29 Land resources of central Nigeria Agricultural deveippment possibilities Volume 6B Kano Plains ° ° . o , " ,

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Land resources of central Nigeria Agricultural development possibilities Volume 6B The Kano Plains

ISSN 0305-6554

ISBN 0 902409 91 3

1H5S Land Resources Development Centre

Land resources of central Nigeria Agricultural development possibilities Volume 6B The Kano Plains

Land Resources Development Centre Central Nigeria Project Team (ed. J R D Wall)

J Abah, J G Bennett, A Blair Rains, P N Gosden, W J Howard, A A Hutcheon, J Ibanga, S Kalejaiye, W B Kerr, J E Mansfield, L J Rackham, R Rose-lnnes, J Valette

Land Resource Study 29

Land Resources Development Centre, Ministry of Overseas Development, Tolworth Tower, Surbiton, Surrey, England KT6 7DY 1979 LAND RESOURCES DEVELOPMENT CENTRE*

The Land Resources Development Centre of the Ministry of Overseas Development assists developing countries in mapping, investigating and assessing land resources, and makes recommendations on the use of these resources for the development of agriculture, livestock husbandry and forestry; it also gives advice on related subjects to overseas governments and organisations, makes scientific personnel available for appointment abroad and provides lectures and training courses in the basic techniques of resource appraisal and development.

The Centre works in close cooperation with government departments, research institutes, universities and international organisations concerned with land resources assessment and development planning.

*The name of the former Land Resources Division was changed to Land Resources Development Centre in June 1978.

CENTRE DE DEVELOPPEMENT DES RESSOURCES DE LA TERRE*

Le Centre de Developpement des Ressources de la Terre (l'un des organismes scientifiques du Ministère britannique de Developpement Outremer) apporte son aide aux pays en voie de developpement en matière de cartographic, recherche et evaluation des ressources de la terre et fournit des recommandations quant a 1'exploitation de ces ressources pour le developpement de 1'agriculture, l'elevage et la sylviculture. Le Centre conseille egalement, dans les domaines annexes, gouvernments et organismes outremer, se charge de trouver du personnel seientifique pour les postes a pourvoir a l'etranger et organise des conferences et des stages de formation sur les techniques de base relatives a 1'evaluation et la mise en valeur des ressources.

Le Centre travaille en etroite cooperation avec services gouvernementaux, instituts de recherche, universites et organismes internationaux s'occupant d'evaluation des ressources de la terre et de plans de developpement.

*L'ancienne Division des Ressources de la Terre (Land Resources Division) a éte renommée Centre de Developpement des Ressources de la Terre (Land Resources Development Centreren juin 1978.

IV List of volumes

Title: land resources of central Nigeria: agricultural development possibil­ ities. LRDC Central Nigeria Project Team (Eds I D Hill and J R D Wall)

Volume 1A The Bauchi Plains, Executive Summary Volume 1B The Bauchi Plains

Volume 2A The Jos Plateau, Executive Summary Volume 2B The Jos Plateau

Volume 3A The Jema'a Platform, Executive Summary Volume 3B The Jema»a Platform

Volume 4-A The Benue Valley, Executive Summary Volume 4B The Benue Valley

Volume 5-A- The Kaduna Plains, Executive Summary Volume 5B The Kaduna Plains

Volume 6A The Kano Plains, Executive Summary Volume 6B The Kano Plains

Volume 7 An atlas of resource maps

v WOTBCE TO READERS

This published report is derived from a draft issued to the Nigerian Federal and State Authorities in 1977.

Readers concerned primarily with administrative or policy decisions in relation to agricultural development will find a summary of the various types of agricultural development considered and where each can be located in the Kano,. Plains in Volume 6A of this report, together with a precis.

The attention of readers requiring more detailed discussions is drawn to the section on the use of the report in Part 1 (p.5) of this volume. Technical, supporting information can be found in the reports listed on p. xiii.

Throughout this report the word "agriculture" has been used in a broad sense to include crop production, range management and forestry.

vi Contents

LIST OF TEXT MAPS ix

LIST OF SEPARATE MAPS ix

ABSTRACT AND KEYWORDS xi

LIST OF LRDC REPORTS ON THE KANO PLAINS xiii

PART 1 INTRODUCTION 1 Preface 1 Summary v 2 Objectives 3 Methods 3 Fieldwork and team composition 3 Reporting 4 Use of the report 5 Crops considered 7 Administrative units 8 Acknowledgements 8

PART 2 ASPECTS OF THE ENVIRONMENT 9 Location 9 Climate 9 Relief and drainage 13 Geology 13 Landforms 14 Soils - Soil classification 16 Soil genesis 17 Soil patterns 17 Soil fertility 19 Vegetation 20 Present land use - Density of cultivation 23 Distribution of cultivation 24 Present farming systems 25 Livestock 26

vii Agricultural infrastructure 27 Rangeland 28 Forestry 32

PART 3 ENVIRONMENTAL LIMITATIONS TO DEVELOPMENT 35 Introduction 35 Climatic factors in relation to crop growth 35 Land systems with five crop options 38 Land systems with four crop options 44 Land systems with three crop options 51 Land systems with two crop options 59 Land systems with one crop option 70 Land systems with moderate or severe limitations to arable crops 73 Land systems unsuitable for arable crops 79

PART 4 AGRICULTURAL DEVELOPMENT POSSIBILITIES 81 Types of development 81 Assessment of areas for agricultural development 81 Integrated agricultural development projects 86 Large mechanised farms 96 Improvement of traditional grazing 100 Establishment of grazing reserves 105 Establishment of dairy farms and feedlots 108 Forestry development for production of timber 112 Forestry development for production of firewood and poles 112 Forestry development for environmental reasóns 119 Research needs 124 Constraints to development 126

PART 5 REFERENCES 129

APPENDIX 1 INTERPRETATION OF SOIL DATA AI APPENDIX 2 ASSESSMENT OF EROSION HAZARD (\IS APPENDIX 3 MINIMUM SIZE OF ECONOMIC FARM UNIT A17

viii following page TEXT MAPS

6.1 Project area 1 6.2 Location of the Kano Plains 2 6.3 Administrative boundaries post-1976 4 6.4 Isohyets and length of rainy period lO 6.5 Thiesson polygons and rainfall lO 6.6 Relief 14 6.7 Drainage basins 14 6.8 Physiographic units 16 6.9 Vegetation 20 6.10 Areas suitable for integrated rural development projects 88 6.11 Areas suitable for large mechanised farms 100 6.12 Areas suitable for improvement of traditional grazing 102 6.13 Areas suitable for establishment of grazing reserves 106 6.14 Areas suitable for cattle ranches or dairy farms 112 6.15 Forest reserves for production of firewood and poles 114 6.16 Areas requiring reservation or strict conservation 120

-SEPARATE MAPS (in separate folder)

1. Land systems - the Kano Plains (Sheets a, b and c) 2 Present land use - the Kano Plains (Sheets a, b and c) 3 Crop options based on environmental limitations - the Kano Plains (Sheets a, b and c) 4 Agricultural development possibilities - the Kano Plains (Sheets a, b and c)

MICROFICHES(inside back cover)

BENNETT J G, HUTCHEON A A, IBANGA J, KERR W B, MANSFIELD J E, RACKHAM L J, ROSE INNES R & VALETTE J (1978) Land resources of central Nigeria. Landforms, soils and vegetation of the Kano Plains. Volume 1, Landforms and soils. Volume 2, Climate and vegetation. Volume 3, Land systems. Land Resource Report 20.

IX Abstract and keywords

ABSTRACT

The Kano Plains area (30 970 km2) of the LRDC Central Nigeria Project is briefly described in terms of its climate, landform, geology, soils and natural vegetation. Present land use is described in relation to the intensity and distribution of cultivation, present farming systems, cattle production and forestry activities. This information is used to identify areas in which the environmental limitations are at a minimum for the growth of maize, millet (Pennisetum americanum), sorghum, groundnuts and cotton. Areas suitable for different types of agricultural development, including livestock and forestry, have been identified.

Microfiches of reports supplying additional data on the area are appended.

RESUME

La region de Kano Plains qui fait partie de l'aire etudiee par le Projet

* *» • •* Nigeria da Centre est brievement decrite en termes de climat, modele, geologie, sols et vegetation naturelle. On decrit 1'utilisation de la terre par rapport a l'intensite et la distribution des cultures, les systemes de cultivation, l'elevage du betail et la sylviculture. Par moyen de cette information, on distingue les aires ou les limitations imposees par le milieu sont minimales en egard de la cultivation du mais, du millet (Pennisetum americanum), du sorgho, des arachides, et du coton. Les aires qui conviennent aux divers types de la mise en valeur agricole, inclus l'elevage de bétail et la sylviculture, sont signales.

Des microfiches fournissent des donnés additionelles sur la region.

DESCRIPTORS FOR COORDINATE INDEXING

Nigeria, Kano, climate, landform, soils, present land use, farming systems, livestock, forestry, agricultural development, maize, millet, sorghum, groundnuts, cotton.

XI List of LRDC reports on the Kano Plains

A full list is given below of the reports on the Kano Plains issued by the Land Resources Development Centre. They contain information for the specialist. They are obtainable only with the agreement of the Nigerian Government.

BAWDEN M G & RACKHAM L J (1969) The physiography of the basement land province: interim report on the land resources of central Nigeria. Miscellaneous Report 75«

BENNETT J G, HUTCHEON A A, IBANGA J, KERR W B, MANSFIELD J E, RACKHAM L J, ROSE INNES R & VALETTE J (1978) Land resources of central Nigeria. Landforms, soils and vegetation of the Kano Plains. Volume 1, Landforms and soils. Volume 2, Climate and vegetation. Volume 3, Land systems. Land Resource Report 20.

BLAIR RAINS A (1975) Livestock production in the Central Nigeria Project area. Miscellaneous Report 198.

BLAIR RAINS A (1977) Land resources of central Nigeria. Rangeland and live­ stock production. Land Resource Report 18.

GOSDEN P N (1978) Land resources of central Nigeria. Farming systems. Land Resource Report 17.

BENDY CRC (1977) Land resources of central Nigeria. Animal production in Kano State and the requirements for further study in the Kano Close Settled Zone. Land Resource Report 21.

HOWARD W J (1976) Land resources of central Nigeria. Forestry. Land Resource Report 9«

MANSFIELD J E (in preparation) Land resources of central Nigeria. The interpretation of environmental data in terms of limitations to crop growth. Land Resource Report 22.

POSNETT N W, REILLY P M & WHITFIELD P (1971) Nigeria. Volumes 1,2,3. Land Resource Bibliography 2.

Xlll Parti Part 1 Introduction

PREFACE

In June 1968 the Nigerian Government asked the British Government to investigate the land resources of parts of what were then the six northern States of Nigeria. The investigations have been undertaken by the Land Resources Development Centre of the British Governments' Ministry of Overseas 2 Development. The project area covers almost 230 OOO km . Its western and eastern boundaries are marked approximately by 7 and 10 longitude and it extends from south of the Benue Valley northwards to the border with the Niger Republic (Text Map 6.1).

The Kano Plains occupy some 14% of the project area and lie largely within Kano State, formerly Kano and North Central States (Text Map 6.2). TEXT MAP 6.1

LOCATION OF CENTRAL NIGERIA PROJECT

Prepared and printed by Directorate of Overseas Surveys 1978

1 SUMMARY

The Kano Plains (30 970) km ) occupy a substantial part (approximately 14%) of the total project area. From an assessment of the environmental features studied, it is shown to contain large areas of land with little scope for agricultural development in the north; the areas having any potential are almost entirely confined to the south.

The climate is markedly seasonal, yet during the 3-5 month growing period conditions are generally satisfactory for several annual crops and pasture, but marginal in the north for some crops and all but a few trees. The plains are slightly dissected,yet there remain numerous areas of gently sloping land where mechanised farming can be undertaken. The soils are erodible, chemically rather poor and locally stony but in general they are freely drained, deep and of light to medium texture. The presence of floodplains in.places extends the variety of environment available for development.

Except in the south-east,the area is densely cultivated throughout. Present-day agriculture is based on a labour-intensive, non-mechanised subsistence economy in which sorghum, millet and cowpeas play the most important part as both food and cash crops. Other significant cash crops include groundnuts and cotton in the south, with sugar cane, peppers and tobacco being locally important. Tsetse has been eradicated in recent years and migrant fulani cattle utilise dry-season grazing, particularly in the south. Current forest production is low, as northern areas in particular are climatically unsuitable.

In this milieu there appears to be little room for extension of currently grown crops, the chief limitation being lack of unused land. Intensifica­ tion of production is, however, possible in many areas.

There are areas where all the forms of agriculture under consideration can be established. Such areas are indicated in the report but it is re-emphasised here that at this reconnaissance scale of survey all statements are generalised of necessity, both in text and on map. The most versatile and extensive areas, i.e. those in which most forms of development would be possible, largely occur in the southern half of the Kano Plains.

2 LOCATION OF THE KANO PLAINS TEXT MAP 6.2 9°00' 10°00' iroo'

13°00' - 13°00'

12°00' - 12°00'

1100' 11 00

. BAUCHI PLAINS BAUCHI O j J 10 00 10 00' ) o /$ / JOS /

9 oo 9 00 °WAMBA JHENDAM JEMAfA PLATFORM)

8 00' ^VENUEVALLEY 8°00'

MAKURDI

3f °GBOKOX TAKUM KATSINA ALA 700' 7°00'

+ CAMEROON

6°15' 6°15' 7°00' 8 °00' 9=00' 10°00' 1 TOO'

Kilometres 25 0 25 50 75 100 125 150 I .... I I J L I Project boundary Report area boundary

D.O.S. 3269Bb Prepared and printed by Directorate of Overseas Surveys 1978 OBJECTIVES

The objectives of the project were to investigate and describe the upland (non-flood plain) resources with particular reference to their agricultural development potential. More specifically, at the request of state and federal authorities, an assessment has been made of the area's suitability for the growth of seven annual rainfed crops - maize, millet, sorghum, yams, rice, groundnuts and cotton - together with its rangeland and forestry potential. Agricultural development in the more suitable areas has been considered in the context of improving and expanding existing agriculture and establishing new large-scale, capital-intensive schemes. Mapping the areas where the environment offers the greatest scope for the above crops and forms of development was the final objective.

METHOD

From a study of air photographs the area was divided into units with similar landforms. Ground investigations of the soils and vegetation within these units, linked with climatic studies, enabled areas with the same pattern of climate, landform, soil and vegetation to be defined. Such areas are called land systems. These land systems are identified by numbers, are shown in Separate Maps 1-4 which accompany this report and are referred to whenever development possibilities are discussed.

The environmental data for each land system were interpreted in terms of suitability for various crops, grazing and forestry. This information, taken in association with studies of present land use, was used to identify a number of development possibilities. Details of the methods used are contained in the reports listed on page xiii.

FIELDWORK AND TEAM COMPOSITION

Fieldwork in the Kano Plains started in October 1975 and was completed by the end of 1976. Details of the progress of fieldwork have been given in six-monthly progress reports issued by the Land Resources Development Centre to the Federal Department of Agriculture.

3 The project team included agriculturalists, ecologists, a forester, a rangeland specialist, geomorphologists and soil scientists. Details of the team which surveyed the Kano Plains are given below.

Team

Project manager J R D Wall 1976-77 Agriculture J E Mansfield 1975-76 P N Gosden 1976-77 S Kalejaiye** 1976-77 Ecology J Abah* 1976 R Rose-Innes 1975-76 Forestry W J Howard 1975-76 Rangeland A Blair Rains 1975-76 Geomorphology L J Rackham 1975-76 Soil Science A A Hutcheon 1975-77 J G Bennett 1975-76 W B Kerr 1975-76 J Ibanga* 1975-76 J Valette* 1975-76

REPORTING

As the project area is so large it has been divided into six major physiographic regions, the Bauchi Plains, the Jos Plateau, the Jema'a Platform, the Benue Valley, Kaduna Plains and the Kano Plains. These physiographic regions are shown on Text Map 6.2 and 6.3 in relation to administrative boundaries. Each region is reported on separately.

The extent of the project area has been modified since its inception, in 1968, in the region of the Kano Plains. The original intention was to include all areas as far east as the North-East Project, also completed by Land Resources Development Centre (Aitchison et al, 1972) (Text Map 6.3). Subsequently, however, more detailed surveys for irrigation poten tLal have been male in the Hadijia,

*Staff of the Institute of Agricultural Research, ABU, Samaru. **Staff of the Federal Department of Agriculture.

4 TEXT MAP 6.3 POST-1976 ADMINISTRATIVE BOUNDARIES OF THE KANO PLAINS 8°30' 9°00'

13°00'

12°30' - 12°30'

12°00'— - 12°00'

11°30 11°30'

7°30'

DOS. 3269BC Prepared and printed by Directorate of Overseas Surveys 1978 Valley (Schultz, 1975) and in the region north-east of Tiga Dam (Nedeco, 1974). Consideration was given in incorporating the results of these surveys into a present project but no agreement on this could be reached in 1976 at inter- Government level when fieldwork had reached these areas. Consequently they were excluded from the project area, whose final boundaries are as shown in Text Map 6.3. A small area that was covered by airphoto interpretation study in the extreme north-east (Bawden and Jones, .1973) is also excluded. The north-western boundary joins an area surveyed by FAO/UNDP (1969).

The agricultural development possibilities in each region are discussed in separate volumes of this Land Resource Study: the six volumes are listed on page v. An executive summary has been prepared for each volume .

Environmental data collected during the survey for each of the major physiographic regions are contained in a series of reports published by this Division; those relating to the Kano Plains are listed on page xiii. The list also includes reports dealing specifically with farming systems, rangeland and forestry for the whole project area.

USE OF THE REPORT

This report will be of use to technical and planning officers responsible for formulating plans or implementating planning decisions. In it, environmental data have been summarised and an interpretation of these data presented in the form of a number of development possibilities. The development possibilities have been assessed on environmental criteria: it is stressed that no attempt has been made to rank them in economic terms.

Readers requiring general information about the environment should turn to Part 2. Those requiring more detailed environmental and present land use information in relation to development possibilities are referred to Part 3. Part 4 deals with actual agricultural development possibilities and, following discussions with federal and state authorities, has been structured so that it can be used in three ways:

1. Selection of areas for a particular type of agricultural development or project

5 2. Selection of areas for increasing the production of a given crop

3. Selection of the types of agricultural development for particular administrative units.

The report should be used mainly in conjunction with Separate Maps 3 and 4. Separate Maps 1 and 2 give information about the environment and present land use and are included for reference purposes.

1. Selection of areas for a particular type of agricultural development

The various types of development are defined in Part 4 of this report and are identified by a number. Given a decision on which type of development is to be followed, the most suitable areas for this type of development can be found by reference to Part 4. For example, if it has been decided that a large mechanised farm is to be established somewhere in the Kano Plains, reference to Separate Map 4 and to Part 4 (Table 36) shows that few areas appear suitable and, for example, such farms could be established in the Birnin Kudu Local Government Area in Land System 331.

2. Selection of areas for increasing the production of particular crops

Given a decision that the production of a certain crop must be increased, the areas in which the environmental limitations are at a minimum for that crop can be obtained from Part 4 (Table 37) and identified on Separate Map 3. For example, Table 37 shows that there are no or only minor limitations to the growth of maize in Land Systems 301, 304 and 306, which occur in Rano Local Government Areas. Table 4 shows the number of crop options in each of these land systems and more detailed descriptions can be obtained from Part 3. The geographical location of these land systems is obtained from Separate Map 3.

6 3. Selection of the types of agricultural development within particular administrative units

The types of development that are possible in particular administrative units are discussed in Part 4 of this report. The administrative areas can be located on Separate Map 4 and numbers and symbols indicate the types of development for which the environmental limitations are at a minimum. For example, if it is decided that some form of development should take place in the Dutse Local Government Area, reference to Part 4 (Table 36) and to Separate Map 4 shows that the only type of agricultural development thought to be advisable is an improvement of the existing agriculture, possibly within the integrated rural development project. Separate Map 3 shows that there are either no or only minor environmental limitations to the growth of three crops; millet, sorghum and groundnuts. Further information about the area is obtained by reference to Part 3 of the report in the section dealing with areas with three crop options.

The decision as to which type of development should be undertaken or which crops should be grown depends on economic and social factors that are outside the terms of reference of this project.

The report can also be used to determine the limitations to the growth of particular crops in areas chosen for development. For example, if it is decided that some form of development should take place in Minjibir Local Government area, reference to Separate Map 3 shows that the area lies within Land System 333 and is considered to have soil limitations to the growth of two crops. These limitations can be found by reference to the legend of Separate Map 3 or to the appropriate section of Part 3.

CROPS CONSIDERED

At the request of federal and state authorities the following crops were considered: maize, millet, sorghum, yams, rainfed rice, groundnuts and cotton. Rainfed rice is a special case: in this area, water is probably the most important factor in its cultivation and water relationships will be most favourable in floodplain areas. The largest of these areas are shown on the accompanying maps. Some have been the subject of more detailed investigations for an assessment of their potential for irrigated crops such

7 as rice. Similarly, climatic factors limit the growth of cotton/sorghum and maize in the northern Kano Plains and the whole area is unsuited to yam production on free draining soils. Soil limitations for these crops are, therefore, only assessed in the south. Forestry is likewise hampered in the north by an unfavourable climate.

ADMINISTRATIVE UNITS

The boundaries of the new States announced in January,1976, have been derived from a Federal Surveys 1:500 OOO-scale map of Nigeria (1976). Data in the report are referred to local government areas whenever possible. The boundaries of these local government areas have been derived from the best available published maps and are shown in Text Map 6.3. The part of the Kano Plains reported on here covers approximately one third of Kano State. The remainder is taken up by Kaduna State.

ACKNOWLEDGEMENTS

We wish to thank the staff of the Federal and State Ministries of Agriculture and Natural Resources for assistance during the project. Thanks are also due to the Director and staff of the Institute for Agricultural Research, Ahmadu Bello University, for help and cooperation in all stages of the survey and the staff of the International Institute for Tropical Agriculture, Ibadan for technical advice.

8 Part 2 Part 2 Aspects of the environment

The information presented here is summarised from reports, listed on page xiii, which contain detailed information and supporting bibliographies.

LOCATION

Text Map 6.2 shows the area referred to here as the Kano Plains. It occupies some 30 970 km2, within longitudes 7° 30' E and 9° 50' E and latitudes 10° 30* N and 13° 20' N.

The Kano Plains comprises an area of lightly dissected, gently rolling plains. Separating the Kano Plains from the Kaduna Plains in the south and west are low laterite scarps which form the watershed between the Chad and Niger drainage systems. In the south-east the Liruei and Ningi Hills are prominent massifs dividing the Kano Plains and the Bauchi Plains. The eastern boundary is artificial and follows the margin of land surveyed at semi-detailed level (NEDECO, 1974; Schultz, 1975) except in the north-east where the western limit of dunefields is used. In the north-west the boundary is that delimiting land surveyed by FAO/UNDP (1969). The Plains extend northwards into the Niger Republic.

CLIMATE

Full synoptic data are available only for Kano. This information is published in the Agrometeorological Bulletin by the Nigerian Meteorological Department. Rainfall records for several other towns in the area are also available from this source but most are of short term only.

As a general statement it can be said that, in spite of a long, severe dry season in the Kano Plains when vegetative growth decreases to a minimum, the growing period within the rainy season is sufficiently wet and receives enough radiation for a wide range of crops. Most suitable are those of moderate to high photosynthetic capacity, principally hot- season crops, able to mature within the 3-5 month growing season.

9 Rainfall

Although the mean annual rainfall over the Kano Plains ranges between 700 mm in the north to 1 20O mm in the south-east (Text Maps 6.4 and 6.5) the monthly distribution pattern is the same throughout the area.

The long dry season between late September/early October and May/early June may be punctuated by sporadic showers, in the south particularly. It ends when warm, relatively moist, south-westerly winds begin to penetrate the area in late March to early April. There is a rapid build­ up of rainfall thereafter which peaks in late July-August after which there is a rapid fall-off through October to early November.

South of the Kano Plains, proximity to hills results in increasing precipitation through orographic lift to rain-bearing, winds. It seems probable that this effect operates in the south-east Kano Plains where the hill ranges rise by 200-400 m above the adjacent plains. This is within the context of a gradual regional decrease of rainfall from the forested south of Nigeria to the dry savanna of the extreme north.

Kowal and Knabe (1972) have analysed rainfall data over northern Nigeria to produce Thiesson polygons. These are constructed around synoptic climate stations and represent areas within which rainfall data has been statistically averaged. The polygons covering the Kano Plains are shown on Text Map 6.5 and on Separate Map 3. Variations within the polygons occur, but as all the climatic data needed to quantify these variations are not available, zones of natural vegetation are taken as indicators of conditions that are wetter or drier than the average defined for a given polygon.

For each polygon Kowal and Knabe (1972) have calculated a rainy period*, which is taken to be the safe growing period for crops. The length of the rainy period for the polygons in the Kano Plains is shown in Table 1. This has been calculated using data grouped into 10-day periods, so that the actual

*Defined as the number of decades (lO-day periods) between the start of rains (first decade with rainfall greater than 25.4 mm and with two subsequent decades of precipitation greater than half evapotranspiration) and the end of the rains (last decade in rain season with more than 12.7 mm of rain and evapotranspiration in the previous decade not less than rainfall).

10 TEXT MAP 6.4

ISOYHET MAP SHOWING MEAN ANNUAL RAINFALL AND LENGTH OF RAINY PERIOD 7°30' 8°00' 8°30' 9«00' 9°30'

Length of the rainy period in days Mean annual rainfall in mm Source: Agroclimatological Atlas of the Northern States of Nigeria (KOWAL and KNABE 1 972)

12°30' 12°30'

11°30'

10°30' 10°30'

J J

D.O.S. 3269Bd Prepared and printed by Directorate of Overseas Surveys 1978 i TEXT MAP 6.5 POLYGONS SHOWING MEAN TEMPERATURE, POTENTIAL EVAPOTRANSPIRATION, AND RAINFALL DISTRIBUTION 7°30' 8°00' 9"30' "

J-J POTENTIAL EVAPOTRANSPIRATION ----- 0.5 -v ^ * Length of rainy period (growing season

13°00' X"y Source: Agroclimatological Atlas of the Northern — States of Nigeria (KOWAL and KNABE 1 972)

12°30'

i2°oo: 12°00'

11°30'

11°00'

10°30'

9°00'

D.O.S. 3269Be Prepared and printed bv Directorate of Overseas Surveys 1978 length of the rainy period could be as much as 18 days shorter than shown. The dates for the start and end of the rains are also shown in Table 1. During the rainy period, crops are unlikely to suffer moisture stress long enough to affect yield significantly, so it can be considered as the safe growing period.

TABLE 1 The length of the rainy period, and the date of its start and finish in polygons covering the Kano Plains (Kowal and Knabe, 1972)

Rainy period Polygon Starting Finishing Length (days) date* Date?*

Bauchi 140 May 21-31 Oct I-IO Kano 120 June 1-10 Oct 1-10 Katsina 120 June 1-10 Sept 21-30 Samaru 150 May 11-20 Oct 1-10

*First 10-day period in which rainfall exceeds 2.5 cm followed by two 10-day periods in which rainfall exceeds 0.5 cm evapotranspiration /Last 10-day period in which rainfall exceeds 1.3 cm and is greater than evapotranspiration in previous 10-day period

Temperature

The range of daily maximum and minimum temperatures during the rainy period in each of the polygons covering the Kano Plains is given in Table 2

11 TABLE 2 Range of mean maximum and minimum daily temperatures, in 10-day periods, during the rainy period, in polygons covering the Kano Plains

Temperature range, °C Polygon Maximum Minimum

Bauchi 28.4-34.3 19.4-23.3 Kano 28.9-35.0 20.6-23.O Katsina 29.0-37.8 20.4-23.9 Samaru 27.3-34.0 18.6-21.6

The highest temperatures occur in April and May at the beginning of the rainy season. At Kano the mean monthly temperature reaches 30.5° C in April and drops to 21.2 C in December. Exacerbating the effect of the high temperatures in the early part of the year are the very low humidities which accompany the strong harmattan winds.

VJIOUSI räuidtiOn äfiu iiCiirS Oi SUnSiiiilS

The range of mean daily global radiation and the range in mean actual hours of sunshine during the rainy period are given in Table 3 for the polygons covering the Kano Plains. In Samaru and Bauchi the mean actual sunshine is less than 5 hours daily only in the last 10-day period in August, whilst in Kano and Katsina it exceeds 5 hours daily throughout the rainy period.

TABLE 3 Range of mean daily global radiation and mean actual hours of sunshine, in lO-day periods, during the rainy period, for polygons covering the Kano Plains

Range Polygon Mean daily global Mean daily actual radiation cal/cm^/day sunshine hours

Bauchi 349-488 5.60-8.88 Kano 374-506 5.47-9.18 Katsina 356-499 5.02-8.98 Samaru 345-504 4.75-9.45

12 RELIEF AND DRAINAGE

The Kano Plains comprises extensive tracts of almost level to gently undulating lightly dissected land, broken in the south and east by groups of rocky hills and inselbergs. Rather greater dissection has taken place locally in the headwaters of rivers draining westwards.

The general relief features can be seen on Text Map 6.6. Much of the area lies between 400-700 m with scattered hills rising 50-400 m above the surrounding land. The highest and most extensive massifs occur in the south-east where the Liruei Hills reach 1 230 m and the Ningi Hills 970 m. On the plains the general height difference between valleys and adjacent crestal areas is only 10-20 m. Typical cross-sections consist of (a) a broad crestal area locally with ironpan cappings; (b) long, straight middle slopes of less than 2° and (c) short, steep lower slopes showing signs of accelerated erosion.

The drainage net (Text Map 6.7) is predominantly tributary to the Niger in the north-west via the Rima River. All of the southern part is drained by Hadejia River tributaries such as the Kano, Chalawa, Gari and Jamaare Rivers. The Hadajia drains into Lake Chad.

Downcutting by rivers is most active in the western part of the Kano Plains, although gullying by ephemeral streams occurs in many small areas throughout, notably in the densely cultivated south and west of Kano region. The most extensive floodplains are associated with the Hadejia River tributaries in eastern areas (Separate Map 4).

GEOLOGY

Much of the area is underlain by a basal complex of igneous and metamorphic rocks of mainly Precambrian to Lower Palaeozoic age. Younger sedimentary rocks of cretaceous age overlie this basement in the north while Pleistocene lacustrine sediments cover the extreme south-east. The only recent sediments are various colluvial and alluvial depositis, and wind-blown drift which can be traced over the entire area. Laterite cappings are evident over all rock types; their age ranges from upper Tertiary to Quaternary.

13 The Basement Complex rocks are essentially granites, gneisses, schists and quartzites. The Quartzites commonly occur as linear ridges, while the granites and gneiss fcrm inselbergs and undifferentiated plains. It is significant to soil development that these widespread rocks are quartz- rich and low in divalent cations. The Cretaceous sediments consist of felspathic clayey sandstone, grits and pebble beds, of which some are arkose. The total thickness of these sediments is less than lOO m and in many places they have been eroded and removed by streams and gullies leaving outliers on the higher interfluves.

Lateritic caps are also associated closely with crestal sites throughout the Kano Plains. They are believed to be residual from a more extensive and level late-Tertiary, lateritised surface that has since been gradually eaten into by the present river systems. Erosion of the margins of the caps or mesas has led to redistribution of ironpan fragments downslope and, locally, in their recementation into detrital, footslope laterite.

Pleistocene clay, silts and interbedded sand and gravel beds of the Chad Formation occur in the extreme south-east. They were laid down as freshwater deposits and form a thin veneer over rocks of trie Basement Complex.

Of the younger sediments, the floodplain deposits are most varied, chemically and physically. The wind-blown drift or loess in this area is most readily identified in the northern parts where its depth and uniformity in fine sand texture is distinctive. Coarse aeolian material occurs as fixed dunes orientated east-north-east to west-south-west in the extreme south-east, around Birnin Kudu.

