This study investigated the effect of biochar on dispersible clay and soil chemical properties. The treatments consisted of four rates of milled biochar (0, 450, 900 and 1344 kg/ha) arranged in a Completely Randomized Design with four replicates. Surface (0-15 cm depth) soil of Iwo (Sandy loam) and Egbeda (Loamy sand) soil series were collected from the Teaching and Research Farm, Obafemi Awolowo University, Ile-Ife, Nigeria. 1kg of each soil sample was thoroughly mixed with milled biochar at different rate and maintained at field moisture capacity for a period of 12 weeks in the screen house. Soil particle size distribution, bulk density, dispersible clay, soil pH, soil organic carbon and available phosphorous were determined. Data obtained were subjected to analysis of variance, Duncan’s New Multiple Range Test was used to separate significant means at p ≤ 0.05. It was revealed from the results that biochar addition at rate 450 and 1344 kg/ha appeared to be more beneficial and adequately improved soil pH, organic carbon and available phosphorous. biochar at 900 kg/ha significantly reduced dispersible clay. It was concluded that short term biochar amendment did not improve soil quality of loamy sand.
Keywords: Biochar, Dispersible clay, Soil organic carbon, Available phosphorus, Soil pH