a demonstration stove of the Ministry of Energy and Water Resources.
(8) Lorena stove (McGarry): a lorena stove similar to the Hlekweni stove in interior construction except lacking the hot water tank, a demonstration stove at Silveira House.
(9) Brick stove (Hlekweni): a brick, lorena and cement stove holding three pots and incorporating a door, internal baffling, dumper, chimney and hot water tank, promoted by Hlekweni Training Center.
FUEL: CHARCOAL
(10) Metal stove (Sable): a pair of metal cylinders each supporting one pot and each incorporating an internal wire fuel basket and a jet for provision of air by means of an external pump, manufactured by Copperwares (Pvt.) Ltd. (16) Metal stove (Jiko): the traditional East African charcoal brazier, a short sheet steel bucket supporting one pot incorporating a grate and air door manufactured by the informal sector, East Africa.
FUEL: COAL
(11) ~rick/metalstove (Coalburn): a low brick stove supporting three pots on a flat cast iron top and incorporating a grate and chimney manufactured by Zim Cast (Pvt.) Ltd. for Wankie Colliery.
(12) Metal stove (Colray 100): a cast iron stove on legs, supporting one pot and incorporating a grate, door and chimney manufactured by TJilliam, Smith and Gourock (Pvt) Ltd.
FUEL: PARAFFIN
(13) Wick stove: a tin stove with adjustable cotton string wicks, supporting one pot, widely used in urban areas, manufactured by Tregers (Pvt.) Ltd.
(17) Pressure stove: a brass primus type stove supporting one pot and equipped with pump, valve and jet burner, imported from Primus, Sweden.
FUEL: GAS
(14) Ring: a valved burner attached to a gas cylinder, supporting one pot, manufactured by GEM (Pvt) Ltd. FUEL: ELECTRICITY
(15) Hot plate: a switchable electric resistance heater equipped with a metal plate supporting one pot, used in many urban households, manufactured by Tregers (Pvt) Ltd.
The schedu of tests was organized as follows: each hearth or stove was subjected to five or more repetitions of the standard water boiling test, in order to establish basic performance characteristic on a generally comparable basis and in order to ascertain the degree of variability in performance of each stove. Constant power test series were then performed on a subset of sixhearths and stoves in order to clarify the relationship between efficiency and output power. Solid fuel stoves were selected for the constant power tests, as it was judged that the efficiency/power relationship was defined adequate1y for other stoves by the standard water boiling test. The stoves chosen for the constant power tests, were the three stone hearth (in widespread use), the shielded grate (performance indistinguishable from the high grate in widespread use), the low grate (a simple modification of the high grate which nearly doubled efficiency in the standard water boiling test), the Hlekweni stove (the distinctly superior high mass stove in the standard water boiling test), the jiko (an inexpensive charcoal stove) and the Colray 100 (the less dangerous coal stove). Standard meal tests were performed on all hearths and stoves save the Jairos Jiri and the Sable stoves, which were judged too unstable to be desirable cooking stoves. The tests were carried out with great proficiency and accuracy by the A.T.- Zim Services staff. Inter-test variations were reduced to a minimum with the U e of highly standardized procedures, fuels and equipment ( 47 . Each task was regularly performed by the same individual and both cooking and fire management were in the charge of an experienced cook. Tests were conducted indoors to minimize environmental variations. All data was recorded on preprinted forms designed for the tests.
4. RESULTS AND DISCUSSION
The data acquired in these tests was obtained using the values for energy content of fuels and other physical parameters accepte S standard within the Zimbabwe Energy Accounting Project dt 47 . Figures calculated for the standard water boiling test included the energy and power output (for each stage of the test and for the test as a whole), the energy input and efficiency, (for each stage of the test for stoves with which it was possible to obtain an accurate measure of fuel consumption of the intermediate point, and for the test as a whole for all stoves), an alternative measure of efficiency which discounts energy lost in the evaporation of water from the pots, the ratio of high output power to low output power, and the time taken to bring a standard quantity of water to the boil. The mean and standard deviation of each figure was calculated for each stove. Figures calculated for the constant power tests included output power based on the duration of the test, input power based on the period of fuel feeding and on the duration of the test, and efficiency. Linear regressions of each of the power variables against efficiency were computed and the output power/efficiency regression was plotted. Figures calculated for the standard meal test included the time and energy input required for the cooking task, and the rank and proportion of the mean time and energy required by the stove. The large amount of. quantitative data obtained through the tests is not tabulated here. Instead, as a concession to the requirements for brevity, the significant findings are discussed below. Dramatic differences in the performance of the various hearths and stoveswere revealed in the results of the standard water boiling test. Performance differentials were most striking between devices using different fuels, but they were also highly significant among hearths and stoves using the same fuel. Most importantly, the test clearly identified deviceswhich were superior in two aspects of key concern to users, fuel efficiency and time required to bring a pot of water to the boil. These distinctions were unambiguous. The coefficient of variation of fuel efficiency figureswas generally no greater than 10% for the five test replications, and that for the time to boil figures was about 15%. In general, the fuel efficiency of the hearths and stoves tested rose with the quality of fuel employed, although the coal burning stoves were an exception to this relationship. The wood hearths and stoves showed test efficiencies of 6% - 22%, the charcoal stoves 17% & 21%, the coal stoves 5% & ll%,the paraffin stoves 46%, the gas ring 52% and the electric plate 63%. These figures can be useful in planners' estimation of the demand implications of fuel substitution. However, the relative efficiency of stoves using different fuels is of interest to users principally in relation to the relative cost of the fuels, and thus to the ultimate cost of use of the stoves. Since most Zimbabwean households have little choice but to use fuelwood, the variation in fuel efficiency of the woodburning hearths and stoves may be more salient. One striking observation was that the much maligned three stone hearth turned in quite a good performance, with a test fuel efficiency of 17%, one of the highest for the woodburning devices. The considerable discrepancy between this figure and the much lower efficiency usually ascribed to the three stone hearth highlights the importance of management and environment in determining performance. A great deal of the difference can probably be attributed to the care taken to maintain a wind free environment throughout the testing. An equally striking revelation was the relative inefficiency of the iron grate, now used in a majority of rural households and desired by many of those which still use the three stone hearth. The iron grate, although it holds two or more pots above a similar open fire, showed an efficiency of less than 10%, slightly more than one-half that of the three stone hearth. This substantial reduction in efficiency was due to the greater distance interposedbetween the fire and the pot by the grate, As it is ordinarily sold, the grate has a pot to ground clearance of about 18 cm. In an effort to check whether the efficiency of the three stone hearth could be recovered while preserving the advantages of the grate (its ability to hold several pots securely for simultaneous cooking) a series of tests were made of a grate lowered to a pot to ground clearance of 8 cm. This grate actually performed better than the three stone hearth, with an efficiency of almost 22%, the increase probably attributable to the heat captured by the secondary pot. Another experiment, testing whether the efficiency of the high grate could be improved by applying a sheet-metal shielding to three sides in order to prevent draughts and reflect radiant energy back toward the pots, met with less success. In fact the test efficiency of the shielded grate, 8%, was slightly less than that of the same grate unshielded. However, it must be remembered that these tests were conducted in still air. It is quite possible that shielding could preserve the efficiency of the grate in the presence of wind, which, even when slight, dramatically impairs the performance of open fires. The importance of the free height between the pot and fire was again revealed in the poor performance of the shielded fire, a tubular stove in which the pot is suspended in a chimney, about 26 cm above the base of the fire. This stove, which might be expected to gain considerable efficiency in heat transfer by forcing all of the hot gases from the fire through the narrow clearance around the sides of the pot, exhibited an efficiency of slightly less than 11%,probably because the pot was held so far above the fire. Another metal stove, the Jairos Jiri, is designed to maximize the efficiency of the combustion process, burning small bits of fuel in an insulated but well aerated combustion tube mounted directly beneath the pot. This stove performed quite well, with an efficiency of over 19%. The two remaining wood burning stoves tested are high mass stoves, built of brick, clay, sand and cement. They burn their fuel in a combustion chamber at the front of the stove, then pass the hot gases back through a passage beneath holes cut out to allow contact with the bottoms of several pots, to a chimney. Both stoves are equipped with flue dampers. One, the "Seke," is equipped with a grate for aeration of the fire. The other, the "Hlekweni," is equipped with a door at the entrance of the combustion chamber to regulate air flow to the fire and with pot holes and baffles in the smoke passage to increase heat transfer from the gas to the pots. Although generally similar in appearance, the two stoves performed very differently, The Seke turned in one of the poorest performances among the devices tested, displaying an efficiency of about 6%. The Hlekweni performed nearly twice as well, with an efficiency of 11%,and was slightly superior to the high grate. The charcoal and coal stoves tested alsovaried in efficiency. The difference in the charcoal stoves was not particularly marked; however, the Sable, with a shielded screen charcoal basket,was more efficient than the jiko, a simple metal brazier, the stoves showing efficiencies of 21% and 17%, respectively. The difference in performance of the coal stoveswas again substantial; the Colray 100 showing an efficiency of about 5%, while the Coalburn, which features a compact firebox and baffled smokepath to increase heat transfer to the cast iron top,showed an efficiency more than twice as great, almost 12%. The other similarly fuelled stoves tested, the paraffin wick and pressure stoves, performed with identical fuel efficiency, at 46%. It is important to note that these efficiency figures are not absolute characteristics of the hearths and stoves examined. As has been mentioned previously, they may vary a great deal under other management or environmental conditions. Perhaps more to the point, performance figures may also vary according to the type of task for which they are evaluated. In efficient performance of the tasks embodied in the standard water boiling test (attaining a vigorous boil at high power, sustaining it for fifteen minutes, then maintaining a simmer for an hour with minimal fuel consumption) considerable weight is given to low power performance. An examination of the relationship between low power and high power efficiencies reveals that low power efficiencywas substantially greater than high power efficiency for the solid fuel stoves, whereas the relationship was reversed for the liquid, gas and electrically fuel led devices. This unlikely inconsistency points up an anomaly of the measure of efficiency used here. Energy output, the denominator of the measure of efficiency, includes, as computed here, the net energy used to heat pots and water and to evaporate water. It does not count energy transferred to the pots but then lost to the environment (for two reasons: because it is difficult to measure, and because in the ideal configuration of pot and stove no heat would be so lost). The exclusion of the heat lost from the pot to the environment from the calculated energy output makes little difference at medium to high rates of heat transfer. However, at very low power outputs, it has the unfortunate effect of misrepresenting efficiency downwards. Clearly the most efficient way to maintain a simmer is to burn only enough fuel to transfer to the pot energy just sufficient to compensate for losses to the environment. Any energy transferred in excess of this amount is, in terms of the ultimate product (water, kept at boiling temperature for a given period), wasted in evaporation, with the further effect of discounting the energy already embodied in heating and simmering the water vaporized. Thus the truly efficient simmering process involves a minimum energy output, approaching 0 in the limit. As energy output figures as the denominator in calculation of efficiency, it follows that the calculated efficiency also approaches 0 in the limit as the real efficiency of the process increases. The effect of this anomaly of calculation is to discount the low power efficiency of the liquid, gas and electrically fuelled devices, which are in fact most efficient because their actual energy output can be adjusted to a low level, just in excess of that required to maintain the simmer. A moreusefulapproachto the evaluation of low power efficiency can be had in the comparison of the energy required for performance of the task, rather than in terms of net energy transfer. A look at the figures for energy input in the low power stage of the test confirms the low fuel requirements of the non-solid fuelled stoves. Another task- based comparison can be found in an alternate calculation of efficiency, in which energy output for the test is taken as the energy theoretically required to bring the pots and the final volume of water to their final temperature. In the standard water boiling test this alternative efficiency is very much an inverse function of low power output. In a comparison on the basis of the alternative efficiency, the low grate was again the superior woodburning device, with an efficiency of 9.6%, nearly twice that of the high grate (5.2%), and three times greater than the efficiencies of the three stone fire (3.2%) and the shielded grate (3.0%), and nine times greater than that of the shielded fire (1.1%).The Jairos Jiri made a relatively poor showing, at 2.3%, and the Seke and Xlekweni performed moderately well, at 3.5% and 4.4%, respectively. The relative efficiency of the charcoal stoves was inverted, with the Sable and jiko exhibiting alternate efficiencies of 2.2% and 5.2%, respectively, while the relative efficiency of the coal stoves was preserved, with figures of 5.6% for the Coalburn and 1.6% for the Colray 100. The alternative efficiency of the paraffin stoves diverged somewhat, the pressure stove achieving 16.9%, while the wick stove dropped to 12.5%. The gas ring showed a figure of 20.9%, and the electric plate led the ranking, at 29.1%. Again, these figures are meaningful to the extent that the standard water boiling test simulates the actual application of the stoves. Users of stoves are often concerned more about time than about fuel. The time required to bring a pot of water to the boil is generally a function of high power output, though the relation is somewhat confused by inclusion of energy transfer to secondary pots in the power output calculations. The time to boil varied tremendously between stoves, from a low of 8 minutes for the shielded fire to a high of 58 minutes for the Seke stove. Most of the wood burning hearths and grates showed roughly similar times to boil; 15 minutes for the three stone hearth, a slight reduction to 14 minutes for the low grate, and a slight increases to 17 minutes for the shielded grate, 18 minutes for the high grate, 19 minutes for the Jairos Jiri. The Hlekweni high mass stove imposed only a moderate increase in time to boil, to 21 minutes, but the Seke required all of 58 minutes. The charcoal stoves were fairly efficient in time, with figures of 24 minutes for the jiko and 26 minutes for the Sable, at least in comparison to the coal stoves, at 39 minutes for the Coalburn and 54 minutes for the Colray 100. The paraffin stoves were again effectively identical, the wick stove bringing the pot to the boil in 34 minutes, while the pressure stove took 32 minutes. The high power capacities of the gas ring and electric plate brought the time required by these stoves down to 29 minutes and 27 minutes, respectively. The above discussions have shown that the capacity to operate at low power output is desirable for fuel efficiency and that the capacity to operate at high power output is desirable for time efficiency. The ratio of high power to low power capacities provides a crude measure of the ability of a hearth or stove to meet both of these desiderata, although the value of the power ratio is somewhat vitiated by the fact that low power output does not necessarily correspond to efficient operation at low power (witness the Seke). However, extreme values can be indicative. Values approaching 1, as seen for the Jairos Jiri and the Sable stoves, indicate little capacity for adjustment to the varying power requirements of different tasks, an indication confirmed by the unremarkable performance of these stoves on the alternative efficiency and time to boil measures. On the other hand, high values, as seen for the gas ring and the electric plate, indicate great capacity for adjustment to specific applications, as confirmed by the excellent performance of these stoves. The relationship between efficiency and output power was explored more fully in the constant power tests. The results of these tests showed that the relationship varied greatly among the stoves tested, with the efficiency of some stoves substantially contingent upon the power at which they were operated and that of others quite independent of power. The three stone hearth showed aclear reduction of efficiency with increasing output power (slope of -.l9 and correlation of -.65). Conversely, the shielded grate and Hlekweni stove showed a strong positive relation between the two factors (slopes of .l2 and .l4 and correlations of .96 and .80, respectively). The jiko showed a weaker positive relation (slope of .l0 and correlation of .29), while efficiency appeared to be completely independent of output power for the low grate and the Colray 100 (slopes of -.01 and .O1 and correlations of -.30 and .l8 respectively). LCio clear generalization is possible, but the potential significance of the relationship is highlighted. The graphic presentation of the constant power test results (Fig VI-1) provides an easily assimilated display of the comparative efficiencies and power ranges of the stoves. Finally, the standard meal test corroborated the general implications of the standard water boiling test, as the various stoves demonstrated a ranking of fuel consumption roughly approximating the order of figures for efficiency obtained in the standard water boiling test. The value of low output power capacity was again confirmed, as was the value of high output power capacity for the time efficiency of one-pot hearths and stoves. /16 Metal Charcoal Stove (llko) / 1 Three Stone Hearth \ \-Grate- Low
/9 Brlck Wood Stove (~lekwenl)
4 Sh~eldedGrate - Hlgh
O O4 12 //MetalCoal Stove (Colray 100)
0 00 1 0 0 0 2 0 4 0 6 0 8 l0 POWER OUTPUT (KH)
FIGURE VI-1 CONSTANT POWER TESTS: STOVE EFFICIENCY VERSUS~R~T --p The standard meal test made a notable contribution in -1arifying the importance to the time efficiency of the 2ooking process of the capacitytohold more than one pot for jimultaneous cooking. The fact that cooking processes are lot simple functions of net energy transfer, but involve a series of operations including low power maintenance of zooking temperatures at low power for protracted periods as iell as short bursts of high power, was emphasized.
5 . CONCLUSIONS The preliminary data developed in the cookstove )erformance testing program have revealed a number of points -elevant to projections of the implications of stove ;ubstitution, Among the most notable of these points are the following, derived from the standard water boiling test:
1) The performance of most hearths and stoves, under reasonably well controlled conditions, is remarkably consistent. The coefficient of variation of efficiency in the standard test is generally less than ten percent.
2) Stoves fuelled by paraffin, gas and electricity perform at efficiencies at least two to three times greater than those of the solid fueled devices. (3) Great differentials in performance are found among the solid fuelled hearths and stoves, even between devices burning the same fuel.
(4) The three stone hearth can attain a surprisingly high degree of efficiency in heat transfer, nearly as high as that of any other solid fuelled device.
(5) While the use of the open grate severely compromises the efficiency of the open fire, it confers a considerable improvement in time efficiency in cooking by holding more than one pot above the fire.
(6) The fuel efficiency of the three stone hearth can, however, be recovered while the advantages of the open grate are preserved by simply lowering the grate to place the pots closer to the fire.
(7) Shielding the grate with sheet-metal sides makes no contribution to its efficiency in still air, although shielding may be quite advantageous in the presence of wind.
(8) Nor is a one pot stove with cylindrical shielding carried up to create a chimney around the pot significantly superior to the high grate, so long as the distance between the pot and the fire is undiminished.
(9) The efficiency of a very small shielded fire placed directly beneath the pot is no greater than that of any other fire placed close to the pot.
(10) The advantages of the brick and clay high mass stoves are not to be found in enhanced fuel efficiency, a1though one of them, the Hlekweni, performs no worse than the ordinary high grate. The other high mass stove tested performs very badly in terms of both fuel and time ef ficiencies.
(11) The charcoal stoves tested are not superior in fuel or time efficiency to the best of the wood stoves, although they operate at nearly twice the fuel efficiency of the ordinary high grate.
(12) The coal stoves tested perform poorly in terms of fuel efficiency.
It is tempting to make inferences on stove cost and choice from the results of these tests. It would be risky to carry these inferences very far, however. The tests reported here have looked only at efficiency in cooking (mostly simulated cooking, in fact) under high1y control led conditions. Hearths and stoves are used, in reality, for many purposes other than cooking, and under highly variable conditions. Fuel and time efficiency are only two of many characteristics affecting use and choice. Conclusive evaluation of the comparative efficiency and desirability of various stoves will require evaluation of the qualitative data obtained in these tests and field observation of the hearths and stoves in actual use. Despite the caveat above, it would appear from the results of the preliminary tests reported here that:
(1) Cooks who choose the open grate over the three stone hearth are sacrificing fuel efficiency in favor of convenience and time efficiency.
(2) Cooks who use ordinary grates could maintain the advantages ofthe grateand regain ahighdegree of fuel efficiency at no cost, by simply lowering the grate.
(3) No other wood burning cooking device among those tested is superior to the low grate, in terms of fuel and time efficiency.
(4) The Hlekweni stove is the clearly superior choice for wood burning households which are willing to accept moderate fuel efficiency in return for the cleanliness and safety advantages of a closed high mass stove.
(5) The potential value of the charcoal stoves tested is not to be found in fuel efficiency, which is no greater than can be attained with inexpensive wood burning devices.
(6) Similarly, the potential value of the coal stoves tested is not to be found in their inferior fuel and time efficiencies.
(7) Paraffin, gas and electric stoves are, in terms of fuel efficiency, the stoves of choice for households with access to these fuels.
FOOTNOTES
(1) By J. Chadzingwa of the Ministry for Industry and Energy Development, by J. Ascough of the Department of Land Management, University of Zimbabwe, by Father McGarry of Silveira House, by J. Gill of the Open University, U.K., and possibly by others.
(2) For full descriptions and dimensioned drawings, see Harris, T., W.J. Ascough, K. Donnelly, g cl, 1984, "Test Data and Preliminary Calculations, Performance Testing Project Domestic Cookstoves." Zimbabwe Energy Accounting Project. (3) Excepting the McGarry, which was judged, upon inspection, to be so similar to the Hlekweni as not to warrant separate testing.
(4) Harris, 1984b, op. cit., fuels and equipment were as follows:
STOVES
All stoves tested were standard commercial models, except for the Seke and the Coalburn, provided by C. Murove of the Ministry of Energy and Water Resources and J. Chirodza, mason contractor to the M.E.M.R. and the Hlekweni, provided by K. Pamaand and M. Moyo of Hlekweni Training Center.
FUELS IJood - gum (Eucalyptus grandis) pole offcuts, supplied air dry in lengths of 15 - 35 cm, diameters of 8 - 13 cm (Lewis Lumber (Pvt) Ltd., Harare)
Charcoal - black wattle (Acacia------mearnsii)------charcoals, supplied air dry in pieces of 3 - 6 cm diameter. (Geo. Elcombe (Pvt) Ltd. Harare) Coal - Hwange bituminous washed cobbles, 4 - 6 cm diameter, (Geo. Elcombe (Pvt) Ltd., Harare) Paraffin - illumination grade (Mobil Oil Zimbabwe (Pvt) Ltd., Harare) L.P. Gas - (Mobil Oil Zimbabwe (Pvt) Ltd., Harare) Electricity - 225V, 50Hz service
EQUIPMENT Balance - Mettler PC 8000 electronic balance with automatic tare, range to 10 Kg in increments of 0.1 g. Thermometer - Zeal glass/mercury thermometers, range from - 10°c to 110~~in increments of 1°c.
Miscellaneous tongs, pans, hot pads, clocks, etc Environment - Tests were conducted in a small (5 meter square) building at the University of Zimbabwe. The building was equipped with windows and a large tilt-up door which could be left open to allow smoke to escape. The structure provided effective shielding from light winds. On breezy days openings were held to the minimum necessary for ventilation and hardboard baffles were set in place to assure adequate screening of wind.
REFERENCES Harris, T., 1984a "Program for Performance Testing Project - Domestic Cookstoves", Zimbabwe Energy Accounting Project. Harris, T., 1984b "Methodologies for Performance Tests of Domestic Hearths and Cookstoves", Zimbabwe Energy Accounting Project. V11. FUELWOOD CONSUMPTION AND SUPPLY PATTERNS. TREE-PLANTING PRACTICES, AND FARM FORESTRY IN RURAL ZIMBABWE
Yemi Katerere
1. INTRODUCTION
This paper examines two different sides of the fuelwood issue in rural Zimbabwe. The paper is split into two parts; the first part examines the patterns of fuelwood consumption and supply in rural Zimbabwe, highlighting the problems and potential solutions surrounding rural Zimbabwe's most important fuel source. The second part of the paper discusses, in greater detail, one of the possible solutions to the fuelwood shortage - tree planting and farm forestry.
