Ameliorating Effect of Biochar on some Physical Properties of Sandy Soil and Water use Efficiency of Tomato (Solanum lycopersicum L.) Plant Grown under Drip Irrigation

Field experiments were conducted in two successive seasons (2018 and 2019)  to investigate the effect of biochar application rates on weight basis (0.0 % (BC₀), 0.2 % (BC₁), 0.4 % (BC₂) and 0.6 % (BC₃)) on soil some physical properties, yield productivity and water use efficiency of tomato grown in sandy soil under drip irrigation. The results indicated that the soil physical properties, yield component and water use efficiency of tomato were significantly and positively affected (P ˂ 0.05) by biochar application treatments. Marked lowering in bulk density, saturated hydraulic conductivity, infiltration rate and cumulative infiltration depth of the sandy soil in both the two growing seasons as results of increasing application rate of biochar. In addition , increasing  rate of biochar application resulted in significant increase of total porosity, mean weight diameter (MWD) , soil moisture constants (i.e., saturation percentage (SP), field capacity (F.C.), and wilting point (W.P.)), and soil water retention of sandy soil in both the two growing seasons. The measured available water content (AWC, %) showed a significant increase with increasing rate of biochar application which can be arranged in the order: BC₃˃BC₂˃BC₁˃BC₀. The results showed that the highest yield of tomato (32.4 and 31.9 ton.fed^-1) was obtained due to BC₂ treatment in both seasons. The maximum values of WUE (10.7 and 10.5 kg / m³) were associated with BC₂ treatment (0.4 wt. % biochar) in both seasons. Consequently, under sandy soil conditions, application of biochar might be a promising amendment for ameliorating soil physical properties and subsequently enhancing tomato plant productivity.
Tomato, Sandy soil, Biochar, Soil Physical Properties, Water use efficiency