Mitigation of boron toxicity in wheat via biochar amendment

Objective: This study was conducted to evaluate the effects of rice husk biochar (BC) on growth and nutrient element uptake of wheat (Triticum aestivum L.) under increasing boron (B) applications.Material and Methods: The experiment was carried out in a climate chamber, where combinations of three boron doses (0, 5, and 10 mg B kg-1) and three biochar levels (0%, 1%, and 2%) were applied. Dry matter yields of roots and shoots as well as concentrations of B, nitrogen (N), phosphorus (P), potassium (K), zinc (Zn), and iron (Fe) were determined.Results: Increasing boron doses suppressed root and shoot growth in wheat; however, biochar application markedly alleviated these adverse effects. In particular, the 2% biochar application increased root dry matter yield by 33% and shoot dry matter yield by 18% under conditions of boron toxicity. Moreover, biochar limited the accumulation of toxic boron, reducing B concentrations in roots and shoots by 37% and 65%, respectively. These ameliorative effects of biochar were attributed to its physical, chemical, and biological properties, including high surface area, negatively charged functional groups, pH buffering capacity, activation of antioxidant defense systems, and support for rhizosphere biota.Conclusion: Rice husk biochar presents significant potential as a sustainable ameliorative organic material in agricultural areas where boron toxicity is prevalent.