Effect of Biochar on some Physical Properties of Two Different Textured soils

A laboratory experiment was conducted to study the effect of biochar produce from two types of plant residues (corncob and wheat straw), which were prepared by two methods of combustion, one of them by old method (hole method) and the other by handmade tank with three rates of biochar (0,15 and 30 ton ha-1) and their combination in two different textured soils (loamy sand/ Basra province and clay loam/Mesan province) on some physical properties of soil (bulk density, total porosity and soil water retention). The results indicated that the soil's bulk density significantly decreased with increasing of biochar rates accompanied increasing in total porosity. Wheat straw biochar prepared by handmade tank at rate of 30 ton ha-1gave the lowest value of bulk density and highest total porosity for loamy sand soil and clay loam soil to reach 1.22 and 1.20 Mg m-3 and 51.68% and 52.71% respectively. Type of biochar, method of combustion, and rate of biochar) and their combination had a significant effect on soil water retention (%) for both studied soils. Biochar prepared from corn cob with handmade tank method at rate of 30 ton ha-1gave the highest value of soil water retention to reached 35.32% for loamy sand soil and 27.39% for clay loam soil