Studies on responses to inoculation in bush bean (Phaseolus vulgaris) were carried out as part of the N2Africa project (www.n2africa.org) in Ethiopia, Tanzania, Rwanda and Zimbabwe.
Inoculant treatments without fertilizer inputs significantly improved yields by 0.27 t ha-1 compared to the unamended control in Ethiopia. The combined effect of inoculation and P fertilization was much larger and significant in all four countries. Trials in Tanzania and in Zimbabwe also included the application of N fertilizer, and manure was included on the trials in Rwanda. Largest yields were achieved when inoculant and fertilizer inputs were combined. Inoculation tended to boost responses to fertilizer inputs in Ethiopia, Rwanda and Tanzania. Detailed results per country are given below.