LANDFORMS

The Kano Plains have been divided into 47 land systems (areas having a distinctive environment most readily identified by their landform*). The land systems can be grouped in turn to form physiographic units having a

*For full definition of land systems see Land Resource Report 20, Vol.3 (Bennett et al., 1978)

14 KANO PLAINS-RELIEF TEXT MAP 6.6

7°30' . 8°00' 8°30' 9"30'

13°00' 13°00'

Vertical interval 1 50 metres Contours ~— Formlines

12°00'

Jkara -A

Report area boundary Main road Secondary road Other road or track • Railway • State capital ^\\ J V 1-r. Local government headquarters ^^1/ -o o Small town *¥& o .Village $£> IST^ > 10°30' Kilometres 20 0 20 40 60 I i , i I I I I 1:1,500,000 _J J Ax- 7°30' 8°00' 8°3Ö'

D.O.S. 3269Bf Prepared and printed by Directorate of Overseas Surveys 1978 KANO PLAINS-DRAINAGE BASINS TEXT MAP 6.7

7°30' °00' 8°30' 9°30' yy /

e- r Maiadawaf

DauraJ 13°00' Katsinat sJVIashi L^ 13°00'

x < TANßWAl I ~A /*r Dutsi/ Is. ^/ ^ v /- J yBindawa^Px v / or .*- Jt ~x5_ v. -K Irwawa Kazaure \ Niger and Chad watersheds Star, Other major watershed 12°30' Other watershed /Kuka0 GAR/

BichT^jjotS&V! sunya

N gwars ~ ^-t?

Dawakin-fr J

I I cria R N l(^ !^ÄlMVvS ^7r JL Birnin Kud 11°30' n

Tudun i^/Vada iika.ra Burjr-

Report area boundary Burrao Main road -/KANO -JAMAA,\AkE —,^ Secondary road Other road or track

Q State capital 'if- Local government headquarters o Small town o Village 7 r ' 10°30' Kilometres 20 0 20 40 60 i i i I I I I 1:1,500,000 _J I 7°30' 8°00' 8°3Ö' 9°30'

D.O.S. 3269Bg Prepared and printed by Directorate of Overseas Surveys 1978 common geomorphological history, e.g. forming a dissected zone, or having similar land forms, e.g. rocky hills. Thirteen such units are recognised (Text Map 6.8), which can be further simplified as follows:

Physiographic Unit i. Hills on Younger Granite

These consist entirely of massive rocky hills associated with granite ring dyke complexes. They rise steeply above surrounding plains by heights of 50-2CO m in general and are largely bare rock.

Physiographic Units ii-viii. Plains on Basement Complex

Together these plains occupy 66 % of the report area. They range in height from 400-760 m and comprise gently undulating land broken only by scattered low hills. Their drainage texture ranges from medium to coarse and the pattern is dendritic giving a moderately low amplitude of relief. Dominant-slope angles are in the order of 1°. There are few rock outcrops and ironpan cappings.

Physiographic Units ix-xi. Plains with hills on Basement Complex

These gently undulating plains overlie Basement Complex rocks mainly, but incorporate small areas of aeolian deposits and Cretaceous sediments. They separate higher and lower plains but are little more dissected than them. In altitude they range from 440-960 m and their drainage is characterised by a subdendritic pattern but a widely varied texture. The dominant slopes are 1-2°. They contain many small to large rock outcrops but relatively few ironpan cappings.

Physiographic Unit xii. Plains on Cretaceous sediments

This extensive area comprises a gently undulating plain on Cretaceous sediments with inliers of Basement Complex igneous rocks. Its

15 altitudinal range is from 430-560 m and the drainage is coarse dendritic to subparalle with moderately low amplitude of relief. The dominant slope angle is about 1.5°. Ironpan cappings and rock outcrops are rare.

Physiographic Unit xiii. Plains with linear dunes on Basement Complex

This small area comprises fixed linear dunes on both Basement Complex and minor lacustrine sediments. They have an amplitude of 5-15 m and extend in straight lines for many kilometres. The inter-dune areas are flat. A few small rock outcrops have been noted.

SOILS

The soils have been studied systematically at reconnaissance levels in such a way that reasonable estimates can be made of the main soil series in each major land system. In a complementary analysis of particle size distribution it was found that the soils could also be described satisfactorily in broad bands crossing the Kano Plains, based on selected particle size.classes of either surface horizon or subsurface horizon of maximum clay content. These texture bands are indicated on Separate Map 1 and are interpreted as being the result of aeolian transport and deposition of silt and fine sand which has blanketed the landscape to o varying depths. An average density of one described pit/18 km was attained, based on catenary traverses previously located on aerial photographs.

Soil classification

The soils are classified primarily on those physical characteristics that are consideredto be most significant to crop growth - depth, drainage, nature of parent material, amount of gravel or coarse material and texture of the B horizon. Chemical characteristics, such as sodicity, are taken into account where relevant. The class limits of the above criteria conform wherever possible with those of international classification systems, in particular that used by FAO (1974).

16 KANO PLAINS-PHYSIOGRAPHIC UNITS TEXT MAP 6.8

13°00' — Katsina Hills on Younger Granite 13°00'

Plains on Basement Complex

Plains with Hills on Basement Complex

Plains on Cretaceous Sediments

Plains with Linear Dunes on Basement Complex and Chad Formation

I*_ Physiographic Unit boundary and number

l^^x/J—_C \. /Kunyä

--' ^agwaiN^fe* JÄKAHA PkAl

-W1^ \ VKANO •A Tora \ _ \ ^ 12°00' Ijwarzo ^^P^/T" X^.—/^J _^f ^\ i Y> ; CHALÄWA PLAJHfS/V'"' -xT -/ # Kiruc / I Cha'*

O PLAINS" r (C/Rogo AINS , XJir-BifiSn-^; •11°30' III (AMANDA PI,

.f^<.

VIII

Jkara \#- /l^v f

Report area boundary m^m 11°00' Main road •^:;x W0 Secondary road Other road or track

===== Railway • State capital "toi Local government headquarters o Small town o Village

10°30' Kilometres 20 0 20 40 60 I ... I I I I 1:1.500,000 _J I 7°30' 8°00' 8°30'

D.O.S. 3269Bh Prepared and printed by Directorate of Overseas Surveys 1978 Soil genesis

In considering the conventional soil-forming factors of parent material, climate, topography, time and the biotic factor it is clear that each has played a signficant role. The various parent rocks, for example, have weathered to yield a largely insoluble quartz-rich residue almost devoid of phosphatic minerals but relatively rich in potassium. The strong seasonality of climate favours alternate periods of chemical and physical weathering with the production of laterite in many areas and the concentration of bases in some profiles. In addition, prevailing seasonal winds result in a winnowing, sorting and deposition of surface material in well defined patterns. The topography, being essentially gently sloping, generates slow rates of surface water run-off which remove fine particles and concentrate sand and coarse material at the surface. The significance of the biotic factor centres around the role of man, vegetation and soil fauna in modifying the fertility and possibly texture of the surface soil.

In general the soils are yellowish to reddish, deep, well-drained, poorly structured with texture ranging from coarse in the north to fine in the south. Sodic soils with impeded drainage occur in the middle of the area. Horizon differentiation is based on increasing clay content in the subsoil, structural and consistence changes, coarse material and iron segregation mottling. The soils are quite strongly weathered but have high base saturation, and the finer-textured soils are therefore not deficient in nutrient cations. The physical status of the soils is adequate in all except sodic soils.

Soil patterns

The land systems shown on Separate Map 1 are not composed of soil associations in the sense that they are patterns of geographically associated soils. Several soil series are widespread in the Kano Plains but it is rare for any single series to be restricted to one land system and the usual case is for seven or eight common series to recur together, but in differing proportions, over several land systems. However, within the texture bands, also shown on Separate Map 1, there is a tendency for one or two series to be dominant, especially in bands 1-5, 7-9 and 13.

17 Toposequences, in which the same arrangement of soils occur from crest through valley sides to lower slopes, can be found but neither consistently within one land system nor between land systems. This is believed to result partly from the intricate pattern of parent rocks within Basement Complex areas and partly from the complex geomorphological history which has resulted in such areas having a relatively level surface relief. The presence of aeolian drift material throughout the area also tends to obscure lithology-topography-soil relationships.

It is, therefore, impossible to predict with certainty the soil series at any given location with the amount of information gained from this reconnaissance survey.

For the purpose of assessing the agricultural value of a land system the soils on the constituent facets, i.e. crest, valley side, valley head, etc., were rated for their suitability for several major crops (Appendix 1) by taking account of drainage, depth, amount of coarse material, texture and certain chemical properties. This approach does not give accurate results but for this reconnaissance survey is deemed to be a reasonable guide, at least for the major land Systems.

It is possible to describe in general terms a few exceptions in soil distribution to the most widespread soils outlined above.

Ironpan cappings occur mainly on crestal and upper slope sites. Almost everywhere they have very shallow gravelly soil interspersed with outcropping ironpan, although pockets of deeper, cultivable soil also occur. Midslopes, below the ironpan cappings, commonly are deep and well drained but locally contain much concretionary ironpan rubble. Concretionary (re-cemented) ironpan may occur at footslopes-.

Very shallow soils are also found near outcropping granite, gneiss and schist, with or without ironpan, but mostly with considerable amounts of quartz. Soils on inselbergs and granite massifs are predominately skeletal. Footslopes to such areas tend to have gravelly profiles.

Valley-head areas, being gently concave, commonly have soils with impeded drainage, shown by either a gleyed matrix colour or a large number

18 of gley mottles. Poorly and imperfectly drained profiles are locally common especially in texture bands 7-10. These correlate well with the distribution of alkaline, sodium-rich soils and are thought to be due to deflocculated clays. These soils are not saline.

Valley bottoms and floodplains have not been examined in detail, but observation and accounts from farmers show them to be very varied both texturally and in drainage properties.

In the Kano Plains there are many soils whose surface or entire profile is dominated by silt or very fine sand. Such silt or very fine sand originated as aeolian material.

Soil fertility

With the possible exception of soils of certain floodplains, sand dunes and those that are sodium-rich, the soils of the Kano Plains have moderate to good physical fertility. They are well or imperfectly drained, thus there is adequate aeration at all times and waterlogging is brief if it occurs at all; they have sufficient rooting depth for most crops, except on and near ironpan cappings and rocky areas - together estimated at less than 5% of the total area; most are neither excessively coarse nor fine textured and the presence of coarse material is limiting to root development only in a few areas.

A recognised physical deficiency, however, is the tendency for the surface to form a thin but hard crust or cap during the first rains of the wet season, which effectively prevents penetration of rain and seedling emergence and causes rapid surface run-off and erosion. This phenomenon is most widespread in silty or very fine sandy topsoils low in organic matter. It can be amended by a variety of cultivation practices, such as mulching, timely ploughing or by the addition of soil conditioners, but except in the latter case, will recur whenever the surface is exposed to rain.

Chemically, the fertility of the most common series is moderate, again with the possible exception of some floodplain soils which are believed

19 to have above-average fertility. They are moderately to strongly weathered but have high base saturation. Exchangeable potassium levels are good and rarely less than 0.1 or as much as 0.5 meq %; calcium and magnesium levels are moderate, sodium is very low and commonly absent. With pH values of 5.0-7.0 the soil acidity is satisfactory. Organic matter, mainly as a result of burning, is very low but well humified almost everywhere and* as might be expected, contributes significantly to topsoil cation exchange capacity and fertility status. Phosphorus levels have not been determined, but by corollary with other areas can be expected to be generally deficient.

VEGETATION

The activities of man have had a greater effect on the soils and vegetation of the Kano Plains than in any of the other reporting areas of this project with the possible exception of the Jos Plateau. Excepting a limited area in the south-east which contains a high percentage of rocky hills (Separate Map 2), the density of population is high, and burning, cultivation, grazing, firewood gathering and cutting for building purposes have tended to postpone or prevent the natural succession of regrowth. In all densely settled areas the result is a remarkably uniform man-made parkland tree savanna of selected mature trees of economic value. On the periphery of these areas where cultivation and habitation are not so dense, all stages of regrowth from shrub to tree savanna may be found, though relics of savanna woodland are becoming rare.

Studies of relic vegetation in forest reserves, river margins and isolated rocky hills, and comparisons with vegetation in similar latitudes and environments outside Nigeria, indicate that the vegetation in the project area of the Kano Plains, both proclimax and regrowth successions, changes gradually in botanical composition from south to north in response to decreasing rainfall. Two major vegetation zones can be differentiated, the Northern Guinea Savanna to the south and the Sudan Zone to the north, with a very small intrusion of the Subsudan Zone between these two in the extreme south-east (see Rackham and Rose Innes, 1978). CSee Text Map 6.9.)

20 Legend for Text Map 6.9 on reverse Legend for Text Map 6.9

Land systems and vegetation: Kano Plains

Land System

1 Northern Guinea Savanna and Sub-Sudan zones. Dominated by Adansonia digitata, Bombax costatum and Boswellia dalzielii with Ficus spp., Lannea acida and Sterculia setigera common.

2 Northern Guinea and Sub-Sudan zones. Similar to land system 1 but also containing upland savanna species common to both zones listed in 301.

5 Not surveyed.

301 Northern Guinea Savanna zone only. Isolated Isoberlinia spp. savanna woodland relicts, separate from or mingled with upland species common to both zones including Anogeissus leiocarpus, Anona senegalensis, Afrormosia laxiflora, Afzelia africana. Butyrospermum paradoxum, Bridelia ferruginea, Combretum spp., Crossopteryx febrifuga. Gardenia spp., Hymenocardia acida, Lannea barter/', Maytenus senegalensis, Parkia clappertoniana, Strychnos spinosa, Terminalia spp., Ximenia americana.

302 Northern Guinea Savanna zone only. Isoberlinia spp. shrub savanna relicts separate from or mingled with common species listed in 301 and/or with Pseudocedrela kotschyi, Pileostigma thonningii and Terminalia macroptera on ill-drained soils.

303 Not surveyed.

309 Mostly in Sub-Sudan zone. Dominated by species indicative of poorly drained soils including Acacia seyai, Anogeissus leiocarpus, Combretum ghasalense. Balanites aegyptiaca, Bombax costatum. Commiphora africana and mingled with common upland species listed in 301.

313 Not surveyed.

323 Northern Guinea Savanna zone only. Frequent Isoberlinia spp. savanna woodland relicts separate from or mingled with common upland species listed in 301.

324 Northern Guinea Savanna zone only. Frequent small relicts of Isoberlinia spp. savanna woodland or shrub savanna separate from or mingled with common upland species listed in 301.

330 Not surveyed.

331 Mostly in Sudan and Sub-Sudan zone. Often dominated by species indicative of poorly drained soils including Adansonia digitata, Anogeissus leiocarpus. Acacia seyal. Balanites aegyptiaca, Bombax costatum, Combretum ghasalense, and Commiphora africana, mingled with common upland species listed in 301.

336 Northern Guinea Savanna zone only. Contains common species listed in 301.

340 Northern Guinea Savanna zone only. Isolated Isoberlinia spp. tree savanna relicts separate from or mingled with species indicative of poorly drained, well-watered soils including Anogeissus leiocarpus, Daniel/ia oliveri, Khaya senegalensis, Pileostigma thonningii, Pseudocedrela kotschyi, Terminalia macroptera and common upland species listed in 301.

341 Mostly in Sub-Sudan zone. Species indicative of well-watered, poorly drained soils including those listed in 340 plus Acacia spp., Adansonia digitata, Bombax costatum. Balanites aegyptiaca. Commiphora africana, Sterculia setigera and common upland species listed in 301.

342 Not surveyed.

343 Sudan zone only. Very small, not surveyed. KANO PLAINS-VEGETATION TEXT MAP 6.9

11°30' 11-30'

11°00'

302 302 Location of Text Map 6.9 302 7°30' 8°00' 8°30' 9«00' 9'30' ;340 /336\ \34l 10°45' <3 302

323

2 ,323:

.2/302.

10°30'

_Vegetation zone boundary Vegetation Zones .Vegetation survey area boundary n'oo A Sudan

B Sub-Sudan

C Northern Guinea Savanna

Tree Savanna and Savanna • Woodland

10°15'l Jl0°15' 8°30' 9°00' 9°30'

DOS. 3269BJ Prepared and printed by Directorate of Overseas Surveys 1978 Because of man's over-riding influence, particularly through cultivation and the use of fire, many species are common to all three zones and few to only one; most are fire-tolerant. The Northern Guinea Zone is dominated by broad-leaved Isoberlinia spp., sometimes associated with Cussonia barteri and Protea elliottii, whilst the Sudan and Subsudan Zones are characterised by five-leaved Acacia spp. and their associates including Balanites aegyptiaca, Commiphora africana and Zizyphus spina- christi. Trees and shrubs common to all zones include Adansonia digitata, Anogeissus leiocarpus, Anona senegalensis, Afrormosia laxifolia, Bombax costatum, Bridelia ferruginea, Borassus aethiopum, Combretum spp; Crossopteryx febrifuga, Daniellia oliveri, Hymenocardia acida, Maytenus senegalensis, Khaya senegalensis, Parkia clappertoniana, Piliostigma thonningii, Pterocarpus erinaceus, Securinega virosa, Strychnos spinosa, Sterculia setigera, Terminalia spp., Vitex doniana and Ximenia americana.

In the Northern Guinea Savanna Zone,Isoberlinia spp. and some of their associates are found over a wide variety of soil conditions whereas other communities tend to be confined to specific edaphic sites. Shallow, poorly drained soils subject to seasonal waterlogging are often indicated by a shrubby tree savanna of Terminalia macroptera and Nauclea latifolia. Deeper heavy floodplain soils carry scattered Mitragyna inermis, locally mixed with Terminalia macroptera. Deep, freely draining soils of river levees and streambanks support communities of Terminalia glaucescens and forest relics such as Daniellia oliveri and Khaya senegalensis. Steep rocky hillsides are occupied characteristically by a tree savanna containing Boswellia dalzielii, Adansonia digitata, Bombax costatum and Ficus spp.

In the Subsudan/Sudan Zones distinctive communities, very similar to those listed above for the Northern Guinea Savanna Zone, occur in appropriate deep heavy floodplain soils, free draining soils of river banks and levees, and shallow rocky soils of inselbergs and mesas. Areas of poorly drained impermeable clays or shallow soils over impermeable substrata are often almost bare of the usual herbaceous cover or may carry a community of annual grasses and herbs mingled with scattered Cissus sp.; the woody element above the sparse ground flora may contain Acacia spp. - chiefly A. seyal - with Balanites aegyptiaca, Commiphora africana, Piljostigma thonningii, Sterculia setigera, Anogiessus leiocarpus and Zizyphus spinachristi. Similar conditions but with a

21 tendency towards waterlogging are often indicated by Pseudocedrela kotschyi and Tamarindus indica, although the latter is also closely associated with termitaria. Deep,light, freely drained, aeolian drift soils (Bennett et al, 1978) support a dense tree savanna wherever cultivation pressure permits its development, which may contain any of the common listed species amongst which Acacia hockii, Afzelia africana, Amblygonocarpus andongensis, Butyrospermum paradoxum, Daniellia oliveri and Pterocarpus erinaceus may be conspicuous.

There are also distinctive herbaceous and woody successions following cultivation, fire and grazingi where the influence of man as the main ecological factor is even more marked. In these often heavily used areas which have evolved into a parkland treee savanna, only selected economically valuable species survive in the long term - for example, the shade trees Daniellia oliveri and Khaya senegalensis which, with Afzelia africana, Pterocarpus erinaceus, Ficus sycomorus and Acacia albida, are valuable dry-season browse trees for cattle. Other species are retained for their fruit, such as Butyrospermum paradoxum, Tamarindus indicus, Parkia clappertoniana and Vitex doniana.

Competition for land between the traditional Fulani graziers and the cultivators is a contentious issue already in the intensively used land and will increase as more and more land is taken up for crop production. Although the remedies for this - formal allocation of grazing rights in well defined reserves and mutually agreed cattle routes to grazing lands and water - are recognised, only limited progress appears to have been made and increasingly bitter disputes can be expected. A full assessment of the vegetation resources in relation to agricultural and pastoral pressures is given by Rose Innes (Rackham and Rose Innes, 1978).

Because insufficient is known of the natural browse plants of the savanna areas, and because Government sees a more important role for cattle in the national economy than hitherto, it is necessary to establish a comprehensive research programme on browse species, based on sustained utilization (see Appendix 2) .

22 PRESENT LAND USE

Density of cultivation

A conventional analysis of land use showing crops and cultural features was abandoned due to difficulties in interpreting features consistently with the airphotographs available. The alternative of delimiting the density of cultivation from 1:40 OOO-scale air photographs taken in 1971 and 197^. was, however, successful. Four percentage classes were distinguished, >60, 6o-35, 34-10 and <10. The assessment was made using a grid of squares, each measuring 5 km^, which is shown on Separate Map 2. Land lying within a field boundary was considered to be in the current cultivation cycle; no attempt was made to distinguish between land used for crops and short-term fallow land.

Areas with more than ^ 60% cultivation These are areas with little spare land. Population is such that there is considerable pressure on land and farmers move out of the area. Nomadic pastoralism is impossible and animal production is usually restricted to stall-fed beasts. The areas are considered unsuitable for the establishment of resettlement schemes, large mechanised farming projects, mixed farming (based on use of cattle for draught purposes)or grazing and forest reserves, because of problems associated with land tenure, and the displacement of population.

Areas with 60-35% cultivation These are areas in which, for the existing farming system, there is a balance between population and available land. Any development in these areas will result either in a change in the farming system or increased pressure on the land, particularly through a shortening of the fallow period. Although nomadic pastoralism is not impossible, there are likely to be severe problems associated with herding and damage to growing crops. Again, land is not available for large mechanised farming and resettlement schemes.

23 Areas with 10-34% cultivation These are areas with either a high proportion of land unsuitable for arable crops or there is unused land. Fallows are longer than in more intensively used areas. They may be areas of new settlement with farmers moving from densely settled areas. Land is available to support the nomadic pastoralist's herds &f not fly-infested or in a game reserve), though burning and other malpractices continue to affect adversely the stock-carrying capacity. Where there are no soil limitations to crops and slopes are^3%, mechanised farming schemes could be established.

Areas with <10% cultivation These are areas of low population density with little pressure on the land; there is usually ample grazing land although, because of its present poor composition, it generally provides relatively satisfactory grazing only during the wet season. Space is available for resettlement and mechanised farming schemes if other factors are favourable.

Distribution of cultivation

There are striking regional difference in the distribution of cultivation, as shown on Separate Map 2. Dense cultivation extends with few breaks from the northern boundary southwards to approximately 11° 30' N. South of this line the density decreases markedly to one of sparse cultivation punctuated by isolated areas of moderate density.

The reasons for this pattern can be partly explained in environmental terms as the high rocky hills in the south-east (Land Systems 1, 2, 302) and in the neighbourhood of Rano (Land System 301) are only lightly used, if at all. Elsewhere, the presence of dams (Tiga Lake) and forest or game reserves cause anomalies in the distribution. Population pressure in northern areas is such that even land systems considered to have moderate or severe limitations to arable crops (Land Systems 315, 316, 317,

24 320) are heavily used. It is not clear why cultivation density is so light on the northern and western fringes of the Ningi Hills; it is possibly connected with the presence of soils which are difficult to work because of impeded drainage and sodicity (see Part 3) or it may equally result from historical causes.

Present farming systems

Gosden (l^lö) describes the agriculture of the Kano Plains as being one of small-scale, subsistence farming in which cash crops play a small but significant part, particularly in the southern half. The crops are largely rainfed and are cultivated by hand hoe, assisted widely by draught animals; tractors are beginning to be used in the Funtua-Malumfashi area. Several cultivated plots or farms make up a typical family holding and these are grouped around villages or hamlets. Few holdings exceed 3 ha in total area.

The main crops are sorghum and gero millet, usually interplanted with cowpeas. Gero dominates in the north and sorghum over the rest of the area; on the southern border, maize becomes an important minor food grain. On this basis, three farming systems are recognised, which grade into one another and are not necessarily static in time or area. A limited number of cash crops are grown in addition to the surplus food crops. Crops are generally grown on ridges except in the gero millet-dominant north where, on the sandy soils of this area, 'flat' planting is more common.

1. Millet/sorghum farming system

This extends southwards to a line running north-west to south-east just to the north of Kano city, corresponding approximately with the mean 120-day rainy period limit. Gero millet and sorghum are the staple crops, with the former dominant. Cowpeas and groundnuts, frequently interplanted with the cereals, are the main cash crops.

25 2. Sorghum/millet, cowpeas farming system

Extending south from the millet/sorghum area and covering the central portion of the Kano Plains, the southern boundary corresponds closely to that of the Sudan Vegetation Zone or the 130-day rainy period limit. Sorghum is here more important than gero millet and, in addition to the interplanted cowpeas and groundnuts, cotton and capsicums are important cash crops on the southern fringes. Sugar cane and some rice are grown wherever fadama conditions allow.

3. Sorghum/maize, millet farming systems

In the remaining southern strip, sorghum continues to be dominant with interplanted gero millet, but maize largely replaces cowpeas as the third important food crop and roots, such as cassava and sweet potatoes, become more common. Cash crops again include groundnuts, but cotton is frequently the most important; capsicums feature prominantly and rice and sugar cane are grown when there are suitable flood plains (fadamas).

LIVESTOCK

Cattle ownership among arable farmers is common, particularly in the two northerly farming systems. Cattle rearing is for milk, meat and manure and the use of work bulls is widespread; it is quite common for a farming family to keep a herd of up to 10 animals. Tsetse fly infestation is nominally absent from the area.

In addition to cattle, nearly every rural family owns a few small stock - sheep, goats and poultry - which are kept in compounds during the rains and allowed to forage in crop residues and fallow land after harvest. Crop residues such as groundnut and cowpea haulms have considerable value for livestock feeding in the dry season and are all carefully protected and stored.

26 There are a few settled Fulani cultivating land and rearing cattle. Nomadic Fulani pass through the area from north to south, including those from the Niger Republic, between grain harvest and planting. They do not stay long in the area because crop residues are largely reserved for the resident cattle and fallow land is restricted.

Agricultural infrastructure

The Kaduna and Kano State Ministries of Natural Resources provide most of the services for the advice and assistance of the farming community. Those parts of the area within the Funtua and Malumfashi Local Government areas of Kaduna State benefit from the Funtua Agricultural Development Project, a World Bank integrated Rural Development Project designed to raise output and farmer income through improved agricultural infrastructure and other services.

Unfortunately it has not proved possible to obtain up-to-date raw data for analysis for the Kano Plains, partly due to the recent restructuring of the States and their changed administrative organisation.

Agricultural extension The extension services under the State's Chief Agricultural Officers were formerly organised on a Divisional basis with a Divisional A.O. in charge of a team of district and village extension workers. Since 1977 this organisation has been redelineated according to local government areas. No recent data could be obtained for the numbers of extension workers in the Kano Plains area, but as in most other parts of the Project, their ratio to the number of farming families is very wide (in Kano State as a whole, fewerthan 1:2 000 in 1977). This, taken in conjunction with the poor communications over parts of the area, means that many farmers (except those fortunate enough to be within the Funtua Agricultural Development Project) will have little or no contact with the advisory services. This must be a major restraint to improvement of the' agriculture in the area.

Agricultural centres Farm centres and tree crop nurseries are established by the Ministry of Natural Resources for the multiplication of improved

27 seeds and planting materials and for crop trials; also established are Farm Training Centres for junior extension workers ana Farm Institutes for teaching farmers' sons improved farming methods. The Institute of Agricultural Research, Samaru, has a sub-station for research in Kano.

Government tractor-hiring units (with the necessary maintenance facilities) are maintained for mechanical cultivation purposes but their numbers and therefore impact has been small to date.

Fertiliser distribution No recent analysis . was available of fertiliser distribution for sale at subsidised prices. It is known, however, that the farmers' demand greatly exceeds the supplies which fluctuate considerably within the area and over the year.

Agricultural chemicals These are mainly seed dressings and cotton sprays and are sold through commercial outlets, so there are no comprehensive records of amounts used. Demand generally exceeds the supply.

In addition to the services provided by the State, the Federal Government has intensified its efforts to encourage food production by introducing the Operation Feed the Nation Campaign, setting up the various national crop production companies such as the National Grain Production Company for large-scale production and storage of food grains, and establishing the Accelerated Food Production Programme for selection, multiplication and distribution of improved seeds, fertiliser and seed dressings.

Rangeland

Rangeland and cattle production in the Kano Plains are described by Blair Rains (1975, 1977) and Hendy (1978). The main factors to be considered in the assessment of the potential of an area for livestock production are the natural vegetation and the ways in which man has modified it. Thus it depends not only on the palatability and nutritive value of grasses and browse and the balance between herbaceous and woody vegetation, but also on the amount of cultivation, the availability of crop residues, the amount of grass that is burnt, and the number of cattle and small stock that are in

28 an area. It is very important to recognise that the carrying capacity of an area may be different in the wet and dry season and, unlike other areas, it is the wet season rather than the dry season carrying capacity which limits the year-round carrying capacity of this area, where there is an abundance of crop residues but relatively little uncultivated land for grazing.

Fodder resources

Grassland The open tree and shrub savannas of the Kano Plains are described briefly in an earlier section of this report and more fully by Rackham and Rose Innes (19 78). They afford very limited grazing for large numbers of cattle in the wet season and fair supplies of crop residues and some good fadama grazing during the dry season. Common upland fallow grass species which are readily grazed include the annuals Pennisetum pedicellatum, P. polystachion, Digitaria spp., Brachiaria distichophylla, Cenchrus spp. and Dactyloctenium aegyptium.

The cultivation of fadamas is increasing, thus reducing the area available for dry-season grazing. In addition, fadama farmlands commonly obstruct access to intervening grazing grounds as the pastoralists are loathe to damage crops in unfenced farms.

Fodder trees The woody vegetation also provides fodder. Trees such as Acacia albida, Khaya senegalensis, Afzelia africana, Pterocarpus erinaceus and Daniellia oliveri are lopped, particularly during the dry season. While this is not harmful to trees if practiced in moderation, excessive lopping is increasingly taking place^which is likely to lead to their elimination.

Crop residues Reference to Separate Map 2 shows the distribution of cultivation within the Kaduna Plains. The farmed areas produce large quantities of crop residues

29 that are suitable for animal feeding. The most valuable are groundnut haulms (harawa) and cowpea vines and these are collected by the farmer for his own stock or for sale. The cereal stover is less valuable but is eagerly sought as soon as the heads have been harvested.

Cattle population

The distribution of cattle in the Kano Plains, most of which are owned by the settled farmers, is mainly confined to the Katsina-Daura region where many are used as draught animals. A few cattle are resident near Kano, and provide some milk for this urban centre.

The cattle are fed on crop residues during the dry season and on whatever grazing they can find outside the farms during the rains. Herds of migrant cattle from the Niger Republic move through this area on their seasonal treks north and south but, as most available feed is conserved by farmers for their own stock, they pass through quite quickly. Temporary Fulani settlements spring up annually around the game and forest reserves in the south-east where grass and trees are, illegally, heavily grazed and lopped for browse, respectively.

Burning

Burning is of little significance in this heavily cultivated region, except in the wooded area in the south-east (Text Map 2.3, Rackham and Rose Innes, 1978). Nomadic pastoralists burn perennial grassland to remove coarse, unpalatable, straw-like material and to stimulate fresh green growth for stock to graze. Burning in itself is not harmful but followed too soon by grazing of new growth, it causes loss of vigour in individual plants and leads to undesirable changes in botanical composition of the grassy ground cover.

Tsetse

Although portions of the Kano Plains were formerly infested with tsetse, the current eradication programme has controlled the fly over the area.

30 However, the large forest and game reserves in the south-east provide suitable habitats for reinfestation and complete elimination may be difficult.

