Response of Bean Grain Yields on Applied Organic Fertilizers in the Semi-Arid and Humid Environments in Southwestern Uganda

Beans are the main source of protein in most Ugandan households, and they are also a cash crop in most rural households. Despite the importance of beans in Uganda’s economy and rural livelihoods, their productivity has been persistently low, mainly due to declining soil fertility in smallholder farming systems. A farm soil fertility trial was established in the semi-arid and humid sub-agroecological zones of southwestern Uganda with five farmer groups. Each farmer group had one learning site on which the experiment was laid with three replicates for the different soil fertility improving innovations. The performance of bean grain yields on the applied soil fertility improving innovations was significant in the dry cattle corridor that had sandy soils and erratic rains. Bean grain yields were unresponsive in the humid agroecological subzone of southwestern Uganda due to fertile volcanic soils and well-distributed rainfall, which masked the effects of the applied soil fertility-improving innovations. From the study, it was revealed that sandy soils that are inherently nutrient-poor should be applied with organic amendments to enhance their fertility and water-holding capacity to support bean production in the dry cattle corridor.