Effect of Conocarpus Biochar Application on the Hydraulic Properties of a Sandy Loam Soil

Biochar research has received greater interest in recent years because of its potential beneficial effects on soil properties and its efficiency as a long-term C sequester. In this study, the effect of Conocarpus biochar application on the hydraulic properties of a sandy loam soil was investigated. Evaporation rate, water retention, soil water infiltration, and soil aggregate stability were measured in soil columns packed with a sandy loam soil amended with 5, 10, 15, and 20 g.kg(-1) of non-activated biochar. Results showed that cumulative evaporation was reduced by 5.4% to 12.1% as a result of increasing biochar application. The application of biochar enhanced the capacity of the soil to retain water by 8.9%, 17.6%, 28.1%, and 30.9% for soils treated with biochar rates of 5, 10, 15, and 20 g.kg(-1), respectively. Water content at field capacity increased in the top 10 cm by 7.2% to 15.9%. Water-holding capacity was increased by increasing the application rate of biochar. The percentage of waterstable aggregates was increased, especially in the larger fractional sizes (2-0.25 mm). On the other hand, the application of biochar decreased saturated hydraulic conductivity and infiltration rate, but had minimal effect on other hydraulic parameters. The ability of biochar to reduce water evaporation and improve water retention of coarse-textured sandy soils can help to enhance soil quality and productivity, reduce the amount of irrigation water, and maintain crop yields for crops exposed to water stress, especially in arid and semiarid regions.