Carrying capacity

Cultivation density on the Kano Plains is so high (Separate Map 2) that little grazing remains except in the wooded area of the south-east; in this area upland grazing is satisfactory in the wet season but poor in the dry, and there is no fadama grazing to supplement it. Browse and a very little burned grassy regrowth is the only other fodder available in the dry season. It would be unwise, therefore, to assume a year-round carrying capacity better than one adult bovine per 8 ha.

In the heavily cultivated zone, cattle exist in the dry season on crop residues conserved at harvest time, supplemented by fadama grazing which is available around Birnin Kudu, south-west and to the north of Kano, and in the Katsina-Daura area. Much of the fadama land' has been cultivated and is no longer available for grazing.

In the southern part of the Kano Plains, with a rainy period ranging from 120 to 140 days, the crop residues available to cattle consist largely of sorghum, whilst groundnut and cowpea hay is reserved for small stock. In the northern area, with a rainy period of less than 120 days, the most important crop is millet. Early millet is interplanted with late millet or sorghum, sometimes with groundnuts or cowpeas. Because early millet is harvested during the rains, when interplanted crops are still maturing, its residues are not available for cattle feed for fear of damage to the other growing crops. Early millet residues decay before the late-maturing.crops are ready for harvest. Sorghum residues are reserved for a variety of purposes including fencing, building and fuel, whilst groundnut and cowpea hay is preserved for livestock resident on the farms; little if anything is left over for transhumant cattle.

31 Forestry

Forest reserves

Forest reserves in the Kano,Plains total approximately 2 440 km^; none can be 2 termed high forest. Medium-sized reserves, 0.1-30 km in area, occur in Katsina, Kazaure, Malumfashi and Daura Local Government Areas (LGA). Mani and all the LGAs in Kano State have relatively few forest reserves. The Falgore Game Reserve on the southern boundary and Iggi River in the east are the largest reserves.

The primary use of many forest reserves, by default; is for grazing. Herdsmen have long since realised that they can graze in forest reserves in comparative peace. Because the Fulani were considered nomadic and therefore had no rights to land, the right to graze was rarely if ever admitted at the enquiry stage of the forest reservation procedure. The correct management regimes for grazing and forestry are completely different. Foresters strive to maximise the tree cover and exclude the grass cover. Graziers on the other hand seek to obtain the opposite result. Either result can be achieved by the timing and intensity of burning. In particular, the practice of early burning encourages the woody growth at the expense of the grasses. The result of a laissez faire policy in which the Forestry Department permit grazing in forest reserves without managing the reserve with grazing in mind, is often the complete destruction of the herbaceous layer and subsequent soil erosion. The soil erosion may be particularly severe on steepened lower slopes.

Forest plantations

In Kano State, developments in recent years have been the roadside plantations along the main road to Gumel and Katsina and the plantations of Acacia nilotica at Kuda Gangara and Gwiwa Korelin Kaduna State. Large plantations, primarily of neem, have been established at Kabakawa and Sandamu, near Katsina and Daura respectively. Irrigated nurseries were first established in Kano and Kaduna States in the early 1960s. Species

32 elimination and growth trials were started at the same time. The main species for firewood plantations are neem and Dalbergia sissoo. Eucalyptus camaldulensis (Katherine provenance) and E. microtheca are the two eucalypts that grow well on upland sites in the Sudan Zone. Acacia senega! (gum arabic) and Acacia nilotica subsp. adstringens (bagaruwa) are two promising indigenous species. Bagaruwa grows well on heavy clay soils with poor drainage, sites that are unplantable with neem. Plantations of bagaruwa could be grown on a firewood rotation with intermediate yields of the fruit for tannin and possibly cattle cake.

33 Part 3 Part 3 Environmental limitations to development

INTRODUCTION

In this part of the report are presented the facts about the environment and present land use which are used to derive and identify the development possibilities given in Part 4. The basic unit of description throughout this section is the land system. Because of their large numbers, the land systems have been grouped for convenience according to the number of crops that can be readily grown in them*. The crops considered are the main subsistence and cash crops, i.e. yam, maize, millet, sorghum, groundnuts and cotton. Land systems grouped in this way, by the number of crop options, reflect the productive versatility of the land. The groups are shown on Separate Map 3, in Table 4, and are described below.

Climatic limitations are important factors in limiting crop distribution in this area and are discussed first for the Kano Plains as a whole. The remaining environmental factors which are significant to agriculture emerge as secondary differentiating criteria between the various groups.

CLIMATIC FACTORS IN RELATION TO CROP GROWTH

The climatic factors of major importance are, firstly, the length of the rainy period,and then maximum and minimum temperatures, global radiation and the number of hours of sunshine during the growing season. These factors, which have been summarised in Part 2, are considered here in terms of their effect on the production of maize, millet, sorghum, groundnuts, cotton, rice and yams.

The rainy period over most of the Kano Plains ranges from a maximum of 150 days in the south to less than 90 days in the north (Kowal and Knabe, 1972). For some of the crops under consideration in this project, this factor is critically short. Yams, for instance require a rainy period of at least 180 days and cannot be grown on free draining soils under rainfed

*The assessment of environmental factors in terms of limitations to particular crops is explained in Appendix 1 and by Mansfield (in prep.).

35 TABLE 4 Land systems grouped according to number of crop options within local government areas

Number of crop options* and land systems (by number) Local government 5 4 3 2 1 area MS/ us// crops crops crops crops crop Bauchi State Ningi ~ 324 309,331, 336 — 330 1,2,5 341,342 Toro ~ 324 ~ 323,336 302 *~ 1,2 340 Kano State Bichi 332 305,307, 311,314, 333,334, 335,344 Birnin Kudu ~ — 331,342, — ~~ ~~ 1,2,5 343 Dambatta — — — 311,333, — — 5 335 Dawakin Kudu - - 329 333 - 330 5 Dawakin Tofa - - 332 307,333 - 317,330 5 Dutse - - 343 - - - 5 Gaya - - 328,331 - - - 5 Gezawa - - - 333,335 - 330 5 Kano - - - 333 - - - Kazaure 305,314, 335,337, 339,344 Minjibir - - - 333,335 - - 5 Rano 304 301,306, 328,329 330 "*" 330 5 324 Tudun Wada 319 301,306, 303 340 302 330 1,2 324,326 Wudil - 301,306 328,331 - - 330 5 Kaduna State Daura ~ ~ — 337,338, — 310 5 339,344 Dutsin Ma - - - 338 - - - Funtua 313,321 312 - - - - - Kankiya 307,308, 315,320 311,314, 337,338 Katsina 307,308, 320 5 337,338, 339 Malumfashi 313,318, 306,312, ~" 307 ** 330 — 321 325,327 Mani 308,337, 320 5 338,339

*Cotton, maize can d sorghum are unsuitable im parts cD f SOIn e northeir n land systems for cliinati c reasons. /Moderate or se^/er e limitations for all crcDp s consiclere d //Unsuitable fo]r annual, rainfed crops.

36 conditions in this area. For optional production local, long-season sorghum requires a rainy period of about 120 days; north of the 120-day isohyet, production becomes increasily unreliable, although a number of short- season varieties could be grown. After planting which, because of prior labour commitments, is rarely earlier than mid-way through the growing season, cotton requires at least an 80 day rainy period and 40-50 days after the end of the rains during which soil moisture can be drawn on. For this crop, therefore, the water-holding capacity of the soil (specifically related to soil texture in the rooting zone) is next in importance to the rainfall itself. Similarly, '120-day' maize is not considered to produce reliably or well to the north of the 130-day rainy period limit.

Finally, of the crops considered, rainfed rice in free-draining soil requires at least a 200-day growing season and a minimum annual rainfall of 1 300 m. Neither of these conditions is fulfilled in the Kano Plains. However, for yams, rice, cotton (also sugar cane, whose water requirements cannot be met under normal rainfall conditions)»the fadamas (floodplains) in many places retain adequate groundwater long after the rainy period has ceased (Turner, 1977) and their cultivation under these special conditions is successful.

For the purpose of the descriptions and discussions that follow,tentative lines have been drawn on Separate Map 3 across the northern Kano Plains which indicate the northern limit of successful or optimal '120-day' maize, cotton and local sorghum production. They are based on theoretical climatic and pedological limitations and field observations; they do not imply that the three crops cannot be grown north of the lines but signify that produc­ tion of these locally favoured varieties will become increasingly erratic and low.

In the case of cotton., an analysis of water-holding capacity potential of Kano Plains' soils has shown that for this factor alone and within a depth of 1O0 cm.the very fine sand fraction is critical. This fraction has the greatest water-holding capacity and where it is dominant in the soils it enables the optimal cotton-growing limit to be extended as far north as the theoretical rainy period limit of 120 days.

37 There are no temperature limitations to the growth of any of the crops. Global radiation and sunshine hours, which indicate the light energy available, decrease from north-east to south-west but are believed not to be limiting to the crops considered.

LAND SYSTEMS WITH FIVE CROP OPTIONS

Unlike the neighbouring Kaduna Plains to the south;there are no areas with six crop options, principally on account of an insufficiently long rainy period.

The main characteristics of the land systems in this group are summarised 2 in Table 5. They total 1 032 km and occur only in the southern Kano Plains within the 130-day rainy period limit. To the north maize, cotton and sorghum are progressively excluded.

Land System 313 is placed in this group with reservations. From air photo­ graph facet analysis some 38% comprises ironpan cappings (Bennett et al., 1978, Vol. 3) but of the (subjectively sited) ten soil pits only 30% consist of shallow, stony soils. It seems from other field observations that although ironpan outcrops are moderately extensive, there are substantial areas of pan covered by soil at least 50 cm deep and that these and remaining non-pan areas are well cultivated.

38 TABLE 5 Summary of main characteristics of areas with five crop options

Land Occurrence Crop Density of Present cropping Draught State of Commun- Rangeland system (Local gov. Forestry options cultivation animals erosion* cations/ and cattle no. authority) Food Cash 304 Sorghum, Rano Low to Sorghum, Groundnut, Common Slight Poor Very small mai ze, very low gero, peppers, lower area - cotton , dauro, sorghum; slope heavily millet, cowpea sugar cane, gullying grazed groundnut rice, onions in fadamas 313 Funtua, Low to Sorghum, Groundnuts, Few Medium Small areas Tsani, Malumfashi, moderate gero, cotton, almost always Tandama, Gwarzo, dauro, peppers; heavily Dabo Ikara maize, sugar cane grazed cowpea in fadamas 318 Funtua, High Sorghum, Groundnuts, Common Slight to Uncultivated Tsaunin Malumfashi gero, cotton, moderate areas are Kura maize, pepper, lower slope heavily cassava', sugar cane, gullying grazed rice in rice, onions by local fadamas in fadamas stock during wet season. 319 Gwarzo, Moderate Sorghum, Groundnuts, Moderate Good productivity Dansosia Ikara,. to high gero, sorghum, to severe low Tudun Wada dauro, pepper, lower maize, cotton slope cassava gullying

321 Funtua, Sorghum, Cotton, Dutsin Malumfashi gero, groundnuts, Makurdi mai ze > peppers; cassava; sugar cane, rice in rice in fadamas fadamas

*Terms defined in Appendix 2. /Refers to estimated proportion of area within 5 km of all-weather, tarred or hard--top roads poor 0-10%, med. 10-50%, good ^50%. Limitations to crop growth

1. Soil physical characteristics

All the land systems in this group have no or only minor limitations to the growth of five of the crops considered: the limitations are shown in Table 6.

The group lies mainly in texture bands 7, 8, 10 and 11 (Separate Map 1) whose topsoils are dominated by silt. Small areas of Land Systems 313 have severe depth limitations for cotton while coarse material is a severe limitation for all crops in some soils of Land System 313. Inperfectly drained soils occur in Land System 318, 319 and 321,but in small areas only.

2. Soil chemical characteristics

The limitation caused by soil chemical features are assessed in Table 7. The range in cation exchange capacity (CEC) signifies that most soils require only a short fallow period for nutrient levels to recover after cropping. Potash levels are satisfactory and phosphorus availability is only slightly limited by soil acidity. Some scattered areas of poorly drained soils have very high base saturation with exchangeable sodium percentage exceeding 6%, especially in Land System 319; they have low conductivity but may be strongly alkaline and will thus require careful management.

Limitations to mechanical cultivation

The dominant slopes of all land systems in the group do not exceed 3% (Table 8), the critical limit for economical large-scale mechanised farming. Land System 313 contains many small to large areas of ironpan capping but parts of the cappings contain deeper soils. Rocky areas are rare and small except in Land System 304 where 24% is covered by small to large outcrops. Fragmentation due to gullying or a fine drainage net is a feature of Land System 313 only. Accelerated erosion is moderate to severe in units 318, 319 and 321.

40 TABLE 6 Soil physical limitations to the growth of certain crops in areas with five crop options: crop options indicated by shading

Area % Soil limitation category (SLC) by crop in each land system with nature of limitation* km2 No. of Land Maize Millet Sorghum Groundnut Cotton system crop % class % class % class % class % cless Nature Nature options no. of SLC of SLC of SLC Nature of SLC Nature of SLC Nature it 2' SLC of SLC of SLC of SLC of SLC of in lend in land in land in land in land limitation limitation limitation limitation limitation system system system system system 5 304 89 47 ISöiÄ liiili liÄöl Hl lillill 1'äolsQli III iiiiii liillllllll Jlllllllllll niiiiï lal i|ÖJ!i||!i!iiiililili ill! üiüi mWmWmWÊ lil iiill! liillllllll 313 106 86 mm iäil IÉA; mMmmmmmmliä i ;iÄ*$: iliïli liaölssil mm laÖIëSil iliiil •mim wis WmfA WMmWmmM liil SiiötSÉii: »8:5 lÄSil iiÄisiiiiiiiiiii BS3ÏB •MMïi !KI IMlIi li;SSlilii!liiililil! lil! illllll illiillll!ii III liifli liillllllllII I WmmsSKiiiilislli l llili liillllllllIE ! 318 107 92 mmm lit All ^|si»||ililil| W:i mm liiiSaöiss mm :SÉ: 111 llPllllillli iillÜll liö^ll!!!!!! ill! i;||||sl liisllllllllll mm iïMas :::Vii|||:||::B:;BB::BB:i:: lÉlliü 111 lil! iilMli iii*iiililiiiililii!l 319 318 245 ii liiÄ mm IliS SÏtSJ iliiösäs« mm BiiÖBJSB il^tililiBBSSSBBB : 111 mmm i|BSi||;|iii|iii;;g ïliïll *:Si&B $: 111 BSÖÏSDJ liäil ilüiölïsil liiiil iÄlliü |^|S||s||||||:i :x:w:::::;:::::;:::::::::::::::::v::;::;::::; Ulli; 1*1111:11111 lill! Äiäää Ill ill Hill lll&illlllll! lil 131*111 ilÜlllllli|ii 321 406 321 mmtmmm IIÜ! Hiïi sifösgöjiigilj^ig mSi S3ÖSS9Ï il*! iAÉI ssbssss lil£lipÖïï9i» ili^clilili!i!ili!i III il:ë^i^|iil||:l|i; iliSli iiilsiii ilii^li|||i|||il lil llill! |||§§|äi«|!l ;B>S5SS*ä*5>?B |äl|li!!i|ii|l! illli "Limitations Depth Drainage Texture Coarse material D Severe W Severe T Severe C Severe D Moderate W Moderate T Moderate C Moderate d Minor w Minor t Minor c Minor

'Area 1 -total area; Area 2-area to which data refer

PR31/NIG/1H/2a Prepared by the Directorate of Overseas Surveys 1978 TABLE 7 Dominant soil chemical characteristics assessed as limitations to crop growth for land systems with 5 crop options (based on mean values for dominant soil series, excluding top horizon)

Limitations due to pH for // Limitation Land CEC meq % Exch. K pH P system soil* meq %/ Ground­ Maize Millet Sorghum Cotton availa­ CEC* K/ nuts bility**

304 4.8- 5.6 0.1-0.2 6.1-6.2 Nil Nil Nil Nil Nil Min SF A 313 5.3- 7.1 0.1-0.2 5.4-6.4 Min-Nil Nil Min-Nil Min-Nil Nil Min-Mod SF A 318 5.1-11.2 0.2 5.9-6.7 Nil Nil Nil Nil-Min Nil Nil-Mod SF-S A 319 6.0-14.2 0.2-0.3 6.2-7.8 Nil-Mod Nil-Mod Nil-Mod Nil-Sev Min-Sev Nil-Min SF-S A 321 6.8-14.2 0.1-0.3 5.9-6.2 Nil Nil Nil Nil Nil-Min Min-Mod SF-S A to *CEC mecI % soil /K meq % for soils'of pri >4.5 **P availability related to pH A >0.10 Adequate pH Limitations S ?8 Suitable for intensive D <0.10 Deficient 6.5-7 .5 Nil agriculture 6.0-6.49, SF 2.0-7.9 Requires a high ratio of 7.51-8.0 Minor fallow to crops 5.0-5.9, 3.1 -8.5 Moderate U/S <2 0 Unsuitable for intensive agriculture (Adetunji, 1974) /yMin = Minor, Mod = Moderate, Sev = Severe TABLE 8 Dominant slope and range of slopes on major facets in areas with five crop options

Slopes of major facet Land Dom. facet system Per cent Degrees (% area of LS) Dominant Range Dominant Range

304 2 1-5 1 0.5-3 Sideslope (49) 313 3 2-5 1.5 1-3 Sideslope (41) 318 3 1-3 1.5 0.5-2 Sideslope (60) 319 2 1-3 1 0.5-2 Sideslope (55) 321 2 1-3 1 0.5-2 Sideslope (62)

Density and distribution of cultivation

Reference to Table 9 and Separate Map 2 shows that areas of dense cultivation are most widespread and that low densities are associated specifically with Land Systems 304 and 313. In the first case the reason is not apparent but in the latter case it appears that areas of ironpan outcrop are being avoided.

TABLE 9 Density of cultivation in areas with five crop options

1 Land areas (km2) in four cultivation densities Admin. Land Total area % under unit % of 60 60-35 34-10 tlO forest reserves 304 88 Rano 2 56 30 313 104 Ikara io 20 58 16 56 318 106 Malumfashi 87 8 7 4 319 318 Ikara 130 55 48 85 80 321 406 Funtua 265 105 31 5 40

43 Forestry

There are few areas where firewood and poles can be obtained readily from the natural vegetation, except possibly in the vicinity of Land System 319. There is a Eucalyptus - Dalbergia plantation in Dansosia Forest Reserve. The young stands of E. camaldulensis has reached a height of 5.5 m in 2 years. The 6-year-old Dalbergia had a mean height of 8.6 m and a mean 3 annual increment of 2 m /ha/a.

LAND SYSTEMS WITH FOUR CROP OPTIONS

This group of land systems is also found essentially south of the 130-day rainy period limit where there are no climatic limitations for maize, sorghum, millet and groundnut. Land systems which straddle this line but which occur predominantly to the south are considered climatically suitable for maize for the purpose of this section (see Separate Map 3). A summary of the main characteristics is given in Table 10. The chief environmental limitations are impeded drainage and associated sodicity

= ,-..3 = 1 1,-. 1 -• -.-: J---

Limitations to crop growth

1. Soil physical characteristics

Land systems in this group have no or only minor limitations to the growth of four of the crops considered. The limitations are indicated in Table 11.

The group lies in texture bands 7-13 (Separate Map 1) whose topsoils are dominanted by silt. Soil depth and texture are only minor limitations for the crops considered suitable in this group and, although coarse material may be a moderate limitation in some soils^ they only occupy small parts of a land system. Impeded drainage, however, is a feature of small areas in every land system and is severely limiting for at least one crop in each land system except 325 and 326. Sodium-rich and locally alkaline soils in which the clay fraction is deflocculated are commonly but not necessarily associated with poor dainage. Such soils do not cover extensive areas and

44 TABLE 10 Summary of main characteristics of areas with four crop options

Land Occurrence Present cropping Crop Density of Draught State of Commun­ Rangeland system (local gov. Forestry options cultivation animals erosion* ications/ and cattle authority) Pood Cash

301** Maize, Rano, Very low in Sorghum, Groundnut, Pew Moderate to Medium Uncultivated and sorghum, Tudun Vada, south to high gero. daura, peppers, cowpea; severe lower accessible areas millet, ¥udil in north cowpea, sugar cane, rice slope gullying. heavily grazed groundnut cassava in fadamas Some sheet during wet season. erosion Crops residues provide valuable fodder for dry Malumfashi, Predominantly Sorghum, Common Medium Agashe, Kurmi, Darenfada, 306** Groundnut, Moderate lower season« Increasing Gwarzo, high, locally gero. maize, cotton, peppers; slope gullying. to good cultivation of Dan Garba, Tsambe, Koto, Tudun Vada, low cowpea, sugar cane, Some sheet Maizaure, Sheka, Tandama Ikara, cassava, rice, onions erosion. fadamas is reduc­ Wudil sweet potato in fadamas ing those key dry- grazing areas. 312 Malumfashi, Low to high Sorghum, gero. Groundnut, Moderate to Medium Tsani, Tsaunin Kura, Funtua maize, rice, cotton, sugar­ severe lower Kukar, Madogara cassava cane, peppers slope gullying

324 Rano, Very low to Sorghum, gero. Cotton, peppers, Few Slight lower Bugau North Ikara, low; locally maize, dauro. groundnuts, slope gullying Tudun Vada, high near cowpea sorghum, sugar­ Wudil, Burumburum cane Ningi, Toro

325 Malumfashi, Low to high Sorghum, gero. Groundnut Severe lower Medium to Gangara, Makaurci Gwarzo cowpeas, peppers, onions, slope gullying good cassava, sweet cowpeas, sorghum potato

326 Tudun Wada, Sorghum, gero. Sorghum, cassava Moderate lower Good - Gwarzo dauro. cowpea groundnuts, slope gullying cassava cowpeas; rice 327** Malumfashi, Predominantly in f adamas Garun Gatari, Dabinuwa Gwarzo dense

•Terms defined in Appendix 2. /Refers to estimated proportion of area within 5 km of all-weather, tarred or hard-top roads; poor 0-10$, med. 10-50$, goody50$. **North of 130-day rainy period limit, climate becomes unsuitable for '120-day' maize variety. TABLE 11 Soil physical limitations to the growth of certain crops in areas with four croo options: crop options indicated by shading

nre a % Soil limitation category (SLC) by crop in each land system with nature of limitation*

No. Of Land Maize Millet Sorghum Groundnut Cotton system crop % class % C/BSS % c/ass % class % class options no. of SLC Nature of SLC Nature of SLC Nature of SLC Nature of SLC Nature it f SLC of SLC of SLC SLC SLC 2 in land in land in land of in land of in land of limitation limitation limitation limitation limitation system system system system' system 4 301 943 585 WMm i$i$ iSiiolääS mm ftSöliäl mm !*9*29l 3 10-29 tC/tc/Wt •ïïösïas iüilliiills $2$ Siaplièli miii^/^fitmmm la! ifÄSOi; tmtWümmmm SSï! ftiÖfÏBÏ ISyiciilliiiiiiiiiilli 4 10-29 W/tC ïlll Hill: l^tpwllii lil iÄllli mMWÊÊmW: lift llfilll WwMliWïmWi 111 illlll?! 5 10-29 DWtC/WtC 306 3259 2770 lälli mm $*! lislSs $!$ fiiiöaä! 2 10-29 t IJläS! $iötiSi:i!Si!:!i!!Si $2$ |Sp!So! sjScliilli!* Siä! SiMss lillilillll: Sal: 3 10-29 tc/C ill WÊÊÊ WMmtM^mm ill lliÄI li|Hi|llllli :|*S WtMmmWïm l|| iilSllll i^ÜÜiiiills 4 10-29 W/CTa 312 98 70 liill lil $*il s'flïïS;:; mm SiSÖlSÖä 1 10-29 liälÄ $zlS Silll! lil llpllili mm Jaspis 3 10-29 Ta SI*! livpillllllllli lilllllllll 111: !i^||i|!il|l|llll 5 10-29 lilllll 11:1Sllllll i III IlSilllilllllll lllllll 324 2882 2623 mm WÊM Ui S30*59S :;:aï*ii!lM;:S:|i|:|: üiü ïtSSïaS 2 10-29 t !!*:! mm IStliÄliSliSSSiS $3$ Aas! iSiWWwtpiSi!!!! mm IwïSöl m0i^&mmm!mi 3 30-50 tc/wt/C ill ISA*!. ill WMÊVMÏë 1*1 S:i9?29| sïvvsz^lllilll III :K>:PS2|:J: :|||I?^||||| 4 10-29 Wt/Mc/wc ill! !illl?l !wÄ^Ts||ii!|||i||i

326 110 102 !Si:SS 1 30-59 2 30-50 w/t Wéiiim: mm SitblisSi mm SiiiÖIÜBft ISIS! ! 3o!sö! :l?i: iiillïlïii MM1SÄ 1 It/ïÈMllllllll 2 30-59 t/c 3 30-59 Ta WE WMMmlmM IIB 326 452 389 11$ ilioÄS lil: S3QÄ $i$ lÜOiSz*: mm iäöftsoi 2 10-29 w/t/c $ä$ SSÖKKS! lilllllllll mm SSÖÏSO! i!*ac/$l!iSii!S!|i lö»/tcii«i|i:||:| 111 SSösaisft sijsiisiliiililiiii 3 30-50 Ta/C/Wt Si:^^*!!:!!!! HI ills i:aé^ïi|w||i|i|||:i:i:i:i 5 10-29 WtCyDCyDC. ill illlül lil i^llllllsllli Hüll 327 490 460 mm ISolS'SSi WMmmmmm mm SäössäS Sal l*6Ö:|:i !itïtMrtS!:$$iS!i Sii! läÖSoS! 2 10-29 c/t mW ilMSS SwSicM^iÄi mim :3M?29;: litßc/wwcllilll; III? mWMÊiMÊÊ ililS sibftïif s::tftÓib$:!i!:iSil:!:B 3 30-59 Ta/Wt Sft*$ mmim Iv&fpSpliiSli mm Stö'Ä mWsMwMmmm lis:! ItoMS |;1Ü8«H:||| 4 10-29 w/wt

'Limitations Depth Drainage Texture Coarse material D Severe W Severe T Severe C Severe D Moderate W Moderate T Moderate C Moderate d Minor w Minor t Minor c Minor

^rea 1-total area; Area 2-area to which data refer X Climatically unsuited north of 1 30-day rainy period limit

PR31/NIG/1H/2b Prepared by the Directorate of Overseas Surveys 1978 occur on all facets. In Land System 326 they appear to be associated with the valley head facet. They are expected to be difficult to work and manage during the growing period but should retain water for slightly longer than most other soils after the rainy period. Such areas may be suitable for rainfed rice.

Cotton is generally an unsuitable crop due to drainage, depth and coarse material restriction.

2. Soil chemical characteristics

Some chemical characteristics are given for soils of dominant facets in land systems in Table 12. The range in cation exchange capacity is quite wide; where values exceed approximately 8, as in parts of Land Systems 301, 306 and 324, it is considered an indication that the soils are suitable for intensive cultivation. The soils with lower values have a weaker ability to retain nutrients and need lengthy fallow periods after cultivation to build up organic matter and nutrient levels. The soil reaction as indicated by pH is in general satisfactory with only moderate limitations in relation to phosphorus availability in Land Systems 306 and 312. This is discussed further below. Potassium availability is everywhere good.

Some subsoils, commonly those that are poorly drained, have high base saturation due to high levels of exchangeable calcium, magnesium and sodium. Sodium levels in the subsoil may exceed 6 meq% when the associated pH is between 8 and 9.5: calcium carbonate concretions also occur in such subsoil. Conductivity of these alkaline, sodic soils, however, does not exceed 0.50 mmhos.

It is not clear to what extent the presence of these scattered areas of poorly drained, alkaline soils is detrimental to agriculture in a land system or, indeed, the crops under discussion. It is apparent, however, that farmers in general avoid these soils which support a sparse thicket vegetation.

This may reflect on inability to manage the soils because of poor drainage or simply that yields are unduly low as a result of an imbalanced nutrient status.

47 TABLE 12 Dominant soil chemical characteristics assessed as limitations to crop growth for land systems with 4 crop options (based on mean values for dominant soil series excluding top horizon)

Limitations due to pH for // Limitation Land CEC meq % Exch. K system soil* meq %/ pH Ground­ P Maize Millet Sorghum Cotton nuts availa­ CEC* K/ bility** 301 5.0-14.0 0.2 6.2-7.2 Nil Nil-Mod Nil Nil-Mod Min-Mod Nil-Min SF-S A 306 5.0-13.4 0.2 5.9-7.8 Nil-Mod Nil-Mod Nil-Mod Nil-Sev Nil-Sev Nil-Mod SF-S A 312 5.0-6.5 0.2 5.9-6.4 Nil Nil Nil Nil Nil-Min Min-Mod SF A 324 6.0-14.1 0.2-0.3 6.0-7.8 Nil-Mod Nil-Mod Nil-Mod Nil-Sev Nil-Sev Nil-Min SF-S A 325 4.2-5.4 0.1-0.2 6.0-6.4 Nil Nil Nil Nil Nil-Min Nil-Min SF A 326 5.0-7.2 0.2 6.0-6.4 Nil Nil Nil Nil Nil-Min Nil-Min SF A 00 327 4.2-7.2 0.1-0.2 6.0-6.4 Nil Nil Nil Nil Nil-Min Nil-Min SF A

*CEC meq % soil /K meq % for soils of pH >4.5 **P availability related to pH S >8 Suitable for intensive A J?0.10 Adequate pH Limitations agriculture D < 0.10 Deficient 6.5-7. 5 Nil SF 2.0-7.9 Requires a high ratio of 6.0-6.49,7.51-8.0 Minor fallow to crops 5.0-5.9, 8.1 -8.5 Moderate U/S <2.0 Unsuitable for intensive agriculture (Adetunji, 1974) /yMin = Minor, Mod = Moderate, Sev = Severe Limitations to mechanical cultivation

Land System 312 has dominant slopes which exceed the acceptable economic maximum of 3% for mechanised farms (Table 13). The remainder contain large areas of gently sloping crests and side slopes. All contain lower slopes which are steepened by moderate or severe gullying except Land System 324 in which this feature is not important. Fragmentation of the area by valleys and/or gully extension is significant in all but Land System 324 which makes it difficult to find compact blocks of land of the required minimum size for mechanised farms of approximately 1 OOO ha. Furthermore, ironpan occupies a substantial area of Land System 312 and patches of intractable poorly drained soils occur in all land systems except 325 and 327.

Only Land System 324 appears to be without any of the above limitations to mechanised farming in this group.

TABLE 13 Dominant slope and range of slopes on major facets in areas with four crop options

Slope of major facet Land Dom. facet system Per cent Degrees (% area of no. LS) Dominant Range Dominant Range

301 2 1-3 1 0.5-2 Sideslope (42) 306 3 1-5 1.5 0.5-3 Sideslope (51) 312 5 2-7 3 1-4 Sideslope (38) 324 2 1-3 1 0.5-2 Sideslope (53) 325 1 0-2 0.5 O-l Crests (65) 326 2 0-3 1 0-2 Crests (65) 327 2 0-3 1 0-2 Crests (71)

49 Density and distribution of cultivation

TABLE 14 Density of cultivation in areas with four crop options

Land areas (km2) in four cultivation densities Admin. Land Total area • % under unit system km2 cultivation % of <10% (dom.) class in 60 60-35 34-10 •£10 forest reserves

301 943 Rano 151 201 319 272 306 3 259 Tudun Wada 1473 761 802 223 46 312 98 Malumfashi lO 1 11 76 72 324 2 882 Tudun Wada 249 372 496 1 765 49 325 107 Malumfashi 62 117 14 14 loo 326 452 Tudun Wada 220 132 77 23 327 490 Gwarzo 362 87 38 3 67

Referring to Separate Map 2 and Table 14 it can be seen that most areas occupied by this group are taken up by Forest or Game Reserves or are densely to moderately densely cultivated. The exceptions are in Land System 306 west of Dansosia FR and west of Tiga Lake, in Land Systems 301, 306 and 324 south and east of Rano and in Land Systems 301 and 324 between Falgore Game Reserve and the Ningi Hills.

