Effect of Biochar and Rhizobium Inoculation on Nodulation, Yield of Faba Bean ( Vicia faba L.), and Selected Soil Properties

Soil fertility depletion is a major constraint in the North Gondar highlands of Ethiopia leading to the reduction of faba bean yields. Limited access organic fertilizer and heavy reliance on mineral fertilizers have degraded soil quality and crop productivity. This study investigated the effects of biochar and rhizobium inoculation on nodulation, yield of faba bean ( Vicia faba L.), and selected soil properties in Dabat district, North Gondar. A total of six treatments were made from the factorial combination of three biochar levels (0, 5, and 10 tons ha −1 ) and two inoculation levels (inoculated and uninoculated) in a Randomized Complete Block Design (RCBD) with three replications. Soil samples were collected from a depth of 30 cm to determine soil properties. The effective nodule number was assessed by counting nodules per plant. Biochar application and rhizobium inoculation had a significant effect ( p < 0.05) on selected soil properties, nodulation, and grain yield of faba bean. The highest soil pH (6.66), organic carbon content (2.28%), total nitrogen (0.26%), available phosphorus (51.61 ppm), effective nodule number per plant (197.65), and yield (2617.76 kg ha −1 ) were recorded following the application of 10 tons ha −1 of biochar combined with Rhizobium inoculation. Furthermore, this synergistic approach a significantly improved faba bean nodulation by 134.9% and grain yield by 74.39% compared to the control. The application of biochar combined with rhizobium inoculation significantly improved soil nutrient levels and faba bean yields. Future research should investigate the effects of varying biochar application rates on the yields of other crops.