Yield Response of Faba Bean to Lime, NPSB, and Rhizobium Inoculation in Kiremu District, Western Ethiopia

Faba bean (Vicia faba L.) is one of the most important winter legume crops for human consumption as a green or dried, fresh, or canned. Low soil fertility and acidity are the major constraints of faba bean production in Ethiopia. A field experiment was conducted in the Kiremu district of West Oromia, Ethiopia, under rain-fed conditions on a farmer's field to evaluate the effect of different rates of lime and NPSB-blended fertilizer application with and without inoculation on yield components and yield of faba bean. The three factors, lime rates (0, 2, and 4 t ha−1), mineral fertilizer rates (0, 60, 120, and 180 kg·ha−1 NPSB), and rhizobium inoculation (with and without), were combined in 3 x 4 x 2 factorial arrangement of RCBD in three replications. The data were collected on yield and yield components and subjected to the analysis of variance (ANOVA). The ANOVA results revealed that the number of pods per plant, number of seeds per pod, hundred seeds weight, harvest index, aboveground biomass, and grain yield were significantly affected by the treatment. Therefore, the highest faba bean yield was obtained from the application of 2 t limes ha−1, 120 NPSB ha−1, and 500 g·ha−1 rhizobium inoculation, and thus, the integrated application of the aforementioned rates of lime, NPSB, and rhizobium inoculation could be recommended for maximizing the productivity profitability of faba bean production in the study area and similar agro-ecologies.