for a changing gworld Sieg Snapp ICRISAT 40 th Anniversary Science Symposium

Transcription

1 Resilient smallholder farming systems for a changing gworld Sieg Snapp ICRISAT 40 th Anniversary Science Symposium

2 Rapidly pdychanging gworld Volatile markets Output expanding - in some cases Input markets vary with subsidies, supply limitations, infrastructure Climate variability Depending on location: Land ownership & access Connectivity

3 Africa: Staple crop price variability

4 Christensen et al., 2007 IPCC

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6 Ingredients for Resilience Diversity Natural resource health Local innovation

7 Dominant farming systems Maize based systems Sorghum-millet-livestock systems Irrigated double and triple cropped rice, Rice-wheat systems

8 Functional tradeoffs High Relative Growth Rate Low Low-nutrient Tissue Quality High-nutrient

9 Agrodiversity Missing function Biomass m for marginal areas (Carbon, cover) Legumes (Nitrogen and phosphorus) Triple services (Resilience, food, fodder)

10 Biomass for marginal areas Sorghum Cassava Sweet potatoes t M lti l G i /T b L f V t bl Multiple uses: Grain/Tuber, Leafy Vegetable, Beverage (fermented), Fodder and Construction

11 Semi-perennial legumes Tarwi (Lupinus mutabilis Sweet) Pigeonpea (Cajanus cajan)

12 Legume Legume Legume Annuals for food and sale: Bean, g nut, gnut, soybean, cowpea Semi-perennial legumes: Pigeonpea, lupin, doubled up legumes Agroforestry/g. manure soil fertility and fuelwood: Mucuna, gliricidia, tephrosia

13 Legume nitrogen tradeoffs Low N contribution Maize/grain legume e.g., Soybean rotation Maize/doubled up legumes e.g., Pigeonpea+ Groundnut rotation Maize/Agro-forestry e.g., Tephrosia relay Pigeonpea intercrop High N contribution Groundnut

14 Doubled up legumes = triple purposep Intercropping of two grain legumes on the same piece of land for resilience + food + fodder Up to 2 t ha -1 biomass from groundnut, and 18to t ha -1 leafy biomass from pigeon pea + grain

15 On-farm: Yield ed stability of maize 25 Coef fficient Variation a a b a a a a a Semiperennial legume b b Malawi wide n=3300 S.Malawi n=750 0 Snapp et al., 2010 PNAS

16 Principles for soil building = resilience Biomass Cover Deep rooting C-fixation N-fixation P-access

17 Phos phorus uptake (mg/m) Enhancing phosphorus: Maize - fababean intercrop a b No barrier c Mesh Solid barrier a ab b Maize Fababean Hinsinger et al. 2011

18 Multiple services = resilient systems Twomlow et al., 2001

19 Participatory Action Research (PAR) Review results, iterative co-learning Niche opportunities Better bet options Best bet options On-farm PAR Innovation & Adoption

20 Mother and baby trial design for PAR Snapp, 1998

21 Calories X Calories per technology vs average calories per farm site solemz mz/pp 8.00 leg/pp mz/tv 6.00 Linear (solemz) 4.00 Linear (mz/pp) 2.00 Linear (leg/pp) Linear (mz/tv) Environmental Index (average calories)

22 Annual pigeonpea = Annual pigeonpea = recommended practice

23 PAR for innovation Current system: Banana/bean Maize mixed Niche diversification with best bets semiperennial legumes: Mucuna Crotalaria

24 Green manure vs. products? Technology Researcher Farmer adaptation recomm. Cortalaria Intercrop with maize Intercrop with beans & Improved fallow bean storage (pest before maize control) Mulch with residues Boundary planting Mucuna Green manure/cover with banana Improve fallow before maize Cook (process) Animal feed seed and mulch Nyende and Delve, 2004 Expt Ag

25 Participatory research and modeling Farmer assessment Modeling of Maize- pigeonpea rotation on different soil types, weather files Combinations for niches: with and without small fertilizer doses, compost, diverse crops

26 APSIM Simulation: Seasonal Soil Water Recovery 80 Clay soil water rotation continuous maize maize-pigeonpea Sand so oil water Ollenburger & Snapp, 2012

27 Model: Water stress reduced over time l water stress cumulative soi Kasungu LATE early mid Intercrop Maize Rotation Mean Soil HF Soil MF Soil LF lateearly Ollenburger & Snapp, 2012

28 Model: Maize yield in Central Malawi 4500 Kasungu Soil HF Soil MF Soil LF 4000 Maize yie ld (kg/ha) Maize Intercrop Rotation Years from establishment

29 Linking modeling and PAR Models provide sensibility analysis to ID best bet options for different niches Understanding d of tradeoffs (water vs N,P) Develop discussion tools

30 Ingredients for Resilience Diversity Natural resource health Local innovation Discussion tools to understand tradeoffs Participatory i t action research Innovation platforms