Forestry

Few areas are well endowed with natural vegetation that can supply the demand for firewood and poles for the generally high population density. The most favourable areas are around Rano in Land Systems 301 and 324 and between the Ningi Hills and Falgore Game Reserve, also in Land System 324. Informa­ tion about the growth rate of plantations in the Reserves is not available.

50 LAND SYSTEMS WITH THREE CROP OPTIONS

The main characteristics of this group are given in Table 15. Further aspects are discussed below.

The land systems lie almost entirely south of the 120-day rainy period limit,which is the northern limit of successful cotton and local sorghum growth. Several land systems occur,largely north of the 130-day rainy period limit and for these the climate is not suitable for consistently high '120-day' maize production. Only Land Systems 303 and 340 are entirely suitable on climatic grounds for maize.

Millet, groundnuts and sorghum are the crops considered most generally suitable in this group. The main limitations are inadequate depth and poor drainage.

Limitations to crop growth

1. Soil physical characteristics

Land systems in this group have no or only minor limitations to the growth of three of the crops considered.

The group lies in texture bands 5-13 (Separate Map 1) where topsoils are dominated by fine sand and silt particle sizes.

Only Land System 340 is suitable for cotton as most of its area is estimated to have no soil limitations for this crop. Soil depth, coarse material and texture are the least significant limiting factors, although in some land systems coarse material is moderately limiting in minor areas.

Impeded drainage is a limiting aspect of all land systems. It is a moderate or severe limitation, but only in minor areas, for at least one of the crops being considered,except in Land System 341. Cotton is most affected. As discussed for the four-crop-option group it is likely that some of these poorly drained areas will present worse management problems than usual due to the deflocculated nature of the clay fraction in the subsoil. The

51 TABLE 15 Summary of main characteristics of areas with three crop options

Land Ocourrencè Density of Present cropping Draught State of Commun­ Rangeland Crop Forestry system (dom. local options cultivation animals erosion* ications/ and cattle no. govt, area) Pood Cash 303 Sorghum, Ikara, Moderate in Sorghum, gero. Cotton, peppers, Nil Moderate lower Medium On less intensively Kariya River maize, Tudun Wada west, low in maize, cassava, groundnut; sugar slope gullying farmed systems - Bugau South groundnut east sweet potato cane, onions in fallows are longer fadamas and thero are some large uncultivated 309»* Millet, Ningi Very low Sorghum, gero. Groundnuts, Pew Poor areas - however groundnut dauro, cassava, pepper, cowpeas: grass species are sorghum cowpeas sugar cane in mainly poor fadamas annuals useful for only 2 or 3 months - crop 328»* Tudun Wada, High Moderate to Good Maje ¥adil, Ranq severe lower residues are Gay a slope gullying valuable. Gradual reduction in the extent of fadama 329»* Tudun Vada, Slight lower Groundnuts, Medium to grazing Rano, sorghum, rice, slope gullying good Gwarzo, cowpeas Dawakin Tofa to Dawakin Kudu

331* Wudll, Gaya Low in south, Groundnuts, Medium Gurmina Birnin Kudu high in north peppers, sugar cane, cowpeas

332// Dawakin Tofa High Cowpeas, Moderate lower Bunku, Kantawa Bichi groundnut s, slope gullying Mata, Gagun cassava; onions, tomatoes

340 Maize, Tudun Wada Very low Sorghum, gero. Groundnuts, Poor sorghum Toro, Ningi maize, dauro. cotton, peppers, cotton cassava sorghum, cowpeas; rice in fadamas

341* Millet, Ningi Sorghum, gero. Groundnuts, None groundnut dauro. cassava peppers, observed sorghum cowpeas cowpeas; sugar cane, in fadamas 342 Birnin Kudu High Slight lower Good Gurmina Ningi slope gullying

343// Birnin Kudu Iggi River Dutse _L •Terms defined in Appendix 2. /Refers to estimated proportion of area within 5 km of all-weather, tarred or hard-top roads: poor 0-10$, med. 10-50$, good >50$. **South of 130-day rainy period limit, climate becomes suitable for '^O-day' maize variety. //North of '120-day1 rainy period limit, climate becomes unsuitable for cotton and sorghum. affected areas are thought to be scattered rather than extensive and are not associated clearly with any single facet.

2. Soil chemical characteristics

In Table 17 it can be seen that soil chemical characteristics in dominant facets vary widely. In general, however, soil potassium is adequate and phosphorus availability as deduced from pH is nowhere severely limiting, although in several land systems phosphate fertilising should be beneficial.

The cation exchange capacity values range from less than 3 meq% to about 13 meq%. The lower figures indicate that the soils are only weakly retentive of nutrients, and that lengthy fallows are required after cultivation if artificial fertilisers are not used. The most affected soils, in Land Systems 331, 342 and 343, are those associated with sand dunes and areas marginal to sand dunes in the south-east.

Some soils in this group are strongly alkaline in the subsoil and have high exchangeable sodium in relation to calcium and magnesium. These are associated most closely with poorly drained patches in Land Systems 329 and 331, especially where sodic soils with exchangeable sodium exceeding 6% account for more than 25% of the soils analysed. Inter-dune flats of Land Systems 342 and 343 are alkaline but not sodic.

Limitations to mechanical cultivation

In Table 18 are shown dominant slopes and range of slopes of the most common land facets in the land systems. With the possible exception of Land System 340 none has dominant slopes in excess of 3%, which is the critical limit for economical mechanised farming. However, among the features which made land less useful for this purpose is a fine or strongly gullied drainage net which results in a fragmentation of suitable areas; this occurs in Land Systems 303, 309, 328, 340 and 341. In addition,the presence of ironpan or rock outcrops further reduces the area of easily cultivable land; Land Systems 303 and 309 are the only unsuitable land systems in this respect. The interdune parts of Land Systems 342 and 343 have significant areas of poor

53 TABLE 16 Soil physical limitations to the growth of certain crops in areas with three crop options: crop options indicated by shading

Area »i Soil limitation category (SLCI by crop in each land system with nature of limitation* 2 km Maize No. of Land Millet Sorghum Groundnut Cotton | crop system , % class % class % class % class % class options no. of SLC Nature Nature Nature l' V SLC SLC of SLC of SLC of SLC Nature of SLC Nature of of SLC of SLC of SLC in land in land in land in land in land of limitation limitation limitation limitation limitation system system system system system 3 303 709 504 «Sis« slftäas 2 30-59 tc/t IM SSÖäS»:- säöSsp 1 10-29 «was« SÄ!»;; StÄlsÄlSs' 4 10-29 WC S3s' S'SQÄ iêiaiËlSü&Slfs SSäS BmM 10-29

111:; :;;;;;*;• lllll: Ä; l^llllllli; 10-29 WtC 309 499 454 2 30-59 t/w/c X miii •838; sä'össs; sszs lllil :8S:^iii#;i#is;;;;SS;s;sS'; ïlölÜI 30-59 Ta/W/C/wt 3 10-29 wt/Wt ISSwtJtcS'SssSsSs;;;; ;8:4s M*||lllll|; Hm slöïïal; 30-50 W/Wtc 4 10-29 W/ffic III lil iliilll l^fÜi^ll^- 328 338 31 1 2 30-59 t/C X s;sis; ssosss; w2Ï: mmw 3 30-59 Ta/C/Wt/v«t 3 10-29 wt/tc/C/W/Wt SS28 SHÖsÄS SäMcSsSSmSiiäS'; lJH|?ll sä;;* SJ;Ö¥Ï9'4 S:;S^*S;;;;;;;;;:;S;i;;;:;S 10-29 DtC/DC 4 10-29 Wt/Dtc/Wtc :;;;:*ï:; lil; SsiS; S;:töS©wS;:s;SSS;;;; 329 714 657 2 30-59 t/w X $:*;& mm®. |M; säQSSäS 30-59 Ta/W/Wt 3 10-29 lil llSilllllslll : wt/tc/Wt ;sSs; siässs;; ||ïf^(|||||||| l 2s; :si;tMs llltllilll 10-29 Wc/Wt 111 DWtC/DWC lllll; uil liiili 10-29 331 1904 1752 1 10-29 X ;sl;S; iSA'sKS; MM Säftäss; sS;i;s ISÖlSl 30-59 Ta/Wc/tC 2 30-59 t/c S;ïs;; SiöäS; StywJfcJcSKSSSSS; |:(|ip©^ffi|||;;;;;; 3 lil lil ;ÉQA: ïifWMÊiïMM 10-29 TavyC/Wt/W/Wc 10-29 Wt/wt/W/Ct III sioä»;: ËMAI11I lilli lil

332 300 264 1 10-29 SilSS SäöSs»; sSöSSä'S; StfëiHcywSssïsirxS; ;;;s»;;s ï-aössö;:; 30-50 Ta/Ct 2 30-59 t/c SÏÏSS aêïiiiiiiïifii-ws sis :;I:QÏ29ÏÏ Siiiä^jsSssiis sis; siösïS;: 10-29 w/tc 3 10-29 wt/tc/C/Wt lllll 111 sïiïs'; StOÄ Ä&illllllll; Sas; stösiäs IwfilllIIl Li_ 10-29 DtC 340 57 51 w-im :;sossoä 2 30-59 tc/wt ïsiSS SäÖSios' 2 30-50 t ?3oÄ; ħ; Mmü 4 30-50 W/Wtc s:*« lllll SMäS 3 10-29 tc/Wt iiÄi§yi.i ïiÉiiiiiiii S;S;S; :;2SïSa;;;; IlS^illllill 4 30-60 W/Wtc Älsllllll; Jmital ions t Depth Drainage Texture Coarse material D Severe W Severe [ Severe C Severe D Moderate W Moderate 1 Moderate C Moderate d Minor w Minor t Minor c Minor

'A Vrea 1 -total c rea; Area 2-area to which data refer x Climatically unsuited north of 1 30-day rainy period limit: areas of three-crop option land systems south of this limit may be physically suitable. _ XX Climatically unsuited north of sorghum/cotton line (120-day rainy period limit) PR3i:NiGntr:v Prepared by the Directorate of Overseas Survey* 1078 TABLE 16(cont) Soil physical limitations to the growth of certain crops in areas with three crop options: crop options indicated by shading

Area % Soil limitation category {SLC) by crop in each land system with nature of limitation* km* Maize Millet Sorghum Groundnut Cotton No. of Land crop system % class % class % class % class % class Nature Nature Nature Nature Nature options it 2f SLC of SLC SLC of SLC SLC of SLC of SLC of SLC no. of SLC SLC of in land in land in land in land in land limitation limitation limitation limitation limitation system system System system system 3 341 123 80 2 30-59 t X all iäSsäls WMWMÏ BälslBgä *ii laöfiBö! 3 30-59 Ta 3 10-29 Wt iiw siülu !W:;iiiiii:*:-: 13!' ii|8|j|| !§li!!l!ii 4 10-29 Wt : 342 357 329 ii! laö>sb?i !:»! iÄägS liliiilpxi s|i ! äö!soi 1 10-29 3 30-50 Climatically unsuitable WÊMWmmSi am Ta ill lillilllll! iSi III IfMi! itÉfpliiiil 4 30-50 w/wt

343 764 741 lil? IAS;: iil liSSil lÄllliili 11! llisis 3 S60 Ta/Wt Climatically unsuitable SSÏSÏ mmmmmmi 111 S^ÄilWlIli: IMS! 4 10-29 vyt/w is*:! iÄÄiillilll lllili !*! wWtÊÊMM

'Limitations Depth Drainage Texture Coarse material D Severe W Severe T Severe C Severe D Moderate W Moderate T Moderate C Moderate d Minor w Minor t Minor c Minor

fArea 1 -total area; Area 2-area to which data refer X Climatically unsuited north of 1 30-day rainy period limit: areas of three-crop option land systems south of'this limit may be physically su table. XX Climatically unsuited north of sorghum/cotton line (1 20-day rainy period limit)

Prepared by the Directorate of Overseas Surveys 1978 PR31/NIG/1H/2c TABLE 17 Dominant soil chemical characteristics assessed as limitations to crop growth for land systems with 3 crop options (based on mean values for dominant soil series excluding top horizon)

Limitations due to pH for // Limitation Land CEC meq % Exch. K pH system soil * meq %/ P Ground­ Maize Millet Sorghum Cotton availa­ CEC* K/ nuts bility**

303 Insufficient data 309 4.8-13.4 0.1-0.2 6.1-7.8 Nil-Mod Nil-Mod Nil-Mod Nil-Sev Min-Sev Nil-Mod SF-S A 328 3.4- 7.2 0.1-0.2 5.5-6.4 Nil Nil Nil Nil Nil-Min Nil-Mod SF A 329 4.2-10.3 0.1-0.2 6.0-6.3 Nil Nil Nil Nil Nil-Min Min SF A 331 2.5-11.2 0.1-0.2 5.8-6.7 Nil Nil-Min Nil Nil-Min Nil-Mod Nil-Mod SF-S A 332 Insufficient data 340 6.3- 8.1 0.2-0.4 6.0-6.1 Nil Nil Nil Nil Nil-Min Nil-Min SF-S A 341 6.4-13.2 0.3-0.4 6.0-6.6 Nil Nil-Min Nil Nil-Min Nil-Mod Nil-Min SF-S A i 342 2.7- 9.3 0.1-0.2 5.5-8.5 Nil-Sev Nil-Sev Nil-Sev Nil-Sev Nil-Sev Nil-Mod SF-S A 343 2.7- 5.7 0.1-1.5 6.0-8.5 Nil-Sev Nil-Sev Nil-Sev Nil-Sev Nil-Sev Min-Mod SF D

*CEC mecI % soil /K meq % for soils of pH^ 4.5 **P availab.Llit y related to pH S > 8 Suitable for intensive A ^0.10 Adequate pH Limitations agriculture D <0.10 Deficient 6.5-7 .5 Nil SF 2.C)-7. 9 Requires a high ratio of 6.0-6.49, 7.51-8.0 Minor fallow to crops 5.0-5.9, 3.1 -8.5 Moderate U/S <2. 0 Unsuitable for intensive agriculture (Adetunji, 1974) //Min = Minor, Mod = Moderate, Sev = Severe drainage. Land Systems 329, 331 and 332 have the fewest environmental limitations to mechanised farming.

TABLE 18 Dominant slope and range of slope in major facets in areas of three crop options

Slope of major facet Land Dom. facet system Per cent Degrees (% area of no. LS) Dominant Range Dominant Range ...... 303 3 1-7 1.5 0.5-3 Sideslope (49) 309 3 1-3 1.5 0.5-2 Sideslope (60) 328 1 0-2 0.5 0-1 Crest (69) 329 1 0-2 0.5 0-1 Low. slope (63) 331 2 0-3 1 0-2 Crest (49) 332 2 1-3 1 0.5-2 Sideslope (62) 340* 7 2->100 4 1-90 Low. slope (46) 341 1 1-2 0.5 0-1 Sideslope (63) 1 i-2 0.5 O-l Interdunes (59) 343 1 1-2 0.5 0-1 Interdunes (60)

*Crestal area occupies3 44% land system with dom. slope of 1%, range 0-2%.

Density and distribution of cultivation

Comparing Separate Map 2 and Table 19 it can be seen that this group has a predominantly high cultivation density. The exceptions are in the south­ east on the northern flank of the Ningi Hills in Land Systems 309, 341 and parts of 331, and Land System 303 in the south. The reasons for this low density in an otherwise heavily used region are not apparent, except where reserves occur such as the Iggi River Forest Reserve and the Falgore Game Reserve.

The specific causes for unequal density of cultivation are not known but it is likely to be a combination of remoteness, former occurrence of tsetse fly and historical factors,rather than inferior soils.

58 TABLE 19 Density of cultivation in areas with three crop options

Land areas (km2) in four cultivation densities Admin. Land Total area unit % under system km 2 % of .£10% (dominant) cultivation class in forest reserves 60 60-35 34-10 <:io 303 709 Ik ara 94 158 212 245 38 309 499 Ningi lo 489 328 3 38 Wudil 245 48 28 17 35 329 714 Rano 436 182 96 331 1 898 Wudil 751 321 343 483 6 332 299 Dawakin Tofa 269 9 11 10 100 340 57 Ningi 57 88 341 122 Ningi 122 342 348 Birnin Kudu 190 76 43 39 82 343 764 Birnin Kudu 615 67 51 31 61

Forestry

Most areas are heavily used for agriculture, and firewood and pole produc­ tion is minimal. Exceptions are southern parts of Land System 303 and in Land Systems 309, 341 and parts of 331 on the northern border of the Ningi Hills. No information is available about the growth of plantations in these land systems, but the growth rate in Land System 309, 331 and 342 will be much the same as for Ningi Town. Here, 13 year-old neem had a height of 8 m and a growth rate of 2 m /ha/a, and E. camaldulensis of 3 the same age has a height of 11.1 m and MAI of 3 m /ha/a.

LAND SYSTEMS WITH TWO CROP OPTIONS

This large group occurs in the extreme south-east among the Ningi Hills and nearby rocky land systems and north of the 130-day rainy period limits which effectively excludes the successful cultivation of local '120-day' maize (Separate Map 3). With increasing distance northwards, cotton and local sorghum are also excluded due to shortness of the growing season, so

59 that only groundnuts and millet are successful and reliable crops. It occupies approximately half the Kano Plains.

Land systems which straddle climatic limits for specific crops are considered here and in Separate Map 3, according to which side of the limits lie their greatest area. A summary of the main characteristics in the group are given in Table 20.

Limitations to crop growth

1. Soil physical characteristics

Land systems in this group have no or only minor limitations to the growth of two of the crops considered. The main limiting physical characteristics are given in Table 21. The group occurs entirely within soil texture bands 1-7 in which topsoil textures typically become progressively finer from fine and medium sands in band 1 to silts in band 7.

Shallow soils over ironpan occur in Land Systems 307, 311, 33 3, 337 and 339. For the crops in this group, however, only a few soils present minor to- severe depth and coarse material limitations, in parts of Land Systems 307, 311, 323 and 334. Texture is also a minor limitation in some land systems. Imperfect drainage occurs in small areas of Land System 323.

2. Soil chemical characteristics

As can be seen from Table 21, the cation exchange capacity of soils on the dominant facets of several land systems is very low, such that intensive agriculture cannot be practised without expensive inputs of fertiliser. Land Systems 307, 323 and 336 are least affected in this respect. These are derived to a large degree from Basement Complex rocks and are least affected by surface additions of coarse-textured drift material.

Land systems in which surface textures are markedly sandy show deficiencies of potash: those particularly affected are Land Systems 334

60 TABLE 20 Summary of main characteristics of areas with two crop options

Land Crop Occurrence Density of Present cropping Draught State of Commun­ Rangeland Forestry system options (local govt. cultivation animals erosion/ ications* and cattle no. authority) Pood Cash 305 Millet, Bichi, Low to Sorghum, Groundnut, Few Moderate Medium The very Bukudu, Zauma, Dutsin Kiya, Dutsin Pandi, groundnut Kazaure, moderate gero, dauro rice, sugar lower slope limited Dutsin Barade, Bayan Daura cassava, cane, cowpea, gullying areas of Dutsin, Dutsin Kwaita, cowpea cassava upland Dutsin Kodawa, Dutsin grass- are 307 Malumfashi, High Groundnut, Good utilised by Korogo, Yashi, Gwarzo, Bichi, cowpea, small stock Tama, Gangara Dawakin Tofa, sorghum, and by Kankiya, cassava; locally Katsina rice in owned fadamas cattle. There is an 308 Katsina, High; low Groundnut, abundance Dan Manau Mani, to moderate cowpea,cassava; of useful Kankiya patches onions,tomato crop sugar cane in residues fadamas which are conserved Moderate to Poor Raddbho, Matan Fadan, 311 Bichi, Groundnut, and Kankiya severe Daddare, Marmara, cowpea, utilised. lower slope Lugge, Tumuku, Zare sorghum,cassava; The con­ rice in fadamas gullying tinuing 314 Bichi, High Groundnut, Slight Good reduction Fefeku, Roni E & N Kankiya, cowpea,sorghum, lower slope in fadama Kazaure cassava; rice, gullying grassland sugar cane in is more fadamas serious for non-settled 323 Sorghum, Toro Very low Sorghum, Cotton, rice, None Poor stock. maize to moderate maize groundnuts, Inputs gero,dauro. cowpea, would - sweet peppers improve potatoes small stock 333** Millet, Rano, High Sorghum,gero Groundnut s, Moderate Good husbandry Samanja Badume, groundnut Dawakin Kudu, dauro, cowpea,cassava; lower slope Alako, Bunku,Buzu, Dawakin Tofa, cowpea, onions,tomatoes, gullying Bawtorami, Dukawa, Gezewa,Bichi, cassava peppers in Gwame, Jinjau, Minjibir,Kano fadamas Kalebawa, Town Res.

334 Bichi Groundnuts, Pew Dakwa cowpea,sorghum, cassava; rice, sugar can in fadamas

* Refers to estimated proportion of area within 5 km of all-weather, tarred or hard-top roads: poor <10%^med. 10-50%, good >50% / Terms defined in Appendix 2 ••South of 120-day rainy period limit, climate becomes suitable for sorghum TABLE 20 Contd.

Occurrence Present cropping Land Crop Density of Draught State of Commun­ Rangeland (local gov. Forestry system options cultivation animals erosion* ications/ and cattle no. authority) Pood Cash

335 Millet, Gezawa, Bichi, High Sorghum, gero, Groundnut, Pew Slight Good The very Hurmi, Kurma, groundnut Minjibir, dauro, cassava; rice, lower slope limited Muhuwa, Makadi Dambatta, cowpea, onions, gullying area of Kazaure cassava tomatoes, upland sugar cane in grass are fadamas utilised by small stock 336 Maize, Ningi Very low Groundnut; Poor and by Burra N. sorghum cowpea, cassava, locally sorghum; rice owned in fadamas cattle. There is a 337 Millet Kazaure, High Cowpea, Common Medium abundance Werdawa, Gwiwa groundnut Daura, Mani, groundnut of useful Korel, Dan Kabba, Katsina tigernut, crop Dawan Allah, Dono, Cassava residues Garu Giginya, ON which are Madatai, Dutsin conserved Bamli, Kirbo and Dutsawa utilised. 338 Katsina, Good The con­ Daura, Kaya, Tsanni, Mani, Daura, tinuing Barawa, Kabakawa Kankiya, reduction Dawan Allah, Koda, Dut sin Ma in fadama Rukuba, Dutsin grassland Bamli, Dan Manau, is more Yangora serious for 339 Kazaure, Groundnut, non-settled Gunzu, Gwiwa, Katsina, cassava, stock. Korel, Kuda Daura cowpea Inputs Gangare, Werdawa, would Zauma, Daura, improve Kaibaki N & S, small Kaya, Rade, Dan stock Babba, sandamu husbandry 344 Daura/ Groundnut, None Gunzu, Kuda Kazaure cowpea, observed Gangare, Wawar, cassava, Rafi, Zungunba, tigernut Rogogo TABLE 21 Soil physical limitations to the growth of certain crops in areas with two crop options: crop options indicated by shading

Area % Soil limitation category (SLC) by crop in each land system with nature of limitation km2 Maize Millet Sorghum Groundnut Cotton No. of Land crop system % C/BSS % C/BSS % class % c/ass % class options no. of SLC Nature of SLC Nature of SLC Nature of SLC Nature OfSLC Nature it SLC of SLC of SLC of SLC SLC 2* in land in fand in fand in /and of in land of limitation limitation limitation limitation limitation system system system system system 2 305 129 70 Climatically unsuitable mm|§§|s| § Climatically unsuitable 111S|ää*B9 l Climatically unsuitable X 307 1055 897 2 30-50 2 30-59 t/tc/c/w 3 30-50 Ta/TaC/W/0W/DC 3 10-29 t/c/tc/w siililiilii 5 10-29 DtC/DC 5 30-50 0C/0TaC 4 10-29 Wt/tC 1lui t il 308 725 645 Ää&Hoä Climatically unsuitable plllifpli!! Climatically unsuitable Climatically unsuitable 11111*1 1 11II A 311 354 304 mimi Climatically unsuitable iïÖêïaASiiMl Climatically unsuitable ON Climatically unsuitable Älll 1illll : • WÊÊ&isiiiiiiill l 314 211 148 iillllilll Climatically unsuitable ill 11111 Climatically unsuitable • lïlll: Climatically unsuitable 323 352 292 SSÖS8ÖB 2 30-59 t/tc 2 30-50 t/c 1 10-29 11 'mmM 4 10-29 Wc/Ct 111 !§§§$i$w||§l|| 3 10-29 tc/wt/W 2 10-29 t/c III f 4 10-29 Wc/Wct/Ct 4 10-29 Wc/C/Wl 333 2144 1758 Climatically unsuitable 1 !!!§ïl!!§§!i Climatically unsuitable • ;::|sé81|l|l||:|;;:; Climatically unsuitable "Limitations Depth Drainage Texture Coarse material D Severe W Severe T Severe C Severe D Moderate W Moderate T Moderate C Moderate d Minor w Minor t Minor c Minor

fArea 1 -total area; Area 2-area to which data refer X Climatically unsuited north of 130-day rainy period limit

PR3l'NlG'1H/2d Prepared by the Directorate of Overseas Surveys 1978 TABLE 21 (cont) Soil physical limitations to the growth of certain crops in areas with two crop options: crop options indicated by shading

Area % Soil limitation category (SLC) by crop in each land system with nature of limitation* km2 Maize Millet Sorghum Groundnut Cotton No. of Land crop system % class % class % class % class % class Nature Nature Nature Nature Nature options no. l' 2f SLC of SLC SLC of SLC SLC of SLC SLC of SLC of SLC of of of of SLC of in land in land in land limitation in land limitation limitation in tand limitation limitation system system system system 5 system 334 283 269 ill 3 S60 2 Climatically unsuitable IIA Climatically unsuitable Climatically unsuitable III iBlllllllllll 5 10-29 DC 335 687 639 lilIËi!fiö|!: 1 *60 Climatically unsuitable Climatically unsuitable Climatically unsuitable llliillllll 3 10-29 tc/C 336 162 93 sIÄ! 2 30-59 t/tc 2 30-50 t 1 10-29 III !§ÄS |ig(w||||||||§ 3 10-29 tc/WI 2 10-29 i iiiiii 4 10-29 W/t£ ON

337 1888 1567 s Climatically unsuitable III 11111 Climatically unsuitable in IIA! Climatically unsuitable 338 1656 1556 Climatically unsuitable II! IS«!! Climatically unsuitable »*i ||*|j}|;: Climatically unsuitable 339 1258 1056 mm ÄS9ä Climatically unsuitable III l|t|l!!!i!!!! Climatically unsuitable III Iflil; nil Climatically unsuitable 344 267 233 Climatically unsuitable III IIIBI! Climatically unsuitable II! Ills! Äiillüil Climatically unsuitable 'Limitations Depth Drainage Texture Coarse material D Severe W Severe T Severe C Severe D Moderate W Moderate T Moderate C Moderate d Minor w Minor t Minor c Minor

1 Area 1 -total area; Area 2-area to which data refer

PR31/NIG'1H/2rf Prepared by the Directorate of Overseas Siirvpys 1978 TABLE 22 Dominant soil chemical characteristics assessed as limitations to crop growth, for land systems with 2 crop options (based on mean values for dominant soil series excluding top horizon)

Limitations due to pH for // Limitation Land CEC meq % Exch. K pH P system soil* meq %/ Ground­ Maize Millet Sorghum Cotton availa­ CEC* K/ nuts bility**

305 Insufficient data 307 2.1-12.8 0.1-0.2 5.4-7.2 Nil-Min Nil-Mod Nil-Min Nil-Mod Nil-Mod Nil-Mod SF-S A 308 1.5- 2.1 0.1 5.7-5.9 Nil Nil Nil Nil Nil Mod U/S D 320 1.7- 2.7 0.1-0.2 5.4-5.9 Nil-Min Nil Nil-Min Nil-Min Nil Mod U/S-SF A 311 1.7 0.2 6.4 Nil Nil Nil Nil Nil Min U/S A 314 1.5- 2.7 0.1-0.2 5.4-5.9 Min-Nil Nil Min-Nil Min-Nil Nil Mod U/S-SF A 323 6.3-13.2 0.2-0.4 6.0-6.6 Nil Nil-Min Nil Nil-Min Nil-Mod Nil-Min SF-S A 333 1.9- 5.4 0.1-0.2 5.6-6.0 Nil Nil Nil Nil Nil Min-Mod U/S-SF A 334 1.7- 1.4 0-0.2 5.7-6.4 Nil Nil Nil Nil Nil-Min Min-Mod U/S D-A 335 1.7- 3.0 0-0.1 5.7-6.4 Nil Nil Nil Nil Nil-Min Min-Mod U/S-SF D 336 6.4-13.2 0.3-0.4 6.0-6.6 Nil Nil-Min Nil Nil-Min Nil-Mod Nil-Min SF-S A 337 1.5- 2.1 0.1 5.6-5.9 Nil Nil Nil Nil Nil Mod U/S-SF A 338 1.5- 2.1 0.1 5.6-5.9 Nil Nil Nil Nil . Nil Mod U/S-SF A 339 1.7- 2.1 0.1 5.4-5.9 Nil-Min Nil Nil-Min Nil-Min Nil Mod U/S-SF A 344 1.5- 2.1 0.1 5.6-5.9 Nil Nil Nil Nil Nil Mod U/S-SF A

*CEC mecI % soil /K meq % for soils of pH >4.5 **pP availability related to pH >8 Suitable for intensive A;*0.10 Adequate pH Limitations agriculture D^O.10 Deficient 6. 5-7.5 Nil SF 2.0-7.9 Requires a high ratio of 6 0--6. 49,7.51-8 .0 Minor fallow to crops 5 0--5. 9, 8.1 -8 .5 Moderate U/S \2.0 Unsuitable for intensive 5.0 agriculture (Adetunji, 1974) //Min= Minor, Mod = Moderate, Sev = Severe and 335. The range in pH of the dominant soils is no worse than moderately limiting with respect to phosphorus availability for the crops concerned.

Limitations to mechanical cultivation

TABLE 23 Dominant slope and range of slopes on major facets in areas with two crop options

Slopes of major facet Land . Dom. facet system Per cent Degrees (% area of LS) no. Dominant Range Dominant Range

305 27 O-lOO 15 0-45 Ridge (40) 307 2 0-2 1 0-15 Crest (71) 308 3 2-3 1.5 0.5-2 Sideslope (51) 311 3 + 3 1.5 1-2 Sideslope (53) 314 2 1-3 1 0.5-1.5 Sideslope (48) 323 2 1-3 1 0.5-2 Sideslope (55) 333 2 0-3 1 0-2 Sideslope (61) 334 2 0-3 1 0-2 Crest (81) 335 2 1-3 1 0.5-2 Sideslope (64) 336 3 1-7 1.5 0.5-3 Sideslope (61) 337 3 1-3 1.5 0.5-2 Sideslope .(61) 338 3 1-3 1.5 0.5-2 Sideslope (55) 339 2 1-3 1 0.5-1.5 Sideslope (63) 344 2 1-3 1 0-2 Crest (86)

Land systems with less than three crop options are not recommended for large-scale mechanised cultivation. All but Land System 305 have dominant slopes less than 3%, the limit for economical fully mechanised farming (Table 23). However, Land System 336 contains common rock outcrops and is fragmented by a fine valley and gulley net, and ironpan outcrops occupy extensive areas of Land Systems 311 and 314.

67 Density and distribution of cultivation

Reference to Separate Map 2 and Table 24 shows that virtually the whole area is densely cultivated. Only scattered isolated patches remain unused or little used and these are principally in Land System 336 in the Ningi Hills, Land System 323 in the south, and Land System 311 and 338 in the north.