PART I. FUELWOOD CONSUMPTION PATTERNS AND SUPPLY IN RURAL Z I MBABWE
2. BACKGROUND
This part of the paper discusses the results of the fuelwood modules of the Rural Energy Survey. The survey was an attempt to document the fuelwood supply and consumption pattern at a micro level. This section also focuses on the supply and demand of fuelwood at the provincial and national levels. The fuelwood survey is part of the Rural Energy Survey which was carried out to gather basic information on rural energy needs. The survey was designed to provide information on woodfuel scarcity, cooking appliances, methods of gathering wood, and distance travelled for communal area farmers, resettled farmers and small scale communal (SCCF) farmers. To examine clearly the status of energy supply and demand at the household level, the survey used two types of disaggregations. The first stratified households according to agricultural production systems: communal, smal l scale commercial and resettlement. This was necessary since each system has its own unique conditions and constraints affecting energy supply and demand. The second level of disaggregation stratified households according to natural regions. The natural regions influence potential land use and therefore rural energy development plans. The survey consists of a large core questionnaire documenting basic household information including fuel- related issues. The core is complemented by seven extension sections one of which is the fuelwood section. The overall structure of the survey is described in detail elsewhere in this volume. 3. FUEL TYPES, APPLIANCES AND PREFERRED FUELWOOD SPECIES
All households in all three production systems use wood as the main fuel for cooking. Paraffin is used as a lighting fuel by 100 percent of the small scale farm households, 80 percent of the resettlement, and 36 percent of the communal households. Crop residues are used as a minor cooking fuel by 58 and 20 percent of the communal and resettlement households, respectively. The use of crop residues is seasonal and was recorded only in the Chegutu District. About 5 percent of the households in the communal areas use dung as a minor cooking fuel. The use of dung was recorded in Gwanda and Chegutu Districts. The diversion of animal and crop residues from agricultural to fuel use results in the decline of both crop and livestock production. Although still at a fairly low level, the use of crop and animal residues for fuel can be expected to increase as fuelwood supplies decline. The portable grate is the most widely used cooking appliance in the rural areas followed by the three stone hearth and the fixed grate. The mud/brick closed stove and the closed metal stove with oven are used by a negligible percentage of the rural population. The parts of the tree usually used as fuel preference are summarized in Table VII-1.
Table VII-1 TREE-PART USE AS FUEL --p
% of Households Part of Tree ...... Used as Fuel Communal Small-scale Resettled
Branches 60 67 Trunk and Branches 13 0 Branches and Twigs 10 33 A1l including Roots 17 0
Most households prefer using branches and twigs for fuelwood. The trunk and branches are more commonly used by households in the communal and resettlement areas. It is only in the communal areas that households are using roots as fuel. This is an indication that fuelwood is more difficult to find in the communal areas than in other rural areas. The use of eucalypts as fuelwood is not widespread. Only 10 percent of the households in each of the small scale farms and resettlement areas use it. In the communal areas, 20 percent of the households use eucalypts. Although there is a surplus of preferred fuelwood species in resettlement areas, eucalypts are being used by some. This is probably due to the fact that these schemes are established on former large scale commercial farms on which eucalyptus woodlots are fairly common. Species commonly used for fuelwood are listed in order of preference by ecological zone. Unfortunately, the list does not provide an indication of availability.
(1) Ecological Zone I Brachystegia speciformis (musasa or muura)
(2) Ecological zone I1 Brachystegia boehmii (mupfuti) Julbernardia globiflora (munhondo) Brachystegia speciformis (musasa)
(3) Ecological zone I11 Combretum molle (mubonda or mupembere) Julbernardia globiflora (munhondo) Brachystegia speciformis (musasa) Brachystegia glaucescens (4) Ecological zone IV Combretum molle (mubonda) Parinaria curatellifolia (muchakata) Colophospermum mopane (mupani) Julbernardia- globiflora (munhondo) Other species that have been cited as good for firewood are listed below: Piliostigma thonningii (mutukutu) Dichrostachys cenerea (mupangara) Terminalia sericea (mukonono) Ziziphus mucronata (muchecheni) The most commonly cited qualities of the fuelwood of preferred species are: wood is easy to light; the coals last for a long time; the wood does not spark; and the wood is easy to obtain.
4. WOOD STORAGE No information was collected on wood storage by small scale farm households. In the communal and resettlement areas there is very little difference between households storing wood during the wet season and those doing so in the dry season. At least 56 percent of the communal households store wood throughout the year compared to only seven percent in the resettlement areas. Most households store wood to reduce labor conflicts and to "free" members of the household to perform other tasks. 5. Hob? FUEL IS OBTAINED
On the small scale commercial farms and the resettlement areas, all wood is gathered. In the communal areas, 95 percent of the households collect their own wood while five percent either pay someone to collect and/or transport. There is presently an abundant supply of wood on resettlement schemes as new land is being cleared for agriculture. Reconnaissance trips into communal and resettled areas established that communal area residents are collecting substantial quantities of wood from the resettlement schemes. Two methods of securing wood were identified. In the first, the communal area residents assist the resettlement farmer with land clearing and are allowed to take the cut wood as a form of payment. Alternatively, the resettlement farmer clears his own land and sells the wood to communal farmers at $16.00 per tractor load. The small scale commercial farmers, unlike their counterparts, have tenurial rights. The tenurial rights that these farmers enjoy gives them some control over (and the incentivesto manage) their wood resources in a sustainable manner. In the communal lands, on the other hand, wood is regarded as a common resource and consequently its exploitation tends to be indiscriminate. Non-communal area residents also collect from these lands. The result is that fuelwood is becoming increasingly difficult to find for many communal area households. As a result, more time is expended in collecting wood. The cornmodification of wood in Zimbabwe's rural areas is likely to develop in response to the complex process of supply shortages, socio-economic factors, and physical changes if no efforts to ease the fuelwood crisis are taken. The increasing distance to the source, or an increase in the labor requirements of obtaining fuel can all bring about commodification. L7omen and children collect fuelwood in over 86 percent of the households. Men collect fuelwood when women are ill or too busy and when wood collecting requires the use of an axe or scotchcart.
6. SOURCE OF FUELWOOD
As mentioned earlier, wood resources on communal lands are exploited by everyone including urban vendors. Although no estimates are available, some smal l-scale farm households will collect fuelwood from the communal areas if the distance is not great. Most of the households on resettlement schemes (90 percent) collect wood from their own lands and those held communal ly. The remaining households collect from government plantations. In the communal areas, 82 percent of the households collect wood from the communal lands while the rest collect from private farms or government plantations. Only 10 percent of the households on small scale commercial farms and resettlement schemes experience difficulty in collecting wood. On communal lands, 68 percent of the households have difficulties obtaining fuelwood. Table VII-2 summarizes the distances travelled by households to collect fuel. For both small scale and resettlement areas, 99 percent of the households travel 4 km or less compared to 84 percent for communal areas. In the latter case, 16 percent of the households travel distances greater than four km. In the case of resettled and small scale farming areas, only one percent of the households in each case travel distances greater than 4 km.
Table VII-2 DISTANCE TO FUEL SOURCE --P
% Of Households Distance ...... To Fuel Communal Small Scale Farm Resettlement ...... < l km 22 78 38 1<4km 6 2 21 6 1 4 < 10 km 15 1 1 10 < 20 km 1 0 0
7. TRANSPORT In the communal and resettlement areas wood is carried on the heads of women, in over 80 percent of the households (see Table VII-3). The scotchcart is the next common form of transportation used in both these areas. Greater use is made of the scotchcart and motorized vehicle by small scale farm households. Only 54 percent of the households have wood carried on the head by women in this area.
Table VII-3 FORM-- OF TRANSPORT ...... % Of Households Type of Transport Communal Small Scale Resettlement ...... Head 83 54 96 Scotchcart 16 23 3 Sledge 1 0 1 Tractor/truck 0 23 0
The paper thus far has provided a synopsis of fuelwood trends in Zimbabwe's rural areas based on survey data. The survey established some interesting patterns: (1) Communal areas are the worst hit by the fuelwood shortage.
(2) The rural dwellers rely almost exclusively on fuelwood as their primary energy source.
(3) Fuelwood is seldom purchased except in localized pockets of serious wood shortages.
(4) Walking is the predominant method of reaching collecting areas which are usually located some distance from the area of need.
8. DEMAND AND SUPPLY
The second half of this part of the paper discusses the supply and demand of fuelwood at the national and provincial levels. The discussion highlights the fuelwood problem in Zimbabwe, particularly for the rural people. On a national level, Zimbabwe has a surplus of wood. However, at a micro level it becomes evident that the fuelwood problem is localized, and that the communal areas are the worst hit. Half of the communal area households have problems finding fuelwood. The extremely localized nature of the fuelwood shortages is masked by viewing the problem at the provincial and national levels. The demand for and supply of wood was analyzed in a study in Volume 8. of this series, using the LEAP model (Energy Sytems Research Groups 1983). The national fuelwood supply and demand relationships are presented in Table VII-4 and broken down by Province in Table VII-5. At a national level, the first shortfall occurs in 1997. Although no shortfall occurs between 1982 and 1992 a significant cutting of wood stocks does take place, and certain areas will experience supply shortfalls.
Table VII-4 NATIONAL FUELWOOD SUPPLY AND DEMAND RELATIONS HIPS^ 'm-ionTons ) ...... 1982 1987 1992 1997 2002 Demand 8.33 9.47 10.63 12.14 13.69 Yields 7.13 6.81 5.63 4.92 4.67 Stocks 1.20 2.66 3.77 1.57 3.01 ...... Shortfall 0 .O 0.0 1.22 5.65 6.35 Total Stocks 666.29 654.49 633.32 603.19 605.87
The patternemerging from Table VII-4 and VII-5 warrants some discussion. In Manicaland, Mashonaland East, and Masvingo provinces, the process of cutting wood stocks begins in the base year. In Midlands, it begins in 1987. All four provinces have a population of at least one million people. The national shortfall in wood supply occurs in 1997 which is when provincial shortfalls occur in Manicaland, Mashonaland East, and Masvingo. In the base year, 17 percent of Manicaland's fuelwood demand is supplied from existing stocks. For Mashonaland East and Masvingo, it is 28 and 46 percent, respectively. There is currently insufficient fuelwood available on a sustainable yield basis to meet all the wood demand in these three provinces. The cutting of woodstocks is the beginning of a process which is likely to lead to a future fuelwood shortage and accompanying serious environmental decline.
Table VII-5 PROVINCIAL FUELWOOD SUPPLY AN0 DEMAND (Million Tons) ...... Manica Mashona Mashona Mashona Matabele Matabele Mid Masvingo Land Land Land Land Land Land Lands Central East West North South ...... Demand 1982 1.39 0.76 0.93 1.02 0.60 0.70 1.26 1.35 1992 1.86 0.98 1.18 1.29 0.74 0.88 1.59 1.77 2002 2.31 1.27 1.58 1.68 0.99 1.15 2.07 2.30 ...... Shortfall 1982 1992 1982 None 2002 None 1987 1982
1982 Yields 1.15 0.76 0.67 1.02 0.60 0.70 1.26 0.73 Stocks 0.23 0.00 0.26 0.00 0.00 0.00 0.00 0.62 1992 Yields 0.46 0.82 0.13 1.29 0.74 0.88 1.24 0.15 Stocks 1.40 0.16 1.05 0.00 0.00 0.00 0.35 1.62 2002 Yields 0.00 0.47 0.00 1.68 0.91 1.15 0.47 0.00 Stocks 0.00 0.81 0.00 0.00 0.00 0.00 1.60 0.00
Tot. Supply 1982 1.39 0.76 0.93 1.02 0.60 0.70 1.26 1.35 1992 1.86 0.98 1.18 1.29 0.74 0.88 1.59 1.77 2002 0.00 1.27 0.00 1.68 0.99 1.15 2.07 0.00
Pop. Density 31.5 20.6 60.0 14.2 12.0 7.8 18.5 23.3 (1982)
9. WOOD RESOURCE ADEQUACY
As has previously been described, wood resources for meeting fuelwood, paper and pulp, rural construction wood and industrial wood are derived from yields and stocks from the various non-agricultural land-use categories. Supply and demand relationships determine the amounts and types of wood consumed. The accessibility of wood resources, which depends on geographic, technological, socio-economic and ecological factors, also influences supply patterns. In areas where demand exceeds annual production of woody biomass, a net depletion of the standing stocks will occur in order to meet demand. This process is already being experienced at a provincial level in Zimbabwe. At present, virtually no animal waste and very little crop residue is being used as a source of rural energy. Presently, about 14 percent (1.11 million tons) of Zimbabwe's wood resource demand is being met by a net reduction in standing stocks. This figure is projected to increase to 26 percent in 1987. The future adequacy of wood resources will depend on the amount of accessible wood and the rate at which standing stocks are depleted. As can be expected, an accelerated rate of stock depletion is likely to contribute to serious soil fertility and other environmental problems. The LEAP model used to analyze the estimates in tables VII-4 and VII-5, does not attempt to identify areas of unsatisfied demand at the microlevel. Particularly in Manicaland, Mashonaland East and Masvingo provinces, localized areas with insufficient supplies for current demand levels exist. At the national and provincial levels, it appears that wood demands are currently being met. The Rural Energy Survey identified several communal areas completely denuded of vegetative cover in Mashonaland East and Mavingo Provinces More serious problems, however, begin to emerge on a national basis by 1992 when 46 percent of the demand for fuelwood is met through the cutting of standing stocks. By 1997, demand exceeds supplies from both yields and stocks. The gradual depletion of standing stocks means that yields are further decreased, causing the continued and accelerated depletion of the remaining stocks. This relationship is summarized in Figure VII-1. Table VII-4 shows that, on a national basis, a wood problem already exists with respect to net stock depletion. Stock depletion is likely to continue until checked by the constraints of accessibility. When accessible stocks become depleted, local populations are left without means of obtaining their fuelwood requirements. Total standing stocks are expected to decline by about nine percent between 1982- 2002. Although the decline may appear small, the depletion of accessible stocks is much more dramatic. This is evident from the rapid increase in supplies from stocks after 1982, followed by a decline in 1997. Supplies from stocks increase again in 2002, providing 35 percent of the supplies or 19 percent of the fuelwood demand. In this year, the demand shortfall is 46 percent of total demand or 6.19 million tons (see Figure VII-1).
Mashonaland West and Matebeleland South do not experience any stock cutting at all. Mashonaland west is the third largest province in Zimbabwe and includes parts of the Lake Kariba area which has a low population density and numerous parks and reserves. Matebeleland South is the second largest province and has the lowest population density. As a result of these low population densities, both provinces have adequate accessible supplies of wood resources to meet demand. Mashonaland Central, Matebeleland North, and Midlands do not experience any shortfalls during the 1982-2002 period. These provinces have rather low population densities on a province-wide basis. However, in order for demand to be met, net removal of standing stocks begins in 1992 in Mashonaland Central, in 2002 in Matebeleland North, and in 1987 in Midlands. By 2002, more than 77 percent of the wood resources supplied to Midlands will be derived from standing stocks. For Matebeleland North, 10 percent of the demand for wood will be met through stock cutting. For Mashonaland Central, this figure will be 64 percent.
Table VII-6 FUELIJOOD SUPPLYAND DEMAND FOR MANICALAND, MASHONALANDASTAND MASVINGO PROVINCES ( ~illionTonsT
Manicaland Mashonaland Masvingo East ...... Demand 1992 ...... 2002 1992 Yields 0.46 0.13 0.15 Stocks 1.40 1.05 1.62 2002 Yields 0.00 0 .OO 0 .OO Stocks 0.00 0 .OO 0.00 ...... Shortfall 1997 1997 1997 Depletion 1982 1982 1982
Shortfall as % of Demand 1997 100 100 100 2002 100 100 100
Contribution to National Shortfall (Million Tons) 1997 2.08 1.38 2.03 2002 2.31 1.58 2.30 ...... Serious problems of wood shortages can be expected in the densely populated provinces of Manicaland, Mashonaland East and Masvingo. Supply shortfalls in these three provinces will begin in 1997. The provincial impacts of these three provinces are summarized in Table VII-6. The rural sector which depends almost exclusively on wood energy cannot endure the shortfalls in resource supplies that are expected in 1997 and 2002. More than 45 percent of the national fuelwood demand will go unmet in 1997 and 2002 unless some major policy affecting the current supply trends is undertaken. In the absence of adequate fuelwood supplies, rural energy consumption patterns will change. More people will be forced to use dung and crop residue for cooking. Removal of animal waste and crop residues from the soil nutrient cycle could reduce soil fertility and consequently agricultural productivity. As wood resources become more scarce, the commodification of fuelwood in the rural sector can be expected to develop more completely. As local supplies of fuelwood become depleted, the household labor time allocation will have to be adjusted to allow for increased fuelwood searching time with decreasing prospects of finding adequate supplies. Such a burden on the labor time budget could have the consequence of keeping family sizes larger and/or increased rural to urban migration. The combined effects of diminished food production, lack of cooked food or decreased cooking times could decrease nutritional and health levels. On a national level, this could seriously hamper Government plans for overall economic development. The importance of fuelwood as an energy source particularly in the rural areas must be given greater attention. Accordingly, the rural development strategy must place a high priority on the provision of adequate fuelwood supplies or alternative energy sources to the rural areas. (Republic of Zimbabwe 1982). The major strategy options with the greatest promise for meeting Zimbabwe's fuelwood needs should be reviewed. End- use and conversion technology efficiency improvements are not, by themselves, sufficient to make substantial reductions in the projected potential biomass shortfalls. This means that major efforts to enhance supply will have to be undertaken. The formulation of long-term strategy policies to deal with the wood supply problem is crucial. The practical possibilities of meeting the national fuelwood requirements should take place within an overall energy policy framework whichencompasses technical, institutional, economic, and cultural factors. To overcome any constraints that these factors might cause, research and thoughtful planning are needed in a wide variety of areas - alternative fuels, better systems of wood production and distribution, more efficient use of wood fuels, and the development of new wood-production systems. For Zimbabwe, the £01 lowing are possible options for wood supply enhancement (Current tree-planting practices in rural Zimbabwe are discussed in the next section.):
(1) Farm Forestry
(2) Improved management of natural forests
(3) Fuelwood plantations
(4) Village woodlots.
FARM FORESTRY
This is an important option and is discussed in great detail in the second half of the paper.
MANAGEMENT OF NATURAL FORESTS
The introduction of communal area management practices for existing natural forests might be a solution to the uncontrolled exploitation of the "free" wood resources in these areas. This approach provides an opportunity for expanding the wood resource base in Zimbabwe by transforming exploitation into sustainable management. It has the advantage of using an already existing resource base. This approach will involve the community to whom the benefits of sound resource management will accrue. By so doing, the community has a direct stake in managing the wood resources. When compared with costly plantations, natural forests offer the potential for greater return on investment in fuelwood production systems. Natural forests that are currently exploited for commercial timber can be managed in such a way that waste is reduced. In some cases, harvesting wastes could be transported from these areas to centers of population for use as fuel. However, the limitation of this approach lies in the fact that it is only economically feasible to transport fuelwood over relatively short distances. Hence, only managed natural forests located near population centers could serve as sources of fuelwood. The management of natural forests is not considered as a priority area when compared with other pressing needs such as food production. Considerable staff and financial resources would be required for natural forest management.
FUEL'IIOOD PLANTATIONS
These are large scale efforts to plant blocks of trees with the objectives of generating fuelwood and poles as well. (Peri-urban plantations near urban centers where fuelwood demand is high can also be considered as fuelwood plantations) This supply enhancement option has both positive and negative qualities. There are the advantages that management and silvicultural techniques are already established. The projects are usual l y concentrated near the market place, generating employment, and acting as demonstrations that something can be done to ameliorate the fuelwood deficit. The cost benefit ratio is the most crucial of the disadvantages. Fuelwood harvested from these plantations will have to compete with fuelwood being harvested free. In addition, limited land availability can affect plantation establishment. Also, there are high administrative costs associated with the projects so that the cost of establishing enough plantations to meet fuelwood requirements would likely be too costly for any government or donor agency.
VILLAGE liOODLOTS
These are usually smaller-scale plantations established on common land and where, theoretically, there is labor sharing. Once again, the advantages must be careful l y balanced against the disadvantages. To consider the advantages: this approach responds to the need to get rural people involved; it provides demonstration and introduces knowledge into the areas; and woodlots spread throughout the rural landscape can contribute to an improved environment. On the other hand, there is the problem of careful selection of species, and if the outcome of the project is negative, then the rural people will not be receptive to future reforestation efforts. Once again, if the cost/benefit ratio is not positive, people might prefer collecting free wood to investing their labor in community woodlots. Communal land for planting might be hard to find and trees wouldbe seenas competing for land with other farming activities. Finally, the question of whether those who contributed to the establishment of the woodlots will eventually receive the benefits remains unanswered.
PART 11, TREE PLANTING PRACTICES AND THE POTENTIAL ROLE OF FARM FORESTRY IN ZIMBABbJE'S RURAL AREAS
10. INTRODUCTION
There has been increasing recognition that trees are an essential component of the environment. Trees can play an important role in helping to increase agricultural productivity, to improve rural welfare, to alleviate the negative impact of the energy crisis (as discussed in part I) and to preserve the environment. Trees are better able to withstand severe moisture stresses than most agricultural crops. In drier zones, tree growing can provide a source of income in times of crop failure. It is also important to know why rural people plant trees. Men commonly plant trees for construction wood or for additional money in the future. Since the task of collecting fuelwood is the responsibility of women, men rarely plant trees for fuelwood. However, as wood becomes increasingly difficult to gather, the attitudes of men towards planting trees for fuelwood are likely to change. A Tree Planting Survey was carried out as part of the Rural Energy Survey. The major objective of this study was to establish whether or not there was tree planting in rural Zimbabwe and if so, the level of such tree planting. More specifically the study sought to establish the following:
(1) Types of trees planted
(2) Source of seedlings
(3) Reasons for planting trees
(4) On whose initiative trees are being planted.
Here, we first summarize the results of the tree planting study, and proceed to examine the potential role of farm forestry in the rural areas and how the findings of the tree planting study can facilitate its implementation.
11. RESULTS OF THE TREE-PLANTING SURVEY
Seventy percent of the households interviewed indicated that they had planted trees. The rest either did not plant or did not respond to the question. Tree planting is carried out by all members of the household although the male members appear to the most active in this activity. Table VII-7 summarizes the type and frequency of trees planted by rural households.
Table VII-7 TYPE AND FREQUENCY OF TREES PLANTEFTNCOMMUNAL-- AREAS- ...... Type of Trees Frequency of Planting Percentage
Fruit Eucalypts Jacaranda Pine Indigenous ...... Total 116 100 ......
The most frequently planted trees are fruit (67%) followed by eucalypts (31%)and Jacaranda (2%). The planting of jacaranda trees might increase in the drier zones as they appear to be more termite resistant than eucalypts and the foliage is fed to cattle and goats. In some communal areas jacaranda also provides poles. Less than one percent of the trees planted were indigenous. Indigenous species are planted mostly as live fences. The main sources of seedlings in the study areas are presented in Table VII-S. Table VII-8 PERCENTAGES -OF SEEDLING SOURCES ...... Source of Seedlings Number of Households Percentage ...... Self grown 22 43 Collected wild 7 14 Free on Tree Day 14 27 Purchased 8 16 ...... Total 51 100
Fifty seven percent of the households either raise their own seedlings or collect them wild. Only 16 percent of the households purchased their seedlings. Twenty seven percent received seedlings free on National Tree Planting Day. The different initiatives by households in planting trees are listed in Table VII-9. Sixty six percent of the households planting trees did so on their own initiative, 15 percent on the initiative of schools and eight percent on group initiative. Only three percent cited extension as having in£luenced them to plant trees. The main reasons cited for planting trees are fruit (GO%), poles (17%), shade (14%)and fuelwood (6%). Drought, termites and animal browsing were consistently cited as the most serious problems affecting tree growing efforts in rural areas.
