The role of biochar in the improvement of degraded soils: a review of literature
Samuel Obeng Apori , Pius Nina
Uganda Martyrs University, Fac. of Agriculture, Uganda
The positive impact of organic resources on the reclamation of degraded soils in the tropics is often short-lived because of their elevated decomposition and mineralisation rates. One novel technology for the long-term improvement of degraded soils is applying black carbon known as biochar. Biochar is a stable, recalcitrant organic carbon (C) by-product of thermochemical decomposition of biomass (feed stock) under low or no oxygen conditions for use as a soil amendment. Although there is substantial literature on the impact of biochar on improving the health of degraded soils, the mechanisms by which this is done are still inadequately examined. Therefore, this review attempts to examine literature that explains the mechanisms by which biochar improves degraded soils. The review results indicate that the availability of nutrients and their content in biochar is affected by the biomass type, and processing conditions. In addition, the alkalinity nature of biochar creates a conducive environment for the soil microbes to rapidly multiply, leading to their higher population and enhancing their numerous activities in the soil. The application of biochar also improves the chemical properties of degraded soil through the increase of pH, cation exchange capacity, soil nitrogen, available phosphorus, exchangeable bases and a decrease in exchangeable Al and soluble Fe. Biochar enhances the physical and chemical properties of the soil which in turn enhances the cell division and physiological performance of the plant. Also, biochar decreases CO2 emissions by decreasing the bio-availability of soluble organic substrates on their surface by absorption. New research viewpoints are also briefly discussed.
Keywords: Chemical, greenhouse gases, keywords: biochar, microbial diversity, physical, plant hormones
Contact Address: Pius Nina, Uganda Martyrs University, Faculty of Agriculture, P.O. Box 5498, Kampala, Uganda, e-mail: piusm.ninagmail.com