Effect of Biochar Application on Soil Water Retention and Pepper Yield in Sokoto State

Biochar derived from agricultural residues improves soil water-holding capacity in sandy soils and offers potential for improving pepper production efficiency in the water-limited conditions of North West Nigeria. This study investigated the effect of three biochar application rates (0, 2, and 4 tonnes per hectare) on soil volumetric water content and pepper (Capsicum annuum L.) yield in Tangaza LGA, Sokoto State, North West Nigeria. A field experiment was conducted during the 2023 dry season at a research plot at Usmanu Danfodiyo University using a randomised complete block design with three replications. Tatase variety pepper was transplanted at 5 weeks after sowing. Soil volumetric water content was monitored weekly using a TDR probe. Pepper plant height, number of fruits per plant, fruit weight, and total fresh fruit yield were recorded at three harvest intervals. Results showed that 4 t ha-1 biochar significantly increased soil water content by 21.4 percent compared to the control at peak moisture stress periods. Fresh fruit yield at 4 t ha-1 biochar was 12.7 tonnes per hectare, significantly higher than the control (8.3 t ha-1) and the 2 t ha-1 rate (10.9 t ha-1). Biochar produced from rice husk was used and found to raise soil pH marginally from 6.0 to 6.3 without adverse crop response. The study recommends rice husk biochar application at 2 to 4 t ha-1 as a soil ameliorant for pepper production under irrigation in Sokoto State and supports its local production from abundant rice milling waste.