Abstract

The biological fixation of nitrogen by legumes is a well-known ways of fixing atmospheric nitrogen to plant-available form. Effectiveness in nitrogen fixation depends on the genotype of legumes and requires host specific rhizobium strain for nodulation and optimizes faba bean productivity. Thus, the field experiment was conducted to evaluate the effectiveness of rhizobium inoculants of faba bean laid in randomized complete block design with three replications. The experiment consisted of 8 treatments: control, 121 kg ha^-1 NPS, 60 kg ha^-1 NPS+FB 1018, 60 kg ha^-1 NPS+FB 1035, 60 kg ha^-1 NPS+FB 04, 60 kg ha^-1 TSP+FB 1018, 60 kg ha^-1 TSP+FB 1035 and 60 kg ha^-1 TSP+FB 04. Rhizobium inoculation revealed a highly significant (p ≤ 0.05) effect on yield and yield attributes compared to the un-inoculated plants. Over years results showed that inoculated plants gave a significant (p ≤ 0.05) increase in nodule number and grain yield advantage against the un-inoculated plants. The highest yield (5.87 ton ha^-1) was recorded from inoculates of FB 1018+60 kg ha^-1 TSP compared to the un-inoculated that gave 2.48 ton ha^-1. Inoculated rhizobium strains performed better in ecologically competent and symbiotically effective in nodulation for increased yield, thus recommended for the study area and similar agro-ecologies.

Keywords: Faba bean; Fertilizer; Rhizobium strain; Yield