If N use efficiency (here used to refer to the efficiency of N capture rather than the efficiency of N use within the plant) is poor, then much more of the N available in the crop/soil system will be susceptible to loss. In situations where crop growth is strongly limited by lack of P, and where there is a strong crop response to P the amount of mineral N in the soil that is susceptible to loss decreases strongly with P addition. If response to P is weak due to other problems for plant growth, such as where soil acidity or poor soil physical properties restrict crop response, then as well as realizing only poor crop growth and yield, the potential losses of N from the soil/crop system are increased. Thus efficient targeting of nutrients depends on the position within soil fertility gradients.
Analysis of these farming systems is focused on households as the primary units, with analysis of production benefits in terms of nutrients, labour, cash and environmental costs. The aim is to both describe existing systems and understand current practices and to use the framework to design alternative new systems. See www.AfricaNUANCES.nlfor further information.
The project involves collaboration with a large number of Universities and national and international research institutes in Africa
Several courses are relevant such as Analysing Sustainability of Farming Systems, Crop Ecology, Systems Analysis & Simulation, and QUALUS.
Location and Period
Wageningen and possibilities in many countries in East, West and southern Africa. Any time
Ken Giller 0317 – 48 58 18 firstname.lastname@example.org