Systems Agronomy: From Fields to Farms and Farming Systems. Ken Giller Plant Production Systems, Wageningen University

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1 Systems Agronomy: From Fields to Farms and Farming Systems Ken Giller Plant Production Systems, Wageningen University

2 CIMMYT-Africa in the 1990s Building on a strong legacy of farming systems research Focus on diversification with legumes and croplivestock integration Regional network supporting national research teams Waddington, Murwira, Kumwenda, Hikwa, & Tagwira (1998) SoilFertNet/CIMMYT-Zimbabwe,

3 The problem Maize-dominated farming systems Declining soil fertility Need for diversification

4 Green manures on smallholder farms there are no silver bullets. Steven Waddington, CIMMYT Tim Reeves, CIMMYT DG

5 NPK NPK NPK Options Giller et al. (2006) Agricultural Systems, 88, 8-27.

6 Reducing complexity farm and field types

7 Tittonell & Giller (2013) Field Crops Research, 143,

8 N2Africa is a development to research project Research M&E D&D Delivery and dissemination are the core Monitoring & evaluation provides the learning Research analyses and feeds back Putting nitrogen fixation to work for smallholder farmers in Africa

9 Climbing beans in Rwanda No manure With Manure and P Putting nitrogen fixation to work for smallholder farmers in Africa

10 Response of climbing bean to P fertiliser, segregated by wealth category in N Rwanda 7 Climbing bean yield with P fertiliser and manure (t grain ha -1 ) Very poor Poor Well-off Rich Without P fertiliser (kg/ha) With P fertiliser (kg/ha) Very poor Poor Well-off Rich Climbing bean yield with manure only (t grain ha -1 ) Franke, Baijukya, Kantengwa, Reckling, Vanlauwe, Giller (2016) Exp. Agric. online Putting nitrogen fixation to work for smallholder farmers in Africa

11 Soil fertility in climbing bean trials affected by resource endowment Variable Very poor Poor Well-off Rich Significance ph n.s. C (%) N (%) Avail. P (mg/kg) Sand Silt Clay n.s. Franke et al. (2016) Exp. Agric. online Putting nitrogen fixation to work for smallholder farmers in Africa

12 Yields segregated by gender 7 Climbing bean yield with manure and P fertiliser (t ha -1 ) Women Men Without DAP (kg/ha) With DAP (kg/ha) Women Men Climbing bean yield with manure only (t ha -1 ) Franke et al. (2016) Exp. Agric. online Putting nitrogen fixation to work for smallholder farmers in Africa

13 Climbing bean yields depend on the length, number and quality of stakes Poorer farmers have fewer, shorter stakes of inferior quality Fresh grain yield (t / ha) Very poor or Poor Well-off or Rich Stake density (no. / m2) r = 0.63 r = Stake height (cm) Franke et al. (2016) Exp. Agric. online Putting nitrogen fixation to work for smallholder farmers in Africa

14 Crop management factors that determine climbing bean productivity Planting time Timing of 1 st weeding Staking density Stake length Organic input use P fertiliser use Labour input The poorest farmers are very hard to reach! Putting nitrogen fixation to work for smallholder farmers in Africa

15 maize following maize maize following climbing beans

16 Meta-analysis of grain legume residual benefit to cereal crops in Africa Relative yield increase after legumes (%) Mean increase = 0.82 t ha -1 Cowpea Groundnut Soybean Pigeonpea Cereal yield after cereal (t/ha) Franke, van den Brand, Vanlauwe & Giller (2016) Agric Ecosyst Env (submitted) Putting nitrogen fixation to work for smallholder farmers in Africa

17 Improving food self-sufficiency climbing beans in DRC With manure No manure Long rains season 2010 in Sud Kivu, DRC

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20 Major issues for Global Food Security 1. Climate change 2. Demography 3. Poverty 4. Inequality

21 Diversity and trends in global farming systems Low Capital availability High Intensive pigs/poultry Europe, greenhouse horticulture USA Intensification Rice smallholders China, cotton smallholders West Africa Subsistence smallholders sub-saharan Africa Cereals Australia USA, SAmerica Shifting cultivation Brazil, nomadic livestock herding Mali Developed regions Developing regions Low Land availability High van Vliet, Schut, Reidsma, Descheemaeker, Slingerland, van de Ven & Giller (2015) Global Food Security, 5,

22 Food availability across >13,000 small farms Frelat et al. (2016) PNAS, 113, sites 17 countries

23 Changes in population Average farm sizes are starting to grow in Asia, but will continue to shrink in Africa Masters et al. (2013) Global Food Security, 2,

24 Conclusions and Challenges Smallholder farmers unable to realise yield gains from new varieties soil fertility is key! Need best fit (legume) technologies with a basket of options for all rich and poor Productivity gains rapidly overtaken by population growth Concerns of small farm size, poor economic gains, ageing of farmers Need to focus on future farming systems rather than on technologies at field level Diversification for nutrition Mechanisation (both small-scale and contracted services) Transitions out of agriculture and land consolidation Agricultural development depends on development outside agriculture (and vice versa)