Table VII-9 PERCENTAGE --OF TREE PLANTING INITIATIVES ...... Initiative Number of Households Percentage Own idea 93 66 Group idea 12 8 School 22 15 National Tree Day 9 6 Tree Day and School 2 2 ...... Agritex 4 3 Total 142 100 Table VII-10 PERCENTAGES -OF -TREE PLANTING PURPOSES
Purpose Number of Households Percentage ...... Shade 17 14 Ornamental 0 0 Fruit 76 60 Fuelwood 6 6 Poles 21 17 Sawn Timber 4 3 Fodder 0 0 Prevent Soil Erosion 0 0 ...... Total 126 100
12. DISCUSSION Contrary to the belief that rural people do not plant trees, the survey shows that tree planting is a fairly common practice. This finding is supported by observations made during visits to Mashonaland East, Manicaland and Masvingo Provinces. The type of trees planted vary from locality to locality depending on the environment, seed availability and social circumstances impinging upon each settlement. Fruit trees are by far the most common trees and the first to be planted. Once a tree has been introduced into an area, it becomes fairly common. Trees are introduced by individuals or seed obtained from neighbouring commercial farms or from coffee, tea and other commercial plantations. Hedges and live fences are also established early to try and keep animals out. The practice of raising seedlings or collecting them wild is common. Once a tree has been introduced into an area and has produced seed, neighbours collect the seed and raise their own seedlings. This finding is an important one as it demonstrates that rural people already have the knowledge necessary for tree establishment. The fact that 66 percent of the households are growing trees on their own initiative illustrates the willingness to plant and the recognition of the importance of trees by the rural people. Schools are fairly important in the dissemination of tree planting knowledge and their role is likely to increase. Together with extension agencies they can be an important vehicle for the introduction of tree planting knowledge in the initial stage. Once in the area, the knowledge will diffuse through the informal sector. Tree growing to produce fuelwood in the future was not cited as an important reason for growing trees. This is explained by the fact that tree planting is predominantly carried out by male members of the household while fuelwood gathering is the responsibility of women. Individual woodlots are established to provide construction wood for use by the men of the household or for sale. Fruit trees are the most abundant trees in the rural areas because they provide the household with food and some money in the future. Animals are a constant problem to tree establishment. Tremendous efforts to protect young trees against browsing are being made. Seedlings are protected individually by wood fencing and thorn bushes until they are beyond the reach of browsing animals. Another method for reducing damage by browsing animals is to plant unpalatable and hardy species. Efforts to involve rural farmers to include trees in their farming systems will be made easier since some knowledge and willingness to grow trees already exists. The present tree planting efforts are using local inputs and the rural people are trying to find local solutions to protection problems.
13. FARM FORESTRY
Those concerned with rural development are increasingly becoming aware that the problems facing the rural people are interrelated. In Zimbabwe where the communal areas were never created as viable production systems, the major issue is the declining capability to produce food required to feed an ever growing population. This situation creates a tremendous pressure on the land leading to intensifled cultivation and the clearing of more marginal lands for agriculture. The consequences are soil degradation and overall diminution of environmental stability. Any projects or activities whose sole purpose is fuelwood production will not always be successful. Such projects must be seen to address the woodfuel problem, as well as providing environmental protection. Tree planting efforts should therefore be integrated into the agriculture and rural development policies and programs. This means working with farmers to promote tree planting using local inputs on the farms. Farm forestry refers to the sustainable forestry production by individual farmers on their own land (Catterson 1984). This can be achieved through increased planting efforts or through better management of existing woody biomass resources. Farm forestry has many components namely, agroforestry, small woodlots and individual tree plantings. Whatever the approach, there must be a careful incorporation of tree components in the farming system. Before Zimbabwe's independence in 1980, the rural sector was neglected and the issues of fuelwood and environmental protection were ignored. This neglect was prompted by a narrow view of development which concentrated on the establishment of state-run block plantations to supply commercial markets. Today, the needs are quite different and the commercial approach cannot be applied to the rural areas. In the future, fuelwood will be produced by farmers using less capital intensive methods and planting trees in different configurations around the farm. This approach has the potential of providing farmers with tangible and multiple benefits. Perhaps the greatest advantage of farm forestry is the integration of agriculture and forestry. This is an efficient means of utilising land. Wood supplies associated with farm forestry would be located on farms where people live and work. The time, effort and income expended by the rural households on acquiring fuelwood could be reduced, thus freeing the rural population for other valuable activities. With well-designed farm forestry projects, the possibility for farmers to earn additional income from sales of wood and fruit are increased. The integration of trees and other woody perennials into traditional farming systems, using management techniques which are ecologically and culturally compatible with local practices should be encouraged. A long-term, national solution to the fuelwood problem among the rural people cannot be achieved without encouraging and assisting the individual land users to cater for their own needs. Farm forestry is one system that can help achieve an increased fuelwood production while at the same time addressing some of the many problems related to land productivity. There is abundant evidence that trees and agricultural crops can be grown together without degradation of the site. The taungya or hill cultivation system, which originated in Burma in 1856 (King 1979) has spread thoughout Asia, Africa and parts of South America under different names, such as the shamba system of forest plantation in Kenya (Mburu 1980). In the initial stages of a forest plantation or woodlot existence, trees can be grown together with annual agricultural crops. There is also evidence that generally most agricultural crops have no adverse effects on forest crops and vice versa. Studies in Zambia showed that intercropping of Pinus oocarpa and Eucalyptus cloeziana with both sunflower and groundnuts did not affect the rates of tree-growth (Zambia Forestry Department 1980). Yields from both groundnuts and sunflowers were comparable to those reported under more conventional cultivation. If agroforestry is to be adopted as a farm forest option, then attention should be drawn to agroforestry research and development projects which have already been undertaken by FAO, and SIDA in many African countries. This information can be used in establishing projects with little prior silvicultural research. Finally, the success of any farm forestry option will depend largely on the social acceptability of new techniques. The system must be compatible with the cultural practices of the local people. It must be profitable and satisfy the needs of the people. It must have economic advantages such as use of locally available inputs. Finally, it must offer a means of reducing losses while creating ecological stability. As discussed earlier in this paper, the fuelwood shortage in Zimbabwe is likely to attain a critical level. The production of fuelwood outside the forests is a useful and necessary diversification of resources. The seriousness of the problem has been illustrated earlier and what is needed is the reduction of pressure on the remaining natural forests. This is intended to conserve some of the more essential protective features of the forest while at the same time being able to produce substantial amounts of food and wood for cooking and shelter. The chances of attaining self-sufficiency would be considerably greater if locally-designed farm forestry and or tree planting projects were undertaken. The development of any such tree planting technologies must take into consideration the whole range of problems facing the farmer. The selection of suitable tree species might involve an initial survey to determine trees already introduced into different areas. Melia azadirach, which is closely related to the neem tree grows well in the Bikita area. Leucaena leucocephala is another species that should do well in the Zrier zones,-~hese species can be planted in pure stands, in rows, or mixed with annual crops. Some acacias have a great potential for use in agroforestry systems as they are generally drought-resistant and useful for environmental protection. They can be intercropped, grazed or cut for fodder. Zimbabwe has a number of potentially useful agroforestry acacias. Acacia -albida- is a nitrogen fixer and provides fodder. It retains its leaves in the dry season thus providing crops with shade and protection against rain and wind. Acacia tortilis has similar potential. Grevil lea robusta, is a good agroforestry species for the high rainfall areas because it can be regularly pollarded to provide fuelwood and poles. Some species in the genus Prosopis, such as P, tamarugo, are suitable species for fuelwood and fodder production for the drier areas. They draw little water from the soil or the water table and can spearhead efforts at rehabilitating the marginal zones. The £01 lowing examples illustrate some of the possibilities for the integration of trees and shrubs on agricultural land:
CLOSED TREE STANDS OR PLANTATIONS
These would be woodlots, farm forests, home gardens, woody £allows (rotated with crops). Eucalyptus woodlots are already common in Zimbabwe along railways and on farms. The trees produce construction and utility poles and fuelwood in coppice systems. Extensive plantations of Acacia mearnsii are found in the Eastern Highlands. The bark is used in tanning processes while the trunks are used for charcoal making and sometimes treated and sold as fence posts. The planting of eucalypts on small land holdings needs careful evaluation. Eucalypts are known to have high moisture requirements which can affect agricultural production. At the small farm holding-level (particularly in the drier zones), preference must be given to species other than eucalypts. Multipurpose trees would be most desirable.
TREE ROWS
Tree rows are planted for wind breaks, shelterbelts, living fences, hedge rows in farm fields and along roads. Live fences and hedge trees should have good fencing properties and other beneficial characteristics such as unpalatability to protect against browse damage or high nutritional value for use as fodder. Species used for hedges vary from province to province. In Makoni communal area mutiti and mupwanda are indigenous species used in the area. Both species reproduce vegetatively. Areas near Juliasdale are using black wattle as live fences as well as growing it in small woodlots. This species was introduced into the area by wattle companies. Indigenous species can be left standing to serve as fences when clearing land. This is possible where trees are growing fairly close together. The advantage is an instant fence which can provide some fuelwood.
TREES PLANTED AROUND ?'HE FARM
Preferably these trees should be easy to establish and fast growing. Trees intergrated into the farming system should wherever possible be multipurpose with light crowns. The integration into the farming system and management of multipurpose trees should aim at maximizing both tree and agricultural products as well as environmental benefits. This should be achieved with as little land as possible being plantedtotrees. Farm trees should alsohave one ormore of the following characteristics:
(1) Fixing nitrogen:
(2) Making efficient use of soil nutrients;
(3) Fast-decomposing litter;
(4) Producing fuel timber, fodder, food and/or other useful products: and
(5) Coppicing abilities.
The selection of suitable farm trees might involve an initial survey to determine trees already introduced into different areas. Trees possessing desirable characteristics can be integrated into the farm system. Melia azadirach which is closely related to the neem tree grows very well in the Bikita area. This tree is extensively grown in dry areas in Sudan. A school in the area appears to be the source of seed. The tree can also be established vegetatively. Acacia belanitis is deliberately left standing in the field probably because of its function as a nitrogen fixer.
FRUIT TREES OR ORCHARDS
Depending on land availability these could be planted around the house as individual trees or in blocks. Pruned branches can be used for fuel. The fruit bearing mango and avocado are widely planted in the rural areas and can be regarded as ideal for agroforestry.
14. GENERAL DISCUSSION
The production of wood in the rural areas of Zimbabwe can be significantly increased by planting trees on individual landholdings in the form of small woodlots, farm trees, hedges, windbreaks and fruit trees. By the year 2002, it is estimated that there will be 0.91 million households in the rural areas. If each household is able to plant 300 trees around the farm, a total of 273 million trees will have been planted. Assuming an average countrywide growth rate of 7 m3/ha/yr (based on lGOO trees/ha), each tree would be expected to produce 0.004 m3 per year. The expected biomass production from such an agroforestry approach in the rural areas is estimated at 0.94 million tons. This will reduce the fuelwood shortfall of 6.19 million tons in the year 2002 by 15 percent. Three hundred trees can meet 20 percent of the fuelwood requirements of an average household. It is important to remember that fuelwood is not the only problem faced by the rural people. They also require wood for construction purposes. In some areas the shortage of suitable construction poles might be more critical than the fuelwood problem. Food is also a serious problem in the drier regions of Zimbabwe. The food problem has been exacerbated by three drought years. The problems of the rural people should therefore not be viewed in isolation. Farm forestry appears to be a land use system that can address the problems of the people living in fragile systems in an integrated manner. With well designed farm forestry projects, it will be possible to produce more wood for construction and fuelwood, address the problems of land productivity, and reduce pressure on the land. One of the most general constraints on farm forestry in addressing the problems of the rural poor is the very magnitude of the problem itself. Nine hundred thousand rural farmers are spread over the different ecological zones of Zimbabwe. These people are faced with physical and socio- economic limitations to rational land use. There are subsequent problems of rapid population growth and subsequent land pressure, poor infrastructure, soil erosion, drought, declining soil fertility and land tenure issues. Farm forestry must therefore be seen in the context of physical and social development problems. For instance, many farmers who are uncertain about their tenurial status may be unwilling to make long-term investments. Changes will have to be made in the many facets of sector development from policy through institutional, legislative and regulatory framework to technical options and practices in the field. For such changes to occur, the foresters themselves must also change their attitudes and ways of doing things. The overall policy and direction of forestry must change to service the largest group i.e. the rural people. The conventional methods of extension should also change. Extension must permit dialogue between the people and the service being provided. Since the development of farm forestry as a concept is recent, there is a lack of hard facts. The methodologies of farm forestry are not well developed and documented as they are in other areas of agricultural or silvicultural science. Other fields have a vast body of data against which to compare results. However, the importance of farm forestry is being increasingly realised and adequate and appropriate technology must be injected into it. There is therefore, a great need for further research. Clearly, a dilemma exists. While on the one hand, it is apparent that further research in farm forestry systems is necessary, on the other hand, there is an urgent need to prevent or reduce environmental collapse. The best solution is to address the problem from both angles. Where the need is apparent and conditions suitable, farm forestry projects should be introduced drawing on experience and results from comparable conditions in other countries or localities. At the establishment of such projects, it is recommended that appropriate research programs be initiated to provide data for later adjustment of continuing agroforestry projects. The integration of trees into the farm systems is not an alien concept to Zimbabwe's rural people. Farm forestry practices are carried out by communal people at different levels of complexity and in different forms. Researchers should examine such systems where they exist and advise farmers on how they can intensify and improve their practices so as to derive the maximum benefit from both tree and agricultural crops. Information gathered during the Rural Energy Survey established that tree planting is being carried out and that the rural people do raise their own seedlings. The majority of those planting trees are doing so on their own initiative. Clearly, tree planting knowledge already exists in the rural areas. It is important that before any tree planting projects are proposed, we clearly establish the existing knowledge and level of tree planting. If there is tree planting in an area, then the approach should be to build on that existing knowledge and intensify tree planting. Projects that take this approach and consider the needs, aspirations and cultural values of the local people are likely to have a greater impact on the community than those imposed on the community. Efforts should also be made to promote tree growing at the farm as well as the community level. The community approach will not always be successful since the rural people perform most of their farming activities individually. However, the community woodlot approach such as that being promoted by the Forestry Commission should continue. The method will work in some areas and has the advantage of introducing tree planting knowledge into an area. If rural people are tobe encouragedto cater fortheir own wood resource needs, then the necessary inputs should be locally available and at little or no cost. The establishment of seed orchards on communal areas will avoid the establishment of costly centralized nurseries, and will introduce new knowledge into these areas. The orchards can be sub-divided into four sub-units, each of which can be planted to different species. The size of each orchard will vary from area to area with the requirements of the people, but should be small in size. The species planted should produce seed quickly (3-5 years) and should serve numerous purposes. The orchard is fenced and then planted with a live hedge. Once the hedge is established, the fence can be removed and re-used. The hedge is then able to provide both fodder and wood. The seed orchard just discussed can be established as a one-time project. It becomes a source of seed for the communal areas. Once people have planted their own trees, these in turn become a source for future seed. This approach has the advantage of not requiring the development of a centralized nursery or special infrastructure which are very costly. The raising of seedlings does not pose a major problem since most households are already doing so. Different approaches to tree establishment will have to be adopted depending on prevailing local conditions. One possible method of establishing prosopis in the drier regions of Africa is to use a water catchment program. This might have some applications in Zimbabwe, particularly in those areas where land is available. This method had been used to establish trees in areas with a rainfall of about 800 mm per annum (van Gelder 1984.) This approach may not be possible in the communal areas but in other drier zones where land is available, it should be tried. Several of these water catchment areas can be constructed in any chosen area provided the land is available. Where possible the trees can be intercropped with suitable agricultural crops Most agricultural crops including hardy varieties cannot survive the severe climatic conditions under which trees can grow. It is recommended therefore, that for natural regions IV and V, a greater emphasis be placed on growing trees for fruit and fodder. Fodder trees should be emphasised in areas where cattle are found. By so doing, people can spread their risks especially during drought years when crops fail and grazing is scarce. The trees will also help improve the fertility of the soil. Soil fertility is very important because it is not only rain that is always responsible for lower yields. The trees introduced into such environments should a1so provide some f uelwood. Rural people living in drier areas, like their counterparts in other sectors of the economy want to secure an income. This can be guaranteed through planting fruit and other multipurpose trees which can provide fruit fodder for their cattle, and some fuelwood "sticks" while at the same time improving the soil fertility. The selection of suitable species in the fragile and brittle environments is very important. Eucalypts, because of their high demand for soil moisture should not be the choice for these dry regions. Research on multipurpose species should be intensified. The trees should have desirable characteristics.
15. CONCLUSIONS
Woodfuel fulfils the basic energy needs of over 80 percent of Zimbabwe's population and constitutes 46 percent of the total energy consumed. In spite of its importance, very little investment was made in the area of fuelwood prior to independence. The domestic energy source of the bulk of the rural and urban population was ignored. To provide both agricultural land and fuelwood for these two sectors, large areas of rural Zimbabwe have been deforested. The heavy reliance on and consequent indiscriminate exploitation of wood resources is causing serious environmental degradation. The outlook for the future in terms of woodfuel and the sustained viability of Zimbabwe's wood supplies is rather grim. At present, supplies are being drawn from both standing stocks and sustained yield. The significant cutting of wood stocks has caused supply shortfalls in many communal areas. According to the projections undertaken as part of the ZEAP effort, more than 45% of the national fuelwood demand will go unmet in 1997 and 2002 unless current supply trends undergo considerable change. If this problem is not faced now, the qualityof life in communal areas canbe expectedto deteriorate dramatically. Part I of this chapter discussed the nature and severity of the problem, and presented several potential solutions. In part 11, survey results were presented indicating that most rural housholders are familiar with tree-planting and have planted trees in the recent past. While a few of those interviewed purchased the seed1ings, most raised them or gathered them in the wild. Rural householders tend to plant trees on their own farmland, and not in communal woodlots or plantations. As a result, farm forestry, or agroforestry, holds the greatest promise as a partial solution to the woodfuel problem. Emphasis should be placed not on getting rural households to participate in community woodlot schemes, but rather on supporting current tree- planting practices and species choice. In particular, rural farmers, especially women, must be provided with support in planting trees for firewood, fruit, poles, and other productive purposes. By harnessing the knowledge and activities of rural Zimbabweans, farm forestry or agroforestry can provide a multi-faceted contribution to solving the woodfuel and environmental problems facing rural Zimbabweans.
REFERENCES
Catterson, T.M., 1984 "AID Experience in the Forestry Sector in the Sahel - Opportunities for the Future. " Paris: OECD.
Energy Systems Research Group, 1983 "LDC Energy Alternatives Planning System." Volume 1. Boston, Massachusetts: ESRG.
FAO, 1981 "Map of the Fuelwood Situation in the Developing Countries at a Scale 1:25,000,000." With Explanatory Note (in English), pp. 1 - 11. Rome : FAO.
King, K.F.S., 1979 "Agroforestry and the Utilisationof Fragile Ecosystems." Forest Ecology and Management 2: 161- 168.
Mburu, O.M., 1980 "Agroforestry in Forest Management in Kenya." Proceedings of the Kenya National Seminar on Agroforestry Nairobi: ICRAF.
Republic of Zimbabwe, 1982 Transitional National Development Plan 1982/83 - 1984/85. Volume 1. Harare: Government of Zimbabwe.
VanGelder, B., 1984 Personal communication. Nairobi: Beijer Institute.
World Bank, 1981 "Mobilizing Renewable Energy Technology in Developing Countries: Strengthening Local Capabilities and Research. " Washington, D.C. : World Bank.
Zambia Forestry Department, 1980 Personal communication. Kitwe: Research Division. VIII. WOODFUEL HARVESTING AND SOIL EROSION IN ZIMBABWE
David K. Munasirei
1, INTRODUCTION
The most important source of energy in the economy of Zimbabwe is woodfuel which accounted for about 46.8 percent of the total energy consumed in the country in 1982 (Beijer Institute, 1984). Commercial wood, an energy resource used largely for rural poles, industrial sawn timber, and construction materials, accounted for another 11 percent of total energy consumption. Woodfuel and commercial wood combined accounted for 57.8 percent of all energy used in Zimbabwe in 1982 (Beijer Institute). These figures serve to highlight the heavy dependence on wood in Zimbabwe. However, the rural households, and the high-density urban household sector accounted for consumption of more than half of all the energy used in Zimbabwe in 1982. Most of this energy is in the form of wood. Most of the wood-energy resources are obtained from open woodlands used for grazing. Conventional closed forests supply a very small percentage of wood in the country. In 1982 Zimbabwe's wood resources were not sufficient to meet estimated woodfuel demand from sustainable yields (Katerere, 1984). Tree-stocks are being cut at a more rapid pace than they are able to regenerate themselves. The demand for fuelwood in urban and rural areas is the single largest drain on Zimbabwe's forest resources. The demand for wood will grow to nearly 13.4 million tons by the year 2002 (Katerere, 1984). This will result in a serious wood shortage, where neither yields nor stocks will be sufficient to meet the demand in the most-scarce provinces. Already the communal areas of Manicaland, Mashonaland East and Masvingo provinces are experiencing a wood shortage (Katerere 1984). It is estimated that these provinces will each begin to experience an absolute shortage of accessible wood resources in 1997. Midlands, Mashonaland Central, and Matebeleland North provinces will all be at the stage of an incipient wood shortage by the year 2002. The continued heavy reliance on wood energy can lead to accelerated deforestation and environmental degradation. The sparseness of trees and the small-tree sizes of regenerate areas in communal areas of Manicaland, Masvingo and Mashonaland East provinces are testimony to accelerated deforestation. In the same areas where trees have been cleared for fuelwood and cultivation, soil erosion has been accelerated. Where the natural vegetation has been cleared, soil splash and erosion have increased; drainage density is increased through rilling and gullying; and headward rates of erosion and the corresponding sedimentation in the main valleys are increased. The chain reaction from a decrease in vegetal cover is already seen in the increased number of channels (gullies) and increased rill and sheet erosion evidenced by heavy sedimentation in the main valleys. The three provinces mentioned above have communal areas where the rates of erosion are considered critical (especially Mutoko in Mashonaland East). Erosion rates in Zimbabwe are already high enough to generate concern about the thinning of soil profiles. The highest rates of erosion occur in the most densely settled communal lands of the three provinces.
2. FACTORS INFLUENCING SOIL EROSION AND EROSION RATES IN Z IMBABHE
An understanding of soil erosion is largely based on empirical studies. In these studies, a wide range of data and independent variables af fecting soil loss have been anal yzed. The great number of permutations of vegetation cover, density of cover, crop management types, soil type and rainfall characteristics make the task of thorough and controlled research formidable. However, Stocking and Elwell (1973a) identify the following as the major factors influencing soil erosion in a study of the erosional hazard of Zimbabwe: erosivity, relief, vegetal cover, soil erodibility and human occupation. While a brief summary of each of the factors will be considered, emphasis will be given to vegetalcover, as it is affected greatly by woodfuel harvesting and cultivation.
EROSIVITY
Erosivity is defined as the potential ability of rain to cause soil erosion. The physical characteristics of precipitation that are closely related to erosivity are intensity, and quantities, such as kinetic energy, which are functions of both raindrop mass and terminal velocity (ilischmeier et a1 1958). A raindrop falling on bare ground generates a splash which dispenses and mobilizes soil, allowing it to be transported. The size of the splash and the amount of soil moved are largely determined by the kinetic energy of the raindrop (iiischmeier et a1 1958). Thus the energy of rainstorms during a year has been shown to be highly correlated with the annual soil erosion rate (Elwell and Stocking, 1975).
RELIEF FACTORS
Relief is an energy or causative factor of erosion. In the form of potential energy, gravitational forces not only cause run-off but also a step-by-step migration of splashed soil particles (Stocking and Elwell, 1973a). The relief parameter used commonly as a major factor in soil erosion is slope. Slope affects the velocity of run-off and the shearing force which it can apply toward mobilizing and transporting soil.
SOIL ERODIBILITY
The ability of soil to resist erosion depends upon those physical and chemical properties which determine its detachability and transportability. Erodibility has been correlated with a bewildering array of soil characteristics. Elwell (1971) lists and discusses as the dominant soil characteristics, texture, structure, and organic content of the surface layer.