TABLE 24 Density of cultivation in areas with two crop options

Land areas (km2) in four cultivation densities Total Admin. Land area- unit system 2 % under % of <.10% km (dominant) cultivation class in forest reserves > 60 60-35 34-10 <10 305 129 Kazaure 44 41 18 26 81 307 1 055 Gwarzo 773 117 129 36 67 308 725 Mani 420 184 96 25 52 311 353 Kankiya 152 40 77 84 55 314 211 Kankiya 138 36 27 lO loo 323 352 Toro 3 58 101 190 44 333 2 143 Dawakin Tofa 1 995 76 55 17 76 334 283 Bichi 262 18 3 2 100 335 683 Gezawa 589 63 18 13 54 336 162 Ningi 15 147 12 337 1 887 Mani 1 142 478 164 103 91 338 1 655 Mani 839 363 312 141 72 339 1 257 Daura 780 265 108 104 80 344 267 Kazaure 123 64 50 30 63

Forestry

Because of the generally dense cultivation pattern there remains very little natural vegetation from which firewood and poles can be gathered. There are, however, many small forest reserves which supply local needs for this kind of timber. The growth rate in the northern areas can be predicted from the plantations at Kabakawa and Sandamu, where the mean

68 TABLE 25 Summary of main characteristics of areas with one crop option

Occurrence Density Present cropping Land Crop Draught State of Commun­ Rangeland (local gov. of Forestry system option animals erosion* ications/ and cattle no. authority) cultiv. Food Cash

302 Millet Toro, Very low Sorghum, Groundnuts, None Slight Poor Some crop Tudun Wada, to moderate gero, maize, cotton, lower slope residues; Ningi dauro, sweet sorghum, gullying over- potatoes cowpeas utilisation of browse by migrant livestock

*Terms defined in Appendix 2. /Refers to estimated proportion of area within 5 km of all-weather, . tarred or hard-top roads: poor<10%, med. 10-50%, good >50%. annual increment for neem is 0.2-0.3 m /ha/a. Further south (with more than HO rain days) growth of neem is better, being in the order of 2-3 m /ha/a.

LAND SYSTEMS WITH ONE CROP OPTION

The sole land system is situated in the south in a generally hilly area of Toro Local Government Authority. Its main characteristics are summarised in Table 25. There are no climatic limitations for cotton, sorghum, maize, millet and groundnut.

Limitations to crop growth

1. Soil physical characteristics

Reference to Table 26 shows that the land system contains significant areas of shallow and poorly drained soils, which are limiting for all crops except millet. The land system occurs in texture band 12 (Separate Map 1) whose topsoil is dominated by silt and clay particle sizes.

2. Soil chemical characteristics

In Table 27 it can be seen that the main chemical features are all favourable for growth of the crops considered. The cation exchange capacity range is reasonably high and reflects the presence of a clayey subsoil.

Limitations to mechanical cultivation

Land systems with less than three crop options are not recommended for large-scale mechanised cultivation within the steepness limit of 3%.

Land System 302 is in general suitable for mechanised cultivation (Table 28). However, it is unduly fragmented by its valley and gully pattern and contains substantial areas of rock outcrop.

70 TABLE 26 Soil physical limitations to the growth of certain crops in areas with one crop option: crop options indicated by shading

Area % Soil limitation category (SLC) by crop in each land system with nature of limitation*

Maize Millet Sorghum No. of Land Groundnut Cotton crop system % c/ass % cless % class % class % class Nature Nature options no. of SLC of SLC of SLC Nature of SLC Nature of SLC Nature 1' 2f SLC of SLC of SLC of SLC in land in land in tand in land of SLC in land of limitation limitation limitation limitation limitation system system system system system 1 302 6SS 445 2 10-29 c/t mmm 2 30-50 c/t/w/vtf 1 10-29 3 10-29 Ta/WTa/CTa 3 10-29 W/tc/Wt/tC Wmm 3 10-29 wtc 3 10-29 Wt/tc/C/Ct 4 10-29 W.'Wt 4 10-29 w/wt Wiii 4 10-29 W/Wt 4 10-29 Wt/W/Wc 5 10-29 DTaC/WTac "Limitations Depth Drainage Texture Coarse material D Severe W Severe T Severe C Severe D Moderate W Moderate T Moderate C Moderate d Minor w Minor t Minor c Minor

fArea 1-total area; Area 2-area to which data refer Please note that the SLC figures for Land System 302 are incorrectly annotated in the legend on Map 3

PR3WNir,'1H/2f Prepared by the Directorate of Overseas Surveys 1978 TABLE 27 Dominant soil chemical characteristics assessed as limitations to crop growth for land systems with 1 crop option (based on mean values for dominant soil series, excluding top horizon)

Limitations due to pH for// Limitation Land CEC meq % Exch. K pH system soil* meq %/ Maize Millet Sorghum Groundnuts Cotton availability CEC* K/

302 6.3-14.1 0.2-0.4 6.0-6.9 Nil Nil-Min Nil Nil-Min Nil-Mod Nil-Min SF-S A

*CEC meq % soil /K meq % for soils of pH> 4.5 *P availability related to pH to S ->8 Suitable for intensive agriculture A 0.10 Adequate PJL Limitations SF 2.0-7.9 Requires a high ratio of fallow to D 0.10 Deficient crops 6.5 - 7.5 Nil U/S 2.0 Unsuitable for intensive agriculture 6.0-6.49, 7.51-8.0 Minor (Adetunji, 1974) ^Min = Minor, Mod = Moderate, Sev = Severe TABLE 28 Dominant slope and range of slopes on major facet in areas with one crop option

Slopes of major facet Land Dom. facet system Per cent Degree (% area of no. LS) Dominant Range Dominant Range

302 3 2-10 2 1-6 Sideslope (51) ., , ...

Density and distribution of cultivation

Most of the land system is little used for cultivation (Separate Map 2 and Table 29), partly because of Falgore Game Reserve and Lame Burra Forest and Game Reserve.

TABLE 29 Density of cultivation in areas with one crop option Land areas (km2) in four cultivation densities Total Land Admin. area % under system unit % of <.lü% km2 cultivation (dom.) class in forest reserves 60 60-35 34-10 <10 302 655 Toro 22 loo 130 403 54

Forestry

Poles and firewood are available from the natural vegetation. There are no plantations in the area from which growth rates could be predicted.

LAND SYSTEMS WITH MODERATE OR SEVERE LIMITATIONS TO ARABLE CROPS

This group of land systems is widespread as members of it are scattered throughout the Kano Plains. They occur in a variety of texture bands (Separate Map 1) and are not confined to any length of growing season

73 TABLE 30 Summary of main characteristics of areas with moderate or severe limitations to arable crops

Land Occurrence Density Present cropping Crop Draught State of Commun­ Rangeland system (local gov. of Forestry option animals erosion* ications/ and cattle no authority) cult. Pood Cash

310 None Daura, Low to Gero, sorghum, Groundnuts, Common Slight lower Good Cover on the Gunzu, Roni E, Kazaure high dauro. cowpea, cowpea, cassava slope gullying; uncultivated Zauma, Bukudu, cassava some sheet land is sparse Kaibaki S, Rogogo erosion in the more northern areas. Kankiya Moderate lower Medium KuAkurai, Marmara, 315 r High As above plus Composition Bichi fadama rice and slope gullying; Raddoho, Soketa poor as a result cotton some sheet erosion of uncontrolled grazing over 316 Gwarzo, Sorghum, Groundnuts, Few Slight to Good many decades Dokoki, Gagun, Biehi gero, cowpea, cowpeas; peppers, moderate Kuskurmi, Sakau cassava, onions, cotton in lower slope sweet potato fadamas gullying

317 None observed Dundun Bature, Katata, Tokara 320 Katsina, Gero, cowpea, Groundnuts, Common Slight lower Kandawa, Masibi, Mani, sorghum, cowpea, cassava} slope gullying; Tama, Mawashi, KankLya cassava rice, cotton in some sheet Tserawa, Makaru, fadama erosion Tuwaru

322 Ikara Sorghum, Groundnuts, None Slight lower Medium gero. maize, cotton; sugar slope gullying cassava, cane, peppers,, sweet potato onions in fadamas Maje, Dabinuwa, 330 Daura, Low to Sorghum, Groundnuts Common Severe Poor Kazaure, high gero. maize, cotton, sugar lower slope Siran Gezawa, cassava, cane, peppers, gullying Rano, sweet potato rice, cassava Dawakin Kudu, Dawakin Tof a, Malumfashi, Tudun Wada, Vudil, Ningi *Defined in Appendix 2 /Refers to proportion of area within 5 km of all-weather, tarred or hard-top road: poor 0;10#, med 10-50$, good >50j6. (Separate Map 3). The main characteristics are indicated in Table 30. 2 Their total area is 2 553 km or 8% of the area.

Limitations to crop growth

1. Soil physical characteristics

Land systems in this group have either severe limitations to the growth of all crops considered, or occur in areas unsuitable for various crops on climatic grounds. By reference to Table 31 it is apparent that the main soil limitations are inadequate depth, poor drainage or the presence of coarse material. In general, texture is not a limiting feature.

2. Soil chemical characteristics

The range of chemical characteristics in soils of the dominant facets are shown in Table 32. The main limitations are associated with areas of coarse-textured topsoils where the cation exchange capacity is very low. Such soils are unsuitable for intensive cultivation without careful management and fertilising with phosphorus and nitrogen in particular. The potash status appears to be adequate and the pH is not limiting to phosphorus uptake.

Limitations to mechanical cultivation

Land systems with less than three crop options are not recommended for large-scale mechanised cultivation. There are no physical restraints to mechanised cultivation except in Land System 310 which contains considerable areas of rock and is fragmented, and in Land System 330 which is badly gullied.

75 TABLE 31 Soil physical limitations to the growth of certain crops in areas with moderate or severe limitations to arable crops

fo Soil limitation category (SLC) by :rop in each land sys tem, with nature of limitation*

Area Maize Millet Sorghum Groundnut Cotton Land of system land no. Nature Nature Nature Nature Nature system SLC % of SLC * of SLC * of SLC % of SLC * of limitation limitation limitation limitation limitation

310 152 Climatically 1 IO-29 Climatically 1 10-29 Climatically unsuited 2 IO-29 t/wt unsuited 3 10-29 wt unsuited

315 269 1 10-29 1 10-29 2 10-29 tc/o/w 2 10-29 c/w 5 10-29 DC/Dtc 5 10-29 DC/Dtc

316 432 1 10-29 1 10-29 1 10-29 l 10-29 1 10-29 2 IO-29 t/o 2 IO-29 t/tc 2 10-29 t/tc/wt 2 10-29 ct 2 10-29 Ta/WTa 5 30-50 DtC/DC 5 30-50 DC/Dtp. 5 30-50 DtC/DC 5 30-50 DC/DtC 5 30-50 DtC/DC -a 317** 394 2 30-59 c/t/v 2 30-59 tc/t/wt/c 2 30-59 c/t/w/tc 2 10-29 t/w/o 3 30-59 C/te/V/ct 4 IO-29 Vco/C/iT 4 10-29 Vc/tC/Vt 4 10-29 Vtc/C/W 3 30-59 tc/wt/tC 4 10-29 C/tf 5 10-29 TC/DtC 5 10-29 DtC/DC 5 10-29 Dp/DW 4 10-29 Vc/C/Vt 5 10-29 D¥tC/DC/Dt£

320 659 Climatically 1 IO-29 Climatically 1 10-29 Climatically unsuited 2 10-29 t/tc unsuited 2 10-29 t unsuited 4 10-29 c/tc. 4 10-29 c/tc

322 148 1 10-29 2 30-59 wt/c 1 10-29 2 10-29 t 2 10-29 t 2 IO-29 w 4 10-29 Wtc/Wct 2 10-29 w 3 10-29 wt/wt 3 10-29 w 4 10-29 Wc 5 IO-29 DtC. 4 IO-29 Wc 4 10-29 Wtc 4 10-29 V/Vc

330 498 1 <10 1 IO-29 1 <10 1 10-29 1 < 10 2 10-29 i/c 2 <»10 t/tc 2 10-29 t/c 2 <10 t 3 10-29 Ta 4 •CIO W/¥C 4 *10 wp/nc 4 «10 W/tfc 4 <10 Wtc/tft 5 < 10 DVfC/DC

*Limita1s i ons Depth Drainage Terture Coarse material JD Severe W. Severe JT Severe C_ Severe D Moderate V Moderate T Moderate C Moderate d Minor w Minor t Minor c Minor

**45# oiP unit climf iticai: Ly suited to maize, sorghum, cotton and a further 45^ suited to sorghum and cotton //6o# 0 P unit dim«itical ' Ly suited to all crops, + 30$ suited to cotton and sorghum only + 10$ unsuited to all crops TABLE 32 Dominant soil chemical characteristics assessed as limitations to crop growth for land systems with moderate or severe limitations to arable crops (based on mean values for dominant soil series excluding top horizon)

Limitations due to pH for// Limitation

Land CEC meq % Exch. K pH P system soil* meq %/ Maize Millet Sorghum Groundnuts Cotton availability CEC* K/ **

310 1.5 0.1 5.7 Nil Nil Nil Nil Nil Mod U/S A

315 2.1-7.3 0-0.2 5.4-6.7 Nil-Min Nil-Min Nil-Min Nil-Mi«. Nil-Mod Nil-Mod SF A 316 4.0-7.3 0.1-0.2 6.0-6.7 Nil Nil-Min Nil Nil-Mi«. Nil-Mod Nil-Min SF A

317 2.1-7.2 0.1-0.3 5.4-6.5 Nil-Min Nil Nil-Min Nil-Min Nil-Min Nil-Mod SF A

320 1.7-2.7 0.1-0.2 5.4-5.9 Nil-Min Nil Nil-Min Nil-Min Nil Mod U/S-SF A

322 6.3-13.2 0.2-0.3 6.0-6.6 Nil Nil-Min Nil Nil-Min Nil-Mod Nil-Min SF-S A

330 5.0-5.1 0.2 6.2-6.4 Nil Nil Nil Nil Nil Mod SF A

*CEC meq % soil /K meq % for soils of pH >4.5 **P availability related to pH S >8 Suitable for intensive agriculture A >0.10 Adequate ES. Limitations SF 2.0- 7.9 Requires a high ratio of fallow to D <0.10 Deficient 6.5 -7.5 Nil crops ' 6.0-6.49,7.51-8.0 Minor U/S <2.0 Uns ui tab le for intensive agriculture 5.0-5.9 , 8.1 -8.5 Moderate (Adetun ji, 1974)

//Min = Minor, Mod = Moderate, Sev = Severe TABLE 33 Dominant slope and range of slopes on major facets in areas with moderate or severe limitations to arable crops

Slopes of major facet Land Dom. facet system Per cent Degree (% area of LS) Dominant Range Dominant Range

310 2 1-3 1 0.5-1.5 Sideslope (53) 315 2 1-3 1 0.5-1.5 Sideslope (55) 316 2 1-3 1 0.5-2 Sideslope (64) 317 2 0-3 1 0-1.5 Crest (68) 320 2 1-3 1 0.5-1.5 Sideslope (69) 322 3 2-3 1.5 1-2 Sideslope (56) 330 no facet analysis • •

Density and distribution of cultivation

In spite of their overall physical limitations, large areas in this group are densely cultivated, especially in the north (Table 34). They are less heavily used where population pressure is lighter, for example Land System 322.

TABLE 34 Density of cultivation in areas with moderate or severe limitations to arable crops

Land areas (km2) in four cultivation densities Total Admin. Land area unit: % under % of 410% • system km2 (dom.) cultivation class in forest reserves 60 60-35 34-10 *10 . 310 152 Daura 33 41 38 66 40 315 269 51 68 9 89 Kankiya 141 316 432 73 36 16 Bichi 307 loo 317 394 57 8 Gwarzo 314 15 loo 320 659 Kankiya 472 101 56 30 loo 322 148 Ikara 14 17 lOl 16 330 498 Tudun Wada 90 102 196 110 28

78 Forestry

The land systems are extensively cultivated, in the north particularly, and it is only likely that adequate supplies of firewood and poles can be obtained from natural vegetation in Land System 32 2.

LAND SYSTEMS UNSUITABLE FOR ARABLE CULTIVATION

This small group of two land systems, numbers 1 and 2, is unsuitable for crop cultivation as the limitations are too severe. Their combined area 2 is small, totalling 1 590 km or 0.5% of the Kano Plains. They occur only in the south-east, neighbouring the Bauchi Plains and Jos Plateau.

Limitations to crop growth

The general absence of soil and occurrence of bare rock over most of Land Systems 1 and 2 precludes the growth of crops except in very small, isolated patches. In addition, steep erodible slopes exceeding 6 are dominant.

Density and distribution of cultivation

Reference to Separate Map 2 shows that almost all these areas are sparsely cultivated. They are, however, extensively used for grazing, and for firewood collection when located near centres of population.

LAND SYSTEM 5

Land System 5 comprises the longer valley floodplains and terraces. These areas have not been examined during the course of this survey, but it is clear that if drainage and/or irrigation can be managed effectively, they can be highly productive for a wide range of crops. They are used widely for cash crops and for dry-season grazing by both migrant and resident livestock.

79 Part 4 Part 4 Development possibilities

TYPES OF DEVELOPMENT

Various types of agricultural development have been considered with reference to the Third National Development Plan, 1975-80, and after discussion with federal and state authorities and the staff of research institutes in Nigeria. The definitions given in Table 35 and in the following sections of this report are based on these discussions and experience of similar development projects in Nigeria. Areas where the types of development are most appropriate are shown in Table 36, both by land systems and administrative units, and in Text Maps 6.10-6.16. Similarly, areas having minimal environmental limitations for particular crops are shown in Table 37 by land systems and administrative units.

It is stressed that the different development possibilities have been assessed solely on environmental criteria. No attempt has been made to rank them in economic terms. It is further emphasised that social and related factors, which may be vitally important in development projects, have not been considered. It is assumed for capital-intensive, technologically complex projects that only the highest quality management will suffice.

ASSESSMENT OF AREAS FOR PARTICULAR TYPES OF DEVELOPMENT

The Kano Plains are located where the 'safe' growing period (rainy period) becomes marginal for a number of major agricultural crops on free draining soils. Those northern areas with less than a 120 day rainy period are considered unsuitable to the successful production of the present varieties of cotton and tall sorghum, thus land systems here are only suitable for two major crops or less. Furthermore, the situation is aggravated by the high percentage of the land in the cultivation cycle (see Separate Map 2) and farming systems in which the resident livestock utilise virtually all the wet and dry season fodder, leaving very little for the transhumants.

81 Significant factors with regard to agricultural development in the Kano Plains can be summarised as follows:

1. Cultivation density is high over 75% of the area

2. The climate, specifically the length of the rainy period, is inadequate for rainfed upland rice, yam, cotton, local tall sorghum and 120-day maizey in the north

3. Wind erosion and damage to crops is significant in the north

4. Large forest and game reserves occur in the south, where additional land is also excluded from agricultural development because it is environmentally unsuitable

5. Tsetse fly has been eradicated from the Kano Plains

6. Only in the south do limited areas remain which are suitable for several major crops, large-scale mechanised farming, integrated

7. Road communications are generally moderate to good except in the south-east where they are only fair

8. The current level of agriculture is one of an intricate, labour intensive, family based subsistence type, with limited cash crop production

9. The use of cattle for draught purposes is widely practiced throughout the area, although becoming less common to the south

lO. In contrast to areas further south,the problem of providing adequate fodder supplies for cattle during the rains is greater than during the dry season. Because of the competition for cattle food supplies,nomadic herds are only tolerated if they move quickly through the area, particularly in the north

82 TABLE 35 Types of agricultural development

Type of development Summary definition of development

Establishment of integrated agricultural development projects aimed at increasing existing agricultural production per ha by (a) In densely improving infrastructure (communications, supply of agricultural inputs, produce marketing, credit facilities and extension cultivated areas service coverage). Run by a semi-autonomous project authority and making use of self-help wherever possible. Allied to general 1. Integrated improvement of social services. agriculture (b) In sparsely As above but also able to increase production by increasing the area under cultivation and/or introducing 'mixed farming». cultivated areas

Establishment of large mechanised farms (? 1 000 ha) requiring a high level of management expertise and mechanisation of all 2. Mechanised farming stages of production from land preparation to harvest. Good planning and adequate conservation measures are essential. Limited to sparsely cultivated areas.

Improvement of traditional grazing including control of stock numbers, the elimination of unregulated lopping and the introduction 3. Traditional grazing of forage species into natural grassland. These measures, together with the establishment of grazing reserves and the allocation of grazing rights, are components of a suggested programme to be organised at inter-state level. Limited to sparsely cultivated areas.

Establishment of reserves in the major traditional wet and dry season grazing areas and along migration routes, with additional 4. Grazing reserves reserves within areas free or being freed of tsetse by the eradication Programme. Provision of adequate water supplies, veterinary services and improved natural grassland, coupled with strict control of stock numbers. Limited to sparsely cultivated areas.

Establishment of ranches for «growing out' cattle drawn from Fulani herd. Stock numbers restricted to 2 000 head until the viability of the ranch is established. Area not less than 2 000 ha per 1 000 head of cattle, with 1 200 ha for wet season and early dry season grazing and 800 ha for fodder grass to provide additional dry season roughage. Supplementary dry season feeding- by cottonseed, cottonseed cake, groundnut cake, brewers grains or molasses as available. Limited to sparsely cultivated areas. 5. Cattle ranoh»n and dairy farming Establishment of dairy herds of not more than 100 milking cows. Total area not less than 250 ha, with 130 ha improved pastures for wet and dry season grazing and 50 ha to provide additional dry season feed, supplemented by locally available concentrates and crop residues. Dairy farm using zero grazing techniques should be not less than 195 ha, 50 ha of grassland and 75 ha of fodder which is chopped and fed to stock.

7. Production forestry (a) Production by state and federal departments for firewood, poles and minor forest produce (gum arabic and tannin )

(b) Production by farmers on small woodlots, backed by extension service

(c) Extraction of low yield from areas of natural vegetation in forest reserves,using high girth limit and felling cycle (a)Protection of existing and establishment of new forest reserves in areas with slopes greater than 1C (6°) where conservation is 9. Protection forestry, reservation to required protect areas against erosion or (b) Protection against wind erosion by establishing shelter belts strict conservation resource* (c) Conservation and management of natural vegetation in forest reserves for environmental reasons and to provide some produce (eg browse) Note. Development fype 6, production of sawn timber from reserve, is not feasible in the Kano Plains TABLS 36 Agricultural development possibilities in relation to administrative units and land systems in the Kano Plains

Administration Land systems suitable for different types of agricultural development unit 1, Integrated agriculture 3. Traditional grazing improvement 7. Firewood, pole production from • 8, Protection forestry (local 2, Mechanised 4. Grazing 5. Dairy government reserves firm3, feedlots (a) Forest reserves (b) Farmera (c) Natural (a) In densely (t>) In sparsely farming (a) Forage crops (b) Raseeding (c) Rehabilitation (a) Steepland (b) Shelterbelt (c) Environ area) cultivated areas cultivated areas Käme Land system voodlots vegetation Bauchi State Ningi 331,342 309,324,331, 324,331 309,324,331.336,341,342 - 309,324J31, 309.324,331, - - 331,342 - 1.2,330 - - 341,342 336,341,342 336,341,342 Toro - 324 324 302,323,324,336 - 302,323,324, 302,323,324, - - 302.323 - 1.2 - - 336 336 Kano State Bichi 332 - - - 307,316,333 - - Dakwa.Dokoki, 316,332,333, 307,314,315, 305,311 - - Cagun.Hurmi, 335 316,317,332, Kantava,Kuskurmi, 333,334,335, Mat a, Samanja 344 Badume, Sakau, Blrnln Kudu 331,342,343 331,342,343 331 331,342,343 - 331,342,343 331,342,343 Gunnina, Iggi 331,342,343 331,342,343 - 1,2 - - River Danbatta ------Kurma,Mahuva 335 333,335 - - - - DaYOkln Kudu 329 329 329 329 - 329 329 - - 329,333 - 330 - - Dairakin Tof a 329,332 " Alako.Bunku, 332,333 307,317,329, 330 ~ BovtoramijBuzUf 332,333 " Dunava.Gwame, " JinjaUjKalebava Dutse 343 ------Iggi River 343 343 - - - - Gay a 328,331,343 ------. - 328,331,343 - - _ _ Cezava ------. 333,335 - 330 _ . Gvarzc 306,319,325, 306,319,325, 319 306,313,319, - 306,319,325, 306,319,325, Dundun Bature 317 306,307,316, - 330 - - 326,327,329 326,327 325,326,327 326,327 326,327 Kat at a 317,319,325, Tokara 326,327,329 Ikara 303,306.319 303.306,319. 319,324 303,306,313,319,322,324 - 303,306,313, 303,306,313, Kariya River 303,306,324 303,306,319, - 2 - - 324 319,322,324 319,322,324 Bugau N 4 S 322 Kano not considered for development purposes Xazaure 310,337,339, Gunzu, Korel 310,314,335, 310.314,335, 310314,335, 305,311,330 310,314,337, 310,337,339, 344 Kuda Gangare, 337,339.344 337,338,339, 337,338,339, 338,339,344 344 Makadi.Roni N &g 344 344 Vavar Rafi, Verdava.Zauma, Zungunba, Fefeku Minjiblr - - -' ------333.335 - - - - Rano 324,328,329 306,324,328, 324,328,329 304,306,324,328,329 - 304,306,324, 304,306,324, Rurum 306,324 304,324,328, - 301,330 - - 329 328,329 328,329 329,333 Tudun Vada 303,306,319, 303,306,319, 319,324,328 302,303,306,319,324,326,327, - 302,303,306, 302,303,306, Danposla 303,319,324 303,306,319, - 1,2,301, - - 324,326,326, 324,326,327; 328,340 319,324,326, 319,324,326, Falgore 324,326,328, 330 329 328,340 327,328,340 327,328,340 329 Vudil 306,324,328, 306,324,328, 324,328,331 306,324,328,331 - 306,324,328, 306,324,328, - - 306,324,328, - 301,330 - - 331,343 331 331 331 331,343

Kahuna State Daura - - - 310,337,338, - - Bukudu,Daura, 310,338,339, 310,337,338, 310,338,339, 305 310,337,338, 310,338,339, 339 Gunzu.Kaibakl 344 339,344 344 339,344 344 N ft S,Kaya, • Rade,Rogogo, Sandamu TABLE 36 Continued

Dutsin Ha ------Barava, 338 338 338 - 338 338 Kabakava, Tsannl Funtua 306,318,321 - - Dabo, 313,321 306,313,318, - 312 - - Dut sin Makurdi 321

KanMya 307,315,320 Kandava,Korogo, 307,315,320 307,308,314, 311 308,337,338 Kunkurai, Marmara, 315,317,320, Masibl,Mavashi, 337,338 Raddoho,Soketa, Tama,Tserava, Tas hi

Katsina 338 Dan Babba, 307,320,337, 307,308,320, 337,338,339 308,337,338, 337,338,339 Dan Kabba, 338,339 337,338,339 339 Davan Allah Dono,Garu Gigtnya, Kabakava, Kab°M,Koda, Madatai,Rukuba, Tama,Tsannl

Malumfashi 306,318.321, 325 307,325 307,325 307,325 Aqashe,DanGarba, 306,307,313, 306,307,313, 312,330 325,327 Darenfada, 325,327 318,321,325, Gangara, Garun, 327 C atari, Koto, Kurmi,Makaurci_ Mazaure, Tandama.Tsanbe, YflTTTmnt^^

Man! 308,320,337, Dan Manau, 308,320,337, 308,320,337, 308,337,338 308,337,338, 308,337,338 338 Dutsava, 338 338,339 339 Dutsin Bamli Kirbo.Makaru, Tuiraru.Yangora

Notes. Development Type 6,. Production of savn timber from reserves, is nowhere feasible in the Kano Plains, Development Types 3c and Be are specific to the Kano Plains. Development Types 3, 4, 5 and 8b are given a different emphasis compared with the other reporting areas. Small areas of land systems unsuitable for a given purpose, but which are included in mapping units on Separate Map 4 for cartographic convenience, are excluded from this table. TABLE 37 Land systems with few limitations to the growth of particular crops, in relation to

administrative units

Admini strat ive Land system unit (local govt. area) Maize Millet Sorghum Groundnut Cotton

Bauchi State Ningi 324,336,340 309,324,331,341, 309,324,331,336, 309,331,341 324,340 340,341 Toro 323,324,336,340 324 323,324,336,340 324,340 Kano State Bichi 305,307,311,314, 332 305,307,311,314, 332,333,334,335, 332,333,334,335* 344 344 Birnin Kudu 341,342,343 341,342,343 341,342,343 Dambatta 333,335 333,335 Dawakin Kudu 333 333 Dawakin Tofa 307,332,333 332 307,332,333 Dutse 343 343 343 Gaya 331,343 331,343 331,343 Gezawa 333,335 333,335 Gwarzo 306,313,319 325, 306.307,313-319, 306,313.319,325, 306,307,313,319, 313,319 326,327 325,326,327,329 326,327 329 325,326327,329 I kar a 306.313,319 303,306,313,319 303,306,313.319 303.306,313 319 313.319 Kano Not considered for development " Kazaure 305,311,335,337, : 305.311 335 337 339.344 339,344 Minjibir 333,335 333,335 Rano 301,304.306 301,304,306 301,304.306 301 304,306 304 Tudan Vada 301,306,319,323, 301,302.303,305 301,303,306,319, 301303 305 306, 319,324 324,326,340 306,319 324,326, 323 324,326.329, 319,326,329- 340 329 340 . Wudil 301,306,324 301,306,324,328, 301,306,324,328 301,306.328.331 324 331 331 Kaduna State Daura 305,337,338,339, 305,337,338,339, 344 344 DutsinMa 338 338 Funtua 312,313,321 312,313,321 312,313,321 312,313,321 313,321 Kankiya 307,308,311,314, 307,308,311,314, 337,338 337,338 Katsina 307,308,337,338, 307,308,337,338, 339 339 Mani 308,337,338,339 308,337,338,339 Malumfashi 306,312,313,318, 306,307,312,313, 306,312,313,318, 306,307,312,313* 313,318 325,327 318,325,327 325,327 318,325,327

86 Due to these factors, large areas of the Kano Plains, particularly those north of the 120-day rainy period limit, do not fulfil the requirements for most of the forms of agricultural development considered in this survey; only limited recommendations can therefore be given for these areas at present.

Research is needed to alleviate limitations imposed by the rainfall deficiency and might include investigation into the groundwater-irrigation potential, the breeding and selection of shorter-season crop varieties and the introduction of other crops successful elsewhere under similar arid conditions, and the production of suitable fodder crops for cattle during the rains. A socio-economic analysis of the whole area is also recommended. As a result of such work and with the introduction of environmentally suitable varieties, development of the area should be possible.

The forms of development under consideration in this report should result in significantly increased agricultural production in most parts of the southern Kano Plains at least, but to be most effective the form of development should be located in areas where environmental and present land use limitations are at a minimum. In assessing whether an area is suitable for a particular type of development the following factors have been considered within the framework of land systems:

Climate Size and distribution of the land system Soil limitations to crop growth Slopes in relation to erasion hazard Distribution and intensity of present cultivation Present farming systems Present grazing status and cattle movements Existing forestry activities

87 1. INTEGRATED AGRICULTURAL DEVELOPMENT PROJECTS

(CRITERIA: all areas with three or more crop options, dominant slopes less than 10%, no severe gullying, no large areas of rock or ironpan)

An integrated agricultural development project* involves the concentration of agricultural, medical and educational resources in selected areas with associated improvement in services and communications. Although only the agricultural aspects of such a project are discussed in this report, it must be emphasised that these aspects cannot be considered in isolation, as successful development is dependent on improvements in the whole range of rural services.

