Effect of Biochar on Soil Properties, Soil Loss, and Cocoyam Yield on a Tropical Sandy Loam Alfisol.

Among agricultural soil amendment that can enhance crop productivity and soil sustainability is biochar. Hence, two-year field experiments were conducted on a sandy loam Alfisol at Owo, southwest Nigeria, to evaluate the effects of biochar produced from hardwood on soil physical and chemical characteristics, erosion potential, and cocoyam ( (L.) Schott) yield. The study was a 2 × 4 factorial experiment with two years (2017 and 2018) and four biochar levels (0 (control), 10, 20, and 30 t ha). The treatments were laid out in a randomized complete block design with three replications. Results indicated that biochar application significantly in both years improved yield of cocoyam and soil physical (bulk density, porosity, moisture content, mean weight diameter (MWD) of soil aggregates, dispersion ratio, and infiltration rate) and chemical (soil organic matter, pH, N, P, K, Ca, Mg, and CEC) properties and erosion resistance. Soil characteristics and cocoyam yield improved with level of biochar from 0-30 t ha. When 2018 is compared with 2017 in term of soil loss, in the amended plots, 2018 reduced soil loss by 7.4, 20, and 73.5%, respectively, for 10, 20, and 30 t habiochar, whereas there was an increase of 2.7% soil loss in the control plot in 2018 compared with 2017. Therefore, application rate of 30 t ha biochar is considered as suitable for severely degraded soil because this application rate efficiently improves cocoyam yield and soil properties and reduces soil loss.