HUMAN INFLUENCES
Land-use is commonly associated with the radical alteration of the vegetation cover often resulting in an increased erosion rate (Dunne -et -al.- 1981). On the other hand, soil conservation practices such as terracing, and crop-residue management may decrease soil erosion. The variability of erosion in different areas can be explained in terms of the human influence independent of other factors. Stocking and Elwell (1973a) introduced population density as a suitable parameter for estimating the erosional potential which might result from man's interference. Population density reflects the absolute number of people living in a unit area and, in rural areas, it directly measures the number of people who attempt to gain a living from the land. Somewhat less directly, population density suggests such parameters as the degree of land utilization, the extent to which lands unsuitable for cultivation are opened up and the numbers and densities of cattle (Stocking and Elwell, 11973a). All these direct and indirect factors add up to creating different erosional situations.
VEGETATION COVER
Vegetation cover is manifestly one of the most important control ling influences of soil erosion. The total protective value of vegetation to soil is provided by ground cover, canopy and litter. Vegetation cover intercepts rainfall kinetic energy and thereby decreases the mobilization of soil particles. It is generally agreed that soil erosion is extremely sensitive to the type and density of vegetation cover. Vegetation cover is also an important factor of erosion because it is easily manipulated by man. Unfortunately very little is known concerning the relationship between vegetation cover and soil erosion. However, there are basic relationships which have been established through empirical studies. Screenivas et a1 (1947) compared the .mass of soil splashed from small trays and concluded that the height and percentage of cover were important. In Z+mbabwe, Hudson (1971) demonstrated the remarkable differences in soil loss between a bare plot and a plot protected by mosquito gauze. In the experiments carried out at Henderson Research Station, Hudson demonstrated that in the period 953-56 mean annual soil loss from bare ground was 4.63 kg/mi compared with 0.04 kg/m2 from ground covered with a dense Digitaria. This role of cover is emphasized by the mosquito gauze experiment in which soil loss was compared from identical bare soil plots (Hudson and Jackson, 1959). Over one plot was suspended a fine wire gauze which had the effect of breaking the force of raindrops, absorbing their impact and allowing the water to fall to the ground from a low height as a fine spray. The mean annual soil loss over a six-year period was 141.3 m3/ha for the open plot and 1.2 m3/ha for the plot covered by gauze. In a more recent assessment of the influence of cover on soil loss, Elwell (1971) compiled the results of the full research program, for a Tatagura clay soil on 4.5 percent slopes. The results were astounding. The soil surface which was protected from the raindrop impact had 127 times less soil loss than the unprotected plot. This seems to indicate that soil loss varies according to the degree of protective cover provided by plants. To confirm this, soil loss values for a variety of cover conditions were compiled and are shown in Table VII-1. From these figures, the percentage of vegetal cover would appear to be the most reasonable measure of the protective value of vegetation.
TABLE VIII-1 SOIL LOSS FROM CROPS HAVING VARYING COVER VALUES
(Aver- oFfivarar;;7-- p ...... Crop Cover Soil Loss ...... Ratings ( t/ha/a) Bare Soil Nil 96.6 Late-planted legumes Poor 6.9 Low-density maize Average 2.3 Napier fodder Good 2.0
Notes: Tatagura clay soils on 4.5 percent slopes at Henderson Research Station (Elwell 1971).
The vegetation component which protects soil most efficiently against erosion appears to be ground cover and the associated litter rather than canopy cover (Dunne et al, 1981). Many of the canopies in communal areas lying in natural regions 111, IV and V are thin because of intense woodfuel harvesting and cultivation. In natural regions IV and V the sparseness of the canopy is also attributed to the amount and variability of rainfall. Thin canopies a1low raindrops to strike the ground surface directly. However, in areas, such as in Manicaland province (particularly in natural regions I and IIa), where dense canopies are common, soil erosion is effectively reduced. For adequate erosion protection at least 70 percent of the ground surface must be covered (Fournier, 1972; Elwell and Stocking, 1976). Where canopy is sparse there is a large difference between herb density under and between canopies. In such areas, however, the proportion of the area having a high cover density is small, and the removal of the canopy could reduce the ground cover on only a small area. For such areas in natural regions IV and V, particularly in Matebeleland provinces, rainfall erosivity is low. Apart from very dense canopies, basal (ground) cover, a dense growth of grass with an associated litter, protects soil most efficiently against erosion. In Table VIII-2 five arbitrary categories into which basal cover is divided in Zimbabwe, are shown (Stocking and Elwell, 1973a). Figures vary from about 1 000 mm of rainfall for good cover conditions and therefore lowest erosion - to below 400 mm for the poor cover conditions indicating the greatest erosion hazard. While basal cover is effective in reducing erosion it should be noted that the effect is related to total vegetation cover. It is also the factor least influenced by the normal range of management conditions, although radical changes can be brought about by extremes of mismanagement (Stocking and Elwell, 1973a). Such radical changes are experienced in communal areas where the human factor has contributed to high rates of soil erosion.
TABLEVIII-2 THE CATEGORIES OFEROSION IN ZIMBABWE ...... Category Natural Rainfall Basal Cover Slope Hunan Cccupation Region (mm) Estimated % (degrees) ...... Low I Above 1000 7 - 10 0 - 2 Extensive European Ranching National Parks
Below Average I1 800 - 1000 5 - 8 2 - 4 Mostly European Farms
Average I11 600 - 800 3 - 6 4 - 6 Low Density Communal Areas and SSCF below 5 p.p. lan2
Above Average IV 400 - 600 1 - 4 6 - B Moderately-settled Communal 2 Areas 5 - 30 p.p. km
High IV Below 400 - Above 8 Densely Settled Communal Areas above 30 p.p. km2 ...... Notes: Cover, and Huma'n Occupation are only tentative and cannot be expressed on a farm quantitative basis. (Stocking and Elwell, 1973a)
p.p. km2 = persons per square kilometer SSCF = Small Scale Commercial Farms 3. SOIL EROSION HAZARD
Stocking and Elwell (1973a) used factoral scoring on a scale of 1 to 5 involving the factors discussed in the preceding section (i.e. erosivity, slope, erodibility, ground cover and human occupation). Each of the factors was given equal weight and the values summed to g,ive an overall result. There is, however, a methodological weakness in such an analysis, in that, summing the factors, instead of multiplying them, may allow synergistic interaction. Another weakness lies in giving equal weight to each factor, as some factors, such as erosivity, may be more important than others. However, the results of this analysis are very revealing in terms of critical erosional areas.
TABLE VIII-3 SOIL EROSION HAZARD IN SELECTED COMMUNAL AREAS ...... Province/Communal Area Natural Region Erosion Category Major Factors
Mashonaland East Chinmora-Chinmano IIa Above average Eroaivity Uzumba III/IV High Erosivity and Slope Mutoko III/IV Very High Erosivity, Slope and Human Occupation Manicaland St Swilhinis-Matizi-Saunyama 11s-V High Erosivity and Slope Manyika IIb/III Above Average Human Occupation Makoni IIb/III Above Average Hman Occuptation
Masvlngo Manga IV/V Above Average Hman Occupation Chibi V Above Average Hman Occupation ......
Based on A factorized Erosion Survey Map of Zimbabwe by Stocking and Elwell (1973a)
Notes: The factors that are related to vegetation cover are erosivity and human occupation. Erosivity and cover factors are in large part complementary.
Communal areas experiencing wood shortage in Mashonaland East, Manicaland and Masvingo are shown, in the results of the factor analysis, as experiencing critical rates of erosion (Table VIII-3). However, this does not imply that the major factor contributing to erosion is the cutting down of trees for woodfuel. The cutting down of trees and the clearing of vegetation for cultivation nevertheless contribute to the total erosional situation in these areas. Mutoko (Mashonaland East) is a good example of an area where a combination of factors has resulted in the highest erosional hazard in the country, To the north of Mutoko village the combination of high erosivity, slope and population density makes the area very vulnerable to erosion. Beitbridge (in NR V of Matebeleland South) experiences erosion rates which are very high because of poor vegetation cover and erodibility. Poor vegetation cover in areas lying in natural region IV or V is attributed partly to limited and unreliable rainfall and, cultivation and woodfuel harvesting. Areas in Manicaland, Mashonaland East and Masvingo provinces, considered in the factor analysis as experiencing erosion rates above average, high or very high as a result of vegetation cover and related factors like erosivity and human occupation, are shown in Table VIII-3 above. It shouldbe notedthatthe situation in these areas has been exacerbated by the increase in population. Some communal areas in Manicaland province were visited by the writer in 1984. Observations were made on the erosion and fuelwood situation in these areas.
4. SOIL EROSION OBSERVATIONS
The short duration of the consultancy did not allow the use of reliable means of assessing soil erosion, namely direct monitoring of soil loss from plots under disturbed and undisturbed vegetation over many years. Instead, site indices of susceptibility to erosion were observed for a period of one week. Systematic field observations were made expressly for the purpose of assessing the impact of woodfuel harvesting on soil erosion. Eight communal areas were visited in three districts of Manicaland (Tables VIII-4 and VIII-5). Each area was examined for its standing crop of fuelwood and an assessment of the erosion status was made. The qualitative assessment was based upon:
(1) Slope
(2) Ground cover
(3) Population density
(4) The role played by the present wood canopy in soil erosion. This involved considering whether the canopy fosters a ground cover of herbs or litter; whether the ground cover is grazed or trampled beneath the canopy; and whether the tree roots trap significant amounts of soil.
(5) Signs of rill sheet or gully erosion. Rill erosion is the removal of soil through the concentration of over land flow into numerous smal l but conspicuous channels or rivulets. Sheet erosion can be described as "Interill" erosion, meaning both movement by rain splash and transport of raindrops-detached soil by surface flow whose erosive capacity is increased by raindrop impact turbulence (Meyer, 1979). Gully erosion is the removal of soil resulting from the excessive concentration of run-off water which causes the formation of relatively large channels.
TABLE VIII-4 EROSION OBSERVATIONS IN MAKONI DISTRICT ...... Erosion Class of Major Description and remarks Fuelwood Status Type Erosion Factors
Tandi Communal Area
Sheet Slight Human Occupation Erosion deduced from poor cover, Bare of tree cover, over wide Vegetation Cover sediment deposits on plant pedestals areas and there is a definite Moderate Plant Cover very poor and sediment wood shortage. The vegetation deposits extensive. Small rills are is characterized by the evident. sparseness of tree cover and the small tree size.
Rill Slight Small shallow (malnly "O.lm) rills are present.
Gully Slight Gullies, usually up to 1 m deep on foot slopes of hills and along secondary roads. Moderate A limited number of gullies of depths mainly 1 to 3 m.
Gandanzara/Rugoyi Area ...... Sheet Moderate Human Occupation Plant cover very poor and sedlment This is another wood-shortage Vegetation Cover deposits extensive, especially along area with very few standing river valley bottoms. trees.
Rill Moderate Rills of depths 0.1 to 0.4 m.
Gully Moderate Deep gullies 1 to 3 m deep, exposing soil profiles.
Chendmbuya Area
Sheet Sllght Human Occupation Erosion deduced from poor cover and Lack of fuelwood is as bad as Vegetation Cover sediment deposits in fields. in Tandi. There is no none in Moderate Plant cover very poor and sediment communal areas. Communal de~ositsextensive. farmers depend for their fuel wood on the neighboring Mayo Rill Slight Small, shallow rills evident on bare and Chinyika resettlement land (0.1 m). areas where land is being cleared for cultivation. Gully Sllght Gullies usually up to 1 m deep along badly constructed roads and around deep tanks and grazing areas. TABLE VIII-5 EROSION OBSERVATIONS IN MARANGE DISTRICT ...... Erosion Class of Major Description and remarks Fuelwood Status Type Erosion Factors ...... Zimunya Communal Area
Sheet Moderate Human Occupation Plant cover very poor, cultivation 1s Tree cover 1s definitely Erosivity, Slope common on slopes, and sediment greater than areas vislted in Vegetation Cover deposits on floors: coarse textures, in Makoni District rolled pebbles.
Rill Moderate Rills of considerable depth, 0.1 to 0.3 m.
Gully Slight Gullies usually up to 1 m deep, and occur along roads and between fields...... bcha Communal Area ...... Sheet Moderate Human Occupation Plant cover is very poor and Tree cover is quite Erosivity, Slope deposition is evident comparable to Zimunya area in Vegetation Cover some locations, like the homesteads near Wzl Rlver , but 5 to B lan sway, trees are a rare site and these are areas of definite wood shortage......
5. EROSION CLASSIFICATION SCHEME
The system used for systematically cataloging evidence of soil erosion intensity was developed by the Southern African Regional Commission for the Conservation and Utilization of the Soil (SARCCUS, 1981). The system identifies the degree and intensity of erosion within a given area of land or agro-ecological zone unit. The identification of different classes in the eight areas visited was done through field checks. The fol lowinq five classes of erosion are specified in the system.
CLASS 1 No apparent erosion
No visible signs of sheet or rill gully erosion. The general stand of crop and veld management is high. Plant cover is adequate to provide effective protection against accelerated erosion. CLASS 2 Slight Erosion
Erosion is noticeable, but not obvious, with sheet and very occasionally rill erosion. Plant cover is somewhat poor and it is not effective in providing adequate protection of the soil. Occasional rills and broken conservation structures may be observed on arable land. small alluvial deposits are often discernible in grazing lands where soil displacement and surface compaction by trampling have taken place.
CLASS 3 Moderate Erosion
A considerable area of bare eroded soil is clearly discernible. Erosion of various lands has reached a stage where tillage operations are hindered and the potential for crop and livestock production is significantly reduced.
CLASS 4 Severe Erosion
CLASS 5 Very Severe Erosion
For the eight communal areas visited there were no visible signs of severe and very severe erosion on a large scale, hence descriptions of these classes have been omitted.
6. GENERAL CONCLUSIONS FROM FIELD OBSERVATIONS
Many of the sites to which the erosion classification scheme was applied showed signs of moderate erosion. This is a critical situation which was identified about ten years ago by Stocking and Elwell (1973a). A combination of the field observations and the work of Stocking and Elwell (1973a) on the erosion situation in the areas visited is highlighted in Tables VIII-4 and VIII-5. Note that the major factors that are considered as contributing significantly to soil erosion are vegetation cover and the related factors of human occupation and erosivity. The implication of this is that woodfuel harvesting, clearing for cultivation and grazing play a significant role in causing a critical erosion situation. The situations detailed in the tables can be considered similar to a number of communal areas in Zimbabwe. It is in these areas that man, strongly backed by natural forces, has created for himself the greatest actual or potential erosional situation. The pattern of population density, as documented by Kay (1972), shows strong clustering of population in communal areas to the north, east and south of Harare. Equally high densities of up to 60 persons per square kilometer are shown north of Mutoko and generally in a wide arc coincident with the south-east Middleveid, stretching in the north from the edges of the Zambezi escarpment, through Mutoko, Rusape and the densely settled communal areas of the Sabi-Gutu-Buhera-Bikita-Chibi area (Kay 1972). High population density, while not directly affecting erosion, must be taken in context as a major contributing factor of erosion. A high density of population on land that at the present stage of technology is incapable of supporting such a population unless large and ever-increasing areas are brought under the plough, and which is settled in an area where the natural incidence of erosion is potentially very great, must be conducive to erosion (Stocking, 1973). The situation is best exemplified in parts of Manicaland, Masvingo and Mashonaland provinces where slopes are steep, and vegetation is poor, due to limited and unreliable rainfall and indiscriminate clearing. The pressure of population on the land is accentuated by the paucity of areas suitable for cultivation and settlement. Some communal areas in these provinces are already experiencing acute fuelwood shortages. The three types of erosion identified in the areas visited were rill, sheet and gully erosion. Rill erosion with subsequent deposition on lower slope concavities and valley floors was noted. "slight" to "moderate" rill erosion was characterized by rills ranging from shallow rills (mainly below 0.1 m in depth) to those of considerable depth (about 0.3 m ). Rills occurred in areas where natural ground cover is poor and where fields were abandoned. The sheet erosion observed ranged from "slight" to "moderate". Slight sheet erosion is characterized by poor cover and sediment deposits, where moderate sheet erosion occurred especially on fields where plant cover is very poor. Sediment deposits are extensive on the downslope of fields along roads and on valley bottoms. Small rills associated with this type of erosion were evident. The gully erosion observed also ranged from "slight", with gullies of up to 1 m deep, to "moderate", with a limited number of gullies of considerable depth (mainly between 1 to 3 m). Some of the gullies observed in the vegetated areas of Mapungwana, Rugoyi and Tamandayi were probably a result of natural forces. However, most were caused, either directly or indirectly, through the misuse of land by man. In arable areas, gullies occurred as a result of broken contours. Some of the contours broke either because of siltation or due to their sub-standard size. The absence of contours in some areas allowed the accumulation of run-off which led to rill erosion and eventually the formation of gullies. Discharge of storm water from contours into unstable areas, especially along badly constructed roads (a typical sight in the areas visited), led to gullying. In communal grazing areas, poor livestock management led to the destruction of ground cover. This resulted in excessive run-off along livestock tracks and the collapse of drainage lines which lost their equilibrium when forced to carry excessive run-off. The drainage lines and some livestock tracks have resulted in gullies of considerable depth. Road culverts and drains often have the effect of concentrating runoff to areas which collapse. Along most of the dusty roads visited, this concentration of run-off was evidenced by the formation of gullies. A large proportion of the communal areas visited had little or no fuelwood because of the sparseness of tree cover, due to indiscriminate clearing, and because of the small tree size. Many of the existing canopies were thin and a1lowed raindrops to strike the ground directly. This had resulted in rain splash soil detachment, and rill and sheet erosion, especially where the ground cover was poor. Many of the trees that had been removed had also affected the litter which would help protect the soil. The contribution of tree canopy was localized beneath the few trees in the areas. The trapping of deposits by the roots of trees was also insignificantly localized. Because of the thin canopies, poor ground cover and a limited amount of litter, the ground was not sufficiently protected from the impact of raindrops. Thus, a variety of signs of accelerated erosion beneath tree canopies and bushes and between canopies was observed. The canopy cover in densely forested areas in which the standing stock is not accessible to communal farmers plays a significant role in protecting the soil. These areas (Large Scale Commercial Farms, Parks and Wild Life areas and Tree Plantations), particularly in Manicaland showed no apparent signs of erosion.
REFERENCES
The Beijer Institute, 1984 Policy Options for Energy and Development in Zimbabwe. -p-- - Volume I1 Main Report Harare.
Dunne. T.. Aubrv.A. B... and Wahome. E.K.. 1981 Effect of \?oodfuel Harvest on soil Erosion in Kenya. The Beijer Institute.
Elwell, H.A., 1971 -Soil--- Loss Estimation: _A Planned Approach $9 jhe -Protection of the Sol1 and Water Resources m the Southern Tropics of Central Africa. Thesis submitted for the degree of Master of Science, in the Faculty of Engineering Southampton, England: University of Southampton.
Fournier.. F... 1967 "Research on Solid Erosion in Africa." African Soils, p 53-96.
Hudson, N.W., 1971 Soil Conservation London: Bats ford. p-- Jackson, J. C. 1959. "Results Achieved in the Measurement of Erosion and Run- off in Southern Rhodesia," pp. 557-583 in Proceedings of the Third Inter-African Soils Conference Dalaba, Guinea. Volume 2 Commission for Technical Cooperation in Africa, South of the Sahara.
Kay, G., 1972 Distribution and Density of African Population $ Rhodesia. University of ~iell~isc.Series in Geography No. 12.
Katerere, Y., 1984 Chapter 7, present volume.
Meyer, L.D., 1979 "Water Erosion," in The Encyclopedia of Soil Science Part 1_L Edited by ~x~airbridgedT.\J.~inklJr. Powden, Hutchinson and Ross Stroudsburg: Pennsylvania, USA.
SARCCUS, 1981, A System for the Classification of Soil Erosion. -p-- Pretoria: SARCCUST
Screenivas,L., Johnston, J.R., and Hill, H.\{., 1947 "Some Relationships of Vesetation and Soil Detachment in the Erosion Process" --Proc. ---Soil, -Sci. --Soc. Am. 12: p 471-474.
Stocking, M.A., 1972a "Relief Analysis and Soil Erosion in Rhodesia using Multivanote Techniques," Zeitchaift for Geomorphologie 16: p 43-443.
Stocking, M.A., 1973 "Aspects of the role of Man in Erosion in Rhodesia" Zambezia, p 1-10.
Stocking, M.A., 1978 "Relationship of Agricultural History and Settlement to severe Soil Erosion in Rhodesia." Zambezia (ii) p 129-145.
Stocking, M.A., and Elwell, H.A., 1973 "Soil Erosion in Hazard in Rhodesia." Rhodesia-- - Agricultural Journal, 70 (4), p 93-101.
Stocking, M.A., and Elwell, H.A.,1976 "Vegetation and Erosion: A review," -Scottish------Geographical Magazine 92 (1) p 4-16. Whital1,P.C. , 1984 A Guide g Gully Control and Reclamation. Harare: ------P- Agritex.
Llischmeier ,\J.H., Smith, D.D., andUhland, R.E., 1958 "Evaluation of Factors in the Soil-Loss Equation," Agricultural Engineering, 38 (8). IX. THE PROSPECT FOR APPLICATION OF RENEWABLE ENERGY TECHNOLOGIES IN ZIMBABWE'S RURAL DOMESTIC AND AGRICULTURAL SECTORS T. N. Harris
1. INTRODUCTION Discussions of the prospects for application of new and renewable energy technologies are often couched in broad generalizations based on one or another form of utopian technological fetishism. Proponents of improved woodstoves project that tremendous savings in rural domestic fuel use will be achieved when their stoves are adopted, as of course they must be, given their unambiguous advantages. Photovoltaic enthusiasts extrapolate curves of declining costs to project the imminent availability of inexpensive solar electrification. And advocates of biogas sketch visions of self-sufficient rural communities enjoying the fruits of modern technology on the basis of elaborate systems for the conversion of dung to electricity. These visions are attractive and not altogether fanciful, but they ought not be taken seriously without a critical review of the feasibility, costs and benefits of the alternative technologies. All too often they are based on little more than the intuition that renewable energy must be cheaper than commercial fuels and the sense that supply creates its own demand. Experience with the slow pace of adoption of novel renewable energy technologies, and observation of the frequent and often costly failure of programs designed to support them, suggests that application of the alternative technologies is conditioned by factors more extensive and complex than the simple technical capacity to convert available but unuseful natural energy to some potentially more useful form. A realistic appraisal of the prospects for significant application of novel energy technologies will be conducted most logically if it begins with a review of the pattern of energy demand, identifying the socio-economic context and functions performed by current and forecast applications of energy. It could attempt to locate unmet energy demand in applications and contexts which have particular social value in terms of potential increase in production or other enhancement of welfare. The significant tasks and contexts might then be characterized in terms of technical, social and economic factors which condition the match to appropriate forms of supply. Finally, this demand side analysis could be used to screen consideration of the potentially available alternative energy technologies, themselves characterized in terms of their technical, social and economic attributes. This report follows that plan. It commences with a review of current and forecast patterns of energy use in Zimbabwe's household and agricultural sectors. The data and projections used for this review were developed in the course of the Zimbabwe Energy Accounting Project and are featured in the LEAP energy accounting model established by the project. Figures used here are taken from the "base case" scenario, the pattern of demand expected to develop in the absence of substantial changes in government policy or unforeseen events. The structure of the LEAP model and the input data employed in its realization are discussed in other reports of the project, and will not be elaborated here.
2. DEMAND
SECTORAL DEMAND
TableIX-l illustrates the final demand for fuels in the household and agricultural sectors in 1988, with a base case forecast for 2002. Fuel demand is shown as percentage shares of total demand by the sector and total demand for the fuel.
