What are the effects of improved manure management on smallholder farm production in sub-Saharan Africa? Model improvement and explorations.


Manure management and storage is a highly important part of the farm C and nutrient cycles. For instance, up to 100% of N can be lost with poor management (Rufino et al. 2006). Especially for smallholder farms in sub-Saharan Africa (SSA), where mineral fertilizers are often too costly or difficult to access, manure management has a strong influence on the longer term productivity of mixed crop-livestock farms. NUANCES-FARMSIM (Van Wijk et al. 2009)is a whole-farm dynamic model simulating medium to longer term (10-15 years) farm productivity (crop and livestock) of smallholder farms in SSA and carbon (C) and nutrient cycles (N and P) in the farm. HEAPSIM (Rufino et al. 2007)is a sub-model simulating the manure management and storage losses. Results of NUANCES-FARMSIM are used in western Kenya and Uganda to inform the decision making of farmers on input use and farm management. After building a common understanding on farm functioning and basic principles (C and nutrient cycles), also the effects and trade-offs of specific animal husbandry and manure management options on longer term production will be discussed with farmers in co-learning workshops. HEAPSIM needs to be improved and updated for simulating the effects of these specific animal husbandry and manure management options. As part of this project, an MSc thesis could include:

-    Model testing and improvement with new data.

-    Exploring medium to longer term effects on whole farm productivity as a result of observed manure management changes of participating farmers in western Kenya. 

-    Preparing co-learning workshops with farmers by ‘translating’ results from the model into a presentation which can be understood by farmers, of which part is illiterate. The student can possibly join in the co-learning workshops in western Kenya.


In case of field work, this will be done in Africa with local support of the International Institute of Tropical Agriculture (IITA)


Students with an interest in interdisciplinary work, modelling, soil and crop management. Completion of the courses Systems Analysis, Simulation and Systems Management and/or Analysing Sustainability of Farming Systems.

Location and Period

Wageningen and possibly Kenya or Uganda. Any time


Rufino MC, Tittonell P, Van Wijk MT, et al (2007) Manure as a key resource within smallholder farming systems: analysing farm-scale nutrient cycling efficiencies with the NUANCES framework. Livest Sci 112:273–287.

Van Wijk MT, Tittonell P, Rufino MC, et al (2009) Identifying key entry-points for strategic management of smallholder farming systems in sub-Saharan Africa using the dynamic farm-scale simulation model NUANCES-FARMSIM. Agric Syst 102:89–101. doi: 10.1016/j.agsy.2009.07.004


Wytze Marinus                                                                                   wytze.marinus@wur.nl

Katrien Descheemaeker                      0317 − 48 61 02                      katrien.descheemaeker@wur.nl

Gerrie van de Ven                               0317 – 48 21 40                      gerrie.vandeven@wur.nl