Journal of Global Agriculture and Ecology

The potential of biochar as a multipurpose soil amendment substance that enhances soil pH, soil health, crop productivity, while lowering greenhouse gas emissions in agricultural systems is examined in this review. It assessed the characteristics of biochar by the type of feedstock and the conditions of pyrolysis, its performance in various soil environments using data from field investigations, pot experiments, and meta-analyses. Literature revealed biochar greatly improves soil structure, porosity, and water-holding capacity while also supporting microbial activities. The high cation exchange capacity associated with biochar enhances fertilizer use efficiency (FUE) and nutrient retention, resulting in a 10-14 % increase in nitrogen use efficiency (NUE). Biochar is known to be useful in acidic soils, improving nutrient availability and plant growth increasing soil pH by up to 1.9 units and lower exchangeable aluminium by 66-88 %.  In soils amended with biochar, crop responses by; increase in yields of up to 38% have been documented in tropical and degraded soils, while gains of about 10% have been reported in temperate systems. Biochar also contributes significantly to the mitigation of climate change by stabilizing and sequestering 60-90% of soil carbon over extended periods of time and lowering emissions of methane by around 23 % and nitrous oxide by 30-54 %. Despite these benefits, high production and application costs, uneven product quality, and farmers' lack of technical expertise prevent widespread use.  Yet use of biochar remains an important approach to sustainable agriculture, amelioration of degraded soil as well as climate change abatement.  Its wide recognition and application will require favourable legislative frameworks in national soil management policy and the scientific community.