These projects can be established either in intensively cultivated areas or in places where there is room for the expansion of the land under cultivation (Text Map 6.10). The structure of the project can be similar in both cases, but, in the former, any increase in agricultural production must come from increased yields and intensification of the present farming system while, in the latter,there could be a different emphasis on the means of crop production because of the greater area of land available.

la. The alternatives have implicitly different aims. Thus, intensively cultivated areas in this part of Nigeria are invariably well populated: the farming population have already achieved a measure of success through agricultural skill and cooperation that is largely restrained from increasing production by a lack of timely inputs, such as fertiliser and seed, and facilities such as credit and all-weather roads. Their land is generally, but not necessarily, good. The chances of successfully raising the output in this kind of situation are, therefore, high and short term. Practical minimum and maximum area limits for such projects are probably in the order of 1 OOO km2 and 10 OOO km2.

*While being similar in concept to the World Bank rural development projects, such as the one already in operation at Funtua, there are features discussed here which differ in detail.

88 TEXT MAP 6.10 KANO PLAINS AREAS SUITABLE FOR INTEGRATED AGRICULTURAL DEVELOPMENT PROJECTS (based on environmental and present land use factors only) 7°30' 8°00' 9° 30' 1 II

13°00

12°30'

12°00'

11°30' 11°30*

s . Report area boundary 11°00' • Main road Secondary road Other road or track

• Railway Q State capital wl Local government headquarters o Small town o Village

10°30' — 10°30' Kilometres 20 0 20 40 60 I i i i I I I I 1:1.500,000 _l I 7°30' 8°00' 8°30'

D.O.S. 3269Bk Prepared and printed by Directorate of Overseas Surveys 1978 lb. Alternatively, an area could be selected with low cultivation density, and low overall population density. It may be an area with poor agricultural potential because of inferior environment or low internal and external accessibility which denies the availability of infrastructural facilities when they are most required. In this study, however, areas are excluded which, on environmental grounds, limit too severely the choice of crops that can be grown - namely, land systems having two crop options or less (see PART 3); these basically comprise areas with much rock outcrop, ironpan, shallow stony soils and poorly drained land.

Because of the low population density, a significantly increased production must rely on extending the land under cultivation. This can be achieved by encouraging people into the area, by mechanised assistance or by an increased use of ox-drawn implements. Tsetse fly may need to be eliminated in wooded valleys, road networks established and bush cleared. Compared, therefore, with (la)above,the chances of successfully raising output are equally high, given the same degree of commitment, but longer term. The practical area limits for such projects would be in the range 2 OOO km2 to 10 000 km2.

Such projects should be administered by a semi-autonomous project authority and involve the improvement of infrastructures, concentration of extension services and creation of farmers' organisations. They also include some degree of mechanisation, supply of agricultural inputs, arrangement of credit and marketing facilities, as well as associated services such as water supply and health. Experience at Funtua has shown that project proposals must be fully explained to the local population and located only when and where their full co-operation is assured. These factors are discussed below.

Project authority A semi-autonomous project authority should be established to co-ordinate and implement all aspects of the development

89 programme. It should include local farmer representation from the beginning and have the long-term objective of being run entirely by local people with government advice, either as a continuing entity, or as separately run but interlinked functional organisations.

Infrastructure Roads, water supplies, marketing and storage facilities should be provided before the full-scale injection of agricultural inputs, though some inputs should be made available at an early date to establish credibility with the farming community.

Staffing Extension staff trained on the project should be located in the villages. Initially the ratio of extension staff to farming families should not exceed 1:500, but once new techniques have been accepted the ratio can be increased and extension staff made available for similar projects elsewhere, or for the expansion of the project area itself.

Size of holding The farms can be either fixed, single-area holdings as is becoming the case in densely settled areas, or scattered, impermanent plots in the bush-fallow system as in the southern parts of the Kano Plains. They should be large enough to enable the farmer to make a minimum income that will counteract the attraction of moving to an urban area; that is, at least equal to the income of most daily-paid government employees, about N740 in 1976. Norman (1972) has shown that most farmers derive about 22% of their total income from off-farm activities during the dry season in the Zaria area. This would be considered supplementary to the basic income.

The minimum sizes of holding needed to produce an income of N 740 has been calculated using data from IAR socio-economic studies in the Zaria area (Norman^1972 a, b). The size of holding has been calculated for farms using hand labour only; for farms using family labour and two draught oxen; and for farms using family labour, oxen and herbicides. Maize, sorghum, groundnuts, cowpeas and cotton have been considered as the main crops. It is assumed that a single crop is grown which gives the maximum net return per unit area.

90 The various farm sizes under these conditions are given in Appendix 3; details of the calculations are given by Mansfield in Miscellaneous Report 233 (in prep.). The figures show that the minimum size of holdings for a single, most profitable crop, using only hand labour ranges from 5.5 to 7.5 ha: this includes some fallow and assumes that the farmer hires any necessary seasonal labour, additional to the family input; that is,there is no labour restraint.

Holdings using oxen must be much larger; basically in order to provide sufficient fodder for the animals (see below). In practice, actual farm sizes will be even larger than these theoretically calculated sizes as the farmer does not grow single cash crops and some land may not be productive.

In the densely cultivated northern parts of the Kano Plains that have a high population,there is not enough land for each farmer to have a holding big enough to generate an income equal to that earned by many daily-paid government employees.

Oxenisation Throughout Nigeria the term 'mixed farming' denotes farming which entails the use of animals for draught purposes, and this has usually been restricted to ploughing or ridging. Mixed farming, however, has always been envisaged as the integration of crop and animal husbandry involving the feeding of crop residues, the cultivation of fodder crops, the use of manure and the use of animals for a variety of draught purposes: implements for cultivating and planting, and carts, have long been in use elsewhere and the best equipment is simple to adjust and can be maintained by village blacksmiths. It is with this broader concept of mixed farming that this study is concerned.

In areas, where the cultivation density is less than 35% and spare land for larger holdings is available*, an improved system based on a 10-12 ha farm size enables the bulk of the bull's food to be produced on the farm.

*Derived from a four-class analysis of cultivation density through airphoto interpretation (see Part 2 and Separate Map 2)

91 Mechanisation with tractors To make the use of tractors economic, they must be used for most of the farming year. This means that most farming operations need to be mechanised and this necessitates clean stumping, with an associated increase in the risk of erosion and a need for erosion control in susceptible areas. Farms, to be efficient, must also be organised into large blocks. All this involves a radical change in the farming system, and experience in other areas unfortunately shows that the small farmer tends to become less involved and less enthusiastic as these changes occur. Full mechanisation we feel is, therefore, far more appropriate to large mechanised farms.

If tractors are used primarily for land preparation to eliminate the drudgery of hand cultivation and to enable planting to take place earlier, then it is unlikely that the tractors can be operated economically. Even if farms are organised into blocks, the tractors will remain idle for a large part of the year, together with the drivers and maintenance staff. A government subsidy of the service would, therefore, be essential in this case. More efficient use of equipment might be achieved by commercial contractors or individuals who use the tractors for other work during the rest of the year i.e. in general haulage such as firewood collection.

If mechanisation of cultivation is undertaken, erosion control measures are necessary in areas with slopes greater than 1%.

The full benefits of mechanisation will not be obtained unless other inputs are made available at the same time, such as a road network, controlled marketing of cash crops and fertiliser, and a forestry extension scheme.

Credit and marketing Seasonal loans should be provided to enable farmers to obtain improved seed, fertiliser, agricultural chemicals, equipment and tractor hire services. Marketing of scheduled crops should be controlled by the project authority and loans recovered from the revenue arising from the sale of produce. With crops that can be marketed locally, loan recovery is more difficult. It may depend on refusing further credit and services to debt defaulters and by making bad debts a community responsibility.

92 Other agricultural inputs Inputs such as fertilisers, herbicides, pesticides, implements, improved seed and planting material should be available to the farmers at the correct time. Credit may be necessary, so supplies should be available where crops are marketed.

Implementation schedule As it is unlikely that the whole area could be developed at once, development should be phased to keep pace with the build-up of staff and infrastructure. After the initial establishment of the Project Authority, it is assumed that essential baseline preliminary surveys are made to examine the soil, hydrology, erodibility of the land and the human resources. Following an assessment of these,each phase should be scheduled as follows:

Year 1 i. Recruiting and training of new staff and orientation courses for existing staff at agricultural centres

ii. Provision of a. limited supply of inputs to establish credibility with the farming community

iii. Intensive publicity and formation of farmers' groups, followed by their involvement in development of infrastructural needs, including roads, housing and water supplies, as well as the establishment of soil and water conservation works. Project specialists would coordinate and direct in such matters as supply of materials, bridge and culvert construction, road alignment and dam layout and design

iv. The establishment of seed multiplication units for an initial period until these can be run by the farmers

Year 2 i. Continuation of publicity and formation of farmers' groups

93 ii. Extension staff move to their villages and start work on small demonstration farms for which they are solely responsible and on which they carry out the manual work involved with assistance from their family. These are to act as a practical demonstration to the farmers and would help the extension staff to build up their standing within the farming community

iii. Continuation of the build-up of the infrastructure, with the population involved at all stages, concentrating on the building of storage facilities and a mechanical workshop for mechanisation

iv. Establishment of distribution, marketing and credit organisation. The ordering and delivery of all agricultural inputs required for Year 3

Year 3 The project becomes fully operational. All the required inputs are available to farmers, through their group organisations, together with extension advice on the way to use them

Location of integrated agricultural development projects in the Kano Plains

Only areas with three or more crop options have been considered suitable for the establishment of integrated agricultural development projects as a choice of crops is considered essential. On this basis no areas are suitable north of the 120-day rainy period limit, where only millet and groundnuts are successful. The location of all environmentally suitable areas (exceeding approximately 1 500 ha, for cartographic reasons) is shown on Text Map 6.10 and on Separate Map 4 and is given in Table 38 in relation to administratives units and land systems. Note that the areas are somewhat generalised and, due to the small map scale, small areas may be included which are not suitable for this form of development. It is accepted, for practical purposes, that the boundary of a scheme may encompass unsuitable land, especially if the boundaries are those of administrative units. In this case, effort will naturally be emphasised on the suitable land.

94 TABLE 38 • Location of integrated agricultural development projects in the Kano Plains

Land systems suitable for integrated agricultural Administrative unit developme nt projects (local govt, area) Densely cultivated areas Sparsely cultivated areas

Bauchi State Ningi 331,342 309 324,331,341,342 Toro — 324

Kano State Bichi 332 — Birnin Kudu 331,342,343 331,342,343 Dambatta - — Dawakin Kudu 329 329 Dawakin Tofa 329,332 — Dutse 343 — Gaya 331,343 - Ge zawa - — Gwarzo 306, 319,325., 326, 329 306,319,326,327 Ikara 303,306,319 303,306,319 Kano Not considered for development Kazaure — — Minjibis — -t Rano 324,328,329 306,324,328,329 Tudun Wada 303,306,319,324,326, 303,306,319,324,326,327, 327,328,329 328 Wadil 306,324,328,331,343 306,324,328,331

Kaduna State Daura — _ Dutsin Ma _ __ Puntua 312,318,321 — Kankiya - — Katsina — _ Mani _ _ Malumfashi 306,312,318,321,325, 327 —

There are large areas in the south, therefore, which are environmentally suitable for this form of development. Of the densely cultivated area the most favourable is Land System 306, predominently in Gwarzo, Mulumfashi and Tudun Wada LG areas: dominant slopes are gentle and the land is suitable for four major crops.

In sparsely cultivated areas, the most favourable land systems with scope for extending cultivation are Land Systems 324 and 331. With predominantly

95 gentle slopes, these land systems are suitable for four and three major crops respectively.

North of the mean 120-day rainy period limit (Separate Map 4), only groundnuts, short-season millet and cowpeas are consistently successful major crops. These areas have not been considered for this form of . development at present, but it is suggested that if shorter—season varieties suited to the environment could be introduced and it is both practical and economic to exploit the groundwater-irrigation potential, this form of development would become applicable.

Effect on other types of development

The establishment of the second form of integrated development project (lb) can mean an increase in the area under cultivation and a reduction in the area available for grazing. However, there will be a parallel increase in crop residues and, if these are made available to cattle, the loss of dry-season grazing should be offset. The increase in cultivation means a loss of wet-season grazing, however, and in the Kano Plains there remains relatively little uncultivated land available for grazing in the wet season. The possibility of obtaining supplementary feed is discussed in 5., Establishment of dairy farms, below.

If the density of cultivation is increased over a large area, it may be difficult to maintain an adequate supply of firewood and poles. Plantations may need to be established or farmers encouraged to grow woodlots to meet demand (see 7b).

2. LARGE MECHANISED FARMS FOR PRODUCTION OF RAINFED ANNUAL CROPS

(CRITERIA; all areas with three or more crop options; <35% land in cultivation cycle; <\ 3% dominant slope; not severely gullied, rocky or with ironpan; >1 OOP ha blocks)

In Nigeria, these farms have been established by government for the production of large quantities of food crops or as seed multiplication centres. 96 Such projects should fulfil the following requirements:

Size The farm should be at least 1 OOO ha/ the minimum size for fully mechanised production of annual rainfed crops, according to experienced local opinion. This figure is somewhat arbitrary, however, and a detailed economic analysis should be made to verify this.

Site Density of existing cultivation should be low (i.e. less than 35% as shown on Separate Map 2) so that major problems of resettlement and compensation will not arise. Dominant slopes should be less than 3%. Slopes greater than this require complex conservation layouts with horizontal intervals between field boundaries of less than 50 m,resulting in inefficient working of machinery due to short runs and excessive turning time. The selected area should not be too fragmented by valleys or drainage lines so that the efficient layout of fields and roads is not hindered.

Soils Detailed soils information is necessary at an early stage, together with a contour map, in order that a rational farm layout can be made.

Soil and water conservation works The basic layout of field access roads, storm drains, terraces and grassed waterways should be established before cultivation commences. Shelterbelts should be planted up as soon as possible. Dams and weirs should be constructed at this stage,as required.

Machinery and equipment The types and quantity of machinery and equipment should be selected to suit both local conditions and the crops to be grown. Adequate spares, together with repair and maintenance facilities, should be available on site.

97 Buildings These should include adequate cleaning and storage facilities for the crops grown, as well as provision for bulk handling. Drying plants may be necessary in certain cases.

Management Due to the high capital investment in such schemes, it cannot be over-emphasised that experienced and highly skilled management is a key factor in their success.

Implications of mechanised schemes

The aim of these schemes should not be to compete with the local farmers for crop markets or to result in lower prices to the producers. Their main justification is to build up national food reserves speedily and/or boost improved seed production, and as such must be linked with central storage facilities. Where suitable areas are restricted, the establishment of large mechanised farms may compete with grazing, forestry and fallow land requirements.

At present, such schemes are being initiated on an ad hoc basis without adequate information on the following aspects:

Economic viability Their relationship to schemes being initiated elsewhere Their effect on overall crop production, marketing and prices The long-term effects of intensive mechanised agriculture on soils which are often infertile and poorly structured Rotations Possibilities of integration of livestock enterprises with crop production

Location of large mechanised farms in the Kano Plains

Only four land systems, covering a relatively small area of the Kano Plains are suitable for this form of development^ and these lie entirely south of the mean 120-day rainy period limit, where land with three or more crop

98 options occurs (Text Map 6.11 and Separate Map 4). Large blocks, exceeding say 5 OOO ha, may be difficult to locate in some places due to the presence of lightly incised streams or scattered areas of ironpan or rock. In general, the most favourable land is on crests and main valley sides; lower slopes tend to be steepest and prone to gullying.

Other land systems are considered unsuitable because they are intensively cultivated, too small in area, dominant slopes exceed 3% or there are soil/climatic limitations to the growth of several major crops. No land systems are suitable in that part of Kaduna State within the reporting area.

TABLE 39 Areas suitable for mechanised farms on the Kano Plains

Land systems suitable for mechanised farms Administration unit (local govt, area) Potential large Potential med.-small blocks >5 OOO ha blocks 1 OOO-5 000 ha

Bauchi State Ningi 324, 331 Toro 324 Kano State Birnin Kudu 331 331 Gwarzo 319 Ikara 324 319 Kano Not considered for development Rano 324 328 Tudun Wada 324 319, 328 Wudil 324, 331 328, 331

Effect on other types of development

The establishment of large mechanised farms means a reduction in the area of the land for grazing. Unless specific plans are made for their use it is unlikely that crop residues would be available for cattle as under intensive mechanised agriculture most of the stubble would either be burnt off or ploughed in with the addition of nitrogenous fertiliser. Mechanised schemes would preclude any form of production forestry but there would be a need to establish windbreaks and shelterbelts.

99 The effect that production from large mechanised farms would have on local market prices is unknown at present and needs study. If the objective is to build up strategic food reserves, then they are unlikely to compete directly with the farmer.

i

3. IMPROVEMENT OF TRADITIONAL GRAZING

(CRITERIA: all areas with an absence of tsetse fly; dominant slopes 4 6°; < 35% land in cultivation cycle; no severe gullying)

Traditional grazing in the savanna lands involves the use of uncultivated land, fallow land and crop residues by nomadic or semi-nomadic herds of cattle. Herds of cattle belonging to settled and nomadic owners graze uncultivated upland areas during the wet season; in the dry season they utilise crop residue, stubbles and floodplain grasslands.

Settled pastoralists and cultivators owning cattle normally herd them within a short distance of the village or permanent camp site. Nomadic pastoralists herd their cattle over a larger area, moving camp and kraal at frequent (5-15 days) intervals. In the dry season many herds move a distance of lOO km or less, but for some the seasonal search for grazing may involve a trek of 500 km.

Due to the generally,dense cultivation pattern in the Kano Plains, and the region as a whole, there is a high pressure on the grass resources. Uncontrolled burning followed rapidly by the grazing of the subsequent flush of new shoots and the excessive lopping of fodder trees is leading to a gradual deterioration in the productivity of the rangeland.

The cooperation and participation of the pastoralist is essential in any attempt to halt or reverse the deterioration of the rangeland and it is clear that rangeland improvement must involve the control of stock numbers and stock movement. The pastoralist's traditional independence, dislike of interference and his suspicion of authority, however, makes this cooperation difficult to secure. Ideally, their concern for their

lOO TEXT MAP 6.11 KANO PLAINS AREAS SUITABLE FOR LARGE MECHANISED FARMS (based on environmental and present land use factors only) 7°30' 9°30'

13°00' 13°00'

12°30'

12°00'

11°30' 11°30'

Jkara

Report area boundary 11°00' Main road ^-.-^ Secondary road Other road or track h9^ H State capital ifc. Local government headquarters K X T> • Small town ^ J o Village (J 10°30'f 10°30' Kilometres 20 0 20 40 60 I i i i I I I I 1:1.500,000 _J L J I 7°30' 8°00' 9°30'

D.O.S. 3269BI Prepared and printed by Directorate of Overseas Surveys 1978 stock must be extended to include a concern for the environment and its resources; it is difficult to understand their apparent present indifferemce to ensuring the sustained productivity of the rangeland. To encourage a change in attitude it may be necessary to allocate grazing rights to particular groups of pastoralists (Blair Rains, 1978).

Among the measures which are necessary in any attempt to improve rangeland are:

1. The education of the general public as well as the pastoralists about the effects of untimely bush fires during the dry season. For example, while a late burn once in three or four years helps to maintain good quality pasture by eliminating woody regrowth it is difficult to control. Early burns are detrimental to pasture composition in the long term. For forestry, any firing is harmful, but early burning is least harmful

2. The preservation of fodder trees,by demonstrating that less severe lopping ensures a greater yield of fodder in subsequent years

3. Pasture improvement. The introduction of grass in denuded areas and also the introduction of legumes, annual Stylosanthes into the natural grassland would provide valuable herbage in the dry season. However, the problems of establishing grasses and legumes over large areas are considerable: amongst these are problems of seed supply, the question of who would be responsible for planting and the control of stock including small ruminants. In addition, applications of phosphate fertiliser would be beneficial. The long dry-season in the north is unfavourable for many perennial legumes

4. The improvement should form part of a coordinated inter-State policy, which includes the creation of grazing reserves(discussed in the next section)

101 Three types of grazing development are envisaged in the Kano Plains:

1. In the least intensively cultivated areas (Separate Map 2), where farmers would be encouraged to plant forage crops on fallow land. Fadama grazing would play an important role in dry-season feeding, and the identification of blocks of fadama land (which would be reserved for grazing)is recommended

2. In the least intensively cultivated areas, the natural grazing would be improved by reseeding with grasses and legumes, by the regulated use of browse and by control of stock numbers. Fadama grazing would be utilised as in (1.)

3. In northern areas/the natural grazing that remains in this generally heavily cultivated region is degraded and of low value. It could be reseeded with suitable grasses such as Pennisetum pedicellatum, Cenchrus ciliaris and legumes such as Stylosanthes humilis; it might be necessary to apply fertiliser and have stock numbers controlled. After recovery, these areas would become grazing reserves. Fadama grazing would be an essential component of dry-season feeding and the creation of reserves would be correspondingly essential

Areas for improvement of traditional grazing

Areas where the improvement of traditional grazing should be most effective are shown in Table 40 in relation to land systems and administrative units. They are also shown on Text Map 6.12 and Separate Map 4.

It is Government policy to encourage the national herd to move to areas south of 12 N (the latitude of Kano) on account of the deterioration in the natural vegetation during the period of poor rainfall in the early 1970's.

Because of the paucity of grazing,non-settled Fulani are unlikely to remain for long periods in this most northerly area, but it will not affect materially the large numbers of cattle and small stock kept by individual farmers in the north. These stock rely to a large extent on browse and foraging of crop residues in the dry season and on meagre roadside

102 TEXT MAP 6.12 KANO PLAINS AREAS SUITABLE FOR IMPROVEMENT OF TRADITIONAL GRAZING (based on environmental and present land use factors only) 7°30' 8°00' 8°30' 9°00' 9°30'

13°00' Katsina 13°00'

12°30'

12°00'

11°30' 11°30'

Report area boundary 11°00' Main road Secondary road Other road or track

===== Railway Q State capital T-r_ Local government headquarte o Small town o vill

10°30' Kilometres 20 0 20 40 60 I I . ! I I L 1:1,500,000 _J I 7°30' 8°00' 8°30' 9°00' 9°30'

D.O.S. 3269Bm Prepared and printed by Directorate of Overseas Surveys 1978 TABLE 40 Areas suitable for improvement of traditional grazing in the Kano Plains

Administrative Land systems suitable for unit improvement of traditional grazing (local govt, area) a) Forage crops b) Re see ding c) Rehabilitation

Bauchi State Ningi 309,324,336,341, 309,324,336,341, 342 342 Toro 302,323,324,336 302,323,324,336 -

Kano State Bichi Birnin Kudu 331,342 331,342 - Dambatta - — — Dawakin Kudu 329 329 — Dawakin Tofa — — — Dutse — — — Gaya - - - Gezawa - — — Gwarzo 306,313,319,326, 306,313,319,326, — 327 327 Ikära 303,306,313,319, 303,306,313,319, — 322,324 322,324 Kano Not considered for development Kazaure - - 310,339,344 Min j ib ir - - — Rano 304,306,324,328 304,306,324,328 — Tudun Wada 303,306,319,324, 303,306,319,324,. — 326,327,328,329 326,327,328,329 Wudil 301,306,324,328, 301,306,324,328, - 331 331

Kaduna State Daura 310,337,328,339 Dutsin Ma — _ _ Puntua — _ _ Kankiya - — 308,337,338 Katsina - — 338 Mani - - 308,337,338 Malumfashi 307,325 307,325

103 vegetation, leaves stripped from cereal crops and on poor-quality natural vegetation in scattered areas of woodland and fallow in the wet season. As the area under cultivation inevitably increases, it is important that the composition of remaining areas of natural vegetation does not deteriorate further in the northern areas, hence the suggestions for their improvement.

Although tsetse fly has been eradicated from the Kano Plains, relatively little of the cleared area is not being farmed. (The large forest reserves in the south-east are the only areas which would still provide a habitat for fly and which might conceivably be re-infested). Small patches of grazing remain in the close-settled north, commonly coincident with inferior soils or ironpan, whose poor quality herbage might be improved. The largest is in Mani local government area in Land System 338.

In the south land outside the cultivated parklands contains low-quality land systems such as LS 1 and 2, comprising rocky hills, and LS 302 and 303 with much rockband 313 with much ironpan. The latter, and the intervening higher quality areas offer scope for rangeland improvement, especially in Land Systems 306, 324 and 331 in Gwarzo, Tudun Wada, Ikara, Wudil and Ninoi Local Government Areas.

Effects on other types of development

Traditional grazing may be improved without major changes to other existing agricultural activities, but it should be planned in relation to them. Most immediately, policies of rangeland use and improvement in forest reserves need coordination with forestry departments.

It is an obvious but important fact that an increase in the area of land used for, say, arable cropping, means a decrease in the area available for grazing, though this may be partly offset by the increased availability of crop residues. Where an expansion of the area of cultivated land is planned or is actually taking place, the improvement of traditional grazing is particularly urgent. In such areas, eventually there will be insufficient land to support pastoralism as presently practiced and provision should be made for the establishment of managed grazing reserves. The tsetse-eradication programme is making additional land available for grazing. 104 The role of fadama grazing in this development form has been emphasised. To reserve areas of fadama specifically for grazing means that such areas will be preserved from cultivation. In places, however, almost all fadama land is used intensively for year-round crop production. Allocation of land use in such areas is a matter of discussion between individuals, communities and headmen, and will be difficult to resolve.

4. ESTABLISHMENT OF GRAZING RESERVES

(CRITERIA: all areas with an absence of tsetse fly, dominant slopes 6 ; <35% land in cultivation cycle; no severe gullying)

The Grazing Reserve Law, 1965, provides for the establishment of grazing reserves to achieve ultimately the settlement of nomadic pastoralists. None has been gazetted in the Kano Plains.

It is explained below that the Kano Plains offer little scope for this form of development, although the area forms an integral link in the chain of transhumant movements from northern to more southern areas for dry-season grazing. Because of this relevance, the discussion that follows, and which is common to the other five reporting areas of this project, is included so that the problems can be appreciated.

The pastoralist's needs in terms of health and food for his stock have necessitated seasonal migration patterns, principally from these and more northern, drier areas (in part in Niger Republic) to regions in the south where dry-season grazing can be obtained. Because of this the establish­ ment of grazing reserves should aim initially at modifying rather than eliminating the existing pattern of transhumance. This would involve:

1. The establishment of an inter-State body to coordinate policy which cannot be undertaken by State in isolation

2. Main wet- and dry-season grazing areas should be demarcated and gazetted as grazing reserves. Settled and semi-nomadic herds could also be accommodated in these reserves

105 3. Grazing reserves should be established along the main migration routes to act as staging posts for the nomadic herds. They should have fencing, adequate water supplies and veterinary and market facilities to make them attractive to the Fulani. The aim of these staging posts should be to regulate and facilitate transhumance

4. The natural grassland within the grazing reserves should be improved by:

i. An intensive campaign to make the nomadic Fulani aware of the

long-term dangers of dry-season burning for early grazingf and the indiscriminate lopping of fodder trees

ii. Selective reduction in the shrub vegetation

iii. The introduction of grass and legume species by sod-seeding (minimal cultivation)

These measures will only be effective if it can be demonstrated to the Fulani that their cattle will be better off than with their traditional way of life. At the present time, only if the pastoralist is assured that the well-being of his livestock will not be lessened is he likely to be willing to use reserves; owing to a variety of factors, his attitude could change very rapidly.

Settlement and more intensive methods of livestock production are often accompanied by changing livestock disease problems; veterinarians are familiar with this pattern.

Location of grazing reserves in the Kano Plains

Areas suitable for the establishment of grazing reserves only occur south of Kano in land that is not densely occupied. The location of these areas is shown on Text Map 6.13, on Separate Map 4 and is given in Table 41 in relation to administrative units and land systems.

106 TEXT MAP 6.1 3 KANO PLAINS AREAS SUITABLE FOR ESTABLISHMENT OF GRAZING RESERVES (based on environmental and present land use factors only) 7»30' 8°00' 8°30' 9°00' 9°30'

13°00-

12°30'

12°00'

11°30' 11°30'

Report area boundary 11°00' Main road Secondary road Other road or track

G State capital •fr. Local government headquartei o Small town o Village

10°30' 10°30' Kilometres 20 0 20 40 60 I i i i I I I 1:1.500,000

I I 7°30' 8°00'

DOS. 3269Bn Prepared and printed by Directorate of Overseas Surveys 1978 TABLE 41 Location of grazing reserves in the Kano Plains

Administrative unit Land systems suitable for location (local govt- area) of grazing reserves

Bauchi State Ningi 309,324,331,336,341,342 Toro 302,324,336 Kano State Bichi - Birnin Kudu 331,342,343 Dambatta - Dawakin Kudu 329 Dawakin Tofa - Dutse - Gaya - Gezawa - Gwarzo 306,319,326,327 Ikara 303,306,319 Kano Not considered for development Kazaure - Minjibir - Rano 306,324,328,329 Tudun Wada 303,306,319,322,324,326,327,328 Wudil 306,324,328,331 Kaduna State Daura - Dutsin Ma - Funtua - Kankiya - Mani - Malumfashi -

All environmentally suitable areas are shown on Separate Map 4, except small scattered areas of less than 1 500 ha. It is appreciated however that reserves should be in the order 5 000-50 OOO ha to be of most benefit, but few unencumbered areas of this size could be located in the Kano Plains. The most favourable are Land Systems 309, 324, 336 and 302 in the south-east.

107 5. ESTABLISHMENT OF DAIRY FARMS AND FEEDLOTS

(CRITERIA: all areas with an absence of tsetse fly; <35% land in o cultivation cycle; -^3 crop options; dominant slopes 4.6 ; no severe gullying; no widespread rock or ironpan;>600 ha for dairy farm) '

In other reporting areas of this project, this option has included the establishment of cattle ranches for beef production. In the Kano Plains, however, there would be severe difficulties in supplying adequate feed year-round for the size of herd normally considered economic in this kind of enterprise (about 1 000-2 OOO head). Only in the extreme south-east might a ranch be established but, because of the difficulty of obtaining adequate dry-season feed and because of the poor quality of natural grassland, it cannot be recommended. Tsetse fly has been eradicated from the Kano Plains.

Dry-season feeding is also a problem for dairy farms and feedlots for, although there are very large areas of farmed land in the Kano Plains which produce crop residues as forage, the number of resident and transhuinant livestock is such that fodder from this source is not considered, adequate. It is envisaged, therefore, that both types of enterprise would rely heavily on crop-processing or food-manufacturing by-products. In addition, the more exacting food requirements of the milking cow involve the provision of good quality bulk food: this requirement is probably met most satisfactorily by the cultivation and conservation of suitable crops as silage, e.g. sorghum, with a scrambling legume such as Stizolobium deeringianum.

It cannot be over-emphasised that the economics of livestock enterprises require the most careful investigation.

Feedlots

The successful operation of feedlots for fattening cattle during a period of 60-120 days immediately prior to slaughter depends on the availability of agro-industrial by-products and a price structure for live cattle and for meat. To avoid physiological disorders some bulky food is usually included in the rations which have been based on sugar cane tops, citrus

108 waste, molasses, milling offals, cassava processing waste, poultry manure and brewers' grains. The feed-lot should be sited as near as possible to the source of foodstuff; but the siting must not cause a nuisance and must allow for the satisfactory disposal of manure.

Stock, in groups, are held in pens which include a shaded area; with access passage ways, crushes etc. it is probably necessary to allow 2 ha per 1 000 head.

At purchase, stock are given routine treatment against internal parasites and other infections. During the initial period of 10-14 days the ration is gradually introduced. Skilled supervision is essential for successful feedlot operation.

Dairy farms

Herd size Because of the lack of commercial dairy farm operating experience, it is recommended that farms be restricted initially to 100 milking cows which, with herd replacements, corresponds to 160 livestock units.

Breed The herd should consist of Friesians which have been kept successfully under not too dissimilar climatic conditions at Shika, Zaria. They should yield approximately 2 270 kg per lactation, compared with Bunaji (White Fulani) 910 kg, cross-bred Bunaji-Friesian 1 640 kg» and Friesians in the temperate zone 4 200 kg.

