Biochar in Organic Farming

Abstract

Biochar is charcoal-like solid material made from the carbonization (i.e., thermochemical conversion) of biomass in an oxygen-limited environment. This process in which large biomass particles are heated slowly in the absence of oxygen to produce biochar is termed slow pyrolysis. Pyrolysis is the temperature-driven chemical decomposition of biomass without combustion. Biochar may be used as a product itself or as an ingredient within a blended product in a range of applications; it serves as an agent for soil improvement, improved resource use efficiency, remediation and/or protection against environmental pollution, and greenhouse gas mitigation. The conversion of organic waste to produce biochar using the pyrolysis process is one viable option that can enhance the natural rates of carbon sequestration in the soil, reduce farm waste, and improve soil quality. The sustainable use of biochar could reduce global net emissions of carbon dioxide, methane, and nitrous oxide without endangering food security, habitats, or soil conservation. The use of biochar as a soil amendment is proposed as a new approach to mitigate human-induced climate change along with improving soil productivity. Water retention through biochar is possible because of the porous structure and high surface area of biohar. As a result, nutrients, phosphorus, and agrochemicals are retained for the plants’ benefit. Common methods for biochar production include the heap method, drum method, and biochar stove. Prime classes of biochar include the carbon storage class, fertilizer class, fertilizer grade, liming class, and particle size class. Biochar has manifold practical applications, some of which include use in animal farming, as soil conditioner, in the building sector as protection against electromagnetic radiation, in soil decontamination, in cleaning wastewater, as a barrier to prevent pesticides from getting into surface water, in the treatment of pond and lake water for adsorbing pesticides and fertilizers, for improving water aeration, in biogas production, in the textile industry as a fabric additive, as a deodorant, and as a thermal insulator that reflects heat, thereby enabling comfortable sleep without any heat build-up in the summer. Biochar has positive effects on soil’s physical, chemical, and enzyme activities and biological properties, resulting in increased crop productivity. The success of biochar use seems to be dependent on a reduction of biochar price. Biochar price is also largely dependent on the biochar production system, source and availability of biomass, transportation, application costs, efficacy of applied biochar in soil, and the mitigation of climate change.