1. Consortium for the improvement of agriculture- based livelihoods in Central Africa The potential of Integrated Soil Fertility Management for increasing cassava productivity in sub-Saharan Africa B Vanlauwe, P Pypers, N Sanginga TSBF-CIAT, Nairobi, Kenya

2. Consortium for the improvement of agriculture- based livelihoods in Central Africa Context of African agriculture

3. Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl LACK OF PRODUCTION FACTORS  High input prices (1 kg of NPK in East DR Congo costs 1.7 USD)  Recycling of organic residues, mainly manure (but very limited availability)  Limited labor availability (HIV-AIDS, drudgery, low appeal for young people, etc)  Relatively small farms on relatively old soils LACK OF AN ENABLING ENVIRONMENT  Lack of infrastructure, market organization  Civil strife  Climate change, etc, etc,… 1. Farming in SSA…

4. Continental scale 2. Variability!  Continental scale Soils in East and Central Africa Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

5. At the farm scale 2. Variability!  At the farm scale Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

6. At the farm scale 2. Variability!  At the farm scale Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

7. At the farm scale 2. Variability!  At the farm scale Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

8. 3. The opportunity…  Finally, fertilizer and inputs are back on the agenda! Statement in 1996 (Research Director, IITA): ‘You can’t include fertilizer in your work since farmers in SSA are not using fertilizer’  The African Fertilizer Summit declaration: ‘By 2015, increase fertilizer use from 8 to 50 kg fertilizer nutrients/ha’  The Alliance for a Green Revolution in Africa Uniquely African (K Annan): ‘Recognizing its great diversity of landscapes, soils, climates, and cultures…’

9. Consortium for the improvement of agriculture- based livelihoods in Central Africa Facts about cassava

10. 1.Cassava supports ± 25% of farming households in SSA (± 100 mill people) and is a major crop on ± 35% of all agricultural land (± 60 mill ha) Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

11. 2. Cassava production is increasing but mainly due to area expansion Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

12. 3. Cassava productivity is low in SSA Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

13. Nutrient uptake and removal - Macronutrients Y t/ha Plant Source kg/ha NPK 45Fresh rootsAmarasiri, 1975 6210164 Whole plant20232286 37Fresh rootsHoweler, 1985 6717101 Whole plant19831183 18Fresh rootsSittibusaya, Pers comm 32334 Whole plant951064 NPK ratio for roots: 5 : 1 :10 NPK ratio for whole plants:7 : 1 : 7 4. Cassava is exporting substantial amounts of nutrients (mainly K) but requires N and K to grow Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

14. Production (2004) (www.fao.org)  SSA:108 mill ton  LatAm: 35  Asia: 60  World:203 < 30% < 5% < 2% 5. Soil fertility management in cassava systems is very much under-researched in SSA relative to other regions

15. Consortium for the improvement of agriculture- based livelihoods in Central Africa Integrated Soil Fertility Mgt

16. ISFM… ParadigmRole of fertilizerRole of organic inputsExperiences 1960s/70s External Input Paradigm ‘1st Paradigm’ Use of fertilizer alone will improve and sustain yields Organic resources play a minimal role Limited success due to shortfalls 1980s Organic Input Paradigm Fertilizer plays a minimal role Organic resources are the main source of nutrients Limited adoption 1990s Sanchez’ ‘2 nd Paradigm’ Fertilizer use is essential to alleviate the main nutrient constraints Organic resources are the entry point and provide other functions besides nutrient release Difficulties to access organic resources 2000s Integrated Soil Fertility Management Fertilizer is a major entry point Proper management of crop residues On-going; several examples of good potential Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

17. ISFM… ‘The application of soil fertility management practices, and the knowledge to adapt these to local conditions, which maximize fertilizer and organic resource use efficiency and crop productivity. These practices necessarily include appropriate fertilizer and organic input management in combination with of improved germplasm’ Agronomic efficiency = [Increase in yield]/[Fertilizer nutrient applied] Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

18. Yield/ Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

19. Site-specific responses to fertilizer Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

20. Yield/ Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

21. Yield/ Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

22. Yield/ Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl ‘Quick approaches’ - Flyers - Demo kits - Focus on access - Etc Start scaling up today ‘Complex approaches’ - Farmer field schools - Extension expertise - Etc Medium term involvement

