Effects of different levels of biochar on soil physical properties with different textures

Biochar is a charcoal made from biomass and animal manure, which is produced by thermal decomposition under a limited or zero supply of oxygen. Therefore, the current research was conducted to evaluate the effect of different biochar levels on some soil physical and chemical properties in four soil types under greenhouse conditions. The experiment was performed in completely randomized design with four levels of biochar produced from wheat straw in 500oC (0 (as control), 25, 50 and 75 ton ha-1) and four soils having various textures (sandy loam, loam, clay loam and clay) in three replications. Forty days after mixture of soil and biochar and determination of soil moisture content at field capacity, other physical and chemical parameters (soil moisture at permanent wilting point, bulk and particle density, saturated hydraulic conductivity and cation exchange capacity) were measured by taking soil samples from the pots. The results showed that application of biochar enhanced soil physical properties. Increasing biochar levels from 0 to 75 ton ha-1 increased soil available water content, porosity, hydraulic conductivity and cation exchange capacity by 45, 13, 95 and 52 %, respectively. It is concluded that biochar can be used as a soil amendment in coarse textured soil to increase water holding capacity and in fine textured soil to improve the drainage and infiltration.