1 FARMER MANAGED RESEARCH TO ASSESS LEGUME INTERCROPPING IN CONSERVATION AGRICULTURE SYSTEMS IN RURAL ZIMBABWE BY MICHAEL SALOMONS A Thesis Submitted to the Faculty of Graduate Studies of The University of Manitoba in partial fulfilment of the degree of MASTER OF SCIENCE Department of Plant Science University of Manitoba Winnipeg, Manitoba Copyright © 2018 by Michael Salomons 2 ACKNOWLEDGEMENTS To Dr. Martin Entz and his team for their invaluable assistance in planning, conducting, and analyzing the work leading to this thesis; To the office staff at the Department of Plant Sciences for their help with the practicalities of the thesis process; And finally to Maguy, Lucas and Caleb – for giving me the time and space needed to work on and complete this thesis; 3 TABLE OF CONTENTS Acknowledgements ..................................................................................................................... 2 Table of Contents ......................................................................................................................... 3 List of Tables ................................................................................................................................. 5 List of Figures ............................................................................................................................... 6 Abstract.......................................................................................................................................... 7 1. Introduction .............................................................................................................................. 8 2. Literature Review ................................................................................................................... 12 2.1 Conservation Agriculture .......................................................................................... 12 2.2 Intercropping ............................................................................................................... 17 2.2.1 Sustainability Impacts of Intercropping ................................................................ 19 2.2.2 Productivity and Profitability Impacts of Intercropping .................................... 21 2.2.3 Impacts of Intercropping on Equality .................................................................... 24 2.2.4 Resilience Impacts of Intercropping ....................................................................... 25 2.2.5 Food Security Impacts of Intercropping ................................................................ 26 2.2.6 Challenges with Intercrops ...................................................................................... 26 2.3 Integrating Conservation Agriculture and Intercropping .................................... 27 2.4 Intercropping Species for this Study ........................................................................ 29 2.4.1 Cereal Crop: Maize (Zea mays (L.)) .................................................................. 29 2.4.2 Legume Crops ...................................................................................................... 30 2.4.2.1 Cowpea (Vigna unguiculata (L.) Walp.) ....................................................... 31 2.4.2.2 Lablab (Lablab purpureus (L.) Sweet) ........................................................... 33 2.4.2.3 Pigeon pea (Cajanus cajan (L.) Millsp.) ......................................................... 35 2.5 Farmer Managed Research ........................................................................................ 37 3. Intercropping in Conservation Agriculture Systems for Smallholders in Zimbabwe – effects on maize yields and total biomass production.......................................................... 39 3.1 Introduction ...................................................................................................................... 39 3.2 Materials and Methods ................................................................................................... 45 4 3.2.1 Study Sites .................................................................................................................. 45 3.2.2 Experimental Design ................................................................................................ 46 3.2.4 Data Analysis ............................................................................................................. 53 3.3 Results and discussion .................................................................................................... 54 3.3.1 Weather ................................................................................................................. 54 3.3.2 Maize Yields .......................................................................................................... 58 3.3.3 Total Biomass Produced...................................................................................... 64 3.4 Conclusions ....................................................................................................................... 69 4.0 Economic and Food Security Impacts of Intercropping ................................................. 72 4.1 Introduction ................................................................................................................. 72 4.2 Materials & Methods ....................................................................................................... 76 4.2.1 Economics ............................................................................................................. 76 4.2.2 Nutrition ................................................................................................................ 78 4.3 Results and Discussion ............................................................................................... 81 4.3.1 Economics ............................................................................................................. 81 4.3.2 Nutrition ................................................................................................................ 86 4.4 Conclusions .................................................................................................................. 92 5. Final Discussion & Conclusions ........................................................................................... 94 5.1 History of Intercropping in Africa ........................................................................... 94 5.2 Challenges of Intercropping ...................................................................................... 98 5.3 Improving Agricultural Systems in Sub-Saharan Africa ......................................... 103 5.2.1 Future Research: What ........................................................................................... 105 5.2.2 Future Research: How ............................................................................................ 107 6.0 Literature Cited ............................................................................................................. 112 Appendix A: Experimental Design Information Sheet .................................................. 131 Appendix B ........................................................................................................................... 132 5 LIST OF TABLES Table 3.1: Experimental Treatments ........................................................................................ 48 Table 3.2: Agronomic information for the three study sites ................................................ 50 Table 3.3: Treatment means (n=2) and analysis of variance (ANOVA) for selected agronomic parameters from study sites in Zimbabwe ......................................................... 53 Table 3.2: Ratio of Intercrop Biomass to Maize Biomass (in %) at experimental sites ..... 66 Table 4.1: Grain Yield Increase from intercropping in mulched and un-mulched plots. 82 Table 4.2: Economic value (USD) of crops produced on a hypothetical 0.5 ha CA plot . 82 Table 4.3: Annual profit:loss calculations ............................................................................... 87 Table 4.4: Annual profit:loss calculations ............................................................................... 87 6 LIST OF FIGURES Figure 2.1: Jane Wajicko, from Murang’a County, Kenya ................................................... 14 Figure 2.2: Intercropping of maize and lablab bean ............................................................. 18 Figure 2.3 Cowpea (Vigna unguiculata) intercropped with Sorghum .............................. 20 Figure 2.4: Intercropped maize & pigeon pea, Kenya .......................................................... 23 Figure 2.5: Maize (Zea mays) ................................................................................................... 30 Figure 2.6. Cow pea (Vigna unguiculata) ............................................................................... 31 Figure 2.7: Lablab bean (Lablab purpureus) .......................................................................... 34 Figure 2.8: Pigeon Pea (Cajanus Cajun) .................................................................................. 35 Figure 3.1: Total CA Hectarage by ward in Zimbabwe in 2015 .......................................... 42 Figure 3.2: Zimbabwe Agro-Ecological Zones ....................................................................... 46 Figure 3.3: Hand hoe dug planting basins in a mulched CA field