Presentation delivered at the CIALCA international conference 'Challenges and Opportunities to the agricultural intensification of the humid highland systems of sub-Saharan Africa'. Kigali, Rwanda, October 24-27 2011.

1. CIALCA interventions for productivity increase of cropping system components in the African Great Lakes zone CIALCA conference, Kigali 24 Oct 2011 P. Pypers 1 , W. Bimponda 2 , E. Birachi 3 , K. Bishikwabo 4 , G. Blomme 5 , S. Carpentier 6 , A. Gahigi 7 , S. Gaidashova 7 , J. Jefwa 1 , S. Kantengwa 4 , J.P. Kanyaruguru 8 , P. Lepoint 9 , J.P. Lodi-Lama 4 , M. Manzekele 2 , S. Mapatano 10 , R. Merckx 6 , T. Ndabamenye 7 , T. Ngoga 7 , J.J. Nitumfuidi 2 , C. Niyuhire 11 , J. Ntamwira 2 , E. Ouma 12 , J.M. Sanginga 4 , C. Sivirihauma 13 , R. Swennen 6 , P. van Asten 14 , B. Vanlauwe 1 , N. Vigheri 15 , and J.M. Walangululu 16

4. Major farming systems in SSA Cassava-based Banana-based + maize-based in Eastern Rwanda Smallholder production systems in Central Africa

5. Small farms (typically less than 0.5 ha per household), large families (5-10 children), inherently low soil fertility, mixed cropping systems (with grain legumes as most common intercrop), increasingly less fallow periods. Smallholder production systems in Central Africa

6. Poor soils with often low pH, deficient in N, P, K and Mg, and with low CEC Frequent low K concentrations in banana leaves, corresponding with yield losses In bananas… K deficiency Mg deficiency Smallholder production systems in Central Africa

7. Poor soils with often low pH, deficient in N, P, K and Mg, and with low CEC Severe P deficiency in fields grown with legumes (based on DRIS index of maize as test crop), followed by N deficiency, and K in poor soils. In legumes and maize… Smallholder production systems in Central Africa

8. Complex system of different production units (livestock and crops) A range of crops are grown in different small fields (usually a 1-10 ares) with varying management intensity and soil fertility level. Pig stable and ‘compostière’ next to the homestead Banana plantations near homestead Distant fields with sweet potato, cassava and legumes Rented distant fields, maize-legume based Example from Gitega, Burundi Smallholder production systems in Central Africa

9. Limited availability of manure and crop residues for soil fertility improvement Nyagatare, Eastern Rwanda Lurhala, Sud-Kivu, DR Congo Smallholder production systems in Central Africa

10. Constraints on financial and physical access to mineral fertilizer Seed and fertilizer “kiosque” in Luhihi, DR Congo Agrovet in Bukavu, DR Congo Smallholder production systems

11. Poor road infrastructure and market organisation limits income generation from agriculture and re-investment in soil fertility for food production Smallholder production systems in Central Africa

13. Integrated Soil Fertility Management (ISFM) to bridge yield gaps… A set of soil fertility management practices that necessarily include the use of fertilizer , organic inputs and improved germplasm combined with the knowledge on how to adapt these practices to local conditions , aiming at maximizing agronomic efficiency of the applied nutrients and improving crop productivity. All inputs need to be managed following sound agronomic principles Vanlauwe et al., 2010 Integrated Soil Fertility Management

14. Integrated Soil Fertility Management Yield/

15. Focus on agronomic efficiency: maximizing returns on investment by maximizing yield at a given nutrient application rate… (extra yield per unit of nutrients applied) ISFM Integrated Soil Fertility Management

16. Improved banana and legume germplasm Efficient use of mineral fertilizer Optimized organic matter management Targeting inputs & agronomic measures Integrated Soil Fertility Management Yield/

17. Soil fertility major issue on granite and quartzite soils (e.g. Butare) Crop management suboptimal -> room to improve crop densities Banana pests only a minor problem at low altitude (<1500m) sites Targeted crop improvement interventions after quantifying yield loss factors through boundary line analysis

20. Yield under low input: significant improvements are possible… Example for soybean yields in Kabamba, Sud-Kivu: some improved varieties give yields that are more than twice as high, relative to the control. System components: germplasm

21. Exotic, improved and local Musa germplasm evaluation at 18 sites across Rwanda, Burundi and DR Congo. An altitude effect was observed on bunch weight and crop cycle duration. e.g. time from planting to harvest for ‘Mpologoma’ (AAA-EA) was 20.5 months at Karongi (alt. 1,496 m) in Rwanda, and 35 months at Lurhala (alt. 1,981 m) in the DR Congo. System components: germplasm

