Soil and nutrient losses in banana-based cropping systems of the Mount Elgon hillsides of Uganda: economic implications

Abstract

This study investigated the effect of different farmer cropping and soil conservation practices on runoff, soil and nutrient loss in Bududa district, Uganda. Gerlach troughs measuring 0.6m length, 0.4 m width and 0.5 m high were installed on runoff plots (15 m x 2 m) on farmer’s fields under banana sole, banana-arabica coffee or annual crops, with or without soil conservation structures. Soil loss was significantly (P<0.05) higher on annuals than on banana or banana-coffee (38.5 vs 6.6 vs 0.87 t ha-1yr-1), with values much higher for fields without conservation structures compared to those where there were structures. The total monetary value for NPK lost through erosion was US $ 16,663, 4,404 and 442 ha-1yr-1 for annuals, banana and banana-coffee fields respectively; with values much higher for fields without conservation structures compared to those with structures (US $ 15,451 vs 6,058). Soil loss values were much higher than the tolerable limit for Uganda which is 5 t ha-1yr-1 and calls for immediate action to scale up sustainable land management practices.