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Adapting agriculture in Africa to climate change
by
Jens B. AuneDepartment of International Environment and Development
StudiesNoragric
Norwegian University of Life Sciences
Soil organic matter - a key to adaptation to climate change
• Increase soil water holding capacity
• Improves infiltration of water• Reduce soil temperatures• Improves soils ability to store
nutrients• Aeration• Provides media for soil micro-
organsims
Message from World Congress of Conservation Agriculture (2009) in India:
• 2,5 tonn of organic matter should be recycled every year
Why is it difficult to recycle enough organic materials?
• Biomass production is low, often below 1 t/ha• The biomass production is used for other
purposes (fodder, builing materials). Low recycling of soil organic matter.
• Plouging reduces the soil organic matter
How to increase biomass production?
• early sowing• good quality seeds• correct spacing • appropriate varieties• water harvesting/irrigation• Integrated plant protection• Integrated Plant Nutrition Management• Trees on farm land
Seed priming:• Soaking of seed for 8
hours in water• Facilitates crop
establishment • Yield increase 20-30
%• Feasible in pearl
millet, sorghum, cowpea, groundnuts, maize and sesam
Control Priming Priming+
fertilizer (0.3g)
Yields kg/ha 328 435 556
Gross margin (US$/ha) 28.4 57.3 80.0
Value Cost Ratio - - 6.15
Effect of seed priming and micro-dosing on sorghum yields and economic returnAverage for 53 farmers in Kordofan State, Sudan (Dryland Coordination Group)
Seed priming and micro-dosing in Mali.
Non -primed PrimedPrimed + micro-fertilsation
Photo A. Coulibaly
Treatment Yield kg/ha
Control 320
Crop residues 700
N + P fertilizer 900
Crop residues + N P fertilizer 1510
Effect of crop residues and fertiliser on pearl millet grain yields Average of 9 years experiment, Niamey, ICRISAT
Yamoha , Bationo 2002
Treatment Yield kg/ha Straw yield
Control 320 1390
Crop residues 700 2560
N + P fertilizer 900 3060
Crop residues + N P fertilizer
1510 5400
Effect of crop residues and fertiliser on millet grain and straw yields Average of 9 years experiment, Niamey, ICRISAT
Yamoha , Bationo 2002
Effect on fertilisation and crop residue management on pearl millet yield, Niamey, 13 years experiment Source: Bationo and Buerkert 2002
Treatment Organic matter g/kg
Control 1,7
Crop residues 2,1
N + P fertilizer 2,0
Crop residues + N P fertilizer
3,3
Changes in soil organic carbon in top-soil after 13 years of different soil management
Breaking the vicisous cercle low yield and decling soil organic matter content
• Ensure good agronomy• Use micro-dosing of fertiliser and seed
priming• Use mulch, particularly in drought prone areas• Minimise ploughing
Permanent soil cover in conservation agriculture
How to retain mulch in dryland is a challenge
• Increase biomass • Increase fodder production• Demonstrate Integrated Plant Nutrition
Management and conservation agriculture• Development of other types of renewable
energy• Improved grazing management• Build local institution for land-use management
Integration of trees into the farmland
Source: Chris Reij
‘Hypothesis of Hope’ Schematic Framework. ICRISAT 2009A
vera
ge
Cro
p Y
ield
s
Low input Practices
+Current Climate
Low input Practices
+ Climate Change
Improved Practices
+Climate Change
Improved practices
+Improved
germplasm+
Current climate
1 2 3 4 5Management and Climate Scenarios
Current Climate Yield Gap
Improved practices
+Adapted
germplasm+
Climate change
Yield Gap 1
Yield Gap 2