Adapting agriculture in Africa to climate
change
by
Jens B. Aune
Department of International Environment and Development
Studies
Noragric
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 microorgansims
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
Effect of seed priming and micro-dosing on sorghum yields and
economic return
Average for 53 farmers in Kordofan State, Sudan (Dryland Coordination
Group)
Control
Priming
Priming +
fertilizer (0.3g)
Yields kg/ha
328
435
556
Gross margin (US$/ha)
28.4
57.3
80.0
-
-
6.15
Value Cost Ratio
Seed priming and micro-dosing in Mali.
Non -primed
Primed
Primed + micro-fertilsation
Photo A. Coulibaly
Effect of crop residues and fertiliser on pearl millet grain yields
Average of 9 years experiment, Niamey, ICRISAT
Treatment
Yield kg/ha
Control
320
Crop residues
700
N + P fertilizer
900
Crop residues + N P fertilizer
1510
Yamoha , Bationo 2002
Effect of crop residues and fertiliser on millet grain and straw yields
Average of 9 years experiment, Niamey, ICRISAT
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
Yamoha , Bationo 2002
Effect on fertilisation and crop residue management on pearl millet yield,
Niamey, 13 years experiment Source: Bationo and Buerkert 2002
Changes in soil organic carbon in top-soil after 13
years of different soil management
Treatment
Organic matter g/kg
Control
1,7
Crop residues
2,1
N + P fertilizer
2,0
Crop residues + N P
fertilizer
3,3
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 2009
Average Crop Yields
Current Climate Yield Gap
Yield Gap 2
Yield Gap 1
Low input
Practices
+
Current
Climate
1
Low input
Practices
+
Climate
Change
Improved
Practices
+
Climate
Change
Improved
practices
+
Adapted
germplasm
+
Climate
change
2
3
4
Management and Climate Scenarios
Improved
practices
+
Improved
germplasm
+
Current
climate
5