Effect of biochars on the concentration of plant-available elements in the soil

Abstract

To solve environmental problems and reduce economic costs, it is necessary to improve mineral fertilizer application systems by developing and introducing new technologies, including the use of biochars. Due to the lack of effective monitoring of soil changes, it is difficult to adjust fertilizer application rates. This determines the importance of information on the elemental composition of biochar ameliorants used to reduce the mobility of heavy metals in the soil. The use of biochar for remediation of contaminated soils is based on its ability to immobilize heavy metals and organic pollutants. In this work biochars were used, obtained by slow pyrolysis of organic materials of different types: pine sawdust, cattle manure, wheat straw, pine nut shells and brewer's grains. The effect of biochars (biochar application at a dose of 10 t ha−1) on the concentration of 13 elements (C, N, K, P, Mg, Ca, Fe, Mn, Pb, Ni, Cr, Cd, Co) in the soil was analyzed. The data collected after growing of spring wheat (Triticum aestivum L.) on the sod-podzolic soils were analyzed. It has been established that the heavy metals concentrations in the studied soils reclaimed with biochars are significantly lower than the maximum allowable concentrations for soils (MAC). The content of lead (Pb) in soils treated with biochars is 9 or more times lower than the MAC level, and biochar, produced from manure, significantly reduces the concentration of this metal in the soil.