TABLE IX-1 FINAL CONSUMPTION BY SECTOR ...... Petroleum Coal/Coke Electricity Commercial Fuelwood Total Products Wood Nation Sector Nation Sector Nation Sector Nation Sector Nation Sector Energy
...... Rural Households 2.8 0.6 5.6 2.0 0.5 0.1 928 28.6 90.5 76.7 54.6 Urban Households 1.0 3.4 1.8 9.2 13.4 45.4 - 2.8 42.0 3.1 Agriculture 10.3 13.3 10.3 42.2 7.3 9.3 - 6.5 35.1 8.5 ...... Total Energy 11.0 19.7 10.8 12.1 46.3
Rural Households 2.6 0.6 2.8 0.8 0.4 0.1 92.7 21.2 90.7 77.3 54.3 Urban Households 1.5 3.6 3.4 11.1 15.3 398 - 5.0 45.5 5.0 Agriculture 6.2 13.6 13.3 41.9 3.9 9.7 - 4.0 34.8 5.3
Total Energy 11.6 16.6 13.1 12.4 46.3 ...... Notes: (1) Figures are taken from the Base Case Pro~ectionof the LEAP Model used in the Zimbabwe Energy Accounting Project. (2) Nation = X of National Consumption of Fuel (3) Sector = % of Sectoral Consumption of Fuel (4) Energy = X of National Energy Consmption
The most striking aspect of the figures is the extraordinary dependence of the rural household sector on wood. The use of wood in rural households embodies a very large proportion of the national energy budget. The urban households are also highly dependent upon a single fuel, in this case, electricity, and this dependence is expected to increase during the forecast period. Agriculture has only a minor, and declining share of national fuel demand, mostly in the form of coal and wood fuel.
FUEL SCARCITY AND SECTORAL DEMAND
The significance of the shares of fuel demand attributable to the household and agricultural sectors lies in their relation to current and forecast problems in the supply of some fuels. The LEAP model's base case projections show serious shortfalls in national fuelwood supply developing in the late 1990s. It is clear that any demand- side amelioration of the wood scarcity problem will have to come from conservation or substitution in the household sectors, in as much as these sectors are almost entirely responsible for the demand on wood resources. Construction plans will allow electricity supply to increase with demand, but there will be an accompanying increase in electric rates, which could have a damaging impact upon urban households. However, electricity consumption in urban households is only a small portion of national electricity demand. Petroleum products are expensive and scarce in Zimbabwe since they are entirely imported. They do not constitute a major source of energy in Zimbabwe but substitution could have a significant impact upon the importation requirement nevertheless. Coal, of course, is locally produced and available in quantities far in excess of current demand. The rising costs have, however, been a factor in rising input costs for agriculture.
END-USE DEMAND
A much better sense of the distribution of energy demand can be gained in an examination of the fuel consumption for different types of application (or end-use) and the economic context in which this demand is realized. The characteristics restrict the range of potentially appropriate options for conservation or substitution, and the economic context determines the effective cost of alternatives and the ability to undertake them. Tables IX-2, IX-3 and IX-4 display the final consumption of fuel by end-use for each sector, and then proceed to a further disaggregation of end-use consumption for domestic and agricultural subsectors. The end-uses are differentiated according to fundamentally different types of output or bases of demand. The subsectors are established on the basis of substantially different patterns of consumption, access to resources or capacities for transformation and innovation. TABLE IX-2 FUEL CONSUMPTION -BY END-USE ...... 1982 2002 End-Use Fuel Sector Nation Sector Nation ...... Rural Households Energy 54.6 54.3 ...... Cooking/Heating Fuelwood 82.8 90.2 79.3 90.5 Lighting Paraffin 2.4 15.1 8.3 10.8 Electricity 0.0 0.0 0.0 0.0 Ironing Fuelwood 0.3 0.3 0.2 0.2 Construction Fuelwood 16.5 100.0 20.0 100.0
Communal Area Energy 82.4 85 .O ...... Cookingl~eating Fuelwood 62.0 69.2 65.5 74.6 Lighting Paraffin 0.2 9.4 0.2 7.8 Ironing Fuelwood 0.2 0.2 0.2 0.2 Construction Poles 18.8 97.2 19.0 95.0
Resettlement Area Energy 4.0 6.3 ...... CookingIHeating Fuelwood 2.7 3.0 5.2 5.9 Lighting Paraffin 0.0 0.5 0.0 1.0 Ironing Fuelwood 0.0 0.0 0.0 0.0 Construction Poles 0.5 2.9 1.0 5.0 ...... SSCF Energy 2.1 3.1 ...... Cooking/Heating Fuelwood 2.1 2.4 3.0 3.5 Lighting Paraffin 0.0 0.6 0.0 0.6 Ironing Fuelwood 0.0 0.0 0.0 0.0 ...... LSCF Energy 14.1 5.1 ...... Cooking/Heating Fuelwood 14.0 15.6 5.6 6.4 Lighting Paraffin 0.2 4.5 0.0 1.4 Electricity 0.0 0.1 0.0 0.0 Ironing Fuelwood 0.0 0.1 0.0 0.0 ......
Notes : (1)Figures are taken from the Base Case Projection of the LEAP Model used in the ZEAP. (2) Nation = % of National Consumption of Fuel (3) Sector = % of Sectoral Consumption of Fuel (4) Energy = % of National Energy Consumption TABLE IX-3 FUEL CONSUMPTION BY END-USE ...... 1982 2002 Sector Nation Sector Nation ...... Urban Households Energy 3.1 0.2 0.6 0.2 ...... Cooking Fuelwood 26.0 2.7 29.l 4.9 Paraffin 7.7 14.5 8.1 18.2 LP Gas 6.5 100.0 6.0 100.0 Electricity 28.1 5.7 28.4 7.7 Lighting Paraffin 0.2 0.3 0.3 0.6 Electricity 13.0 2.8 12.3 3.4 Refrigeration Electricity 4.2 0.8 3.9 1 .l WaterHeating Electricity12.3 2.6 9.6 2.6 Ironing Fuelwood 1.2 0.2 0.5 0.0 Paraffin 0.0 0.0 0.1 0.3 Electricity 1.8 0.4 1.9 0.5 ...... High Density Area Energy 53.2 64.0 ...... Cooking Fuelwood 21.5 2.3 25.7 4.3 Paraffin 5 .O 9.1 5.9 13.4 LP Gas 2.5 38.5 3.0 49.5 Electricity 15.8 3.3 18.9 5.1 Lighting Paraffin 0 .O 0.0 0.0 0.1 Electricity 5.4 1.1 6.5 1.7 Refrigeration Electricity 0.1 0.3 1.7 0.5 Water Heating Electricity 0.3 0.1 2.4 0.1 Ironing Fuelwood 0.5 0.0 0.5 0.0 Paraffin 0.0 0.0 0.1 0.0 Electricity 1.2 0.3 1.3 2.7
Low Density Area Energy 46.8 36.0 ...... Cooking Fuelwood 4.5 0.4 3.3 0.6 Paraffin 2.7 4.8 2.1 4.8 LP Gas 4.0 61.5 3.0 50.5 Electricity 12.3 2.6 7.2 2.5 Lighting Paraffin 0.2 0.3 0.2 0.4 Electricity 7.5 1.6 5.8 1.5 Refrigeration Electricity 2.5 0.6 2.2 0.6 Water Heating Electricity 12.0 2.5 9.2 2.4 Ironing Electricity 0.7 0.2 0.6 0.2 ......
Notes: (1)Figures are taken from the Base Case Projection of the LEAP Model used in the ZEAP. (2) Nation = % of National Consumption of Fuel (3) Sector = % of Sectoral Consumption of Fuel (4) Energy = % of National Energy Consumption TABLE IX-4 FUEL CONSUMPTION BY END-USE ...... 1982 2002 ...... Sector Nation Sector Nation Agriculture Energy 8.5 5.3 ...... Traction & Tran. Diesel/Gas. 13.8 19.5 13.0 8.7 Curing Coal 32.3 19.8 31.7 9.7 wood 25.1 4.7 25.0 2.4 Irrigation Electricity 9.2 7.3 10.0 3.2 Drying Coal 9.9 6.1 9.9 3.0 liood 5.8 1.8 9.9 0.9 ...... LSCF Energy 90.2 88.2 ...... Traction & Trans. Diesel/~as.12.3 18.0 12.1 7.3 Curing Coal 29.4 18.1 28.8 8.8 \Jood 20.0 3.7 19.6 1.9 Irrigation Electricity 8.5 6.7 8.4 2.7 Drying Coal 9.9 6.1 9.7 3.0 Wood 2.4 1.8 9.5 0.9 ...... State Farms Energy 1.2 2.8 ...... Traction & Trans. Diesel/Gas. 0.6 0.8 1.1 0.7 Irrigation Electricity 0.6 0.5 1.4 0.5 Drying Coal 0.0 0.0 0.2 0.1 ...... Model B Coops Energy 8.3 8.6 ...... Traction & Trans. ~iesel/Gas. 0.2 0.3 0.2 0.1 Curing Coal 2.8 1.7 2.9 0.9 Wood 5.3 0.1 5.4 0.5 Irrigation Electricity 0.0 0.0 0.1 0.0 ...... Small Scale Irrigation Energy 0.0 0.1 Irrigation Electricity 0.0 0.0 0 .l 0.0 ...... SSCF Energy 0.0 0.1 Traction & Trans. ~iesel/Gas. 0.0 0.0 0.1 0.0 ...... Resettlement A Energy 0.0 0.1 Traction Trans. Diesel/Gas. 0.0 0.0 0.1 0.1 ...... & Communal Area Energy 0.1 0.2 Traction Trans. Diesel/Gas. 0.1 0.2 0.2 0.1 ...... & Notes : (1)Figures are taken from the Base Case Projection of the LEAP Model used in the ZEAP. (2) Nation = % of National Consumption of Fuel (3) Sector = % of Sectoral Consumption of Fuel (4) Energy = % of National Energy Consumption RURAL HOUSEHOLDS
Essentially all of the fuelwood consumed by the household sector is used for a single end-use; cooking and heating. Most of this wood is burned in communal area households. None of the households appear to have effective access to alternative cooking and heating fuels. Therefore, in order to play a nationally significant role in the rural household sector, substitution by new and renewable energy technologies must apply to cooking and heating. In addition, an application is possible in energy for lighting which currently consumes the sectoral share of paraffin.
URBAN HOUSEHOLDS
The pattern of energy use in urban households reflects a greater access to a variety of fuels and an increased ability to afford the higher quality fuels and a broader range of end-uses such as ironing, water-heating, and refrigeration. Cooking is again the dominant end-use, although the demand is spread over several fuels of which the most important contributions are made by electricity and fuel wood. The demand is, however, trivial in terms of national demand. Substitution of renewable energy in water heating and lighting might be economically advantageous to households in the low density areas, but it could have little impact on national electricity demand.
AGRICULTURE
The agricultural sector as a whole consumes 8.5% of national energy demand, the majority of which is consumed by the large scale commercial farm subsector. Clearly, therefore, any exploration of means of conserving scarce fuels in agriculture must be focused here, but will very likely also be appropriate to the state farm and coops subsectors. In terms of demand pressure on scarce fuels, the substantial claims exerted on the supplies of diesel and coal (curing and drying play a large role) and the minor claim on electricity can be expected to become relatively much more modest in the fairly near term. On this basis they do not appear to warrant special government effort in conservation or substitution.
OTHER POTENTIAL APPLICATIONS
Although the potential role of renewable energy technologies to mitigate dependency upon scarce fuels is the central concern of this report, these technologies might ultimately achieve greater significance through provision of energy to subsectors which do not currently enjoy adequate access to fuels, for applications now powered by animate energy or foregone. Energy made available for some such applications could have a substantial impact on agricultural productivity, the labor requirements of domestic reproduction or other aspects of general welfare. The energy requirements of these presently unrealized applications will not be found assessed and quantified in accounting tables. By their very nature they do not yet enter economic statistics, thus their evaluation is of necessity somewhat more qualitative, dependent on judgment and a sense of national development priorities. An attempt to identify the most important of these potentially productive or welfare enhancing applications is nonetheless worthwhile. A brief review, on a sectoral basis, £01 lows. One of the most conspicuous needs of the rural household sector is an improved supply of drinking water. Current sources, in most areas surface water, are often distant from the point of use and frequently unclean. The time required for water carrying can occupy a substantial part of the household labor budget. The distinctly unequal access to fuels seen in the urban household sector is manifest clearly in the low level of water heating enjoyed by the households of the high density areas. There are no present plans to assist these households to obtain water heating facilities, but it seems clear that water heating could provide a considerablebenefit to the quality of urban life, were it to become available. The most notable potential new applications lie in the agricultural sector. As the analysis of end-use demand made clear, the communal and resettlement area agricultural subsectors currently consume very little fuel in their production processes. They have virtually no access to mechanical draught power or transport and are forced to rely entirely upon animal or human labor for these functions. Likewise, they have no access to mechanical means of irrigation. Another agricultural application in which new energy resources could prove valuable lies in provision of water for livestock. The provision of adequate easily reached water supplies could reduce the impact of drought damaged grazing. Other settings and applications in which new energy technology could be valuable include supply of a range of energy based services (water pumping, water heating, electric lighting, refrigeration, etc.) for rural institutions such as schools, clinics and the like, and provision of electricity or mechanical shaft power for crop processing and other rural industrial activities. These applications are somewhat outside the scope of this report, but will be mentioned in the discussion of the technologies themselves. 3. RENEWABLE ENERGY RESOURCES ( )
The actual feasibility of employing renewable energy technologies in Zimbabwean applications is, at afundamental level, contingent upon the availability of the primary energy resources upon which they depend. These resources must be available in sufficient power to be economically captured for application. They must be available proximate to the point of use, to minimize expensive transmission. And the temporal characteristics of their availability must approximate those of the application unless they can be economically stored in original or converted form. The following pages outline the conditions of energy supply for the renewable energy technologies which might possibly be employed for the applications discussed above.
SOLAR ENERGY
Solar insolation in Zimbabwe is high by world standards, and the amount of radiation received daily is fairly even throughout the year. The national average daily insolation is approximately 20.5 ~j/m~/da~. The geographic distribution of solar insolation is also fairly even, although annual insolation is slightly graded across the country, with the eastern districts receiving about 8% less energy than the extreme western part of the country. The monthly average insolation for recording devices in Zimbabwe shows a moderate seasonal variation in radiation intensity: the minimum for Harare occurs in June, the maximum in October. Fortunately, the rainy season, and its associated cloud cover, occurs during the hottest months of the year, from November to March, and clear sky conditions obtain during most of the rest of the year. Nonetheless, a series of observations in Harare for the period May-December 1976 recorded 20 occasions in which there were three successive days with less than 51% of annual average sunlight hours. The peak solar flux for t e average clear day in Harare ranges fro3a low of 830 W/mq at the end of June up to a high of 1190 1i/m at the end of December. The net daily radiation on a clear day in Harare varies in parallel, from a 1 W of about 20.1 ~j/m~/da~in June to a high of about 328 Mj/m 2/day in January. However, the annual variation in average daily radiation received is very much dampened by the obstruction of cloud cover during the period when clear day reception is highest.
WIND
Wind energy in Zimbabwe is not as well documented as solar energy. Although the Department of Meteorological Services has wind data going back many years for a fair number of sites, the data has not been gathered in a form which permits accurate evaluation of the actual availability of wind energy. The record of average monthly wind speeds provides an indication of available wind power. This record indicates few sites in Zimbabwe enjoy average wind speeds consistently above the minimum speed generally taken as a threshold for delivery of useful power, 2.6 m/s (corresponding to 9.7 !l/m2) . In fact, that national annual average measured windspeed is only 2.9 m/s. However, the record does indicate considerable seasonal and geographic variation in wind speed, with some sites maintaining higher average speeds and dramatically higher seasonal peaks, such as Chipingo, Masvingo and Harare. In general, the average wind speed reaches its nadir in February, and remains low through the rest of the agricultural season, climbing in July to reach its peak in October, then descending again through the rains. The diurnal variation of wind speed is, in most sites, substantial, with mean hourly wind speed rising from a morning low to a peak at midday, then dropping again in the evening. A more important statistic, perhaps, is the number of occasions on which the 2.6 m/s threshold was never attained during a long period (36 hours or more). The limited data available indicates that this factor is significant for some sites and is not clearly associated with data on average wind speed.
WATER
The discussion of the potential energy resource available in small scale water power is perhaps best introduced in relation to rainfall, as it is rainfall that determines the flow of water available. The rainy season is, at most, of five months duration, approximately November-March, and the rest of the year has little or no rain. Only the narrow mountainous band of the eastern border region escapes the drought of May-September. The geographic distribution of rainfall is far from even. Although the average annual rainfall is approximately 675 mm for the country as a whole (coefficient of variation 25%), areas of the low veld receive as little as 300 mm, while locations in the eastern mountains may receive as much as 3000 mm. In general, the rainfall gradient increases from south to north and fromlowtohigh elevation. After the eastern mountains, regions of relatively high rainfall include the central plateau and the high watershed running southwest toward Bulawayo, as well as isolated areas of high ground. The seasonal distribution of rainfall is in most areas proportionate to the annual rainfall. Zimbabwe may be divided into ten rainfall catchment zones, supporting eight internal river systems. The catchment which receives by far the highest amount of rainfall is Eastern Border, which does not drain internally. The major implication of the pattern of rainfall is that the flows of rivers throughout Zimbabwe are highly seasonal. Extremely large storage facilities would be required to dampen the fluctuation and retain adequate reserves for off season use.
TABLE IX-5 AVERAGE MONTHLY RAINFALL CATCHMENT =A
Catchment Oct. Nov. Dec. Jan. Feb. Mar. Apr. Total ------Hunyani 17.5 82.8 183.4 198.9 173.2 77.2 32.0 765.0 Lundi 24.1 89.4 153.4 150.9 139.1 61.0 29.7 647.6 Sabi 33.5 96.0 165.6 163.8 135.9 67.8 34.5 697.1 Sanyati 29.7 100.1 174.8 177.6 154.2 71.4 32.5 740.3 Gwaai 26.9 83-8 150.6 147.8 124.2 56.6 26.7 616.6 Limpopo 20.8 66.8 99.6 100.3 86.9 41.4 25.7 441.5 Mazoe Ruenya 18.8 86.1 177.8 219.2 170.9 87.9 34.5 795.2 Eastern Border 50.8 133.4 259.8 284.2 251.2 148.8 70.9 1199.1 Kalahari 24.1 76.2 131.1 124.0 119.9 54.4 27.7 557.4 Sebungwe 18.0 79.2 173.5 192.8 160.5 81.3 24.1 729.4
Source: Rain fa1l Report for Season 1980/81 - Zimbabwe Department of Meteorological Services.
Examination of the topography of Zimbabwe's river drainage indicates that, apart from major projects on the Zambesi or other large rivers, settings in which water could be impounded with reasonable economy in significant v01 umes orat high heads, exist only in the mountainous eastern districts, a region already fairly well served with grid based electrification. The numerous small streams and waterfalls of the eastern mountains might well offer sites adequate for installation of micro-hydro generating sets, in the range of 5 - 20 kW, although supporting data on flow rates does not appear to exist at this time. Construction requirements for civil works in these sites would undoubtedly be stringent, due to the high discharge rates at the peak of the rains. Existing dams constructed for other purposes might allow more economical installation of micro-hydro plants, but although there are perhaps 10,000 dams in the country, the possibilities are quite limited. Large dams constituted only 97 of the over 7,000 dams extant in 1978. Of the large dams, 57% were dedicated entirely to irrigation. The 7,207 small dams were also committed largely to irrigation, and apart from seasonal overspill, excess capacity is virtually nil.
WOOD
Zimbabwe is fortunate to have an extensive range of native hardwoods, many of which make excellent fuelwood. Quite uncultivated, these trees grow naturally throughout the "bush" and grazing land of the country. The rural households are dependent upon this supply. Their wood is easily gathered by hand or with simple tools, its accessibility governed by physical proximity to the point of use and by tenurial considerations. Transport is predominantly by means of human and animal labor. A considerable quantity of wood is also produced from exotic species such as the eucalypts, pine and wattle grown for fuel or commercial purposes, which primarily supplies the agricultural sector. Urban households draw from both exotic and indigenous sources. Indigenous and exotic woods both contain a large fractional weight of water when harvested and must be allowed to dry before they will support combustion. Air dried to a moisture content of 12 - 15% (dry weight basis) they embody about 16.3 MJ/kg. The rate of wood consumption for fuel and construction, combined with the destruction due to agricultural clearing, currently exceeds the rate of regrowth in many areas of Zimbabwe. A severe scarcity of accessible fuel is already felt in some localities by households dependent upon natural growth. The situation can be expected to worsen, becoming widespread as general shortages develop in several provinces during the 1990s. Much of the scarcity of fuelwood could be mitigated by a vigorous program of rural afforestation. However, tree growth is not instantaneous, and even an extremely rapid rate of forestry development could not be expected to yield significant fuel for ten years or more. In view of the shortages of wood, fuelwood can scarcely be considered an uncommitted resource. Yet, because fuelwood is a relatively heavy fuel which is awkward and expensive to transport, and because the market for fuelwood is as yet poorly developed, some regions with excess supply do exist. It is estimated that the government and commercial timber and wattle plantations of the eastern districts allow 80% - 90% of the wood that they grow to waste as unused bits or through senescence. Only 40% of the timber harvested reaches the mill, and just 50% of that which enters the mill emerges as product. As much as 60% of the timber harvested annually is thus potentially available for no more than the cost of col lection and transport. The proportion of wood available on the wattle plantations is even greater, as currently most of the wood is burnt on site for disposal after the bark is stripped. Another stock of underutilized wood can be found on large scale commercial farms, many of which have switched from wood to coal for their curing and drying requirements. Where these plantations are accessible to adjacent communal areas they are often a shared resource, but in many situations there is no adjacent demand or the rule of private property remains in force. These excess local stocks do not, however, constitute a significant national resource. In most places, they could be consumed by nearby populations whose supplies are in deficit, if made available.
CHARCOAL
The product of partial combustion of wood or other organic matter, charcoal is a light, easily handled fuel with, at 29.1 MJ/kg, almost twice the energy content per unit of mass as air-dry wood. Charcoal burns evenly and cleanly, without tars or smoke, and is generally considered superior to wood for both domestic and industrial use. It is prepared by burning a carefully structured stack of wood enclosed in a kiln which allows precise regulation of air flow to the fire. Since a part of the initial charge of wood is burned in the process, the energy content of the charcoal produced is necessarily less than that of the wood which supplied it. The efficiency of charcoal production can vary greatly, typically from 20 - 45%, depending upon the type of kiln used. Stationary masonry kilns and transportable metal kilns achieve efficiencies at the upper end of the range. Simple pit kilns tend to perform at the lower end of the range. Despite their inefficiency, pit kilns are used widely by itinerant producers in regions where charcoal is a common commodity, principally because they entail no capital costs and minimize the labor of transport by allowing the charcoal to be produced at the site of felling. The more efficient kilns are relatively expensive (in the range of $2,000 - 3,000) and either require transport of the wood to the site of production or are themselves fairly difficult to move. Charcoal is a fuel very little used in Zimbabwe. Most of the national production goes to industrial firms in the mining and automotive industries, although a significant part of the market is comprised of upper income urban households. The largest manufacturer of charcoal is the Wattle Co. (Pvt) Ltd., of Mutare. This firm produces about 1,100 tons annually. The Wattle Co. employs Missouri-style masonry kilns, which yield 15 tons of charcoal per 60 ton charge of wood: an efficiency of about 44%. The company reckons the cost of production at about $105/ton, about 112 the current retail charge of $1.27 per 5 kg bag (including tax). They estimate that the cost could be cut to $90/ton with increased production. The current capacity of the Wattle Co. operation is about 3300 tons. The company would be eager to expand its operations if a larger market were to develop. They estimate they could ultimately produce as much as 25 000 tons/year (0.7 x 106 GJ) from the wood waste of their own operations. There is virtually no pit kiln production of charcoal in Zimbabwe despite the widespread use of the technique in countries adjacent on the north and the fact that many Zimbabweans must be both acquainted with the technique and desperately in need of income. The concentration and low level of charcoal production in Zimbabwe is almost certainly attributable to the very low level of development of the market. The potential for expansion of production based on the wood currently going to waste in the government and commercial plantations of the eastern districts is considerable. If 50% of the sawmill waste and 60% of the harvesting waste were efficiently converted to charcoal, production would amount to over 899 000 tons (2.59 X 106 GJ, the equivalent of forecast urban domestic fuelwood demand in 1992). If itinerant producers operating outside the demarcated forest areas could find a market and were permitted to freely engage in production, the increase in charcoal supplies would be far greater. There have been a number of proposals that the government encourage expansion of charcoal production and development of the urban market for the fuel. These proposals are generally based on the proposition that the burden of the urban domestic demand for fuelwood could be shifted from the depleted adjacent communal and commercial farm areas to more remote regions enjoying an excess stock of wood. The increased distance for transport would be mitigated by the greater energy density and ease of bulk handling of charcoal. The chief problem with expansion of charcoal production is that it results in a diminution of the net wood energy available, as well as a shift of wood resources from the rural areas. Unless charcoal production draws only upon stocks of fuelwood which are not otherwise accessible and normally go to waste, or allows use of more efficient end-use devices, the sacrifice of energy involved in conversion should not be considered, in view of the forecast fuel shortages. A look at the fuelwood supply/demand balance for Manicaland indicates that the provincial demand for fuelwood is expected to exceed the rate of growth of accessible stock by almost 4.6 X 106 GJ by 1992. Unless this imbalance can be corrected, it would seem most unwise to mine the wood stocks of Manicaland for the sake of the urban consumer. Moreover, there is a great danger that expansion of charcoal production could lead to a further deterioration of the fuelwood supply position of regions already in crisis. Regulation of charcoal production techniques and sources of supply is likely to prove extremely difficult, once an expanded market offers income generation potential to the rural poor. There is good evidence that well managed wood fires under low grates can match the efficiency of charcoal stoves, so there is little to be gained in terms of final energy demand by means of this particular fuel substitution.
