Soil fertility gradients and production constraints for coffee and banana on volcanic mountain slopes in the east African rift
This article (PDF) in the journal Agriculture, Ecosystems & Environment reveals important relations and gradients between soil fertility parameters and its corresponding environment along the slope of the Mt. Elgon in Uganda and Kenya. Mt Elgon is a volcanic mountain and is one of the most productive agricultural regions, dominated by coffee an banana cultivation. These regions suffer from a high and increasing population density with a declining soil fertility status imposing pressure on the available land, which in turn results in encroaching into the national forests. This study documents the soil fertility constraints along the slopes of Mt. Elgon and explores its corresponding gradients in plant nutritional status. Soil pH, soil available P and exchangeable K, Ca and Mg are significantly decreasing with elevation. Thereby, gradients and constraints in macro- and micro-nutrient uptake by coffee and banana are revealed along the top-sequence and different altitude-specific nutrient limitations are determined for both crops. The authors argue that since there are differences in uptake of micronutrients by crops depending on the elevations, a general fertilizer recommendation cannot be made in these regions and that the soil fertility problems along these slopes should be specifically addressed and appropriately managed according to the local requirements.