22. Tolerance to biotic stresses in banana Mitigating the impact of biotic constraints to build resilient Musa production systems in Central and Eastern Africa ( Rony Swennen et al.) A brief overview of the main banana diseases and pests that threaten the region’s banana production. [Xanthomonas wilt, Fusarium wilt, Banana bunchy top disease, black leaf streak, nematodes and weevils] A wide range of integrated pest and disease management (IPM) technologies has been developed over the past years. High yielding exotic and improved varieties were introduced via the International Transit Centre (ITC), Leuven, Belgium and the first highland banana hybrids originating from IITA/NARO Uganda were tested across the region. These varieties combine higher resistance with higher yields. Rapid and healthy multiplication of banana planting material is key to a vigorous and healthy banana sector. Improved linkages between research, extension, the private sector, and policy makers from farm to regional level is required to improve the productivity and resilience of banana systems. System components: germplasm

24. Participatory evaluation and selection of varieties with farmer groups System components: germplasm

25. Musa germplasm participatory evaluation and selection of varieties with farmer groups IMPORTANT BANANA TRAITS Agronomic traits Sensory traits Plant height Appearance Bunch size Aroma Finger length Texture in hand Cycle Texture in the mouth Resistance to pests Taste System components: germplasm

26. Selection of varieties with traits important for soil fertility SB24 AND10 Varieties with high biomass yield and low N harvest index result in positive effects on a subsequent maize crop System components: germplasm

27. Performance of OPV maize varieties in Sud-Kivu, DR Congo Also improved cassava and maize varieties identified (intercropping with legumes) System components: germplasm

28. Performance of improved cassava varieties in Bas-Congo, DR Congo Local variety, severely affected by CMD Improved variety (Nsansi), resistant to CMD Also improved cassava and maize varieties identified (intercropping with legumes) System components: germplasm

29. Making new varieties available to farmers… The introduction of improved germplasm is closely linked with capacity building and organizational strengthening of farmer associations to facilitate multiplication and marketing of seed within their communities. Important …..seed multiplication requires linkages with markets and promotion. Farmers must be able to sell seed! System components: germplasm

30. Banana and plantain are slow-growing vegetatively propagated crops. They do not produce planting material readily. Tissue culture is one way of producing healthy planting material rapidly but it requires expensive laboratory equipment, electricity and technical skills. Macro-propagation is an alternative method for producing and rapidly multiplying healthy planting material that is cost effective, affordable and can be done in villages. System components: germplasm

31. The sheaths are removed individually in order to expose the buds at the v-end of each sheath. A clump of plantlets regenerated from bud sprouts. 16 to 30 plantlets are obtained in 10 to 18 weeks. Paring of sucker Plantlets detached from mother corm in germination chamber for acclimatization (1 to 2 months). Detached plantlets with no root is taken to root initiation chamber. Field planting is after acclimatization. The meristem is scarified and the corm is placed in treated sawdust in the germination chamber. Corm in germination chamber, under 50% shade structure. Regular watering is required. The sawdust is removed to expose the shoot bases. The shoots are cut above the collar and the meristem excised to induce production of secondary bud sprouts. Labeling is very important. Making new varieties available to farmers… Macro-propagation

32.  Screening for drought tolerant Musa varieties K.U.Leuven, Belgium / IITA-Uganda Characterization, development and evaluation of adapted Musa germplasm.  The heterotrophic in vitro model enables to select different phenotypes within a same genetic background Screenhouse model (collaboration with IITA-Uganda) System components: germplasm

34. Current use: data from the CIALCA baseline Average = 10% of all households Average quantity = 9-14 kg ha -1 System components: efficient fertilizer use

35. Fertilizer use in bush beans (Eastern Rwanda) System components: efficient fertilizer use

36. without fertilizer with fertilizer (2 bags of NPK ha -1 ) CIALCA trials in Kabamba, Sud-Kivu, DR Congo. Fertilizer use in cassava System components: efficient fertilizer use

37. Fertilizer use in cassava (Bas-Congo) 2-3 fold increase in storage root yield and net benefits Benefit-cost ratio > 2, despite high fertilizer prices System components: efficient fertilizer use Kiduma Mbuela Rate Storage root yield Net benefits BCR Storage root yield Net benefits BCR (kg K ha -1 ) (t ha -1 ) ($ ha -1 ) ($ $ -1 ) (t ha -1 ) ($ ha -1 ) ($ $ -1 ) 0K 12.7 2493 5.6 10.5 2060 5.4 40K 23.7 4667 5.7 14.9 2744 4.3 120K 31.4 5829 4.5 19.6 3245 3.2 200K 39.6 7094 4.0 18.6 2435 2.2

39. Virtually all households use manure or compost but amounts applied are small. Organic matter is scarce! Hence, there is need for optimizing use efficiency. System components: optimized organic matter management

40. Combining soybean rotation and mixed addition of DAP and FYM increases yield and fertilizer AE. Principles of ISFM confirmed in E-Rwanda: OM improves AE of fertilizer System components: optimized organic matter management

41. Mulching 1 – thin mulch layer already conserves a lot more moisture 2- soil nutrient stocks increase with quantity of mulch applied 3- mulch application can triple yields, particularly on poorer soils System components: optimized organic matter management

46. Density trials: Efficiency of the system Maximum annual bunch yields varied by site Recommendations will be formulated for each agro-ecological zone

47. Intercropping arrangements  CIALCA System components: adapted agronomic measures

50. Merci Thanks Merci Thanks