Growth, nodulation and yield response of field-grown faba bean (Vicia faba L.) to Rhizobium inoculation in Tocha District, Southern Ethiopia

Abstract

Inoculation with effective and crop specific rhizobial strain of bacteria is necessary to improve symbiotic nitrogen fixation and optimize faba bean productivity. Field experiment was conducted at Tocha district, southern Ethiopia during 2017-2019 main rainy seasons to evaluate the effects of Rhizobium strain on the yield and yield components of faba bean. The experiment consisted of 7 treatments: control, FB1018, FB1035, FB04, 50 kg ha^-1 TSP + FB1018, 50 kg ha^-1 TSP + FB1034 and 50 kg ha^-1 TSP + FB04. A starter N-dose (9 kg N·ha⁻¹) was applied with different Rhizobium inoculants except for the control. Soils of the experimental plot before planting was silt loam in texture, moderately acidic in pH with high levels of organic carbon, total nitrogen and cation exchange capacity, and medium content of phosphorous. The experiment was laid out in Randomized Complete Block Design with three replications. Inoculation of FB1018 strain significantly (p < 0.05) increased the plant height (cm), number of pods per plant, above-ground biomass (kg), and grain yield (kg) as compared to the control. The maximum grain yield (3354.2 kg ha^-1) and minimum (1942.7 kg ha^-1) were obtained from the application of FB1018 strains and control treatment, respectively. Therefore, application of FB1018 strain with 9 kg N·ha⁻¹ can be recommended to improve Faba bean yield at Tocha distric and other areas with similar agro ecology and soil conditions.