Effect of Straw Biochar on Soil Acidity and Phosphorus Nutrition in Wheat

Two biochars were produced from the rice and wheat residues by slow pyrolysis (at 400°C) in muffle furnace with an aim to study the effect of their application on some chemical properties of acidic soil such as pH, exchangeable acidity and cation exchange capacity (CEC) as well as their effect on phosphorus uptake by wheat in a greenhouse experiment. The incubation study was conducted incubating acidic soil (Typic Fluvaquent, pH 5.07) with assorted doses of biochars (0, 10, 20 and 60 g kg-1) for 120 days. A dose of lime at half or the lime requirement was also added separately for comparison. Results indicated that incubation period (F, 84.81; Pr>F, <.0001) and application rate (F, 281.05; Pr>F, <.0001) had significant effects (p < 0.05) on the pH of soil. Both the biochars had significant effects on exchangeable acidity and CEC. Application of biochar derived from wheat residues showed relatively greater increase of soil pH. Graded doses (0, 5, 10 and 20 g kg-1) of both biochar addition significantly increased the phosphorus uptake by different plant parts as well as yield of wheat in greenhouse experiment.