Effects of Biochar on Soil Physical, Chemical, and Biological Properties

Biochar is a carbon-rich organic material that is produced from the pyrolysis of organic matter under low or no oxygen. The unique physical and chemical properties of biochar distinguish it from other soil organic matter. Addition of biochar to soil can improve not only its physical properties such as specific surface area, water holding capacity, aeration, and resistance to soil erosion but also its chemical properties such as cation exchange capacity, pH, organic carbon, nutrient availability, and reduced risk of soil contaminants. Moreover, it has such advantageous biological effects as increasing microorganism colonies and their protection against predators, raising soil fertility, enhancing crop yield and carbon sequestration, climate change mitigation, and biofuel production. However, due to its novelty, its positive and negative effects on the environment and interactions with various soil components are not clearly known. In addition, biochar properties may change over time and nothing is yet known about these changes and their long-term effects. Despite the universal attention shown to biochar for its expected beneficial effects on soil and carbon sequestration, few studies have as of yet been devoted to its production and application in Iran, which warrants studies to be conducted on biochar production and application to Iranian soils.