Sustainable intensification of maize-bean production among smallholder farmers in western Kenya. John Achieng
1. Sustainable intensification of maize-
bean production among smallholder
farmers in western Kenya
Achieng, J.1, F. Kanampiu2, Y. Chauhan3, D. Rodriquez4
1Kenya Agricultural Research Institute
2CIMMYT, Nairobi, Kenya
3Agri-Sciences Queensland, Toowoomba, Australia
4The University of Queensland, Toowoomba, Australia
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2. Introduction & Background
• Maize is a major staple food in Kenya
• Often grown in association with beans
• About 80% of maize produced by smallholders
• Current yield: ‹1.0 t ha-1 against potential
of ≥ 3.5 t
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3. Justification
• Conv. tillage practices have degraded the soils
• Droughts and long dry-spells are regular
• Use of inorganic fertilizers is not common
• Demand for maize increases by 4% annually;
Food security is threatened
• Need to embrace Conservation Agriculture to
restore lost soil fertility
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4. Objectives
Long-term:
• To test resilient smallholder maize-bean farming
technologies based on CA principles
Short-term:
• To investigate the effects of minimal tillage and
residue retention on water use efficiency, SOM and
maize-bean yield
• To test the capacity of APSIM to model performance
of maize-beans system under CA practices
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5. Expected Output
• About 30% increase in yield due to
adoption of CA practices within a period
of about 10 years
• About 30% decrease in production risks
due to adoption of CA practices within a
period of about 10 years
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6. Materials & Methods
• Sites: 5
– two in Siaya: low potential zone
– two in Bungoma: medium potential zone
– One on-station: medium potential zone
• Participating farmers: 130; members of
farmers’ groups
• Type of research: Participatory and
farmer-managed
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7. Materials & Methods Cont
Treatments
1. Conventional practice
2. CA + non-inoculated beans
3. CA + inoculated beans
4. CA + desmodium
Varieties: Depended on site and season
Fertilizer: CA treatments = 80 kg N and 60 kg P/ha
Conventional = 40 kg N and 30 kg P/ha
Plot Size: 20m X 17m
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8. Materials & Methods Cont
A farmer showing group
members how to record
Weather data weather data and rainfall trend
that month
• Daily rainfall
• Daily Min & Max temp
• Daily Min & Max temp for 30 yrs
• Daily Radiation for 15 yrs
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9. Materials & Methods Cont.
• Soil Data
Soil sampled from 4 layers (up to
90cm), 3 times a season for:
• Gravimetric water determination
• Bulk Density determination
• Chemical analysis
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10. Materials & Methods Cont.
Scientist and technicians examining Tumaini Farmers’ Field School members
degraded Western Kenya soils discussing pros and cons of CA
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11. Materials & Methods Cont.
• Crop Data
– Maize crop sampled 3 times each season
for chemical analysis
– Maize & bean yield and related parameters
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12. Materials & Methods Cont.
Maize and beans grown under Maize and beans grown under
conventional practice, western Kenya CA practice, western Kenya
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13. Materials & Methods Cont.
Residue retained in a maize Desmodium grown as a cover crop in
crop in CA trial, western Kenya maize in CA trial, western Kenya
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14. Technology Dissemination
The District Commissioner being Provincial Administration staff attended the
field day. DCs and Chiefs are influential and
shown CA plots at Siaya Field Day respected
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15. Result : Water Use Efficiency
Treatment WUE WUE
(kg/mm/ha) (kg/mm/ha)
2010 LR Season 2011 LR Season
Conventional 8.5 8.0
CA + non-inoculated beans 10.8 11.9
CA + inoculated beans 9.5 9.9
CA + desmodium 9.8 9.9
Conventional practice gave lower WUE compared to CA
CA practices progressively increased WUE while conventional
practice progressively reduced the WUE
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16. Result: Crop Yield (2010 Season)
Treatment Beans Maize (kg/ha)
(kg/ha)
Conventional 355c 4,075
CA + non-inoculated beans 626b 4,650
CA + inoculated beans 927a 4,416
CA + desmodium 707ab 4,483
Mean 654 4,406
LSD (5%) 231 ns
Rhizobial inoculation increased bean yield
CA had no effect on maize yield
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17. Result 2011 Season: Crop Yield
Treatment Beans Maize
(kg/ha) (kg/ha)
Conventional 640a 2,810b
CA + non-inoculated beans 520ab 5,150a
CA + inoculated beans 390ab 4,330a
CA + desmodium 320bc 4,310a
Mean 468 4,150
LSD (5%) 240 989
Conventional practice gave highest bean yield
CA practices gave higher maize yield compared to conventional practice
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18. Suitability of APSIM
Predicted yield (kg/ha) 6000 1:1 line
R2=0.9
4500
3000
Beans
1500 Maize
0
0 1500 3000 4500 6000
Observed yield (kg/ha)
The slope of the regression between observed and predicted
yield is R2 = 0.9, indicating a high degree of accuracy 18
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19. Conclusions
Combination of minimal tillage and residue
retention:
– maximized soil water use and hence can be an
effective tool in mitigating effects of drought
and prolonged dry spells
– More than doubled maize yield; food security
among smallholders can be achieved in a short-
run
APSIM can model performance of maize-beans
system under CA practices
Farmers beginning to appreciate CA
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20. Challenges
o Competition for crop residues
o Lack of appropriate implements to be
used under very smallholder farms
o Ants that feed on residue
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21. Acknowledgments
o KARI: For facilitating the research
o CIMMYT: For technical backstopping
o ACIAR: For financial support
o Western Kenya farmers: For
implementation
o WCCA Organizing Committee: For
accepting the paper
o This esteemed audience for accepting to
listen to the presentation
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