Grain yield and economically feasible maize common bean intercropping and tillage practices at Omonada Woreda, Jimma zone

A field experiment was carried out to determine the optimum ratio of intercropping maize with common bean under two tillage systems in Omonada Woreda of Jimma Zone during 2017 and 2018 main cropping season. The experiment was laid out in a strip plot design with three replications. The treatments consisted of two tillage methods (conventional tillage (CT) and reduced-tillage (RT) and five levels of at 1:1, 1:2 and 1:4 maize to common bean ratio, sole maize and common bean) Across season result showed that significant (P<.001) effect of tillages and intercropping were observed on grain yield, biomass yield of both crops and land equivalency ratio. The higher mean grain yield of maize and common bean intercropped (5.82 and 0.96 t/ha) and (4.84 and 0.8 1t ha-1) from CT and RT respectively under maize to common bean ratio (1:2) with LER 1.8. In conclusion, sensitivity analysis on coexisting changes in field prices of inputs and grain (±15%) showed that maize common bean (1:2) ratio gave the highest net benefit 26758 ETB with acceptable MMR 3942% and 20277 ETB with MMR 5622% obtained from conventional and reduced tillage respectively. Therefore, maize to common bean ratio (1:2) under both tillage practices optionally recommended based on farmers inputs and labor availability even under risky market situations in and around the study area.