Maize, Soil Fertility, and the Green Revolution in East Africa

Abstract

The low application of inorganic fertilizer in Sub-Saharan Africa is one of the major constraints to achieving a Green Revolution in this region. In this study, we estimate the direct impact of the soil fertility on the maize yield and examine if the soil fertility increases the returns to inorganic and organic fertilizer based on comparative study of Kenya and Uganda. The results of the analyses indicate that the Kenyan maize farmers have applied the inorganic fertilizer roughly at the optimal level in one out of the two survey years on both the purchased high-yielding varieties and local/recycled maize varieties. In Uganda, even the low application of inorganic fertilizer is not profitable because of the high relative price. Regarding the returns to inorganic fertilizers on degraded soils, we do not find any increasing marginal returns of such fertilizers to the soil fertility.