Biochar Effect on Nutrients Availability to Barley

Abstract

Biochar can serve as a soil ameliorant preventing nutrient leaching. Due to its porous structure and chemical composition, it can also adsorb elements on its surface. However, various biochars have different sorption ability, and the mechanistic understanding of nutrient storage in biochar is missing. It is not clear if nutrients adsorbed by biochar will be available for plants. Therefore, it is necessary to investigate biochar efficacy in pure substrates to characterise its specific influence on plants. In this study, the sorption capacity and ability of the wood-based biochar to provide barley plants with nutrients was investigated. The sorption capacity of biochar was investigated by saturating it with Gelrigel nutrient solution. Then nutrient-enriched biochar was tested for its effect on barley growth in comparison with non-enriched biochar. The results of the sorption experiment showed that the wood-based biochar could adsorb high amounts of nutrients such as ammonium (NH₄⁺), potassium, calcium and phosphate (PO₄^3-), but not nitrate (NO₃^-). Nutrient-enriched biochar showed an ability to support 46% higher dry biomass of barley than non-enriched biochar. These results suggest a potential of nutrient-enriched biochar for recovering essential nutrients for plants.