23. Consortium for the improvement of agriculture- based livelihoods in Central Africa ISFM and cassava

24. Cassava?? Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

25. STEP 1: Germplasm and fertilizer Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

26. STEP 1: Germplasm and fertilizer – WE KNOW… 1. Improved varieties (eg, CMD-resistant) are essential to obtain substantial yield increases; supply needs to match demand by a healthy crop local varietyimproved variety (Nsansi) Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

27. 2. Cassava responds to fertilizer without fertilizer with fertilizer (2 bags of NPK ha -1 ) STEP 1: Germplasm and fertilizer – WE KNOW… CIALCA trials in Sud-Kivu, DR Congo Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

28. Estimated production (kg fresh roots/ha) Extra costs for fertilizer application (USD/ha) Benefits from fertilizer application (USD/ha) Mar- ginal rate of return Manure at 5 t/ha (local practice) 2,500 - 15,000 -- Manure (5 t/ha) + NPK (100 kg/ha) 5,000 - 25,000 170300 -1,6001.8-9.4 CIALCA trials, Sud-Kivu, DR Congo STEP 1: Germplasm and fertilizer – WE KNOW… 2. Cassava responds to fertilizer but minimum benefits are needed to justify its usage Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

29. 3. Fertilizer management affects its use efficiency STEP 1: Germplasm and fertilizer – WE KNOW… Fertilizer recovery by maize Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

30. 1. Optimal application rates for specific soils and AEZs? (Current recommendations are based on info from Asia!) Economically optimal response STEP 1: Germplasm and fertilizer – DO WE KNOW? Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

31. 2. Best fertilizer type for specific soils? (Different soils have different nutrient supply capacities!) STEP 1: Germplasm and fertilizer – DO WE KNOW? 1. Optimal application rates for specific soils and AEZs? (Current recommendations are based on info from Asia!) Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

32. 2. Best fertilizer type for specific soils? (Different soils have different nutrient supply capacities!) 3. Appropriate management of fertilizer relative to land preparation (flat, ridges, mounds, etc) and placement (point-placed, broadcast, etc)? (Proper fertilizer management has been shown to affect its use efficiency by other crops) STEP 1: Germplasm and fertilizer – DO WE KNOW? 1. Optimal application rates for specific soils and AEZs? (Current recommendations are based on info from Asia!) Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

33. 2. Best fertilizer type for specific soils? (Different soils have different nutrient supply capacities!) 3. Appropriate management of fertilizer relative to land preparation (flat, ridges, mounds, etc) and placement (point-placed, broadcast, etc)? (Proper fertilizer management has been shown to affect is use efficiency by other crops) 4. Fertilizer application and tuber quality? (Cassava+, etc) STEP 1: Germplasm and fertilizer – DO WE KNOW? 1. Optimal application rates for specific soils and AEZs? (Current recommendations are based on info from Asia!) Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

34. STEP 2: Germpl/fert + OM mgt

35. STEP 2: Germpl/fert + OM mgt – WE KNOW… 1. Organic resources are best produced in-situ and with multiple purposes for farmers to be interested Dual purpose soybean in west Kenya Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

36. Cassava-groundnut intercropping in Bas-Congo, DRC Cassava-beans Intercropping In Sud-Kivu, DRC Cassava-cowpea intercropping in Bas-Congo, DRC STEP 3: Gpl/fert + OM mgt + Loc adapt – WE KNOW… 2. Cassava-based system are sufficiently flexible to integrate various grain legumes Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

37. CIALCA trials in Sud-Kivu, DRC STEP 3: Gpl/fert + OM mgt + Loc adapt – WE KNOW… 2. Cassava-based system are sufficiently flexible to integrate various grain legumes Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

38. control STEP 2: Germpl/fert + OM mgt – WE KNOW… 3. Organic resources contain nutrients that can benefit cassava but their contents are most often limited for commonly available resources Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

39. STEP 2: Germpl/fert + OM mgt – DO WE KNOW? 1. Do organic inputs provide other functions than substituting fertilizer nutrients that will favor cassava productivity (e.g., reduce P sorption, buffer Al toxicity)? Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

40. STEP 2: Germpl/fert + OM mgt – DO WE KNOW? 1. Do organic inputs provide other functions than substituting fertilizer nutrients that will favor cassava productivity (e.g., reduce P sorption, buffer Al toxicity)? 2. For maize, the combined application of organic matter and fertilizer can create added benefits that can lead to improved use efficiency of the fertilizer and/or the organic inputs for maize which is most responsive to N and P. What for cassava, which is more responsive to K? Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

