Biochar Derived from Agro-Industrial Waste: Applications in Agricultural and Environmental Applications

The aim of this study was to investigate in vegetation and laboratory experiments the impact of biochars derived from agro-food industry waste (wheat bran and cherry pits) on selected soil chemical properties, maize yield, and chemical composition, as well as their ability to adsorb zinc and copper, thereby reducing their uptake by plants. The obtained results indicate that biochars produced under the same pyrolysis conditions differ in chemical composition. Both biochars significantly increased the total organic carbon (TOC) and total nitrogen (TN) content in the soil, but they did not affect the availability of nutrients in the soil. The tested biochars did not enhance plant yields or increase the uptake of N, P, K, Mg, and Ca by plants. However, both biochars reduced the uptake of Zn and Cu by plants due to the adsorption of these elements by the biochars. The results obtained in the laboratory experiment indicate that biochar from wheat bran adsorbed approximately 438.5 mM(+) kg−1 and 566.8 mM(+) kg−1, while biochar from cherry pits adsorbed approximately 239.4 mM(+) kg−1 and 303.5 mM(+) kg−1 from the solution. The ion exchange contribution to the adsorption of Zn2+ and Cu2+ by biochar from wheat bran was approximately 65.8% and 65.0%, respectively. In contrast, for biochar from cherry pits, the contributions were approximately 59.4% and 44.7%, respectively.