• Adaptation to local conditions. As previously stated, soil fertility status within and between farms is highly variable and a challenge before the African Green Revolution is adjusting recommendations to include such variability in soil fertility status. Firstly, soil fertility status can vary considerably within short distances. Often, the soil organic matter (SOM) content is a good proxy for soil fertility status, provided that this parameter is not over-extrapolated across dissimilar soils. Soil organic matter contributes positively to specific soil properties or processes fostering crop growth, such as cation exchange capacity, soil moisture and aeration, or nutrient stocks. On land where these constraints limit crop growth, a higher SOM content may enhance the demand by the crop for N and consequently increase fertiliser N use efficiency.

  • A move towards ‘complete ISFM’. Several intermediary phases are identified that assist the practitioner’s move towards complete ISFM from the current 8 kg ha-1 fertiliser nutrient application with local varieties.