CROP RESIDUES AND DUNG
Crop residues and dung are other forms of biomass from which energy may be extracted directly, by means of combustion, or indirectly, by means of biological decomposition into combustible products. Their energy content, like that of wood and charcoal, resides in organic chemical bonds which release heat in oxidation. It is thus a function of their dry mass and chemical composition. In general the energy content of crop residues does not vary greatly, ranging between a low of 13.4 MJ/kg for wheat straw and a high of 16.1 kg for maize stover (dry matter basis). The range of the gross energy content of dung is somewhat greater, from 14.8 kg kg for poultry to 19.0 MJIkg for pigs (dry matter basis). The annual production of crop residues in Zimbabwe is quite substantial, as would be expected from the extensive development of the agricultural industry. Cereal residues, especially maize stover, form the dominant share, but cotton stalks and sugar cane tops are also significant. Other residues include groundnut and potato vines, vegetable wastes and the like. The annual total yield of cereal residues alone amounts to almost 3 X 106 tons, and has an energy content of over 46.5 x 106 GJ. The availability of the these crop residues for use as an energy resource is contingent on the cost of collection and transport and on their value in alternative uses. Depending on conditions and techniques, the cost of gathering residues on commercial farms can range from $0.351~~to $0.891~~. Most of these residues are, however, already utilized as forage on commercial farms where animals are turned loose to graze on the lands after harvest, or as kraal rations on small scale farms where residues are brought in and stored for dry season feeding. Their economic value as feed, especially where they need not be gathered in from the lands, is generally superior to their value as fuel, and is enhanced by the return of dung to the lands. The total energy content of dung produced by domestic stock in Zimbabwe is also considerable. It amounts to over 96 x 106 GJ in total, over 90% of which comes from cattle. Most of this dung is however, essentially uncollectable, as the stock on large scale commercial farms is generally free ranging, and the domestic stock of the small-scale sector is kraalled only at night. Where dung is collectable, in dairy farms, feedlots and kraals, it is usually found wet, with a moisture content ranging as high as 90% (dry basis) when fresh. The high fractional mass of water and other handling difficulties render transportation of fresh dung costly and make drying impracticable. Most concentrated supplies of dung are gathered moist and transported short distances to be spread on the lands as fertilizer, in which use their value is quite high.
SUPPLY SUMMARY
The above review of the availability of primary renewable energy resources has limited the field of nationally appropriate renewable energy technologies, concluding that while fuelwood will remain the principal rural fuel its increasing scarcity precludes conversion to charcoal or other expansion of its application. Solar energy has been shown to be widely available, although with important temporal constraints, and crop residues and dung are shown to be produced in substantial quantities, although alternative uses and the cost of collection limit their economic availability. Wind and water are dismissed as nationally significant energy resources, present in insufficient quantity or distribution to have general utility. There is no doubt that all of the renewable energy resources are in some sites present in quantities sufficient to be useful, and technologies based on each of the basic resources may well play roles of great local importance. However, a consideration of the national impact of renewable energy devices can more or less be limited to those technologies which use woodfuels more efficiently than present devices and those which exploit available solar energy, crop residues or dung.
4. REVIEW OF APPLICATIONS AND TECHNOLOGY Having in earlier sections identified the significant potential applications for renewable energy technologies in the domestic and agricultural sectors, and assessed the availability of the various primary renewable energy resources in Zimbabwe, this report now moves to a consideration of the capacity of technologies based on available resources to meet the conditions for successful adoption in significant applications. It begins with a brief review of some of the issues which condition adoption of technology, then characterizes in terms of a few key variables the applications previously identified. The available energy supply technologies are similarly characterized, and potential matches noted. The appropriateness of selected application/technology combinations is then explored further in the following pages. The first criterion for assessment of the appropriateness of a technology for use in a particular application is its technical capacity to perform the job required. In the case of energy technologies and applications the job can be characterized, in a crude way, by a few key variables; output/input type, power, availability, timing, and reliability. Although in principle all forms of energy are interconvertible (and energy technologies are devices designed to make such conversions, to useful forms from others which are available but less useful), the cost in equipment and efficiency of most such conversions is high. In considering the characteristics of energy based tasks and potential means of supplying them it is necessary to ensure that the task's requirement for a particular form of energy, e.g., heat, shaft drive, light, etc., is met as directly as possible by the supply technology. Otherwise, the coupling will likely be inefficient. and economically inappropriate. Power, another key characteristic, is the measure of the amount of energy transferred per unit of time. Availability is another key variable. Some applications may be performed intermittently over a long period of time, contingent upon the availability of energy. Others must be performed as needed, with energy available on demand. Problems of supply availability can to a certain extent be bridged by storage of input energy on product, but storage is generally expensive, and often impractical. Timing is essentially a second order factor of availability; it represents the seasonal or diurnal scheduling requirements of the application or of energy availability. Finally, reliability indexes the criticality of a demand and the consistency with which supply conditions are normally met. The key technical characteristics of applications identified in the discussion of demand are described in Table IX-6 The renewable energy technologies can be similarly characterized, although a certain amount of judgment must be used. Table IX-7 describes the key technical characteristics of technologies based on the primary renewable energy resources identified above. Comparison of the input requirements of potential applications and the output characteristics of potential technologies reveals a limited set of possible matches. 17hen technologies general l y unavailable because of an insufficiency of resources are discarded, the list of possibly significant matches between application and technology reduces to the following: Once the condition of basic technical matching is met, a host of other factors enter into the determination of the appropriateness or attractiveness of a technology for a particular application and setting. These factors might generally be described as the cost/benefit matrix of an application/technology combination. Cost benefit analysis is straightforward for commercial settings where distinct processes may be assessed, Even here, though, there is a complex array of different types of cost and benefit. Each technology cost is evaluated at its opportunity cost. But in the household many elements of cost and benefit depend on preferences and the immediate material economy of the household. Moreover, tasks tend to be integrated so that one device serves several aspects of work or leisure. In such a setting, instead of relying upon the computation of mere financial costs, the adoption of successful technology will be a result of trial and error, and the devices used will meet several objectives at once. TABLE IX-6 TECHNICAL CHARACTERISTICS OF SELECTED APPLICATIONS
Sector Application Energy Type Power Avail ability Timing Reliabil~ty ------Rural H.H. Cooking/Heating High/Low Temp Heat 4 kW On Demand 3 X Daily, Year Round High/Not Evenings, Especiall y Critical ...... Urban H.H. Water Heating Low Temp Heat 2 kW On Demand, Year Round, Especially Not Critical Storage Mornings & Evenlngs ...... Agriculture
LSCF Traction/Trana. Internal Combust. 30-90 kW On Demand Year Round High/Not Motor Fuel Critical
Curing/Drying Low Temp Heat Scheduled June-August Not Critical
SSCF Traction/Trans. Internal Combuat. 10-90 kW On Demand Year Round, Especially Very High Motor Fuel October-December Critical
Irrigation Shaft Drive Scheduled Dry Season, Especially Very Hlgh Min Storage March-June Critical
General Stock Watering Shaft Drive Scheduled Dry Season High/Not Storage Critical ...... Institutions Water Supply Shaft Drive On Demand Year Round Very High Storage
Water Heating Low Temp Heat OnDemand YearRound Not Critical Mln Storage
Lighting Light Scheduled Year Round Varies
Cooling Electricity/Gas Scheduled Year Round Very High Critical
Cooking High Temp Heat Scheduled Year Round Hlgh ......
Finally we must recognize that choices which are desirable from the private viewpoint of each individual member of a community are often inimical to their collective welfare, and this justifies an explicit concern for the distributional impacts of government policy towards technology change. Two factors of vital importance are the degree of access to resources, markets or alternative investments, and the discount rate. The former is determined for a household by its own labor constraint and the heavy constraint on capital investment felt by households living under the risk of crop failure without access to credit. TABLE IX-7 KEY TECHNICAL CHARACTERISTICS OF SELECTED TECHNOLOGIES
tmary Resource Technology Energy Type Power Availability Reliability/Timinc
lar Energy kr Heater Low Temp Heat Contingent Year Round High-Dry Season Midday Low-Rains
Water Heater Low Temp Heat Contingent Year Round High-Dry Season Storage Midday Low-Rains
Photovoltaic Electricity, Etc. Contingent Year Round High-Dry Season Min Storage Midday Low-Rains
Reflect. Cooker Med. Temp Heat Contingent Year Round High-Dry Season Midday Wind Energy
Mechanical Mlll Shaft Drlve Contingent Seasonal Moderate-Rains Peak-Rains Low-Dry Season
Generator Electricity, Etc. Contingent Seasonal Moderate-Rains Peak-Rains Low-Dry Season .------:er Energy Mechanical Mill Shaft Drive Contingent High1y Seasonal Moderate-Rains Storage Varies Peak-Rains V. Low-Dry Seas.
Generator Electricity, Etc. Contingent High1y Seasonal Moderate-Rains Storage Varies Peak-Rains V. Low-Dry Seas.
~d Hearth High/Low Temp Heat On Demand Any Time Complete
Stove High/Low Temp Hest On Demand Any Time Cornpl ete
Producer Gas Internal Combustion On Demand Any Time Moderate
%coal Stove High/Low Temp Heat On Demand Any Time Complete
Producer Gas Internal Combustion On Demand Any Time High
Generator Fuel
)p Residue Stove Hlgh/Low Temp Heat On Demand Seasonal Complete
Biogas Generat. High Temp Heat, Llght On Demand, Year Round Moderate Intern. Combust. Fuel If Storage
Producer Gas Internal Combustion On Demand Seasonal Moderate
Generator Fuel
19 Stove High/Low Temp Heat On Demand Seasonal Complete
Biogas Generat. Hlgh Temp Heat, Light On Demand, Year Round Moderate Intern. Combust. Fuel If Storage CookingIHeating ...... Solar Cookers Hearths & Stoves Burning Liood, Crop Residues or Dung Biogas Generators Fuelled With Crop Residues or Dung ...... Water Heating ...... Solar IJater Heaters Hearths & Stoves Burning Wood, Crop Residues or Dung Biogas Generators Fuelled with Crop Residues or Dung ...... Traction/Transport ...... Producer Gas Generators Fuelled with Wood, Crop Residues or Dung ...... Irrigation, Stock...... Solar Photovoltaic~ Watering & Water Producer Gas Generators Fuelled With supply Wood, Crop Residues or Dung Biogas Generators Fuelled with Crop Residues or Dung Animal Traction Mechanisms ...... Crop CuringIDrying ...... Solar Air Heaters
Lighting & Cooling ...... Solar Photovoltaics Biogas Generators Fuelled with Crop Residues or Dung ......
The discount rate reflects the benefits of alternative uses foregone as a consequence ofthe use of capital for some particular purpose. It is a function of access to financial resources and of the degree of desperation for the benefits of capital spending. For renewable energy technology, the effect of the discount rate is to raise the cost of current expenditure as compared to future expenditure. Typically, diminished fuel costs are traded off for inflated equipment charges. This is one of the key reasons that several capital intensive renewable energy technologies have been adopted much less wide1 y than their proponents had forecast. In summary, costs and benefits might be said to be the restrictions on and motivations for adoption of technologies. Accurate evaluation of the comparative cost of alternative technologies can be extremely complex, and is highly contingent on the specific attributes of the economic setting. The most complicated setting is often the one ordinarily thought most simple; the household, with its resource constraints, partially unpriced production, integrated labor and material processes and high discount rate. A precise determination of the "optimum" technology is generally not possible outside the actual experience of the use. An indicative comparison based on the considerations discussed above may be drawn, however, and is all that will be attempted in this paper. In the application/technoiogy review of the £01 lowing pages the significant potential applications for renewable energy technologies identified earlier in this report are briefly described in terms of current practices and technology, and some of the issues and constraints that affect potential substitutions or innovations are highlighted. The candidate technologies for each application are described and reviewed in light of this discussion, application by application, and inferences drawn as to their prospects for introduction and general adoption.
CURRENT PRUCTICES AND TECHNOLOGY Virtually all cooking and heating in the rural Zimbabwean household is carried out with fuelwood, although dried dung may be used to some extent in critically wood- short localities, and crop residues may be used as a supplemental fuel when they are readily available at the end of the harvest season. Except on large scale commercial farms, where fuel 1s often supplied as part of the labor contract and may be grown in plantations, most fuelwood is gathered by hand from indigenous trees and bushes growing on grazing lands, kopjes and other odd lands. In most cases it is carried by headload. Wood gathering can impose significant costs on the household, not only in terms of the effort undertaken and leisure foregone, but also in terms of the opportunity cost of time which could have been devoted to other productive activities. This conflict is partially mitigated by the fact that fuelwood can be stored. Most women make an effort to gather and store fuelwood in the dry season so as to reduce the labor required for this purpose during the rains, when labor for agriculture is at a premium. Cooking is done almost exclusively by women. It is generally conducted indoors in the kitchen, the household -enter for cooking, eating and social intercourse. The fire is built in a small depression in the center of the floor of the kitchen. The fireplace may be a traditional three stone hearth or, more commonly now, a low welded iron grate. The cholce of the grate is quite interesting, in light of the fact that most women acknowledge that its use consumes ane and one-half to three times as much wood as the use of the three stone hearth. The explanation, given by women themselves, for this apparent irrationality provides an instructive example of the complexity of economic 3ptimization within the household. The near universal explanation is that because the grate supports several pots simultaneously, unlike the three stone hearth, it allows the cooking of meals to be concluded in a shorter span of time, thus leaving more labor available for agricultural work during the rains. The additional time required for fuel gathering is not valued so highly, since it can be spent during the dry season, when labor is relatively free. A typical pattern of use of the fire is shown in Figure IX-1 below. Three meals are prepared during the course of the day. The first is typically tea, perhaps with bread. The second and third are more substantial; sadza (stiff maize porridge) with vegetable, or occasionally meat, relish. The latter two meals involve two separate pots in their preparation: the sadza pot, which may contain five kilograms of water or more and requires a high power heat flux over a period of thirty minutes or so, and the relish pot, containing a much smaller quantity of food which must be simmered at low power for a more prolonged period.
FIGURE IX-1 TYPICAL DAILY RURAL COOKING/HEATING SCHEDULE
Flre Burning XXXIXXI~XXXX~XX XXXXXXXXX+ *XIXXIXXXIXIXX
Cooking ~XXIXX xxxxxx ***+X
Water Heating LXX *X
Space Heating XXXXXXXIXX
Cook Present xxxxxxxxx ~XXXXX *,X***
Others Present ****** XXX~XXXXXXX
The fire is used for space heating and as a social center for a brief period in the early morning and for several hours in the evening, even during the hotter months of the year. During the cold nights of the dry season some members of the family may also sleep in the kitchen to stay warm. For much of the rest of the day the fire is let smoulder, the fuel pulled apart to reduce burning, but the coals kept alive for easy rekindling. Asked about advantages of their stoves, a large number of users of the grate comment that in addition to allowing simultaneous and thus faster cooking, it eases management of the fire by facilitating adjustment of the fuel and permitting the use of larger sticks. Other advantages commonly noted include increased safety through greater pot stability and a greater throw of light through the open frame. Asked what cooking device they would most like to have and use, most rural cooks respond that they prefer the grate, though nearly all also, when prompted, respond that they want an oven for baking.
ALTERNATIVES
Solar Cookers
Solar cookers may take a variety of forms; concentrating paraboloid reflectors which focus radiant energy on an absorbent cooking chamber or the pot itself, insulated heat trap boxes with glass covers and a ring of reflectors to increase the flow of light into the box in which the pot sits, and even concentrating collectors which direct radiant energy to a heat transfer fluid, conveying heat to an insulated storage reservoir in which the pot may be placed. No solar cooker has yet met with acceptance by a significant number of people anywhere in the world, despite their very obvious advantage of requiring no fuel whatsoever. This is not to say that solar cookers don't work; they do often cook food quite well and with surprising speed. The problems of solar cookers hinge on the contingency oftheir use upon the supply of adequate solar energyandthe fact that this energy is available in high power only at midday, and then not reliably through the year. Since midday is but one of three daily periods of cooking, and not the time when the largest meal of the day is prepared, which is evening, a solar cooker unequipped to store energy sufficient to allow cooking at other times of day can provide at best only a small portion of cooking energy. Unfortunately, storage cookers are not well developed. The cost of proposed storage designs is quite high, well over $100.00, and none have been tested in practice. Other problems with solar cookers include the necessity of frequent reorientation to track the passage of the sun, the necessity of cooking outdoors in the heat of the sun, the preclusion of normal cooking practices such as stirring, which would cause unacceptable heat loss, and complete inability to provide space heat or serve as a social center. For these reasons as well as their cost and general unfamiliarity it seems unlikely that solar cookers could come to play a significant role in Zimbabwe without substantial and unanticipated innovation.
Biogas Generators
Biogas generators are large volume reaction vessels in which organic materials are partiall y decomposed under the action gf anaerobic bacteria to a medium energy gas (24 MJ/~). Composed of approximately 60% methane and 40% carbon dioxide, biogas lends itself to a variety of applications. It may be burnt to provide light or heat or used to fuel internal combustion engines. Biogas generation has one overwhelmingly attractive feature; its input materials are virtually costless. The most common feedstocks for biogas generation are wet manure and crop residues (Wood, which has a high content of indigestible lignins, is not a suitable feedstock.). The value of these materials as compost or fertilizer is not reduced by their passage through the digestor but enhanced. At the same time, the action of the methanogenic bacteria destroys many pathogens and serves as an effective sewage treatment. This ability to generate a valuable gas while treating and improving the quality of manure has prompted interest in biogas throughout the world. Constraints on the use of biogas arise basically because of the rate limitations of the biological process with which it is generated. The process of anaerobic decomposition is relatively slow, so production of gas at a useful rate requires a large volume permanent culture. Such systems produce continuously and are not easily regulated. Thus biogas cannot be produced on an "as neededlwhere needed" basis, but must be generated at fixed sites and stored. Since compression of the medium energy gas is not economical, biogas must be stored in large leak-proof containers and distributed through piping. These considerations preclude mobile applications and impose heavy storage costs on intermittent high demand uses. The most common forms of biogas generator are modifications of the types of generator developed for household use in India and China. The Indian model consists of a large reservoir, 3 - 10 m3 for domestic use, over which is fitted a floating steel gasholder equipped with a pipe to allow offtake of the gas which bubbles up from the manure or crop residue slurry and is caught within the gasholder. The gas collected is kept at more or less constant pressure by the weight of the suspended gasholder. The reservoir itself maybe an above ground tank, but is usuallybuiltof stone or brick set in the ground. It is equipped with an inlet tube through which raw manure, residues and water are fed, and an outlet tube set at slightly lower elevation to allow the digested material to be exhausted by displacement with new feedstock. The Chinese design differs in that the reservoir is not fitted with the floating gasholder, but is sealed at constant volume so that as gas is collected its pressure rises and slurry is displaced. Both designs have their deficiencies; the floating steel gasholder of the Indian model is very expensive, over $300.00 for the 10 m3 digestor suitable for a household's general needs, while the high pressures accumulated in the Chinese model make it prone to leaks which can be quite difficult to repair. The current cost of the 10 m3 Indian model, as built by the ministry, is about $1467.00, not including sand, stone and the 3000 bricks not normally bought but locally made. Materials constitute $767.00 of this cost; the rest is labor and travel expenses for the Harare based building team. The cost of the Chinese model of 6 m3, as constructed by the Silveira House team, comes to about $400.00, of which about one-half is materials, not counting the sand, stone and 1500 brick locally obtained. Production of gas ranges between 0.45 m3/da 1.5 m3/day, depending upon the temperature, for the 6 m y and Chinese digester fed with 9 kg dung and 9 kg water per day, according to local measurements. This is sufficient gas to cook two meals a day for an ordinary family or provide several hours of high quality lighting, from the dung of 3-5 cows kraaled at night. Biogas generators currently extant in Zimbabwe include both Chinese and Indian models ranging in size from 3 m3 to 10 m3. One, a small Indian model located at Domboshawa Training Center, has been instal led and working we1 l since 1979. Most of the others are institutional, located at schools, clinics, creches, etc. Several Zimbabwean biogas plants are working quite well, but, depending on the region, 13%- 30% of the owner/operators own 3 cows or less. And in many rural areas the fetching of water is more problematic than the acquisition of fuel. Finally, the extent to which introduction of biogas to the household would reduce the consumption of fuelwood is not clear. It would be extremely costly to build a generator of sufficient size to supply the space heating needs now met by the cooking fire. Households which desire space heating and the social center provided by the fire would find it necessary to use fuelwood for this purpose even if all their cooking was done with biogas. Indeed, the household in Chishawasha which displays an exemplary Chinese type biogas generator does build a fire most evenings, although fuelwood is by no means immediately accessible. There is no question but that biogas generators can make a valuable contribution to rural energy supply in Zimbabwe if they are well constructed, adequately supplied with dung or crop residues and water and well managed. But very few households are in a position to invest in and manage a biogas plant for fuel purposes. And it is not clear that fuelwood corlsumption would be substantially reduced if biogas were successfully introduced, since biogas cannot be expected to meet space heating and social needs. It would be better to leave biogas technology to the rural institutions. These potential users will be better equipped with the funds and management capacities to install and maintain a generator, and will also have need of the specific services which biogas can provide, lighting, cooking and cooling. If well situated with respect to supplies of manure and water (e.g., adjacent to a dip) they may possibly be able to extend these applications to driving a pump or other device equipped with an engine. Hearths and Stoves Perhaps the most straightforward approach to tackling the cooking/heating fuel supply problem lies in increasing the efficiency of devices which use the existing fuels. This approach has been taken over the last twenty years by many institutions concerned with rural development in Asia, Latin America and Africa, and more recently, by a number of institutions in Zimbabwe, including the Department of Energy, Silveira House and the Hlekweni Training Center. Substantial sums have been invested in programs intended to bring improved stoves to the rural areas, but few of these efforts have met with any success. Spontaneous diffusion and adoption of the stoves promoted has been extremely rare and there is very little evidence of aggregate fuel savings having been achieved. Reviews of the stove promotion programs reveal that most have been poorly conceived efforts to distribute devices which are from the potential users' point of view actually inferior to existing hearths and stoves. In fact, many of the "improved" stoves have proven, on careful examination, to be less fuel efficient than the traditional hearths they were intended to replace. One conclusion that has emerged very clearly from these failures is that improvement of traditional devices can be a very demanding task, requiring attention to the multiple roles performed by the device, the integration of its use with other activities and the highly developed values and preferences of its users. Technical improvement of performance on one parameter, such as fuel efficiency, may involve unacceptable compromise of performance on others. Thus successful designs will likely be developed out of an iterative process of trial and modification, incorporating both the insights of engineering and the sophisticated evaluation of users. Some guidance as to the prospects for development of an improved hearth or grate for use in Zimbabwe might be found in a review of some of the valued characteristics of the grate currently in use and some of those which would be desired in an improved stove. Valued characteristics of the grate include:
(1) Provision of cooking and space heating energy, and to a limited extent, light (2) Minimal fuel preparation (esp. for long or large sticks)
(3) Ease of observation and adjustment (4) Ability to cook several pots simultaneously (5) LOW cost (6) A wide power range (for both fast and slow cooking)
Desirable attributes of an improved hearth or stove would include :
(1) Increased safety
(2) Smoke reduction
(3) Improved efficiency
Some of these desiderata are probably incompatible with some of the valued qualities of the existing grate. There may well be some room for compromise, but it should be clear that fuel efficiency is only one of a set of characteristics that must be possessed by a stove that is to be seen as "improved" and freely adopted. A careful evaluation of the range of stoves available in Zimbabwe, including known "improved" designs , revealed something of the direction for potential stove development. This work is reported in chapter V1 of this volume, so will not be repeated here. It would appear from the results of the preliminary tests reported in chapter V1 that:
(1) Cooks who choose the open grate over the three stone hearth are sacrificing fuel efficiency in favor of convenience and time efficiency.
