Abstract:

This study reviews and synthesizes the soil fertility status, management among smallholder
farmers and research in the three countries of east Africa, namely Kenya, Tanzania and
Uganda. We observe that many studies note the declining soil fertility, mainly due to soil
fertility mining, putting crop production in an unsustainable path. Studies have shown that
the current soil fertility management practices of recycling crop residue; biomass transfer;
short fallow and other organic practices appear to be inadequate to replenish the nutrient
outflow. Consequently, a number of case studies have shown crop yield decline in the
region.
Soil fertility research in east Africa has concentrated on producing recommendation for
monocrop systems while most smallholder farmers plant crops in complex intercropping
and mixed cropping systems. Additionally even though agricultural prices and soil
characteristics are dynamic, recommendations are always based on static input-output price
ratio and soil conditions. This research approach and assumptions render many
recommendations irrelevant to smallholder farmers. Consequently, adoption of soil fertility
technologies in the region is low, even though many farmers appreciate the benefits of
these technologies. The need to revise the current soil fertility recommendation such that
they take into account the dynamic nature of soils and agricultural prices is apparent.