Influence of Biochar on Soil Physicochemical Properties, Erosion Potential, and Maize (Zea mays L.) Grain Yield under Sandy Soil Condition

Degraded soils in humid tropics are characterized by low fertility and high soil erosion potential. Hence, field experiments were conducted during 2018 and 2019 cropping seasons on an Alfisol at Owo in the forest-savanna transition zone of southwest Nigeria to evaluate the effects of the application of biochar (B) produced from waste wood of trees on physicochemical characteristics, erosion potential, and maize yield. Four treatments considered were control (no biochar application, 10 t ha(-1) B, 20 t ha(-1) B and 30 t ha(-1) B). The treatments were laid out in a randomized complete block design with three replications. Results in both years indicated that B application significantly improved grain yield of maize and soil chemical properties, and reduced bulk density (BD) and penetration resistance (PR), and increased porosity (PO), moisture content (MC), and the mean weight diameter (MWD) of soil aggregates. Pooled over 2 years, B applied at 10, 20 and 30 t ha(-1) increased grain yield of maize by 44.4%, 66.7%, and 88.9%, respectively, compared with the control. Averaged over 2 years, incorporating B into the soil significantly reduced soil loss (SL) by 32.3%, 56.9%, and 69.7% at 10, 20, and 30 t ha(-1) application rates, respectively, compared with the control. The formation of macroaggregates in the B-amended soils is the critical factor to improve soil erosion potential. Therefore, the application rate of 30 t ha(-1) B is considered as suitable for severely degraded soil because this application rate efficiently improves maize yield and soil properties and reduces SL.