Potential value of biochar as a soil amendment: A review

Abstract

This article reviews a range of beneficial impacts of biochar on soil physico-chemical properties and crop yield. Advances in biochar research appeal for identification of beneficial effect of biochar using as a soil amendment before any large-scale field application is recommended. Thus, the purpose of this review are to evaluate the potential beneficial effect of biochar using as a soil amendment. Biochar, a product of biomass pyrolysis, and is usually characterized as rich in recalcitrant C, with a large surface area, and diverse functional groups, although these features largely depend on the feedstock and pyrolysis conditions. Pyrolysis is a thermochemical process that transforms biomass into biochar, bio-oil, and syngas. The use of biochar as a soil amendment has received growing attention due to its ability to enhance crop productivity and improve physico-chemical properties of soil. Compared to other soil amendments, the high surface area and porosity of biochar enable it to adsorb or retain nutrients, contaminants and water and also provide a habitat for beneficial micro-organisms. Generally, the ash fraction of biochar consisted of nutrients including N, P, K, S, Ca, Mg, Mn, Fe, and Zn which are required for plant growth. Although biochar has the potential value to use as a soil amendment but still need efficient road-map for biochar production, classification, and its effect in different soil-environment and cost–benefit analysis, must be developed before implementation of field-scale application.

Keywords: Biochar, Pyrolysis; Soil amendment; Agronomic benefits; Pollutants

http://dx.doi.org/10.19045/bspab.2017.600161