Combating Soil Fertility Degradation in the Desert Margins

Combating Soil Fertility Degradation in the Desert Margins of Africa Problems, Progress and Partnerships A. Bationo

Why Focus on Soils in the desert margins of Africa Ø Low /declining/ unstable land productivity Ø Interactions with the other factors such as climate change, water quality, C sequestration Ø Limited returns to crop breeding Ø Lot of soil research initiatives. What is NEW?

Soil Degradation in Africa

Percentage decreases in soil fertility in farmers’ fields under continuous cultivation in the savanna zone of Nigeria Zones Ca Mg K p. H Sudan 21 32 25 4 Northern Guinea 19 27 33 4 Southern Guinea 46 51 50 10

Annual losses rates of soil organic carbon measured at farm level in WASAT Site Clay + Annual losses silt (%) (K) (%) Bambay 3 7 Saria (non eroded) 12 2 Saria eroded 19 6

Growth rate of millet 1979 -1994 Country Area Yield (%)/ yr Production/ hbt (%)/ yr Production (%)/ yr WA 4. 7 - 0. 4 4. 2 1. 2 Mali 5. 1 - 1. 0 4. 0 2. 3 Niger 3. 9 - 1. 0 2. 8 - 1. 3 Nigeria 7. 7 - 2. 3 5. 2 2. 2 B. F 3. 8 2. 0 5. 9 3. 0

Greater Yield Increase Due to Land Expansion than to Crop Improvement Potential Crops Area Yield Production Cassava 2. 6 0. 7 3. 3 Maize 0. 8 0. 2 1. 0 Yam 7. 2 0. 4 7. 6 Cowpea 7. 6 -1. 1 6. 5 Soybean -0. 1 4. 8 4. 7 Plantain 1. 9 0. 0 2. 0 Based on three-year average for 1988 -1990 and 1998 -2000. FAO database.

The Yield Gap From Station and On-farm Fields

N, P, K Application Versus Loss in Africa

Fertilizer Prices 1998/99 -- DAP Location USA (Kansas) Pakistan Bangladesh South Africa Central Ethiopia C. Kenya Malawi Uganda Price per ton ($) 260 283 286 348 350 415 470 550

Integrated Nutrient Benefits

Sources of Organic Matter Residues Oil palm Imperata Manure

Integrated Soil Fertility Management Strategy Integrated Pest Management Soil Conservation Water Management t r nt E n oi yp Resilient Germplasm /Fertilizer(org+Inorg) ISFM Ecosystem Services

Strategies ISFM Enabling policies ISFM Market/Seed/Fertilizer Farmer participation

Water use (WU), grain yield (GY) and water use efficiency (WUE) for millet in Niger Treatments SADORE DOSSO GY WUE - Fertilizers 460 1. 25 780 2. 04 +Fertilizers 1570 4. 14 1700 4. 25 Improved soil fertility enhances the water use efficiency of crops in the Sahel

Grain response to N levels at degraded and nondegraded sites

N and P use efficiency at Karabedji, Niger 1998 -2002

Farmers managed trials at Gaya, 2002 rainy season

Effect of P sources and placement on cowpea yield and P use efficiency (PUE) SSP: Single Superphosphate , 15 -15 -15: N 2 P 2 O 5 K 2 O compound fertilizer BC: Broadcast at 13 kg P/ha, HP: hill placed at 4 kg P/ha; PUE: P use efficiency kg yield/kg P applied

Farmers managed trials at Karabedji, 2002 rainy season

Millet grain yield response to P and manure applied at different rates, Banizoumbou, Niger, 2002 rainy season

Optimum combinations of Inorganic and Organic at Gaya and Karabedji, Niger, 2002.

Fertilizer equivalency of manure at Banizoumbou, Niger, 2002 cropping season

Cowpea grain yield response to P and manure applied at different rates and methods, Karabedji, Niger, 2002 rainy season

Long term effect of fertilizer, CR and soil physical management on pearl millet grain yield, Sadore, 1998 -2002

Partnerships

Networking } To exchange information and combine collective experience of professionals in the same field } To achieve economies of scale and efficiency by concentrating scarce human, financial and other resources on key national and regional problems } To minimize duplication } Provide increase bargaining power with external partners } Joint capacity building

African Network of the Soil Biology and Fertility Institute (Af. Net) • Established in 1988 • Single most important implementing agent of TSBF programme • Network of scientists collaborating with NGOs in Africa (120 from NARS, 70 from Universities) • Individual membership with 157 male scientists and 33 female scientists, very few Social Scientists

Af. Net Overall Goal To strengthen and sustain stakeholder capacity to generate, share and apply soil fertility management knowledge and skills to contribute to the welfare of farming communities

Af. Net

Network Experiments } Key research themes of regional/ international importance (benchmarks and satellites) } Use of standard methods } Extrapolation of research results through DSS, GIS and modeling

Research topics addressed in the network trials in 2002/3 Ø Long-term Soil Fertility Management Ø Optimum Management of Low Quality Organic Resources Ø Optimum N and P Management in Legumecereal Rotations

Research topics… Ø Optimum Combination of Organic and Inorganic Nutrient Sources Ø Scaling up/ out soil fertility restoration technologies Ø Improving manure management Ø Farmer empowerment to combat land degradation

Research topics… Ø Below-ground biodiversity Ø Conservation tillage Ø Biological nitrogen fixation Ø Use of PR as a capital investment to replenish soil fertility

4 Koulikoro**, Fana** Niono (ICRISAT, IER) 2 Farakou-Ba**, Kouare** (INERA) Sadore**, Banizoumbou** Karabedji**, Gaya**, Gobery** (ICRISAT) 8 1 IRAD, University of Yaounde University of Kisangani 9 10 University of Abidjan-Cocody Lamto** Ndere dance Troupe Makerere university NARO 5 Kumasi** 7 6 11 Lome** Af. Net participating countries and research sites 3 12 Zaria** 17 Chitedze Egerton university, Nairobi university, KAR-KEFRI-ICRAF Mlingano, Sokoine university 16 1. 2. 3. 4. 5. 6. 7. 8. 9. Mali Nigeria Burkina Faso Cote D’Ivoire Ghana Togo Cameroon Congo (DR) 10. 11. 12. 13. 14. 15. 16. Uganda Kenya Tanzania Zambia Zimbabwe South Africa Madagascar 17. ** Established 2002 13 14 15 FOFIFA Misamfu Research Centre, Chilanga University of Zimbabwe University of Witwatersrand University of Fort Hare

The Way Forward } Restructuring Af. Net to be a cornerstone network in soil research for Africa } Strengthening Af. Net to pursue its role in process research on soil biology and fertility

The Way Forward… } Contributing towards the development of methodologies for scaling up and reaching out soil fertility restoration technologies } Building capacity of stakeholders through relevant research and training activities and information dissemination

Reaching the Millions? Best bet technologies Researc h ? ? Delivery Capacity building Scaling up, out, down? Missing links?