(2) Cooks who use ordinary grates could maintain the advantages of the grate and regain a high degree of fuel efficiency at no cost, by simply lowering the grate.
(3) No other wood burning cooking device among those tested is superior to the low grate, in terms of fuel and time efficiency.
(4) The Hlekweni stove is the clearly superior choice for wood burning households which are willing to accept moderate fuel efficiency in return for the cleanliness and safety advantages of a closed high mass stove.
In summary, it would seem that the prospects for achieving an improvement in cooking efficiency through lowering of the grate are quite good. The potential impact on fuelwood consumption is not entirely clear, but if it is assumed that all households using three stone fires will likely be able to obtain grates within the next few years, then a program which persuades users to lower the grate might reduce the consumption of fuel necessary for cooking by as much as 50% and a successful prornotion of the Hlekweni stove might achieve reductions in cooking fuel consumption of as much as 10% in adopting households. If cooking energy demand accounts for perhaps 75% of actual fuelwood use in the cooking/heating fire, as users estimate, then the reduction in fuelwood demand might range as high as 30%, given universal lowering of the grate. If necessary cooking energy is a smal ler proportion of actual household demand, it may be that potential improvements in cooking efficiency would have a lesser effect. Or again, the effect of a fuel efficiency program could be greater if heightened consciousness of fuel conservation resulted in more efficient fire management. Evaluation of the potential value of the improved grate or stove cannot really be conducted without more extensive field data on household needs and use of fuel and actual field tests of the long term change in consumption of households adopting the new devices. In view of the substantial possibility of achieving reductions in fuelwood demand and improvements in household safety and health this work would seem to be a priority.
6. WATER HEATING
CURRENT PRACTICES AND TECHNOLOGIES
Water heating is not carried out in the households of Zimbabwe's rural and high density areas with a special appliance storing a ready supply. Rather, water is heated when needed on the hearth or stove used for cooking. Water heating may be conducted as part of the cooking process or it rnay be done specially. In either case the amount of energy devoted to water heating is fairly minimal. Few households in the rural areas heat water for bathing. Provision of hot water at an affordable cost would be a considerable amenity in either setting, although access to clean water is the prior need in much of the rural area. Urban households of the low density areas are equipped with electric geysers storing hot water for supply on demand. Supply is not a problem with this equipment, but the cost of energy used for water heating amounts to 35% - 50% of the household electric bill, a significant part of the household budget. A technology which reduced this cost could be a significant benefit to the urban household.
ALTERNATIVE TECHNOLOGIES
Hearths and Stoves
There are no clear means of improvingthe open grate for the purpose of water heating. Stoves, unlike grates, can be designed to incorporate a water tank heated by the chimney gases after they have passed the cooking pots and insulated from heat loss by the warm body of the stove. The Hlekweni stove, for instance, includes a 5 gallon water tank which attains a very respectable temperature during the cooking of a meal and remains warm for some hours thereafter, provided the stove has been used sufficiently to warm its mass, Water heating is seen by users to be a valuable capacityin a stove. Since it is an ancillary feature which actually increases net efficiency, it should be incorporated in any high mass stove which is promoted for fuel conservation. Widespread adoption of such improved stoves will, however, not occur without an extensive effort to train builders and bring knowledge of the virtues of these stoves to the rural population.
Biogas Generators
In so far as domestic use is concerned, biogas generators are no more feasible for water heating purposes than for cooking. They cannot be expected to play a significant role in provision of domestic hot water. Rural institutions, on the other hand, may well be in a position to manage the construction and operation of biogas generators for a combination of cooking, water heating, lighting and other applications, provided they have access to construction funds and adequate supplies of manure and water. Institutional plants currently constructed are quite small, at most 10 m3, and thus insufficient to supply water heating energy as we1 l as the fuel for th priority uses of cooking and lighting. However, the 88 m' plant now being built at Kushinga Phikelele should demonstrate the capacity of biogas in this type of setting.
--Solar Water Heaters Solar water heaters designed for domestic use usually consist of a collector attached to a storage tank. The collector is a flat plate, coated with black paint or other materials selected to enhance the capture of solar radiation and its conversion to heat energy, and equipped with tubes through which the water to be heated circulates. The collector plate is usually insulated with one or two layers of glass on the side facing the sun, and with solid insulation on the back and sides to minimize heat loss. The storage tank and any piping are also insulated. In the standard configuration, water, supplied from the mains, circulates in a gravity convection loop between the tank and the collector and is drawn directly, or as input to an electric geyser, as needed. The amount of energy delivered is contingent mainly upon the size of the collector, although a host of other factors have an effect. Three firms manufacture solar water heating systems in Zimbabwe. Their designs and construction techniques vary, but all systems are fabricated to a reasonable standard, and some are of a very high quality. Models suited to urban domestic use range from an integral collector/storage unit of 45 liter capacity to a 220 liter design with separate panels and storage. Costs range from $485.85 for the small integral system to $2109.75 for the large ther~nosyphonsystem. These costs imply, accounting for current electricity prices and a1 lowing generous efficiency and hot water demand estimates, payback periods of 6 - 12 years for high volume consumers in the low density areas, and much longer times for low volume consumers in the high density areas. The only solar water heater manufactured explicitly for the rural market is a 45 liter stand-alone integral model costing $225.00, clearly too much for all but the most wealthy of rural households. The number of units sold for domestic use is quite small, amounting to perhaps 200 m2 of col lector last year. The private market is declining rapidly due to economic circumstances. Government has stepped in to assist the industry, with purchases by the Ministry of Construction for institutions and rural government housing. Unless the costs of solar water heating systems can be considerably decreased, the rate of adoption of the technology will remain very low. According to the major manufacturer, costs could be reduced by one-third and quality greatly improved if foreign exchange allocations for the substantial fraction of imported components were made available and import duties relaxed. Such action has been recommended to government as an indirect means for encouraging adoption of solar water heating, as have more direct means such as regulations requiring installation of solar water heating systems in all new construction. However, little short of complete subsidy would bring the cost of solar water heating within reach of the rural population which commands priority in government aid.
7. TRACTION AND TRANSPORT
CURRENT PRACTICES AND TECHNOLOGIES
There is a fundamental division in the agricultural sector between the capital intensive mechanized farms of the large scale commercial and state farm subsectors and the labor intensive animate powered farms of the communal and resettlement subsectors. The small scale commercial and coops subsectors occupy a somewhat ambiguous intermediate position. All traction and transport on the large scale farms is carried out with tractors and trucks, almost all diesel powered. Their use is highly efficient, but the cost of fuel remains a significant factor in the overall cost of production. Since capital intensive production is highly dependent upon timely performance of tasks, and since there is no ready substitute for imported diesel, an interruption in supply could have a catastrophic effect on agricultural yields. Small scale agriculture depends mostly upon oxen for draught power and transport. There are however not enough animals to service its needs. Fully half of the communal area households of some provinces own no cattle at all. Households dependent on hiring or borrowing animals for ploughing are often unable to plough or plant at the optimum time to take advantage of the rains, consequently suffering substantially decreased yields.
ALTERNATIVE TECHNOLOGIES Producer Gas Generators Producer gas is a medium energy combustible gas formed by the partial pyrolysis and high temperature reduction of carbonaceous solid fuels, most commonly wood chips, charcoal or crop residues. Its principal combustible components are carbon monoxide and hydrogen, although it also contains some methane. The relative composition varies with feedstocks and conditions of production. When made from dry wood it approximates 20% CO, 15% H2 and 3% CH4 as well as some 60% incombustible gases, e.g., N2. Depending upon composition the energy content varles between 4.1 - 5.4 MJ/M~. Producer gas is an efficient substitute for the liquid hydrocarbons in all their fuel applications, including internal combustion engines. It can fuel existing equipment from boilers to diesel engines with only minor modifications and little additional training of operators. And it can be generated as needed/where needed in a simple compact and relatively inexpensive apparatus, free of the storage and distribution problems which plague the use of biogas. Producer gas technology is well known, antedating World War 11, when it was widely used in oil-short Europe and to a lesser extent in other areas such as the then Rhodesia. Although the technology fell into disuse with the post-war flood of inexpensive Mid-Eastern oil, rising oil prices have prompted renewed interest in producer gas. Large scale industrial and agricultural processing plants throughout the world, including Zimbabwe, and a few countries, notably the Philippines, are pursuing transport fuel substitution programs based on extensive use of producer gas. In large scale applications, the gas may be producedin continuous flow processes, with efficiencies as high as 85% - 90% in heating uses. Most installations, however, are relatively small batch type generators. These units may be constructed of masonry in stationary applications, with cast iron fittings for the combustion zone. Many models are small enough to be mounted on a truck, tractor or car, and in fact they can be built to a scale appropriate for any engine, from 3 klJ up. The typical engine fuel generator is a downdraught design; a cylindrical fuel hopper surmounting a funnel-like reaction chamber where combustion takes place, then an ash dump and the take-off for gas. In use, air-dry wood blocks, charcoal or crop residues are loaded through an air-tight door into the hopper/reaction chamber, the bottom of which is constricted, lined with refractory material and equipped with several small tuyere through which a regulated flow of air may be introduced. A fire is lit in this constricted combustion zone. It quickly attains high temperatures. Exposure to this heat causes a spectrum of reactions in the fuel above: drying in the most distant upper region of the reaction chamber, distillation in the next closest region, and thermal decomposition in the region immediately above the combustion zone. The gaseous products of the distillation and thermal decomposition reactions are drawn as demanded through the high temperature combustion zone where they undergo further breakdown and reduction, then through simple particulate filters where they are cleaned of tar and debris, through a radiator for cooling, and are finally fed directly into the intake manifold of a spark ignition or diesel engine. A spark ignition engine (a conventional petrol engine) running on producer gas operates at about the same efficiency as on petrol, consuming 1 - 2 kg of dry wood per liter of former petrol consumption, but produces only 40% - 60% of the power as when run on petrol. Ordinary modern engines with large valves and relatively high compression run at the upper end of this power range after a simple advance of timing. The power reduction may be compensated by use of oversized engines, or a petrol cut-in may be fitted to boost power for intermittent heavy loads. Diesel engines running on producer gas still require some diesel fuel, about 10% - 15% of their former consumption. Diesels running on this mix operate at their former efficiency, using 3 - 4 kg of dry wood and 0.1 liter of diesel per liter of diesel used in conventional operation, and produce 85% - 90% of their former power output. The most serious problem with the use of producer gas lies in the damage done to expensive engines if tars are insufficiently cleaned from the gas. As it turns out, it is extremely difficult to maintain adequate cleaning of the gas produced from wood. This fuel has generally been rejected as a feedstock for producer gas except under conditions of the most dire necessity. Charcoal, coke and hard coal have very low tar content and make excellent fuels for producer gas. Charcoal is generally the fuel of choice, and was the fuel previously used for producer gas in Zimbabwe. It seems, however, inadvisable to encourage the conversion of fuelwood to this purpose, given the scarcity already developing. Coke and coal, on the other hand, are locally produced and compare very favorably to diesel fuel in price per unit of energy. Investigation of the local feasibility of use of these fuels as gas feedstock may be quite worthwhile. Crop residues are another local fuel worthy of investigation for possible use in producer gas generation. If available on farm at the cost of collection, their cost per unit of energy amounts to only 5% - 10% that of diesel. For a number of crops, the energy value of the residue produced is greater than that of the fuel used in field operations. If residues were seen as an energy crop, harvested, dried and stored they could well help to reduce both costs and dependence on imported diesel. Crop residues, however, share some of the problems of tar production which constrain the use of wood in producer gas generators, Moreover, many of the crop residues produce substantial amounts of ash and slag in the high temperature reduction environment of the generator. Minimization of the production of harmful by-products and optimization of the production of useful gas requires that the generator be designed for the specific characteristics of the material to be used as fuel. The work of experimentation and adaptation of gas generators for use with crop residue fuelshasbegun onlyinthe last fewyears, and designs and information are not yet mature. The potential for use of crop residues as a traction and transport fuel seems considerable, but premature adoption could result in severe damage to engines and a profound disenchantment with the possibility of substitution of biomass fuels for diesel.
8. IRRIGATION, STOCK WATERING AND DOMESTIC WATER PUMPING CURRENT PRACTICES AND TECHNOLOGY
Irrigation, stock watering and domestic water pumping have rather different demand characteristics, despite their obvious similarity in involving the transfer of water. Irrigation requires large volumes of water on a highly seasonal basis. Stock watering generally requires fairly small volumes of water, again on a seasonal basis. And domestic water supply requires fairly small volumes the year round. The need for reliability also varies among the three applications: irrigation and stock watering require a moderate degree of dependability, but the continuous reliability of domestic water supply is critical. The differing characteristics of the pumping applications are reflected in the technologies currently used to service them. Virtually all irrigation pumping in Zimbabwe is carried out with high capacity electric pumps running on mains service. Stock watering is conducted with a variety of devices: electric pumps where mains service is available, small diesel engine pumpsets in more remote locations and windmills at a relatively few sites where demand is low or wind conditions are particular1 y favorable. Domestic water pumping is done almost entirely by hand, except in some of the supplied service centers or growth points where electric or diesel pumpsets may be used, depending on the availability of mains service. Electric pumpsets are preferred to diesel pumpsets where mains service is available because in most circumstances the capital, fuel and maintenance costs of diesel engines drive the charge per unit of water delivered to almost twice the charge for electrically pumped water. As with other agricultural technologies, the highly uneven distribution of resources among the Zimbabwean agricultural sectors is manifest in access to and use of pumping devices. The large scale farm sector and the larger population centers are generally able to take advantage of the economy of electric pumping. Diesel pumps are installed only in the most remote locations in these sectors. Economies of scale, proximity to rivers, access to infrastructural and marketing facilities, and extensive state subsidization have combined to support installation of irrigation equipment on a high proportion of large scale farms in the arable zone. Similarly, the environmental and economic resources of the large scale farms involved in cattle ranching have enabled frequent installation of boreholes and pumping equipment for stock watering. The electric grid currently extends to few of the communal and small scale farming areas, however. Although the Government has made a policy commitment to electrification of service centers and growth points in these areas, fiscal and foreign exchange constraints will almost certainly delay its accomplishment for a considerable time. The relatively few mechanical pumping installations in the communal and small scale farming areas are perforce thus mainly diesel powered. Virtually all of the pumping installations in the communal and small scale farming areas are institutional. Boreholes and mechanical pumps operate at capacities greatly in excess of the irrigation of stock watering needs of individual small scale farmers and bear costs far beyond the means of individual farmers. Establishment of the independent irrigation and stock management cooperatives in which small farmers might join to share resources and achieve economies of scale adequate to support investment in mechanical pumping has not occurred. Unsuitable topography and soils provide substantial barriers to irrigation in much of the small scale farming area. Some locations appropriate for sizable multi-plot irrigation schemes do exist, however, and a number of these sites have been developed by the state. Watering points have also been installed in some areas. Surface sources still provide the primary supply of water for domestic as well as agricultural purposes in most of the communal and small scale farming areas, although development institutions and the state have recently undertaken an aggressive program of borehole construction and rehabilitation. Boreholes intended for domestic water supply are seldom equipped with mechanical pumping systems (except in population centers, missions, etc.), handpumps being preferred for their low cost and reliability. The effort required to pump the daily domestic water supply for a household is not great, and the handpump is probably the optimal technology for this application. Pumping and distribution of significant quantities of water without the aid of powered devices requires impracticable amounts of labor, however, so use of these boreholes for irrigation or extensive stock watering is quite rare. Adoption of an alternative technology for extensive use in existing large scale irrigation would depend upon the capacity to pump large volumes reliably at a cost lower than that of the electric pumps used for this purpose in most sites. Adoption in the irrigation sites remote from the electric grid, currently serviced with diesel, would require economic substitution for diesel fuel or alternative provision of large volume pumping at a cost lower than that of diesel engines. A technology which offered comparable service at a cost substantially lower than that of diesel engines could facilitate further development of irrigation schemes in the communal and small scale farming areas. The effect in this regard of moderate reductions in pumping cost would be quite limited, however; the costs of pumping energy are but a fraction of the development costs of irrigation schemes and, in any case, environmental, geophysical and tenurial considerations remain significant impediments in many sites. Adoption of technologies for small scale irrigation will be contingent upon their economic accessibility to small farmers and upon their ability to deliver moderate volumes of water with a high degree of dependability. Here again, site and social considerations will prove, inmany locations, significant obstacles to use of even the most economical of pumping devices. The cost of borehole development effectively precludes adoption of pumps by most small farmers except where natural surface water, a diversion, impoundment or a high water table provides available water. Substitution of alternative devices for the diesel or electric pumps used in current stock water installations clearly depends upon the ability of the alternative devices to provide comparable moderate volume pumping at a lower cost. Adoption in new installations will require performance similar to that appropriate for small scale irrigation (and will be constrained by many of the same factors). The satisfactory performance and extremely low cost of the hand pumps used for most current rural domestic water supply installations set a standard of cost effectiveness probably unattainable by any powered device. Community water supplies, to be constructed at growth points and service centers as part of the rural development programs, will generally be powered by small diesel and electric pumps, unless alternative devices can maintain the necessary high standard of service at a lower cost.
ALTERNATIVE TECHNOLOGIES
Producer Gas
The local economics of producer gas substitution in engines are currently uncertain, due to their dependence upon basic fuel availability, the need and cost of further preparation for fuels such as crop residues (e.g.; drying and briquetting), and the development and testing of fuel- specific generation and filtration equipment to assure efficient gas generation and sustained engine life. Neither briquetting machines nor engine type gas generators are presently available in Zimbabwe, although both types of equipment could be manufactured locally, and their costs are not known. Current indications are that it is not likely that partial substitution of diesel by producer gas would effect a pumping cost reduction sufficient to displace electric pumping where mains service is available, especially in view of the far greater labor and process management requirements attendant on the use of producer gas. Even if producer gasldiesel pumps do prove to be more attractive than straight diesel pumps, yet remain less so than electric devices, their role may be limited to substitution in the relatively small fraction of pumping currently carried out with diesel. Alternatively, the possibility of operating engines with locally derived biomass materials rather than expensive and logistically demanding imported petroleum fuel may allow increased installation of engines in situations where the basic capital costs can be met, particularly in the small sizes for which fuel provision can be accomplished on a more casual basis. Crop residue or raw wood may not be practical fuels for most smal l scale installations however. Efficient production ofclean producer gas requires that generators be optimized for the specific combustion characteristics of the fuel as used. Apart from the basic questions of availability and alternative uses of these fuels, variation in the type of material, its moisture content and particle size can dramatically affect generator performance and engine life. The high cost of engine purchase and repair in Zimbabwe renders any unnecessary risk of engine damage unacceptable. It is clear that possible use of the raw fuels prone to excessive tar production will have to await development of gas generators capable of eliminating this threat. Promising evidence of the potential for practical use of raw fuels in small scale generators is being demonstrated in experiments elsewhere, but the local field trials necessary for a confident assessment of the feasibility of their use in Zimbabwe have not yet been undertaken. Although charcoal is the technically superior fuel for use in producer gas engines, its use for this purpose could tend to accelerate the depletion of already scarce fuelwood stocks. Fuelwood shortages are predicted to become so widespread and acute that extensive development of charcoal based producer gas seems dangerous and inadvisable. Even where local conditions might permit expanded use of fuelwood as charcoal, the prospects for significant adoption of producer gas fuel led pumpsets are very much limited by the prevailing scarcity of capital, necessary for the prior investment in boreholes and diesel equipment as well as for installation of the gas generation devices.
