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 C

rop

Yiel

ds

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