Biochar, a carbon-rich material, contributes to sustainable soil and water management by improving soil health, and understanding its behavior and both its short-term and long-term effects on soil is essential. This study investigates the impact of produced biochar from Populus nigra branches, applied at 32.5 t ha -1 , on runoff, sediment yield, and soil properties in abandoned rainfed plots. Quantitative assessments of runoff and sediment yield following natural rainfall events, coupled with biannual evaluations of soil properties, formed the basis of this investigation. The findings revealed that biochar application in treated plots led to average reductions of 20%, 24%, and 8% in runoff volume, soil loss, and sediment concentration, respectively, compared to control plots. Soil aggregate stability, evaluated through the mean weight diameter (MWD) index, together with soil porosity and soil moisture, showed significant enhancement, with all parameters attaining their maximum values one year after application. Additionally, soil chemical properties, including pH, electrical conductivity (EC), and soil organic carbon (SOC), exhibited substantial improvements, with increases of 4.5, 20.5, and 21%, respectively, relative to control samples. The independent effects of biochar and time on SOC were both significant at the 99% level. Furthermore, the biological index of chlorophyll a (Ch-a) content increased by 31%, with a statistically significant difference in response to biochar at the 95% confidence level. These findings highlight the potential of biochar derived from Populus nigra branches as an effective and sustainable strategy for soil and water conservation in abandoned rainfed semi-arid environments. Future research should investigate long-term biochar effects on carbon stability across soils with varying textures and organic matter.
Moafi et al. (Fri,) studied this question.