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

Abstract

 The 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.