Biogas
Biogas has a number of advantages over producer gas as a fuel for stationary engines. Unlike producer gas, biogas is not prone to causing engine damage; it requires no filtration and imposes no excess risks. Moreover, the wet dung or crop residues fed into the process are ultimately discharged unimpaired for their usual use as fertilizers. The dilution water requirement, which can pose difficulties for domestic installations distant from water sources, is clearly not a problem in pumping applications. Engine operation remains as simple with partial substitution of biogas as on straight diesel, since biogas production is a continuous process, not demand driven and coupled to engine operation as is producer gas generation. On the other hand, biogas generation has some serious limitations as a means of fuelling engines. The rate constraints necessitate construction of expensive large volume reaction and storage chambers. The environmental stability required demands uniform feeding and management in a long term continuous culture. Problems with gas leaks often cause lengthy service outages for repair of the system. The cost of a successfully operating biogas system is located almost entirely in amortization of the initial construction cost of the plant, since the primary feed materials are returned through the process and are usually available for the cost of collection. This cost can be quite high, indeed prohibitively so, for systems capable of generating sufficient fuel for large scale applications. Potential economies of scale in construction of larger systems tend to be outweighed by the costs of additional features required for safety and process management. The high fixed cost component of biogas generation implies that the cost per unit of delivered energy is very much dependent upon the amount of gas usefully produced over time. Reductions in useful delivery of gas due to system problems or due to drops in demand for seasonal or other reasons can cause pronounced increases in the effective cost of delivered gas. The high discount rates applicable to development funds or to the scarce capital of the communal or small scale farming areas greatly exaggerate the impact of this effect. The prospects for economic application of biogas substitution in large scale irrigation or seasonal stock watering are thus much less bright than those for small scale continuous pumping. The limited regional experience with biogas fuelled diesel does not suggest a bright economic forecast for even the most favored of applications. In a particularly well documented installation in Botswana, a 20 m3 Indian type plant provides approximately 80% of the fuel for a 6 kW diesel stock watering pump operating about 6 hours daily, the year round. Even for this installation, a model plant of optimal scale, designed and supervised by experts and operating continuously on free manure, the effective cost of biogas fuel is equivalent to that of imported diesel, under economic assumptions comparable to the Zimbabwean situation. It does not appear, at this time, that biogas generatorswill offer substantial economic advantages in most diesel pumping installations, large or small. A demonstration plant being built with international support at Kushinga Phikelele will in all probability confirm the feasibility of provision of biogas engine power, and hence mechanical pumping and electrification, as well as heat and light, from a larger multipurpose biogas system. The actual economics of such a system remain to be seen, but the general utility of biogas in stationary institutional uses is likely to favor this type of installation over single purpose plants for which less costly conventional substitutes are available. The advantages of increased fuel autonomy may be significant in particularly remote locations, and other special circumstances may support the use of biogas in others. But, in view of the difficulty of financing boreholes and diesel engines themselves, the high additional capital costs of biogas systems will prove a great barrier to their use. Unless the cost and reliability of biogas generation can be greatly improved, the prospect for a significant contribution to pumping or other rural mechanical applications from this technology seem slight. Photovoltaics Photovoltaic devices are synthetic crystalline substances which convert light energy directly to electricity. Groups of photovoltaic cells, each capable of generating a small amount of power, can be configured in arrays to any voltage or power capacity. The electricity generated when the cells are exposed to sunlight can be stored in batteries for later use, used directly as generated or electronically conditioned to characteristics suitable for a particular application. Since the actual output characteristics of photovoltaic arrays are contingent on the amount of light instantaneously incident upon them, such storage and conditioning are necessary for applications which cannot simply £01 low the diurnal and other variations in availability of energy. The batteries and equipment for storage and conditioning are expensive, frequently doubling the cost of a photovoltaic installation. Pumping applications rarely require such additional electrical equipment. The scheduling of irrigation is not particularly critical. And the unmatched timing of stock and domestic water demand can be accommodated much less expensively with water storage tanks than with batteries. Thegreatest advantage of photovoltaic devices is that, since the arrays themselves are solid state and are rarely fitted with mechanical tracking apparatus, they normally require little or no operation and maintenance expense. The initial cost of the photovoltaic arrays themselves are extremely high, however, and may more than compensate for the absence of recurrent charges. This loading of cost on initial capital is a serious economic disadvantage in the high discount rate conditions of small scale farming or development aid. High fixed amortization charges have a dramatic impact on the cost per unit of energy usefully delivered in applications where system capacity 1s underutilized through seasonal or other variation in demand. The high initial capital cost also increases the risk posed by wilful or accidental damage. Photovoltaic systems are far too expensive to be economically competitive with electric pumping where mains service is available. Nor are photovoltaic systems competitive with large scale diesel irrigation, for which economies of scale and the direct dependence of cost upon seasonal demand are significant factors. The extremely high capitalization charges of photovoltaics would, inanycase, preclude use of the technology on a large scale, in view of the competing demands and constraints on development spending. The long run costs of photovoltaic pumping come closer to those of competing alternatives in small scale irrigation, where excess capacity in the minimum scale of diesel equipment available raises the effective cost of delivered energy. However, the far higher initial cost of photovoltaic systems imposes a financial barrier insurmountable by small farmers whose limited capital resources and elevated discount rates dispose them to avoid capital expenses in the present at the cost of increased recurrent charges in the future. The efforts of development agencies to circumvent this problem through organization of group purchase and equipment sharing schemes have met with little success because of management problems and the increased risk of costly equipment damage in multiple user schemes, as well as because of extreme financial scarcity. If photovoltaic systems are uneconomic in irrigation, they are even less appropriate for stock watering. Due to the high fixed capital component of costs and the marked seasonality in stock watering demand, the cost per unit of energy usefully delivered from photovoltaic installations in this application would be considerably in excess of that from diesel engines, for which fixed charges are much lower. The pumping application for which photovoltaic power is best suited is domestic water supply. Use in this application can exploit the full system capacity, showing little seasonal variation,yet can tolerate diurnal and other short term fluctuations in output by buffering supply with inexpensive tank storage. Most rural, mechanical ly pumped water supplies require only the lower power capacities for which diesel engines are most costly but for which photovoltaics can be optimal ly sized. Photovoltaics will not be economically competitive in settings where mains electricity is available or where handpump service is adequate, but they may become attractive substitutes for diesel water supply, pumps in locations where their reliability and capac~tyfor untended operation would be particularly valuable.
Animal Traction
Animals, widely used for draught and transport power in Zimbabwe, are not known to have been employed locally for pumping. However, animal traction devices are perhaps the oldest non-human means of pumping and remain in extensive use in many parts of the world. Animal driven pumps can take a variety of forms: the simplest merely hitch the animal to a lever which pivots, lifting and thendumping abucketasthe animal walks a line, then returning the stroke as the animal retraces its steps. More advanced devices take advantage of continuous rotary power derived from one or more animals attached by shafts to a central pivot and walking in a circle. Mechanical forms of energy are, in principle, interconvertible through gears or other mechanisms, so the form in which mechanical energy is derived need not be similar to that in which it is ultimately used: rotary drives can be coupled through transmission devices to reciprocating pumps, and vice versa. A well designed transmission achieves optimally efficient coupling by matching the speed, power and directional characteristics of both input and output devices, The degree to which it does so is constrained by the materials, design principles and fabrication techniques available to the producer. Traditional animal traction pumps have evolved under the limits of traditional materials and construction methods. Extraordinary examples exist, but most such pumps are crudely built, and often unreliable. Some of the problem lies in the transmission mechanisms, but a good part of it is attributable to the limited quality and capacity of the pumps themselves. It augers ill for transplantation of vernacular pumps to a region unfamiliar with them that they are so limited even where their construction and use benefits from the practised familiarity of long tradition. In any case, most traditional pumping systems are designed for low lifts from open hand-dug wells, not for the high lifts in constricted boreholes necessary to reach the deep water tables prevailing in much of Zimbabwe. The fact that traditional animal driven pumping mechanisms are not particularly attractive for use in Zimbabwe should not discredit the possible use of animal power in modern versions of such mechanisms. The past decade's enthusiasm for "appropriate" technology has matured in a renewed appreciation of the benefits to be found in marriage of modern materials, design principles and techniques with indigenous resources and traditional processes. This approach is just beginning to be applied to animal powered mechanical drive systems, and the results are promising, if not yet all that might be hoped for. One such modern animal drive pumping system has been designed and built in Botswana. It consists of a four stage gear and v-belt transmission, coupling three to six mulesor oxen, walking a ten meter circle at three revolutions per minute, to a small centrifugal shallow well pump operating at a design speed of 1500 rpm. Field tests being performed on a prototype indicate that the basic performance of the mechanism is satisfactory, but that the system has some problems. Animals operating the pump cannot maintain the four to five hour daily shifts they are expected to serve. And the capital cost of the system is high, about $5000.00. It appears that the initial estimates of the power available from individual animals were somewhat high, as they were derived from measurements of the capacity of healthy grade stock such as is foundon the large scale farms, rather than the seasonally undernourished range animals typical of the small scale farm areas. The high starting torque attendant on the radical speed conversion contributes to the excessive difficulty experienced by relatively weak stock. It is also a principal factor in the cost of the machine, necessitating use of high strength bearings and gears. The problem of misestimation of the actual work capacity of animals can be accommodated with a minor design adjustment. The problems £01 lowing from the radical speed increase required for the centrifugal pump are less tractable. Use of positive displacement rotary or piston pumps operating at lower speeds would almost certainly allow construction of more satisfactory animal-driven pumping systems at a reduced cost. It seems likely that a modest engineering effort would soon result in considerable improvement in the technology. Animal traction pumps are inherently small scale devices, since the average draught animal can deliver, on a regular basis, only one-half kW or less for four to five hours a day. The technology is clear1y not suited to large scale pumping. In smal ler scale applications, including irrigation, stock watering and domestic water supply, preliminary figures suggest that improved animal tractlon systems may become the most economic of pumping devices in remote rural areas where animals are kept for other uses. Although the labor involved in the care and handling of animals must be counted a cost of animal powered systems, the economies inherent in the complementary timing of demand for draught power and for irrigation or stock watering, should help to keep the effective cost of operation to a minimum, In addition, the possibility of applying some pumped water to production of the extra rations required for maintenance of animal strength in the dry season, could help in this regard. The capital cost of boreholes, storage and distribution equipment will remain a barrier to installation, as will the absolute shortage of draught stock in many sites. But in view of the general scarcity of capital for rural development and the scant likelihood of tractorization of draught processes in the communal and small scale farming areas, animal traction mechanisms appear to have unusual potential to contribute to development through provision of economical power. The prospects for their doing so will hlnge on further work on the design and local manufacture of appropriate mechanisms.
9 . CONCLUSION This paper has reviewed the prospects for significant new use of alternative energy technologies in the domestic and agricultural sectors of Zimbabwe. The assessment has been oriented to applications of potential national significance, in terms of conservation or substitution of scarce fuels or provision of valuable services. The availability of primary renewable fuels has been examined and technologies based on available fuels have been screened for their basic technical capacity to meet the requirements of the applications identified. Tine prospects for adoption of the selected technologies have been reviewed in a discussion of the technical, economic and social factors which condition their actual suitability to the applications and constrain the ability of prospective users to adopt them. This discussion has been on the whole sceptical and discursive, raising the issues which generally affect the choice of technology, especially those which impede innovation, rather than attempting precise evaluation of the "optimality" of each type of device. As the discussion makes clear, many variables other than the easily quantified financial factors exercise a determinant influence on technical choice, and many of these variables are highly contextual. The discussion of the prospects for application of the alternative technologies indicates that two types of devlces have the potential to make substantial contributions to Zimbabwe's national energy economy through roles in the domestic and agricultural sectors. Improved and more efficient hearths and stoves could help to reduce the demand on fuelwood for rural domestic cooking and could improve the convenience, safety and health impact of cooking and heating. Simple lowering of the height of the iron grate could nearly double its cooking efficiency at no cost. Poor stoves can be much worse in both efficiency and convenience than the open fire, but a well designed high mass stove could eliminate problems with safety and indoor smoke pollution, and provide a water heating or baking facility with no loss in efficiency. Animal traction devices based on modern transmission mechanisms and pumps could dramatically lower the cost and improve access to pumping and other mechanical drive applications in the communal and small farm areas. Other renewable energy technologies are likely to have much lesser roles. Producer gas substitution for diesel fuel could be useful in sites with wood resources sufficiently abundant to support charcoal production, although general application must await development of a generator capable of using raw biomass without passing engine damaging tars. Biogas may find limited application in institutional sites where access to capital is relatively good and where the multipurpose capacity of biogas is particularly useful. Management problems and the high construction costs preclude domestic use of biogas, however. Photovoltaics may also find limited application in institutional settings where electricity is particularly valuable, but are far too expensive for use in pumping or other applications requiring high output capacity. Solar water heaters are too costly for use by any but the high income households of the urban low density areas, for which they are only marginally economic. Intensive efforts to support further development and extension of improved hearths and stoves and animal traction mechanisms are well warranted by the potential value of these technologies. The efficiency and reliability of these ancient technologies can be greatly enhanced by selective use of modern materials and design principles while preserving the advantages of their integration into the traditional domestic and agricultural practices and environment. The sorry history of "appropriate" technology promotion points up the danger of naive "improvement" however, and confirms the importance of field testing prior to promotion. The prospects for application of other renewable energy technologies are too limited to justify extensive programs of promotion. Some further exploration of the economics of possible use of charcoal or coal based producer gas would be worthwhile, as would a search for generator designs capable of safely handling raw fuel. Appraisal of multipurpose institutional scale biogas economics might be valuable, as would efforts to develop less expensive biogas generation and storage tanks. Development and cost reduction of solar water heaters and photovoltaics will be done adequately by local or international commercial firms. A program to monitor and evaluate the economics and performance of these devices would be quite useful, however, both for potential investors and for future reconsideration as prices change and further information develops. Many useful technologies were not discussed in this report because they are unsuited to the domestic and agricultural applications identified for this report or because they are based on primary energy resources not available on a nationally significant scale. Some of these technologies, as well as some of those given a second priority in the discussion above, will find very valuable application in particular settings in the domestic and agricultural sectors and in other sectors. then considering the choice of technology for a specific application and setting, the full range of potential technologies should be evaluated according to local conditions. Generalization on a national scale can scarcely be considered definitive. It is to be hoped, however, that this report has contributed to the development of a sense of priorities for research, development and support for renewable energy devices potentially capable of playing a useful role in development of two of Zimbabwe's most important sectors.
FOOTNOTES
(1) Climatological Data in this section taken from: Climate Handbook of Zimbabwe, and Rainfall Report - Season 1980/81; Published by Zimbabwe Department of Meteorological Services. LIST OF CONTRIBUTORS
D. Q. Chandiwana holds degrees in Geography from the University of Freetown and Urban and Regional Planning from SUNY-Binghamton. She is currently a Planning Officer with the Energy Department of the Zimbabwean Ministry of Energy and Water Resources and Development. Charles Chidiya holds a first degree in Business Administration and is a Planning Officer with the Energy Department of the Zimbabwean Ministry of Energy and Water Resources and Development. Jeffrey Dowd served as a Peace Corps volunteer in Swaziland after finishing his BSc from Drexel University. He also holds an MSc from Princeton University and is currently finishing his PhD in Energy Management and Policy from the University of Pennsylvania. Thomas N. Harris graduated from Amherst College in Biochemistry. He lives outside Amherst Massachusetts and specializes in the analysis of new and renewable energy systems and the social context of their deployment.
Richard Hosier was CO-Project Manager of the Zimbabwe Energy Accounting Project. He holds a PhD in Geography from Clark University and is currently Assistant Professor of City and Regional Planning and Energy Management and Policy at the University of Pennsylvania in Philadelphia.
Kirsten Johnson holds a PhD in Geography from Clark University and specializes in the analysis of social and environmental impacts of development projects. She currently works for CARE as the director of an agroforestry program in Bolivia.
Yemi Katarere earned a PhD in Forestry specializing in entymology from the University of Idaho. He is currently Associate Director of the Zimbabwean Forestry Commission based in Harare. Sam Moyo is an economist and a geographer working on issues in rural development as a Research Associate at the Zimbabwe Institute of Development Studies.
D. K. Munasirei is a geographer specializing in tropical geomorphology and soils. He is currently attached to the Department of Land Management of the University of Zimbabwe.
Daniel Weiner has completed a PhD in Geography from Clark University, and is currently engaged in research on agricultural development in Southern Africa* He is an assistant professor in the department of Geography and Planning at the University of Toledo.
AED 21 Botswana 235, 239 Afforestation 2, 210 Briscoe, J. 8, 85 Agricultural Marketing Brokensha, D. et. al. 8, 126 Authority (AMA) 20, 28 Browne, M. 39 Agricultural and Rural Developmen t Brownstone, D. 93 Authority (ARDA) 26, 28, 64 Brush, S. 138 Agriculture Callear, D. 120, 127, 130 distribution of cultivated Catterson, T.M. 176 lands 67-70 Cecelski, E., et. al. 136 economic efficiency of 22 Central Statistical Office energetic analysis 20, 35-45 (CSO) 15, 28, 36, 37, 60, 63, energy consumption of 32-35 87, 113, 114, 115 energy efficiency of 21 Chadzingwa, J. 157 energy inputs 16, 21-23 Charcoal 211, 234, 241 fertilizer and pesticide stoves 156 use 21-23, 47-49 Chavunduka, G.L. 113 fuel use 201,205 Cheater, A. 127 productivity of 170 Coal 201 subsistence 12 based producer gas 241 uneven development of 52 household use of 88-89 Agriculture, Ministry of 28, stoves 156 36, 39 Cole, R.S. 55, 73 Agritex 25, 53, 60, 64, 69 Colonialism 113-114 Agro-ecological zones 23-25, Commercial Farmers Union (CFU) 60-61, 65 36, 37 and fuel-use patterns 90 Communal Areas 12, 28-29, 63 and land-use categories 61-63 energy efficiency of, 39-42 high-potential regions 9 percent cultivated 67-68 marginal areas 28 population pressure on 68 non-utilizable lands 71-72 as Tribual Trust Lands 86 percent cultivated 67-70 Communal woodlots 135 Agroforestry 137, 176, Community Development & ilomen's 177, 180, 181 Affairs, Ministry of 117, Akinwume, J. 21 126, 129, 130, 132, 135, 138 Alam, M., et al. 84 Compost 47-49 Alvord, E.D. 117 Conservation and Extension, Animal residue 161, 167 Department of 73 Appropriate technologies 111, Construction 214, 241 wood requirements 180, 210 Arrighi, G. 28 Cost benefit analysis 215, 218 Ascough, W.J. 146, 147, 157 Craft production 121 ASTRA 8, 9 Crops A.T. Zim Services Ltd. 146, 149 cash 129-130 Bajracharya, D. 84 cotton 38, 69-70 Barnes, C., et. al. 85 energy consumption by 33-35 Beijer Institute 8, 9, 116, maize 59, 70 126, 185 production by age & gender 129 Biogas 2, 235 rotation of 120 generators 221-223, 227, 236 Crop residue 111, 161, 167, Biomass 180, 234 212, 230, 234 opportunity costs of 85 Deforestation 114, 185-196 woody 111 de Jong, J. 36, 44 Development agricultural 20 intensity of cultivation rural 2, 111-112 68-70 local/community 112 productivity of 73 top-down 111 Fleuret, P.C. & A.K. 8, 126 DEVRES 126 Foreign exchange 2, 45 Dickenson, H. 21 Forest lands 66-67 Domestic Cookstove Performance indigenous 71 Testing Project 143 Donnelly, K. 157 Forestry Commission 64, 66, Dubin, J.A. et. al. 93 182 Dung 111, 161, 212, 213 Fournier, F. 189 Dunne, T. et. al. 187, 188 French, D. 85 ECA 126 Fuels Electricity in agricultural production household choice of 95 32-35 household use of 84, 88, commercial vs. non- 95, 155 commercial 6, 99-104, Hwange generation plant 86 112 Kariba dam complex 86 consumption patterns 88, urban vs. rural use 201 90, 96, 202-204 Elwell, H.A. 187, 188 substitution of 4, 83-84, Energy 99-105 Department of 2, 110, 116, Fuel wood 224 consumption pattern 88 end-use demand 201 commodification of 12, 85, ladder 83-85 112 and Water Resources, dependence on 200 Ministry of 146 depletion of standing stocks Energy planning 167 demand-side 7, 16, 199 forestry of 171 in developing countries 6 household choice of 95 end-use models 5 how obtained 163 LEAP model 6, 21, 165, 167, shortages 114, 201, 210 200, 201, 202, 203, 204 sources of 163, 210 reduced-form model 4 storage of 162, 210 supply-side 5 transport of 164 Energy Systems Research Groups types of 162, 177-179, 185 165 Gelfand, M. 117 Environmental degradation 176, Gill, J. 136, 157 185 Goett, A.A. 93 and livestock 50 Grant, P. 55 impact by gender 131 Graham 135 Erosivity 186 Green, M. 21, 22 FAO 22, 33, 177 Griffen, K. 55 Farms 11, 86 (See also Harris, T. 142, 143, 158, 159 Communal Areas) Haswell, M. 21 large-scale commercial 12, Haugerud, A. 126 28, 63 Henderson Research Station 188 small-scale commercial 11, Hlekweni Training Center 224 21, 26-28, 31, 63 Hosier, R. 8, 9, 85, 86, 87, environmental threats to 126 114 Hoskins, M. 112, 135, 136 Households 126 McFadden, D. 92 energy consumption 15 McGarry, Father 157, 158 energy decisions 85, 87 Mechanical tillage 50-52 fuel choice 91-92, 99, 102 Meteorological Services, fuel use 84-85, 201 Department of 207, 209, 242 heads of 115 Meyer, L.D. 197 labor 116 Mtisi, J. 57 size 170 Muchena, O.N. 117, 120 urban 15, 99 Mudimo, C. 57 Howard, C. 56 Muir, K. 49 Hudson, N.\{. 187, 188 Multinomial logit model 93 Hwange coal-fired plant 86 Mumbengegwi, C. 20 Hymen, E.L. 85 National Household Energy Survey Intermediate technologies 134 15, 87 Irrigation 231, 233, 237 Natural Regions 25, 61-64 Ivy, P. 56, 74 (See also Agro-ecological zones) Jackson, J.C. 188 fuel-use patterns in 90 Johnson, J. 8, 9 Natural Resources & Tourism, Juma, C. 86 Ministry of 64 Kariba dam complex 86 O'Keefe, P. et. al. 23, 85 Katerere, Y. 185 Oleche, F. 8, 9 Kay, G. 194. 195 Openshaw, K. 8 Kennes, W. et. al. 84 Owen, F. 120 Kenyan Fuelwood Project 9 Palmer, R. 28 Kerosene Paraffin 155, 161, 205 household choice of 95-97 Parks and wildlife areas 64-65 household use of 88-90 Hwange National Park 65 King, K.F.S. 177 Matetsi and Deka Safari Kinsey, B.H. 74, 119 areas 65 Labor Perelman, M. 23 affect of wood shortage on Peterson, R. 58 170 Petroleum 201 distribution by age & gender Pimental, D. and M. 22, 23 116-119, 122, 125, 132 Pitt, M. 109 household 116 Population 113-114, 119-120 reserve in Communal Areas 1969 Census 113 28 1982 Census 60, 64 Land Apportionment Act 86 Producer gas generators 229, Lands Resettlement & Rural 233-235, 241 Development, Ministry of Rald, J. 140 (MLRRD) 26, 64, 74 Rappaport, F. 21 LDC Energy Alternative Planning Reddy, A.K.N. et. al. 8, 9, 85 Program (LEAP). (See Energy Renewable resources 2, 207-214 planning) Resettlement Programs 13, 17, Lewis, 0. 21 8 7 Livestock and agricultural land use control of 120, 129 45-47, 64, 69 draught animal power 49-52, energy surveys of 42-43 111, 238-240 Model A (individual) 29-31 watering of 231, 237 Model B (cooperative) 31 Luce, R. 92 Residential Mangombe, F. 37 fuel choice, national-level 94 Mblinyi, M. 140 suburbs 86 Mburu, O.M. 177 Revelle, R. 8 Vegetation cover 187 Rice, E.B. et. al. 74 Vincent, V. et. al. 60 Rodel, M. et. al. 58 Wage remittances 119 Rural growth Water and service centers 17 drinking 206 -with-equity 1, 12, 20, 45, heating 205, 227 5 3 power 111, 208, 209 Rural energy centers 9 pumps 232 Rural industries 17 Wattle Company 211 Rural energy studies 8, 14 Weiner, D. et. al. 87 energy ecosystem 10 Weinrich, A.K.H. 116, 117, 120 energy supply/demand 8, 15 wood supply/demand 9 Whitall, P.C. 198 Rural Energy Survey 111, 116, Whitlow, J.R. 60, 64, 65, 67, 68, 118-120, 122-124, 129, 130, 160 114 173, 180 (See also Zimbabwe Whitsun Foundation 8, 28, 49, Energy Accounting Program) 114 Rural Energy System 11 Wiltshire, J.E.B. 75 Sandford, S. 50 Wind power 207, 208 Saunders, C.R. 74 Wischmeier, W.H. et. al. 186 Screenivas, L. et. al. 187, 188 Wisner, B. 23, 131, 137 SIDA 177 Uoodland depletion 120, 185 Silveira House 224 Woodlots 112 Skutch, M. 135 World Bank 5, 56, 184 Soil Yapa, L. 22 depletion 120, 176 Zambia Forestry Department 184 erosion 114, 185-198 Zimbabwe Solar economy 86-87 cookers 221 Zimbabwe Energy Accounting energy 2, 207 Program (ZEAP) 1, 6, 8, photovoltaics 236, 241 10, 87, 111, 143, 149, 157, Southern African Regional 183,200 (See also Rural Commission for the Energy Survey) Conservation and Utilization methodology of 60 of the Soil (SARCCUS) 194 Zimbabwe Institute of Stocking, M.A. et. al. 186, Development Studies (ZIDS) 189, 190, 194, 195 45 Stoneman, C. 86 Zimbabwe National Household Stoves 142-155, 220, 224, 240 Energy Survey 84 fuel efficiency of 155-157 logit model applied to 94 Sudan 179 Zimbabwe Power Sector Tattersfield, J.R. 49 Development Plan 5 Technology Zimbabwe Women's Bureau 126, availability by gender 129, 132, 135 120-121, 132 need for by project 137 Theisan, P. 58 Tinker, I. 126 Transnational National Development Plan 1 Truscott, K. 58 UNIDO 17 van Gelder, B. 182 !.,&:3,175 &~:C~O[:II.I~cct\~nr,t.i~\, art,: ie:;l.;e irl Aflz;:. hsae k;cc:i irjrit hi1 l?y (he da,uhic
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