Risk management in crop production and fertilizer use with uncertain rainfall; how many eggs in which baskets?

Model results are analysed for risk management options for sorghum production with a range of N fertilizer rates on three soils of a toposequence in three climatic zones in Burkina Faso. The three levels of analysis are: (a) quantifying the probability distribution of physical and economic yield for a range of fertilizer levels and soil types; (b) quantifying the possible variance reduction by soil heterogeneity or by a combination of soils and N rates; (c) developing a procedure for selecting 'meaningful diversity' of soil and N fertilizer combinations