Application of Biochar with Phosphorus Fertilizer Induced Positive Effects on Soil Properties of Acidic Soil and Yield of Faba Bean (Vicia Faba L.) Varieties in Welmera District, Oromia, Central Ethiopia

he problem of soil acidity is one of the challenges to improve crop production particularly in high rainfall areas of Ethiopian. The use of biochar as a soil amendment on soil acidity and phosphorus (P) fertilizer has the ability to improve soil properties and crop productivity. Therefore, the experiment was done to evaluate the effect of combined use of biochar and phosphorus fertilizer on soil physico‐chemical properties and yield of faba bean under acidic soil condition in Welmera District. The experiment was carried out during the main cropping season of 2021 at Holeta Agricultural Research Center. Treatments were arranged in a randomized complete block design factorial combination of four levels of biochar (0, 50, 100 and 150%) and three levels of P fertilizer (0, 46, and 69 kg P ha-1) with recommended (46 kg ha-1Phosphorous fertilizer and 1.5 t.ha-1 lime) with three replications. Composite soil samples were collected from (0-30) cm depth and analyzed for bulk density, pH, soil organic carbon, total nitrogen, available P, exchangeable bases and exchangeable acidity using standard procedures before sowing and after harvesting. Soil bulk density, exchangeable acidity and exchangeable Al were relatively reduced as compared to control plot while total porosity, soil pH, total N, soil organic carbon, available P, and exchangeable bases were increased after crop harvest. Moreover in response to treatment application, the yield and yield components of faba bean were indicated significant improvement. Accordingly, the highest fababean grain yield (6.12t.ha-1) was obtained when 150% biochar applied in combination with 69 kg ha-1 of P fertilizer but statistically at par with the treatment combination of 100% biochar and 46 kg P ha-1 fertilizer. The lowest yield (1.120 t. ha-1) was recorded from control plot. Hence, 100% biochar with 46 kg ha-1P can be recommended to grain yield of fababean in acidic soils of the study areas. In general, results of study suggest that the practice of biochar application (100%) to soil with P fertilizer (46kg/ha) has positive effect on soil properties and productivity of faba bean in acidic soil area.