Improving the Hydraulic and Chemical Properties of Sandy Soil by Using a Mixture of Biochar and Clay

Abstract

In recent years, food demand has risen due to rapid population surge. Meeting this food demand means more land is supposed to be cultivated. Yet, there are many areas in Sindh, Pakistan, particularly “Thar,” where crop yield is inadequate due to the sandy soil’s poor water holding capacity (WHC), water retention, and higher hydraulic conductivity. Thus, this study evaluates the effect of biochar-clay mixture on sandy soil to improve its hydraulic and chemical properties. This study provides positive results of applying clay at three different rates (5, 10, and 20%) in sandy soil. When clay was mixed at these rates with 5% biochar, it not only improved the hydraulic properties of soil but also its chemical properties including soil organic carbon (SOC) and soil organic matter (SOM). The experimental findings improved the sandy soil’s WHC and reduced its hydraulic conductivity. This clay and biochar mixture enhanced SOC, SOM, and Electrical Conductivity (EC) and decreased the pH in sandy soil.  Thus, adding biochar and clay mixture proved to be a better soil amendment than only clay. Further investigation requires modification in biochar particle size before mixing it with the sandy soil.