Wet-season feeding Unimproved grassland will provide maintenance for dry adult cattle for part or all of the wet season, but is unlikely to be a satisfactory source of nutrients for young stock and milking cowsfexcept for a very short period. Milk production must be based on good quality roughage and concentrates and young stock should be given similar rations. Pastures of sown or planted materials will require fertiliser application and irrigation in the dry season.

109 Dry-season feeding Silage should be fed generously (adult cattle eat approximately 7-8 kg dry matter/day). Natural grassland does not make satisfactory silage however (Miller et al., 1963) and it is desirable to ensile a purpose-grown cereal crop such as maize or sorghum. Good- quality hay is useful for calves and sick animals. Haulms of leafy cowpea and groundnut (harawa) are normally available in most northern markets but if supplies are likely to be inadequate a legume crop such as Glycine javanica or Stizolobium deeringianum should be grown and conserved as hay.

Concentrates should be fed to milking cows according to yield, and to immature stock. It is recommended that the concentrate ration be compounded on the farm from purchased materials. Changes in the formula­ tion of concentrate or in the overall rations should always be introduced gradually.

Area of farm The farm size required for 160 livestock units is given in Table 42.

TABLE 42 Dairy farm: area per 100 cows plus followers

Yield, t/ha Category Area, ha (dry matter)

Natural grassland (paddocks for exercise) l.O 50 Improved pasture ( fertilised,zero grazed) 3.0 50 Cereal for silage 2.5 50 Legume crop for hay 2.0 50 Building, yards 15

Total 215

Location of dairy farms and feedlots in the Kano Plains

Although the areas required for livestock enterprises are small or very small, in the case of feedlots they could be established most easily in areas of low cultivation density identified on Separate Map 2. The

110 environmental requirements of the dairy farm are moderately stringent and land systems considered suitable are shown on Separate Map 4 and Text Map 6.14, and are given in Table 43. If it is intended that the projects should provide a large proportion of their own fodder needs, then land suitable for mechanised farming would be most appropriate (see 2. above), which additionally is suitable for at least three major crops.

Such areas occur predominantly in the south. Since accessibility and good roads to nearby urban markets are essential, however, the most desirable areas appear to be in Gwarzo and Tudun Wada local government areas, within o reach of Kano or Zaria. Lightly cultivated areas north of 12 N are not considered for these forms of development because of government policy and because feed problems are severe.

TABLE 43 Location of dairy farms and feedlots in the Kano Plains

Administrative unit Land systems suitable for dairy farms and feedlots (local govt, area)

Bauchi State Ningi 309,324,336,341,342 Toro 302,323,324,336 Kano State Bichi - Birnin Kudu 331,342 Dambatta - Dawakin Kudu 329 Dawakin Tofa - Dutse - Gaya - Gwarzo 306,313,319,326,327 Ikara 303,306,313,319,322,324 Kano Not considered for development Kazaure - Minjibir - Rano 304,306,324,328 Tudun Wada 303,306,319,324,326,327,328,329 Wudil 301,306,324,328,331 Kaduna State Daura - Dutsin Ma - Funtua — Kankiya - Katsina - Mani Malumfashi 307,325 : . . .

111 Effect on other types of development

The establishment of cattle ranches or dairy farms reduces the area of land available for cultivation and forestry. The effect of production from these farms on local markets for meat and dairy products is not known, but it is likely that demand presently exceeds supply.

6. FORESTRY DEVELOPMENT FOR PRODUCTION OF TIMBER

(CRITERIA: all land considered on environmental merits above minimum of 5-lOQ ha)

In the companion report on the Kaduna Plains, recommendations have been made to grow the timber for Kano and Katsina in the Northern Guinea Zone (Wall et al, 197 8). The boundary between the Northern Guinea and Sudan Zone coincides with the southern boundary of the Kano Plains. Owing to the low rainfall and long dry season, the growing of trees to timber size is not a feasible economic proposition in the Sudan Zone.

7. FORESTRY DEVELOPMENT FOR PRODUCTION OF FIREWOOD AND POLES

(CRITERIA: all areas considered with minimum area of 5-100 ha)

The average fuel consumption for the savanna regions is in the order of 3 0.63 m per person per year (Thulin, 1970). Jackson and Ojo (1973) report that the growth of natural vegetation in the Sudan Zone is O.33-0.67 3 m /ha/year. Therefore, there needs to be 1.9-0.9 ha of natural vegetation to meet every person's annual firewood needs from the natural vegetation. With increasing rural population, the bush-fallow period shortens and the land remaining under natural vegetation diminishes. When bush-fallow farming has been replaced by permanent farming the firewood supplies have to be met either by cutting down the economic farm trees or from plantations. The growth rates of some firewood plantation species are as follows:

112 TEXT MAP 6.14 KANO PLAINS AREAS SUITABLE FOR CATTLE RANCHES OR DAIRY FARMS (based on environmental and present land use factors only) 7°30' 8°00'

13°00' 13°00'

12°30' 12°30'

12°00 12°00'

\ __ Jkara

Report area boundary 11 "00' 11°00' Main road Secondary road Other road or track

===== Railway • State capital w_ Local government headquarters o Small town o Village

10°30' 10°30' Kilometres 20 0 20 40 60 I ... I I I I 1:1,500,000 L_ _J , J 7°30' 8°00' 8°30' 9°00' 9°30'

D.O.S. 3269Bp Prepared and printed by Directorate of Overseas Surveys 1978 TABLE 44 Growth rate of plantation species in the Sudan Zone

Mean annual Growth rate mean Species rainfall annual increment mm m^/ha/a

Neem 1 020-760 4-2 (Azadirachts indica) <760 1.5-0.2 Dalbergia sissoo 1 020-815 2 Eucalyptus camaldulensis 1 020-760 3.0-1.5

The area needed for plantations is less than the area of natural vegetation required to meet firewood requirement of the population. Using the 3 increment figure of 4 m /ha/a for neem, the area required per person is 0.16 ha. However this growth rate is low compared with that in the Guinea Zone. To provide the urban population of Kano (using the consump­ tion levels and population forecasts of Grut (1972) and Ferguson (1973)) in 1982 would require 81 625 ha of plantation. To meet Katsina's 1982 requirement, there needs to be an area of 37 950 ha.

The calorific value of firewood

Before beginning a programme of firewood plantation establishment, it is worth considering the relative merits of species for firewood.

The average calorific value of 111 species from Africa, Asia and South America tested by Doat (1977) was found to be 4.77 k cal/kg (oven-dry wood).

The calorific value of air-dry wood (12-15% mc) is about 3 780 k cal/kg; the value does not alter significantly for different species. Because the calorific content depends on the weight, not the volume, slow-growing species with a high density may have an equal calorific yield to fast- growing species with a low density.

Table 44 gives the range of growth rates for some plantation species that grow in the Sudan Zone. Calorific yield is obtained by multiplying the

113 mean annual increment by the density and by the calorific value of wood. It is a useful way of comparing species for firewood and can be found in the right-hand column of Table 45.

TABLE 45 Comparison of calorific yields of firewood plantation species grown in the Sudan Zone

Calorific yield Growth rate Density airdried K. cal/kg x Species m.a.i* 12-15% m.c./ m.a.i. x density m^/ha/a kg/m^ x 106

Neem 4 774 11.703 2 5.851 0.5 1.463

Dalbergia 4 830 12.550 sissoo 2 6.275 0.5 1.569

Acacia nilotica 4 838 12.671 var. adstringens 2 6.335 0.5 1.584

Eucalyptus 4 730 11.038 camaldulensis 2 5.519 0.5 1.380

*m.a.i: mean annual increment. /m.c: moisture control.

The alternative means of production

Firewood and poles can be produced by (a) State or Federal Forestry

Departments making plantations in forest reservest (b) farmers growing small woodlots backed by a forestry extension service (c) management of natural vegetation in forest reserves (for locations, see Table 46 and Text Map 6.15).

7a Plantations for firewood and poles in forest reserves

In the derived Savanna and Guinea Zones we have advocated that urban requirements for firewood and poles can be met from plantations in forest

114 TEXT MAP 6.15 KANO PLAINS FOREST RESERVES FOR PRODUCTION OF FIREWOOD AND POLES, AND AREAS REQUIRING EXTENSION FORESTRY 7°30' 9°00' 9*30'

13°00' H13°00'

12°30'|— H12°30'

12°00'

—I 11°00'

10°30'(— 10°30'

7°30' 8°00' 9°30'

D.O.S. 3269Bq Prepared and printed by Directorate of Overseas Surveys 1978 TABLE 46 Location of firewood and pole production in the Kano Plains

Administration unit Land systems suitable for firewood and pole production from (local govt area) a) Forest reserves b) Farmers woodlots c) Northern forests

Bauchi State Ningi 331,341 Toro 302,323

Kano State Bichi 307,314,316 316 Dokoki,Gagun,Kuskurmi,Sakau 317,322,333,334,335,344 332 Gagun,Kantawa,Mata,Sakau 333 Samanja Badume 334 Dakwa 335 Hurmi Birnin Kudu 331,341,342,-Gurmina 331,342,343 343i Gurmina,Iggi River Dambatta 335 Kurma, Mahuwa 333,335 Bawakin Kudu 329,333 Dawakin Tofa 332 Bunku 307,317,329,332,333 333 Alako,Bunku,Bowtorami, Buzu,Dunawa,Gwame, Jinjau, Kalebawa Dutse 343 Iggi River 343 Gaya 338,331,343 Gezawa 333,335 Gwarzo 317 Dundun Bature, Ka ta-ta, Tokara 306,307,316,317,319,325,326 327,329 Ikara 303 Bugau, south 303,306,319,322 306 Kariya River 324 Bugau, north Kano 333 Town reserve Kazaure 310 Gunzu, Roni East, Zauma 310,314,335,337,338,339 310,314,337,339,344 344

314 Fefeku.Roni East,Roni North 335 Makadi 337 Werdawa, Gwiwa Korel 339 Gunzu,Gwiwa Korel, Kuda Gangare,We rdawa,Zauma 344 Gunzu,Kudu Gangare,Wawar Rafi,Zungunba Minjibir 333,335 Rano 306,324 Rurum 304,324,328,329,333 Tudun Wada 303,324 Falgore 303,306,319,324,326 319 Bansosia 328,329 Wudil — 306,324,328,331,343 Kaduna State Daura 310 Bukudu, Gunzu,Kaibaki 310,337,338,339,344 310,337,338,339,344 South, Rogogo 338 Daura, Kaya 339 Daura, Gunzu,Kaibaki North & South,Kaya,Rade, 344 Gunzu,Rogogo,Sandamu Dutsin Ma 338 Barawa, Kabakawa,Tsanni 338 338 Funtua 313 Dabo 313,321 321 Dutsin Makurdi Kankiya 307 Korogo,Yashi 307,308,314,315,320 315 Kunkurai,Marmara,Raddoho, 337,338 Soketa 320 Kandawa, Masibi,Mawashi, Tama,Tserawa Katsina 307,320 Tama 307,320,337,338,339 307,308,320,337,338,339 337 Dan Kabba, Dawan Allah, Dono,Garu Giginya,Madatai 338 Dawan Allah, Kabakawa,Koda, Rukuba, Tsanni 339 Dan Babba

Mani 308 Dan Manau 308,320,337,338,339 308,337,338 320 Makaru,Tuwara 337 Dutsin Bamli, Dan Manau Dutsawa, Kirbo 338 Dutsin Bamli, Dan Manau, Yangoia] Malumfashi 306 Agashe.Dan Garba,Darenfada, 306,307,313,318,321,325,327 Koto,Kurmi Maizaure,Tandama, Tsambe,Yammama 307 Gangara 313 Dabo,Tandama Tsani, 325 Makaurci, Gangara 327 Garun Gatari

115 reserves. In the Sudan Zone the situation is different. Plantation establishment costs are fixed and unrelated to yield, which means that the cost of production rises steeply with decreasing yield. The effect of this is to make it extremely expensive to grow plantations for firewood in the Sudan Zone. At the same time, the population density is high and spare land is not easily found. There is not sufficient land in the neighbourhood of Kano to make 81 625 ha of plantation. Near to Katsina and Daura there are large forest reserves, but these were established on the land that farmers were most ready to give up, namely the worst land. Both Kabakawa and Sandamu Forest Reserves have thin soils over plinthite. Neem yields on shallow soils like these are usually less than 1 m /ha/a (Howard, 1976 Appendix 2.)

The price of kerosene in northern cities was (in 1972) close to the price of firewood. Nigeria is an oil-producing country and kerosene is a necessary by-product in the oil refining process (Grut, 1972). It would seem sensible for the urban population of the northern cities to use kerosene stoves particularly if the price of kerosene could be kept uniform throughout the country. The natural vegetation in the Sudan Zone might then be spared to serve other environmental purposes. The way in which the forest reserves should be developed is described in Section 8cr Management of the natural vegetation.

Plantations of Acacia producing gum arabic and tannin

The economics of plantations that provide an intermediate yield needs further study. Both Acacia senega! (gum arabic) and Acacia nilotica var. adstringens (bagaruwa) provide valuable crops that can be harvested annually. The world market price for gum arabic has fluctuated widely in recent years. If the market was more stable and reliable it would be possible to grow gum arabic plantations to provide a supplement to the income of the rural people in the arid zones. Bagaruwa grows very well on impermeable clay soils that are unsuitable for neem and difficult to farm because of drainage problems. The attraction of bagaruwa is that it can provide two additional crops; the pods provide tannin, used for curing the well-known Kano leather (morroco leather) while the seeds, which are a waste product of the tanning industry, could be used to make cattle cake (Howard, 1976). At the end of the rotation the tree can be felled for 116 firewood. The trees grow at a rate of about 0.5 m per year for the first five years (op. cit.). At Gwiwa Koral Forest Reserve there were 40 ha of Acacia nilotica var. adstringens in 1975.

Production of poles

There is a need for poles in the urban areas for building traditional style houses, for scaffolding and other purposes like temporary shelters. An estimate of the requirement for poles in 1982 and 1992 and the area of plantation required to meet the estimate are given in Table 47.

TABLE 47 Estimate of volume of poles required in Kano and Katsina, after Ferguson (1973) and Grut (1972)

3 Volume x 1 (300, m Area of plantation*, ha City 1982 1992 1982 1992

Kano 26.5 33.5 6 625 . 8 375 Katsina 11.8 14.4 2 950 3 600 3 *Growth rate assumed 4 m /ha/a

It should be possible to obtain areas of plantation in the vicinity of Kano and Katsina to meet the requirement for poles.

Valley-bottom plantations

The limit to rapid growth in these latitudes is lack of water in the dry season. The parts of plantations in valley bottoms grow very well: the Eucalyptus at Nasarawa and the trial plots at Jibiya have mean annual 3 increments of 5 and 11 m /ha/a respectively. However, planting-up the valley bottom deprives cattle of the best dry-season grazing land, at least initially. In fact, this is not a long-term problem because the grass grows well under the light canopy of eucalypts. Once the trees are established, the cattle can graze beneath them and enjoy the shade that the trees provide.

117 For the purpose of reading the Agricultural Possibilities map (Separate Map 4) the following are included in the category 7a.

i. Establishment of plantations for firewood and poles

ii. Establishment of plantation of gum arabic, tannin and cattle seed cake

iii. Valley bottom plantations

Within the northern zone where shelterbelts should be established, plantation development in forest reserves should be limited to valley- bottom plantations and the establishment of Acacia spp. for gum arabic and tannin.

7b Farmers growing small woodlots

Although there is little economic justification for Government to finance the establishment of firewood plantations for. tne urban population, there are good reasons for subsidising fuelwood supply for the rural population. Unlike people in towns, country people are not in the position to pay for fuel all the year round. The farmer does not cost his labour and so a small plantation that he grows for himself costs him practically nothing. The pattern of small woodlots, rows of trees grown as shelter belts and individual economic farm trees would have large-scale environmental benefits for the farmer, the local community and for the population of the State as a whole.

Neem has considerable soil-improving properties. The leaf litter raises the pH by increasing the humus layer of the surface horizon. The cation exchange capacity and total exchangeable base are increased; calcium and magnesium contents, particularly, are increased (Radwanski, 1977 a and b). It may be possible for farmers to practise agrosilviculture and alternate crops of firewood with farm crops.

The economic farm trees play an important role in the rural economy. Cakes made from the seed of Parkia clappertoniana (dorowa) are traded on quite a large scale (Hill, 1972). Other important trees are Acacia albida (gawo), Adansonia digitata (kuka) and Diospyros mespiloformis (kanya). 118 we, therefore, recommend that Forestry Departments should work through an Extension Service to encourage farmers to plant trees. The Extension Service would provide the following:

i. Trees in polythene pots ready to plant out

ii. Demonstration on how to plant, weed, fence and firetrace

iii. Propaganda about shelterbelts, economic farm trees and the value of forestry

There is a psychological advantage in selling rather than giving trees away; the farmer looks after something he has had to buy. The critical period for the young trees is the first dry season, when watering may be necessary if the trees are not to die of drought. Fencing is also necessary to prevent the tree being eaten by goats.

7c Management of the natural vegetation in forest reserves

Forest reserves managed primarily for environmental reasons (see Section 8c) can provide some produce from selective fellings of the natural vegetation using a short felling cycle and a high girth limit.

8. FORESTRY DEVELOPMENT FOR ENVIRONMENTAL REASONS (see Text Map 6.16)

(CRITERIA: all areas with dominant slopes >10%; severely gullied land)

8a Protection against water erosion

Forest reserves should be established in areas with erodible slopes in excess of approximately 10% (6 ), where the alternative of laying down strict soil conservation measures is not feasible.

Grazing and burning should be prohibited until the reserves are well established and then strictly controlled so that grass cover is not eliminated and the effectiveness of the erosion control reduced.

119 Location of forest reserves for protection against erosion

Areas requiring protection against erosion are shown on Text Map 6.16, on Separate Map 4 and in Table 48.

TABLE 48 Areas requiring protection against erosion in the Kano Plains

Land Existing forest reserves system

301 - 305 Dutsin Kodawa, Dutsin Kwaita, Dutsin Wajila Bayan Dutsi/> Dutsin Pandi, Dutsin Barade 311 Lugge, Tumuku, Zare, Matan Fada, Raddoho, Ma rma ra, Dadda re 312 Tsani, Tsaunin Kura 330 Maje, Dabinuwa, Rurum, Maizaure, Koto, Diran 1 Falgore Game Reserve, Burra North 2 Falgore Game Raserve

8b Protection against wind erosion by establishing shelterbelts

Shelterbelts have been planted in Kano State and Kaduna State since the early 1960s in the Worthern Sudan Zone. Aligned at right-angles to the harmattan wind, shelterbelts provide protection from the wind and a source of wood for fuel. Wind erosion can be a serious problem in the early rainy season: blowing sand whipped up in violent storms that precede rainstorms may cut or bury newly sown millet (Prothero, 1972). The advantages and disadvantages of shelterbelts have been listed by Howard (1976).

The effectiveness of a shelterbelt in providing shelter from the wind depends on four factors: its width, height, permeability and cross-section (Caborn, 1957).

The new research station at Kano should provide answers to the many matters that need further research in shelterbelts. Some preliminary conclusions can be drawn from the existing shelterbelts.

120 TEXT MAP 6.16 KANO PLAINS AREAS REQUIRING RESERVATION OR STRICT CONSERVATION

8°00' 8°30' 9°00' ~1

13°00' 13°00'

12°00'

11 "30'

Report area boundary Main road Secondary road Other road or track

Railway O State capital M- Local government headquarters o. Small town o Village

10°30' Kilometres 20 0 20 40 60 I i i , J I I I 1:1,500,000

_J I 7°30' 8°00' 8°30' 9°30'

DOS. 3269Br Prepared and printed by Directorate of Overseas Surveys 1978 TABLE 48 Location of protection forestry in the Kano Plains

Administrative Land syst em requiring protec tion forestry unit c) Conve r sat ion (local govt a) Water erosion b) Wind rosion area) (forest reserve)

Bauchi State JJingi 1,2,330 - - Toro 1,2 — - Kano State Bichi 305,311 - - Birnin Kudu 1,2 — — Dambatta — — Dawakin Kudu 330 — — Dawakin Tofa 330 — — Dutse — — — Gaya - - — Gezawa 330 — — Gwarzo 330 — — Ikara 2 — _ Kano — — — Kazaure 305,311,330 310,314,337,338, 310 Kuda Gangare 339,344 337 Gwiwa Kordel, Werdawa 339 Gwiwa Kordel, Gunzu, Kuda Gangare 344 Zungunba Minjibir - - — Rano 301,330 - — Tudun Wada 1,2,301,330 — — Wudil 301,330 - -

Kaduna State Daura 305 310,337,338,339, 310 Kaibaki. South 344 338 Daura, Kayo 339 Kaibaki N. Rade, Sandamu 344 Gunzu, Rogogo Dutsin Ma — 338 338 Barawa, Kabakawa Puntua 312 __ _. Kankiya 311 307,308,338 — Katsina 308,337,338,339 337 Dan Kabbu, Dawan Allah, Dono, Garwa, Giginya, Kabobi, Madatai 338 Kabakawa, Koda, Rukuba, Tsanni 339 Dan Babba Mani 308,337,338,339 308 Dan Manau 337 Dutsawa, Dutsin Bamli, Kirbo 338 Dan Manau, Yangora Malumfashi 312,330 - — 121 Neem planted in one or several lines draw on the available water at right-angles to the line and are only competing for water with their neighbours on either side. For this reason neem will flourish in shelter- belts, while in a plantation they would fail.

Belts of neem with indigenous species planted on the outside achieve a rounded cross-section because of the differential rate of growth. The rounded cross-section is undesirable, because the wind clings to the profile of the shelterbelt like an aerofoil; the sheltered area to leeward is thus reduced.

Shelterbelts should be in straight lines and not in circles as they are at Magaji.

The belts should not be made too wide. The present (1975) policy is to plant six or seven rows to form a belt. Growth measurements indicate that the trees are going to grow to a height of about 7 m, in which case the belts should be less than 35 m wide. From the point of view of providing effective shelter while using the minimum amount of agricultural land, single rows or pairs of rows of trees would seem to be the best. To provide shelter near the ground, some kind of hedge would be necessary.

The trees could be harvested by pollarding, leaving a stem of 3-4 m and cutting the branches, possibly on fairly short rotation. If the belt were made up of two rows of trees, harvesting of one row could be effected, without removing all the shelter.

We recommend the establishment of shelterbelts in the densely cultivated lands of the Northern Sudan Zone. There, the soils have a fine sandy surface horizon (Bennett et. al., 1978) that is susceptible to wind erosion. On Separate Map 4 the area recommended for shelterbelts lies to the north of the HO rain-day line. For convenience,this line follows the boundaries of Land Systems 308, 337, 338 and 339.

8c Management of natural vegetation in forest reserves to preserve the climate and meet other requirements

One of the reasons for making forest reserves, as stated in the national forest policy, is 'to ensure the stability of the climatic and water regime'. 122 The extent to which forest reserves can preserve the stability of the climatic and water regime is open to controversy. The Sahel drought brought renewed interest in the function of vegetation in influencing the climatic regime. Both Otterman (1974) and Charney (1975) in studying arid zones, related vegetation to rainfall through the effect of vegetation on absorbing energy and reducing reflected radiation. Walker and Rowntree' (1976), studying the relation between moisture content near the ground and vegetation by means of computer models of arid-zone precipitation patterns, found that a high humidity at the ground increased the likelihood of rain. Transpiring vegetation at the onset of the rainy season would contribute to the moisture content of the atmosphere near the ground.

We recommend that natural vegetation should be conserved for climatic reasons, because there is sufficient scientific evidence to suggest that there is a causal relationship between vegetation and rainfall.

Before the rain touches the ground the water is intercepted by leaves, twigs and branches and tends to run down the main stems into the ground. At the ground surface the soil structure is improved by humus and the roots of the trees and shrubs open pathways into the soil.

Because farming is excluded from forest reserves,they are a sanctuary for Fulani and their herds of cattle. An unfortunate result of grazing and browsing is to reduce the quantity of vegetative material and to compact the ground. This result frequently leads to erosion. If this situation is to be avoided the use of the reserves has to be controlled and the reserve managed to obtain optimal benefit from a variety of uses.

The uses of forest reserves which consist of natural vegetation are as follows:

i. Maintenance of natural vegetation to ensure stability of climatic and water regime

ii. Browse and grazing

iii. Selective fellings for firewood and poles. Frequent cycle of felling but very low yield (See 7c)

iv. Floodplain plantations (See 7c) 12 3 i. Maintenance of natural vegetation to ensure stability of climatic and water regimes

The floristic composition of the vegetation is immaterial, except to the extent that trees and shrubs should be favoured over grasses. The grasses, being mostly annuals, do not provide the cover to reduce the reflection of radiation, neither will they transpire at the onset of the rain season.

ii. Browse and grazing

The browsing habits of domestic stock and the nutritive value of browse in West African savanna have been studied by de Leeuw (in press), Brinckman and de Leeuw (1975), Adam (1966) and Rose Innes (1977). Cattle, sheep and goats browse on a wide range of trees and shrubs in the Sudan Zone in the north, particularly the acacias, Acacia albida, A. Senegal, A. seyal and A. nilotica subsp. adstringens. Further south,species of the families Meliaceae, Leguminosae and Caparidaceae are preferred. .Common lopped,trees have been listed by Rose Innes (Rackham & Rose lnnes,1978^Vol 2.) .

Lopping trees for browse can damage the tree and careful control in management will have to be maintained.

RESEARCH NEEDS

A long-term programme of research should be established to answer some of the problems to be encountered during development. Subjects needing investigation are summarised below.

1. The long-term effects of intensive crop production on the generally infertile and poorly structured soils of the area need study: in particular the long-term effects of mechanised agriculture in relation to differing management practices and rotations, and the phenomenon of surface capping

2. Methods of applying pasture improvement techniques on a large scale need investigation, especially in areas with a short rainy season 124 Practical methods of improving the nutrition and health of young stock in the ordinary herd need to be devised

Reduction of mortality levels of small stock

A socioeconomic study of Fulani practices and attitudes is needed, particularly of those in the Kano to Abuja axis. Related to this is the need to study the desirability of multiple use of the forest estate; that is, should forest reserves be opened for grazing

The Isoberlinia doka woodland has a potential for the production of beeswax and honey. Research is required to improve the local methods of apiculture and to organize the processing and marketing of this minor natural resource

A number of selected browse species, particularly some leguminous shrubs, should be investigated to determine which can be propagated and used for supplementary dry-season livestock feed

Methods by which the productivity of areas in the north having a rainy period of 120 days or less can be sustained or improved under increasing population pressure. Irrigation potential and techniques, crops with a short growing period and the means of feeding cattle and small stock year-round all require examination

Assessment of the economic and environmental role of the so-called 'farm trees'. If the fruits of trees such as Butyrospermum paradoxum are no longer collected, should the trees still be preserved in the farmland for environmental reasons? Research into which species should be propagated and how this should be done is needed

Research is needed in the forestry aspects of erosion control. In particular, investigations are necessary to identify species that will provide ground cover and reduce runoff; and in the best methods of planting

125 CONSTRAINTS ON AGRICULTURAL DEVELOPMENT

The Third National Development Plan, 1975-80, discusses the constraints on agricultural development as follows:

"The constraints are several but the most serious are:

i. Shortage of qualified manpower in key areas ii. Inadequate supplies of agricultural inputs iii. Inadequate extension service iv. The poor condition of feeder roads and other transport facilities v. Inadequate or lack of effective supporting services such as farm credit, marketing facilities, etc vi. The problem of land ownership imposed by the land tenure system in most parts of the country vii. The problem of diseases and pests viii. The problem posed by labour shortage in the rural areas in consequence of rural-urban migration ix. Lack of appropriate or complete packages of technology for many food crops x. Drudgery in farm work and low returns from agriculture which forces rural youth to migrate to urban areas rather than go into farming."

Interviews with about 28 farmers in 14 villages scattered throughout the Kano Plains (see Separate Map 2) confirmed that these factors are indeed constraints to agricultural development. Those factors for which data are available are discussed below and more fully by Gosden (1978)

i. Shortage of qualified manpower in key areas and iii. Inadequate extension services

1. No data were available on the ratio of field agricultural extension workers to farming families for the Kano Plains area but it is known to be very low. Taken in conjunction with poor communications and lack of

126 transport available to the extension worker, this means that a large proportion of the farming population has little or no contact with advisory services. FAO suggest that a ratio of one extension worker to 1 000 farming families is an absolute minimum and existing integrated rural development projects in Nigeria are aiming at a ratio of 1:400

There are very few staff directly concerned with range management in the Kano Plains. Veterinary assistants are responsible for animal health rather than range management and consequently there is very little extension work on grassland improvement

Professional forestry staff and their field assistants are mainly concerned with development of plantations and reserves. They are supported by a considerable number of forest guards in the local authorities. Lack of staff will be a constraint to the development of an extension service intended to encourage farmers to grow woodlots and the local authority staff could be used for extension work

With any extension service, whether it be for crop production, grass­ land improvement, or forestry, there is a conflict between the need to encourage and advise the population and the need for policing to eliminate malpractices. The two functions should be kept entirely separate and policing done by specical inspectors.

viii. The problem posed by labour shortage in the rural areas in consequence of rural-urban migration

Gosden (1978) has produced farming calendars for a number of localities in the Kano Plains that show that shortage of labour is a common restraint to production, particularly at weeding times. Lack of money at this time prevents additional labour being hired, though the labour is available from other areas.

127 Additional constraints

1. There is a lack of effective farmers' organisations which would enable farmers to request and benefit from more effective extension advice, bulk purchase of inputs and handling of produce, credit facilities and tractor hiring units

2. The widespread occurrence of Striga results in reduced crop yields

3. Lack of. satisfactory water supplies in many areas, especially during the dry season

4. Competition for fadama areas between farmers and cattle owners has reduced the area of dry-season grazing in the northern part of the area. This in turn has led to the increase in intensity of lopping browse species which is now causing the death of these valuable species

128 \

Part 5 Part 5 References

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132 Appendixes

Page APPENDIX 1 INTERPRETATION OF SOIL DATA Al

Depth Al Drainage A2 Texture A4 Coarse material • A6 Soil chemical properties A7 pH water A8 Phosphorus A8 Potassium A9 Cation exchange capacity (CEC) A9 Soil limitation categories (SLC) A10 Soil limitation categories in relation to crop yields A10 Soil limitation categories in relation to land systems A12 Ranking of land systems A13

APPENDIX 2 ASSESSMENT OF EROSION HAZARD A15

APPENDIX 3 MINIMUM SIZE OF ECONOMIC FARM UNIT A17 Appendix 1 Interpretation of soil data

The soil physical properties of depth, drainage, texture of the surface 50 cm and the amount of coarse material are considered to have an important effect on crop production. They are all properties that cannot be modified without major soil improvement programmes. They have been divided into classes and given a coded annotation: each class has been assessed as a nil, minor, moderate or severe limitation to the growth of maize, millet, sorghum, groundnuts, cotton or yam.

In addition to soil physical properties, certain chemical properties may be limiting to crop growth. Data are available for pH, CEC, levels of potassium and available phosphorus, and each of these has been divided into classes and assessed as a limitation to the growth of the crops considered.

ßach of the soil properties is discussed below. The classes into which they have been divided, and their coded annotation, are given in the tables,together with the assessment of each class as a limitation to the growth of the crops considered.

Depth

The effective depth of the soil is considered to be that depth beyond which roots will not readily penetrate due to the presence of rock, ironpan or a permanent high watertable. The depth classes and codes are given in Table 1 and assessed as limitations to the growth of crops.

Although all the crops discussed are grown almost everywhere on ridges or mounds it is assumed in the study that the depth classes in Table 1 are from a level surface.

Al TABLE 1 Soil depth as a factor limiting the growth of certain crops

Limitation of the growth of Depth Soil Groundnut class code <140-day cm Maize Millet Sorghum Cotton rainy period

>150 DO Nil Nil Nil Nil Nil 150-100 Dl Nil Nil Nil Nil Nil 100-50 D2 Nil Nil Nil Nil Mod. 50-25 D3 Mod. Mod. Mod. Mod. Sev. 25 D4 Sev. Sev. Sev. Sev. Sev.