41. STEP 2: Germpl/fert + OM mgt – DO WE KNOW? 1. Do organic inputs provide other functions than substituting fertilizer nutrients that will favor cassava productivity (e.g., reduce P sorption, buffer Al toxicity)? 2. For maize, the combined application of organic matter and fertilizer can create added benefits that can lead to improved use efficiency of the fertilizer and/or the organic inputs for maize which is most responsive to N and P. What for cassava, which is most responsive to K? 3. Which measures are needed to restore productivity on degraded, non-responsive sites? Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

42. STEP 2: Germpl/fert + OM mgt – DO WE KNOW? 1. Do organic inputs provide other functions than substituting fertilizer nutrients that will favor cassava productivity (e.g., reduce P sorption, buffer Al toxicity)? 2. For maize, the combined application of organic matter and fertilizer can create added benefits that can lead to improved use efficiency of the fertilizer and/or the organic inputs for maize which is most responsive to N and P. What for cassava, which is most responsive to K? 3. Which measures are needed to restore productivity on degraded, non-responsive sites? 4. Cassava leaves contain a lot of N; could a well- managed cassava crop be an entry point to boost overall system productivity? Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

43. STEP 3: Gpl/fert + OM mgt + Loc adapt Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

44. STEP 3: Gpl/fert + OM mgt + Loc adapt – WE KNOW… 1. Soil physical management for cassava production as a function of soil depth, slope, and moisture status Bas-CongoSud-Kivu Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

45. CIALCA trials in Bas-Congo, DRC STEP 3: Gpl/fert + OM mgt + Loc adapt – WE KNOW… 2. Responses to fertilizer are variable Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

46. STEP 3: Gpl/fert + OM mgt + Loc adapt – DO WE KNOW? Organic C measurements Farmer classLowMediumHigh Low57%33%10% Medium22%61%17% High18%34%48% 1. Local diagnosis of soil fertility status? (Farmers seem to have an idea but will this be sufficient as a basis for recommendations?) Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

47. 2. Fertilizer placement relative to rainfall and physical soil preparation (ridges, mounds, etc)? (Consider soils and roots for optimal recovery) STEP 3: Gpl/fert + OM mgt + Loc adapt – DO WE KNOW? 1.Local diagnosis of soil fertility status? (Farmers seem to have an idea but will this be sufficient as a basis for recommendations?) Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl

48. Consortium for the improvement of agriculture- based livelihoods in Central AfricaConclusions

49. Context Facts ISFMProgress Concl Context Facts ISFMProgress Concl 1. Are cassava-based systems amenable to ‘full’ ISFM?  Most likely yes (All steps are potentially relevant for cassava-based (All steps are potentially relevant for cassava-based systems, but substantial knowledge gaps exist) systems, but substantial knowledge gaps exist)

50. Context Facts ISFMProgress Concl. Context Facts ISFMProgress Concl. 2. Is cassava an entry point for soil fertility rehabilitation?  Leaves contain a lot of nutrients; ‘N-sparing’ effects have been demonstrated for crops following cassava have been demonstrated for crops following cassava (This would only be valid if the cassava itself is showing (This would only be valid if the cassava itself is showing a relatively high productivity) a relatively high productivity)  In agronomic terms, cassava allows intercropping of various other crops, including legumes various other crops, including legumes (These legumes could replenish the soil N stocks, improve the soil P status, etc) the soil P status, etc)  It is unsure whether cassava would be a good crop on non-responsive plots that are being rehabilitated on non-responsive plots that are being rehabilitated

51. Context Facts ISFMProgress Concl. Context Facts ISFMProgress Concl. 3. Are cassava-based systems ready to join the scaling up investments of AGRA?  Yes, for the germplasm component (Activities are on-going to disseminate germplasm) (Activities are on-going to disseminate germplasm)  Probably yes for the fertilizer component (Avoid applying fertilizer where it wouldn’t work) (Avoid applying fertilizer where it wouldn’t work)  Probably not for full ISFM dissemination (While knowledge on cassava-based systems is (While knowledge on cassava-based systems is generated, other AGRA investments will address issues generated, other AGRA investments will address issues related to availability of inputs, access to markets, etc) related to availability of inputs, access to markets, etc)

52. Bedankt! Merci beaucoup! Thanks! Asante sana!