Shallow soils limit root development, thus inhibiting nutrient and moisture uptake which results in low yields. Shallowness is least limiting to shallow-rooting crops such as groundnuts. Even soils of 50-25 cm depth impose no limitations to groundnuts if the rainy period is greater than 140 days, as significant periods of water stress are unlikely.

PV»= 1 1 rv*'r»r>

Drainage

Soil drainage has been assessed on the basis of soil colour, with pale colours being correlated with poor drainage. The criteria used are similar to those given in the Legend to the Soil Map of the World (FAO, 1974). Imperfectly drained soils have been subdivided and the soil codes W2-W4 represent a seasonal watertable increasingly closer to the surface. The only certain way of determining the drainage characteristics of a soil is to record seasonal watertable fluctuations, but this was not possible over such a large area: the drainage classes should therefore be considered as tentative.

The drainage classes and codes are given in Table 2 and the assessment of these classes as limitations of the growth of crops in Table 3.

A2 TABLE 2 Soil drainage classes defined on the basis of colour

Drainage class Colour criteria and depth Soil code

Well drained 1. Soils lacking properties of WO codes W1-W5 2. Gleyic horizon colour or Wl >20% gley-spot mottle at 100-150 cm

Imperfectly drained 1.>20% gley-spot mottles W2 at 50-100 cm 2 . Gley horizon matrix W3 colours at 50-100 cm 3. >10% gley-spot mottles or W4 imperfect matrix colours at <50 cm

Poorly drained 1. Gleyic horizon matrix W5 colours at <50 cm

TABLE 3 Soil drainage as a factor limiting the growth of certain crops

Limitation to the growth of

Groundnut Soil code <140-day Maize Millet Sorghum Cotton rainy period

WO Nil Nil Nil Nil Nil Wl Nil Nil Nil Nil Min. W2 Min. Nil Nil Nil Mod. W3 Min.* Min. Min./ Min. Mod.** W4 Mod. Mod. Min. Mod. Sev. W5 Sev. Sev. Sev. Sev. Sev.

*For maize, if this degree of limitation is found in combination with two others, one of which is texture, it is treated as a moderate limitation /For sorghum as for * **For cotton as for * and / but treated as a severe limitation under these conditions

A3 Impeded drainage is a limitation to the growth of all the crops considered because they will not tolerate the anaerobic conditions of water-saturated soils: groundnuts, cowpeas and other legume crops are particularly adversely affected by waterlogging. Shallow-rooting crops such as groundnuts are less affected by waterlogging in the lower part of the soil profile, whilst deep-rooting crops such as cotton are most affected. Although sorghum and maize have similar rooting habits, the former is more tolerant of wet conditions in the later stages of growth. The limitations imposed by drainage shown in Table 3 reflect the fact that the soil codes W0-W5 are thought to represent seasonal water saturation increasingly near the surface.

A complicating factor in assessing the limitation imposed by imperfectly drained soils is that in a dry year, such soils support better crop growth. This is offset over the long term by the fact that in a wet year soils may be even more limiting than is shown in Table 3.

Texture

Texture of the surface 50 cm only is considered because most of the feeding roots of annual crops are concentrated there.

Four broad textural groups have been defined, corresponding in general to clayey, loamy, sandy and coarse sandy soils. The textural classes in each group are shown in Table 4, together with the assessment of these groups as limiting the growth of certain crops.

A4 TABLE 4 Soil texture as a factor limiting the growth of certain crops

Soil Limitation to the growth of Texture class code * Maize Millet Sorghum Groundnut Cotton

CL, C, SC, SiCL, SiC Tl Nil Min. Nil Min. Nil L, SCL, SiL, Si T2 Nil Min. Nil Min. Nil S, fS, LS, LfS, SL, fSL T3 Min. Nil Min. Nil Min./ cS, LcS, cSL T3c Min. Nil Min. Nil Mod.

*Where appropriate^a subscript + is given to those profiles where 10-20 cm has a finer texture Where appropriate, a subscript - is given to those profiles where 10-20 cm has a coarse texture /For cotton T3 + is a minor limitation (t) , T3 is treated as a moderate limitation (Ta) with regard to Soil Category 2 but as a minor limitation when considering effect of texture in Categories 3, 4 or 5 C = clay, L = loam, S = sand, Si = silt, fS = fine sand, cS = coarse sand

The four textural groups reflect differences in available waterholding capacity (Williams and Joseph, 1970). This is of particular significance in assessing the limitations presented by any soil to the growth of cotton and long season maiwa millet which require a minimum of 11.8 cm and 7.2 cm of available soil water after the end of the rainy period respectively.

Calculation of the mean depths of soil required for various textural- groups to hold the above amount of water indicates that, apart from cs, LcS, cSL (T3C group), the differences are less than 20 cm and the variation in AWC (available water capacity) due to texture has little practical significance for most rainfed crops.

Nutrient availability and aeration are also related to texture so that maize, sorghum and cotton require medium- and fine-textured soils for optimum yields but early millet and groundnuts will yield adequately on coarser-textured soils. In the case of groundnuts this is an indirect effect as they will grow well on heavier soils, but are difficult to harvest. Management of heavy clay soils, particularly of montmorillonitic clays, may also be a limitation because: (a) they become sticky and A5 puddle when wet, (b) they crack on drying out which may cause rupture of roots, (c) in the early rains, rain water flows' rapidly down the cracks whilst little moisture is retained near the surface: when the cracks close, water tends to stand on the surface.

Coarse material

This includes all the hard soil particles greater than 2 mm in diameter; they may be rock fragments, mineral grains or concretions. Both the amount of coarse material and the depth over which it occurs are significant to crop growth, and in Table 5 various combinations of percentages of coarse material and the depths at which they occur are used to define seven classes shown as CO to C6. The percentage of coarse material is assessed in the field as a volume percentage.

TABLE 5 Percentage of coarse material in various depth ranges in seven classes represented by codes CO to C6

Mean coarse material Depth ranges over which Soil code percentages coarse material occurs

<20 O-lOO cm CO

-t20 0-50 cm CI 20-40 50-100 cm

20-40 O-lOO cm C2

20-40 0-50 cm C3 40-60 50-100 cm

<40 0-50 cm C3(s) >60/Rock/hardpan from 50 cm

40-60 O-lOO cm C4

40-60 0-50 cm C5 >60 50-100 cm

40-60 0-50 cm C5(s) Rock/hardpan O-lOO cm

>60 O-lOO cm C6

>60 0-50 cm C6 >60 50-100 cm

(s) Shallow A6 The assessment of coarse material as limiting the growth of certain crops is given in Table 6.

TABLE 6 Coarse material as a factor limiting the growth of certain crops

Limitation to the growth of Soil code Maize Millet Sorghum Groundnut Cotton

CO Wil Nil Nil Nil Nil CI Wil Nil Nil Nil Min. C2 Min. Min. Min. Min. Min. C3 Min. Min. Min. Min. Mod. C3s Min. Min. Min. Min. Sev. C4 Mod. Mod. Mod. Mod. Mod. C5 Mod. Mod. Mod. Mod. Sev. C5s Mod. Mod. Mod. Mod. Sev. C6 Sev. Sev. Sev. Sev. Sev.

Coarse material reduces available waterholding capacity by reducing the volume of soil so that its effect is most pronounced on cotton which requires moisture after the end of the rains to give maximum yields. To a lesser extent this also adversely affects the yields of maize, millet and sorghum. Coarse material also affects root penentration and reduces overall nutrient status. Large amounts of coarse material in the surface horizons of soils may make cultivation more difficult and thus have an indirect effect on crop production.

Soil chemical properties

Low levels of certain soil chemical properties can limit crop yields. The most important for which data from routine soil analyses are available are considered to be 1. Soil pH (water), 2. Phosphorus, 3. Potassium, and 4. Cation exchange capacity (CEC).

A7 1. pH (water) The limitations due to pH are shown in Table 7

TABLE 7 Limitations imposed by pH to the growth of certain crops

Crop pH range (water) Limitation

Maize 5.5-7.5 Nil 5.2-5.4 Minor 4.5-5.1 or 7.6-8.0 Moderate <4.5 or >8.0 Severe Sorghum 5.5-7.5 Nil 5.0-5.4 Minor 4.5-4.9 or 7.6-8.0 Moderate 4.5 or 8.0 Severe Millet 5.0-6.5 Nil 4.5-4.9 or 6.6-7.0 Minor 4.0-4.4 or 7.1-8.0 Moderate <4.0 or >8.0 Severe Rice (swamp) 4.5-7.0 Nil 3.0-4.4 or 7.1-7.5 Minor 7.6-8.0 Moderate <3.0 or >8.0 Severe Cotton 5.0-6.O Nil 4.5-4.9 or 6.1-6.5 Minor 4.0-4.4 or 6.6-7.5 Moderate <4.0 or >7.5 Severe Groundnuts 5.5-6.5 Mil 5.0-5.4 or 6.6-7.0 Minor 4.5-4.9 or 7.1-7.5 Moderate C4.5 or >7.5 Severe

2. Phosphorus There are not sufficient data on phosphorus availability, as determined by the Truog method, to make generalisations related to land systems. Phosphorus availability is related to pH and the limitations due to phosphorus availability were assessed as in Table 9.

A3 TABLE 8 Limitations due to phosphorus availability related to pH

pH Limitation

6.5-7.5 Nil 6.0-6.49 7.51-8.O Minor 5.0-5.9 8.1 -8.5 Moderate <5.0 Severe

3. Potassium The assessment of different levels of potassium in terms of plant needs is given below.

a) At pH>4.5 0.15 meq/lOO gm soil Luxury 0.1-0.15 " " " " Adequate <0.1 " " " " Deficient

b) At pH <4.5 the assessment is based on the potassium saturation percentage: where this is >2, levels are thought to be adequate, where it is ^2 levels are thought to be deficient.

4. Cation exchange capacity (CEC) Little is known about critical levels of CEC with respect to retention of potassium, calcium and magnesium cations under leaching conditions of intensive rainfall. Adetunji (1974) related CEC levels to the ability of a soil to withstand intensive cultivation. These levels are given below, based on his classification.

CEC ^8 meq/100 gm soil Suitable for intensive agriculture 2-7.9 " " " " Requires a high ratio of fallow or grass legume pasture to crops <2 " " " " Unsuitable for production of annual arable rainfed crops

A9 Soil limitation categories (SLC)

Limitations due to any of the factors discussed above may occur in soils in a variety of combinations. For example, reference to Tables 1, 5 and 6 shows that a soil of 25-50 cm depth with a high percentage of coarse material would have two severe limitations to the growth of any of the crops considered whilst a soil of similar depth and no coarse material is considered to have only one severe limitation (due to depth) for cotton and only a moderate limitation for maize or millet or sorghum.

Various combinations of nil, minor, moderate and severe limitations have been used to define five soil limitation categories (Table 9), based on the limitations due only to the physical characteristics.

No attempt has been made to consider the interrelationships of the physical and chemical soil characteristics. A soil is placed in a soil limitation category on the basis of its physical characteristics; any limitation due to chemical characteristics is noted separately.

As the soil characteristics are interpreted differently for different crops, it follows that the limitation category is specific to a given crop.

Soil limitations in relation to crop yields

An attempt was made to check whether soil limitations are related to actual crop production. The yields of a variety of crops grown on State demonstration plots were collected. However, differences in yield due to climatic or management factors were so great that it was not possible to correlate differences in yields with soil differences. In other experiments done in the project area information about the soils is generally inadequate.

The soil limitation categories must, therefore, be considered tentative but, in so far as they have been defined after discussion with a wide range of research workers and practising agriculturalists in Nigeria, they can be considered as a consensus opinion of the limitations imposed by soil 'characteristics to the growth of crops. A10 TABLE 9a Nature and degree of limitations shown in Table 9b

Degree of limitation Nature of limitation Nil Minor Moderate Severe

Depth (D) 0 not used D D Drainage (W) 0 w W W Texture (T) 0 t Ta, Tb* not used Coarse material (C) 0 c C £

*Ta or Tb are treated as a moderate limitation for Categories 1 and 2 only. For Categories 3, 4 and 5 they are treated as a minor limitation

TABLE 9b Combinations of the degrees of limitation acceptable in each soil limitation category for maize, millet, sorghum, groundnut and cotton

Soil limitation category

1 2 3 4 5

0 w D Dw DW + or - c, t, or Ta t wt Dt DWC + or - t, or Ta c wTa DTa DWC + or - t, or Ta wt* wtc/ Dwt/ DWC tc* wTac DwTa DC + or - t, Ta or Tb wc Dtc DC + or - t, Ta, or Tb W DTac D + or - any combination Wt Dc WC + or - t, or Ta WTa wC WC + or - t, or Ta tc wtC/ WC + or - t, or Ta tc wTaC TbC TaC wtC** TbC Ta WTac** Tb Wc C WC W WTa Wtc Wc tc TaC £

*These combinations permitted in this category for sorghum and millet only /For maize if code is ¥3(w) for this combination the drainage becomes a moderate limitation (¥) For sorghum if code is ¥3(w) f or, this combination the drainage becomes a moderate limitation (¥) **For cotton if code is V3(¥) for this combination the drainage becomes a severe limitation (¥) Ta Texture limitation applic able to cotton only

All Soil limitation categories in relation to land systems

The land systems shown on Separate Map 1 and described in Land Resource Report 20 (Bennett et al., 1978) are defined in terms of their landform, soil and vegetation.

For the purpose of assessing the value of each land system for cropping, the soil series (op. cit.) are first grouped according to depth, drainage, texture of the surface 50 cm and amount of coarse material; the groups are represented by codes as discussed earlier in this appendix.

An estimate is then made of the percentage of each land system occupied by soils of a given code. This is achieved by measuring on representative air photographs the area of land facets in every land system, except for these facets occupying less than a mean 18% (11.25% range). These facets together usually comprise more than 70% of a land system.

The soil pits which have been described on each facet are each given a code. The number of pits of a given code, as a percentage of the total number of pits on the facet, is taken as the percentage of the facet occupied by soils of that code. As these percentages are only indicative they are given in percentage classes of lO, 10-29, 30-50 and/or 30-59 and 60. The facets for which there are a large number of described soil pits will clearly have a more reliable code than facets with only one or two described pits.

Soils of a given code can be assigned to one of the five limitation categories defined in the previous section. A land system can, therefore, be defined in terms of percentages of various limitation categories by summing the relative proportions of facets.

For example, in Land System 18 (Table 10) the soils are in three groups. 30-59% of the land system has soils coded as D W T + C i.e. soils of 50-100 cm depth, well drained, coarse-textured surface horizons and 20-40% coarse material scattered throughout the soil profile. Shallow depth, free drainage and coarse texture are not limiting to the growth of millet, but the coarse material is considered as a minor limitation (see Tables 1, 3, 4 and 6). As the soil has only one minor physical limitation for millet, it is classed as limitation category 2 (see Table 9). In the case of A12 maize, the texture and the coarse material are both considered as minor limitations and by reference to Table 9 the soil is placed in soil limitation category 3.

TABLE lO Percentage of soils of various codes in Land System 18 and their relationship to soil limitation categories for certain crops

Soil code % of land Soil limitation category by crop Land system in system D W T C each code Maize Millet Sorghum Groundnut Cotton ...... 18 2 0 3+ 2 30-59 3 2 2 2 4 2 0 3+ 5 10-29 3 3 3 3 5 1 o 3+ 0 10-29 2 1 2 1 3 ...

Ranking of land systems

Land systems with the highest proportion of SLC 1 land have least limitations to the growth of a given crop. If two land systems have a high proportion of SLC 1 land, the one in which the remaining land is SLC 2 or 3 can be considered to be better than the one in which the remaining land is SLC 4 or 5.

A land system is considered especially favourable for the production of a crop if it has one of the following combinations of SLCs:

- at least 30-50% SLC 1 + any other SLC -> 60% SLC 2 - at least 30-50% SLC 2 + 10-29% SLC 1 - 30-59% SLC 2 + 10-29% SLC 3 - 10-29% SLC 1 + 10-29% SLC 2 + 10-29% SLC 3

Land systems with these combinations of soil limitation categories are shown on the legend of Separate Map 3. The legend of Separate Map 1 shows the percentages of the soil limitation categories in all the land systems in the area.

A13 Appendix 2 Assessment of erosion hazard

Erosion hazard has been assessed on the assumption that open-field clean cultivation techniques are to be used. Three main factors affect the degree of erosion to which an area is subject; the length and steepness of slope, the duration and intensity of rainfall and the infiltration characteristics of the soil.

Slope is taken as the most important variable in the assessment of erosion hazard. Four slope categories have been defined.

a) <1% (0.5°) these areas should not require mechanical protection works. The use of grass strips and contour ploughing should give adequate erosion control. b) 1-3% (0.6-1.75 ) These areas require normal mechanical protection works which include graded terraces and grassed protected waterways. Contour ploughing and strip cropping should be practised. Mean contour intervals should range between 46 and 88 m. c) 3.1-10% (1.76-6°) These areas require normal mechanical protection works organised on a catchment rather than an individual farm basis. They should not be used for large-scale mechanised farming schemes based on the rainfed crops considered in this report: the short, inter-terrace intervals and complexity of the layout mean that economic running of machinery is extremely difficult and is only worthwhile for high-value crops such as tobacco. d) >10% (6°) These areas have a high erosion hazard and intensive conservation measures such as bench terracing are required. They are more suited to tree crops than arable crops. Total protection is recommended.

Data are not available for' the project area on the duration and intensity of rainfall, but the start of the rainy season is characterised by short, heavy, violent rainstorms, having a high erosive power. It was not possible to subdivide the area according to the rainfall pattern.

A15 Many of the silty or fine sandy surface soils in the Kano Plains rapidly form a capping at the beginning of the rainy period which reduces infiltration: trampling by cattle may add to the problem. No quantitative measurements have been made so there has been no attempt to rank the soils according to their infiltration characteristics.

A16 Appendix 3 Minimum size of economic farm units

It has been suggested by Mansfield (in prep.) that to be attractive a farm should produce a minimum net income of i* 740 per annum, the lowest institutional wage in 1976. A model has been produced using, where possible, 'hard* data collected by the socio-economic branch of I.A.R., Samaru, to estimate the minimum sized holding required to achieve this level of income, using prices current at the time.

In the model the following assumptions have been made:

1. The farming systems are based on annual rainfed crops only

2. Apart from his food crop area, the farmer puts down the remainder of his farm to the cash crop which will bring him in the highest net return per unit area

3. The crops considered are maize, sorghum, groundnut, cotton and cowpeas

4. The cash crop chosen should be the one with the least environmental limitations for the area (see crop option data)

5. The farmer uses improved practices such as early planting improved seed, fertiliser, good weeding and use of insecticides (as a dust or sprayed on the crop) where appropriate. Yields are based on mean yields obtained by farmers carrying out these practices in the field as measured in surveyed villages

6. An average farmer has 2.1 adult equivalents of family labour. The family spends a mean of 4 hrs per day working 6 days a week, giving an annual labour potential of 2 621 man hours or a monthly potential of 218 man hours

7. When using oxen the farmer only has a pair of work oxen which he feeds entirely on the farm all the year round and he grows 4 acres of planted pasture, in addition to arable crops

Ä17 8. In practice, the farmer will never put down all his non-food-

crop area to one cash crop; thereforefany combination of crops which he may grow will involve a larger area than obtained from the model in order to attain the same minimum net return

Three types of farm are considered:

1. Using hand labour only

2. Using hand labour and oxen (for primary cultivations)

3. Using hand labour, oxen and herbiliser/herbicides to control interplant weeds

When dealing with labour inputs, two approaches have been used. The first relates the total man-hour requirements for growing and harvesting the crop to the labour potential of the farmer over the same period of time in order to decide whether hired labour is required. The second takes into account monthly family labour bottle-necks, using cumulative net returns per month.

Farm sizes calculated using the model are shown in Table 1 for systems having no fallow and 1/3 fallow for the three systems mentioned and the range of cash crops considered.

A18 TABLE 1 The minimum size of farm unit required to produce an annual net income of K 740 for different types of farm and range of cash crops

No fallow 1/3 Fallow Selected Farm type cash crop (a) (b) (a) (b) ac ha ac ha ac ha ac ha

Hand labour only Maize 14.5 5.9 14.6 5.9 21.7 8.8 21.9 8.9 Sorghum 68.4 27.7 72.9 29.5 102.6 41.6 109.4 44.3 Cotton 9.2 3.7 9.3 3.8 13.8 5.6 14.0 5.7 Groundnut 9.2 3.7 10.1 4.1 13.8 5.6 15.2 6.2 Cowpea 8.6 3.5 8.5 3.4 12.9 5.2 12.7 5.1

Hand labour Maize 16.4 6.6 17.1 6.9 17.8 7.2 18.9 7.7 & oxen Sorghum 42.9 17.4 36.9 14.9 57.5 23.3 48.5 19.6 Cotton 14.O 5.7 14.0 5.7 14.1 5.7 14.1 5.7 Groundnut 14.O 5.7 14.3 5.8 14.1 5.7 14.5 5.9 Cowpea 13.2 5.3 13.2 5.3 17.5 7.1 17.5 7.1

Hand labour Maize 16.1 6.5 N/A 17.3 7.O N/A n & oxen Sorghum 38.0 15.4 50.0 20.3 II

M & herbiliser Cotton 14.0 5.7 14.1 5.7 tl

it Groundnut 14.0 5.7 14.1 5.7 II n Cowpea 12.9 5.2 17.O 6.9 II

(a) Area required to earn target income, assuming no monthly family labour constraint (b) Area required to earn target income, allowing for monthly family labour constraint N/A Data not available

Bas 70171 /11567/12 700 7/79 P A19 Publications of the Land Resources Development Centre

These publications have a restricted distribution and are not available to booksellers. The Centre makes a report on each completed project. The report is published as a Land Resource Study or Technical Bulletin only with the consent of the government concerned.

LAND RESOURCE STUDY (ISSN 0305-6554)

*1 SPOONER R J & JENKIN R N (1966) The development of the Lower Mgeta River area of the United Republic of Tanzania (0 902409 75 l).

*2 BAWDEN M G & TULEY P (1966) The land resources of Southern Sardauna and Southern Adamawa Provinces, Northern Nigeria (O 902409 74 3)•

*3 BAWDEN M G & CARROLL D M (1968) The land resources of Lesotho (0 902409 73 5)•

4 JENKIN R N & POALE M A (1968) An investigation of the coconut growing potential of Christmas Island (0 902409 71 9).

5 BLAIR RAINS A & McKAY A D (1968) The Northern Statelands, Botswana (0 902409 70 0).

6 HILL I D (1969) An assessment of the possibilities of oil palm cultivation in Western Division, The Gambia (O 902409 01 8).

7 MITCHELL A J B (1976) The irrigation potential of soils along the main rivers of eastern Botswana: a reconnaissance assessment (0 902409 52 2).

8 VERBOOM W C & BRUNT M A (l970) An ecological survey of West ern Province, Zambia, with special reference to fodder resources. Volume 1, The environment (O 902409 68 9). Volume 2, The grasslands and their development (0 902409 69 7).

*9 AITCHISON P J, BAWDEN M G, CARROLL D M, GLOVER P E, KLINKENBERG K, LEEUW P N de & TULEY P (1972) The land resources of North East Nigeria. Volume 1, The environment (O 903359 06 5).

* Out of print »9 AITCHISON P J & GLOVER P E (l970) The land resources of North East Nigeria. Volume 2, Tsetse and trypanosomiasis (O 902409 02 6).

*9 BAWDEN M G, CARROLL D M & TULEY P (1972) The land resources of North East Nigeria. Volume 3, The land systems (O 902409 08 5).

*9 LEEUW P N de, LESSLIE A & TULEY P (1972) The land resources of North East Nigeria. Volume 4, Present and potential land use (O 903359 H l)•

» *9 TULEY P ed. (1972) The land resources of North East Nigeria. Volume 5, Appendixes and tables (0 902409 09 3).

10 JOHNSON M S (l97l) New Hebrides Condominium. Erromango forest inventory (0 903359 01 4).

»11 BLAIR RAINS A & YALALA M (1972) The Central and Southern State Lands, Botswana (O 903359 04 9).

12 BERRY M J & HOWARD W J (1973) Fiji forest inventory. Volume 1, The environment äjid fofeslriypes ^0 902409 13 lj • Volume 2, Catchment groups of Viti Levu and Kandavu (O 902409 14 X). Volume 3, Catchment groups of Vanua Levu (O 902409 15 8).

13 JOHNSON M S & CHAPFEY D R (1973) A forest inventory of part of the Mountain Pine Ridge, Belize (0 902409 67 0).

14 JOHNSON M S & CHAPFEY D R (1973) An inventory of the Chiquibul Forest . Reserve, Belize (O 902409 17 4).

15 JOHNSON M S & CHAFFEY D R (1974) An inventory of the southern coastal -plain pine forests, Belize (O 902409 22 O).

16 HENRY P W T (1974) Pine forests of the Bahamas (0 902409 18 2).

17 BERRY M J, LAURENCE J F, MAKIN M J & WADDAMS A E (1974) Development potential of the Nawalparasi area of Nepal (0 902409 16 6).

» Out of print 18 HANSELL J R P & WALL J R D (1974-7) Land resources of the British Solomon Islands Protectorate. Volume 1, Introduction and recommendations (0 902409 59 X). Volume 2, Guadalcanal and the Florida Islands (O 902409 20 4). Volume 3, Malaita and Ulawa (0 902409 21 2). Volume 4, New Georgia Group and the Russell Islands (O 902409 37 9)• Volume 5, Santa Isabel (0 902409 60 3). Volume 6, Choiseul and the Shortland Islands (O 902409 61 l). Volume 7» San Cristobal and adjacent island» (O 902409 62 X). Volume 8, Outer Islands (O 902409 63 8).

19 MANSFIELD J E, BENNETT J G, KING R B, LANG D M & LAWTON R M (1975/6) Land resources of the Northern and Luapula Provinces, Zambia - a reconnaissance assessment. Volume 1, Introduction, conclusions and recommendations (0 902409 33 6). Volume 2, Current land use (O 902409 34 4). Volume 3» Land capability and development potential (O 902409 35 2). Volume 4i The biophysical environment (0 902409 41 7)« Volume 5» Social and economic factors (O 902409 42 5)« Volume 6, The land systems (0 902409 51 4).

20 THOMAS P, ACRES B D, BOWER R P, BURROUGH P A, FOLLAND C J, KALSI M S & WRIGHT P S (1975) The soils of Sabah. Volume 1, Classification and description (O 902409 26 3). Volume 2, Sandakan and Kinabatangan Districts (O 902409 27 l). Volume 3, Western parts of Tawau and Lahad Datu Districts (O 902409 28 6). Volume 4, South-western Districts (O 902409 29 8). Volume 5» References and appendixes (O 902409 30 l).

21 MAKIN M J, KINGHAM T J, WADDAMS A E, BIRCHALL C J & TAMENE TEFERRA (1975) Development prospects in the southern Rift Valley, Ethiopia (O 902409 32 8).

22 DUNSMORE J R, BLAIR RAINS A, LOWE G N, MOFFAT D J, ANDERSON I P & WILLIAMS J B (1976) The agricultural development of The Gambia; an agricultural, environmental and socioeconomic analysis (0 902409 64 6).

23 MURDOCH G, OJO-ATERE J, COLBORNE G, OLOMU E I & ODUGBESAN E M (1976) Soils - of the Western State Savanna in Nigeria. Volume 1, The environment (0 902409 49 2). Volume 2, De scriptions of Basement complex soil series (O 902409 50 6). Volume 3, Atlas of sample blocks mapped during the survey (O 902409 47 6). 24 JENKIN R N, ROSE ONES R, DUNSMORE J R, WALKER S H, BIRCHALL C J & BRIGGS J S (1976) The agricultural development potential of the Belize Valley, Belize (O 902409 39 5)•

25 THOMAS P, LO F K C & HEPBURN A J (1976) Land capability classification of Sabah. Volume 1, The Tawau Residency. Volume 2, The Sandakan Residency. Volume 3, The West Coast and Kudat Residencies. Volume 4» The Interior Residency and Labuan.

26 MAKIN M J, KINGHAM T J, WADDAMS A E, BIRCHALL C J & EAVIS B W (1976) Prospects for irrigation development around Lake Zwai, Ethiopia (0 902409 45 X).

27 LITTLE B G, BUCKLEY D K, CANT R, HENRY P W T, JEPFERISS A, MATHER J D, STARK J & YOUNG R N (l977) Land resources of the Bahamas: a summary (O 902409 58 l).

28 JENKIN R Nf HOWARD W J, THOMAS P, ABELL T M B & DEANE E C (1977) Forestry development prospects in the Imatong Central Forest Reserve, southern Sudan. Volume 1, Summary (0 902409 65 4). Volume 2, Main report (0 902409 66 2).

29 LAND RESOURCES DEVELOPMENT CENTRE CENTRAL NIGERIA PROJECT TEAM (edf.I D HILL & J R D WALL (l978)Land resources of central Nigeria: agricultural development possibilities. Volume 1A, Bauchi Plains, Executive Summary (O 902409 80 8). Volume IB, Bauchi Plains (O 902409 81 6). Volume 2A, Jos Plateau, Executive Summary (O 902409 82 4). Volume 2B, Jos Plateau (O 902409 83 2). Volume 3A, Jema'a Platform, Executive Summary (O 902409 84 0). Volume 3B, Jema'a Platform (O 902409 85 9). Volume 4A, Benue Valley, Executive Summary (O 902409 86 7). Volume 4B, Benue Valley (O 902409 87 5). Volume 5A, Kaduna Plains, Executive Summary (O 902409 88 3). Volume 5B, Kaduna Plains (O 902409 89 l), Volume 6A, Kano Plains, Executive Summary (0 902409 90 5). Volume 6B, Kano Plains (0 902409 91 3). Volume 7t An atlas of resource maps (O 902409 92 l)

TECHNICAL BULLETINS (ISSN 0309 - 6416)

1 CARROLL D M & BASCOMB C L (1967) Notes on the soils of Lesotho (O 902409 53 0). *2 PIGGOTT C J (1968) A soil survey of Seychelles (O 902409 00 X).

3 WILLIAMS J B (1978) Soil water investigations in The Gambia (O 902409 79 4).

4 WALL J R D, HANSELL J R P, CATT J A, ORMEROD E C, VARLEY J A & WEBB I S (1979) The soils of the Solomon Islands (O 902409 93 X) .

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LAND RESOURCE BIBLIOGRAPHIES (ISSN 0309 - 1643)

1 POSNETT N W & REILLY P M comp. (l97l) Bahamas (0 903359 05 7).

2 POSNETT N W, REILLY P M & WHITFIELD P comp. (l97l) Nigeria. Volume 1 (0 903359 07 3). Volume 2 (0 903359 08.l). Volume 3 (0 903359 09 X) .

3 POSNETT N W & REILLY P M comp. (1973) Belize (British Honduras) (0 902409 10 7).

4 POSNETT N W & REILLY P H comp. (1973) Fiji (O 902409 11 5).

5 GREENWAY M E, POSNETT N W & REJLLY P M comp. (1974) New Hebrides and New Caledonia (0 902409 12 3).

6 REILLY PM comp. (1974) Nepal (O 902409 19 08).

7 POSNETT N W & REILLY P M comp. (1975) Solomon Islands (0 902409 24 7).

8 REILLY P M comp. (1976) Sabah, Malaysia (O 902409 36 0).

9 POSNETT N W & REILLY P M comp. (1977) Zambia (0 902409 43 3).

10 REILLY P M comp. (1978) Ethiopia (O OO2409 76 X).

11 REILLY P M comp. (1978) Yemen Arab Republic (O 902409 77 8)

12 POSNETT N W & REILLY P M comp. (1978) Dominica (0 902409 78 6).

* Out of print