Unveiling Role of Poultry Litter-Derived Biochar and Boron on Chickpea Growth, Soil Chemistry, Nutrient Availability and Heavy Metal Accumulation

This study explores the combined effects of biochar and boron on chickpea growth, soil chemistry and nutrient composition offering a novel approach to sustainable agriculture. A controlled experiment was conducted using biochar derived from poultry litter at four doses (0%, 2%, 4%, and 8%) and boron supplementation at three levels (0, 1 and 2 mg kg− 1 boron). Growth attributes, soil chemistry, macro and micro nutrient status and heavy metals accumulation were determined in chickpea (Cicer arietinum). Phosphorus, potassium, magnesium and calcium uptake were promoted with higher biochar doses by 20.2%, 16.6%, 20.2% and 25% over control, respectively. Similarly, boron and copper picked with 8% of biochar, while nickel had the highest value with 2% of it. Boron treatments increased magnesium and manganese uptake, whereas they reduced calcium and copper accumulations in plant tissues. biochar inhibited lead, chromium and aluminum absorption at low doses (2%), but increased at higher doses. The highest phosphorus concentration (2458 mg kg⁻¹) was observed with 8% biochar, while magnesium and potassium contents increased by 28.9% and 15.6%, respectively. Principal component analysis showed strong positive correlations between heavy metal uptake and biochar application, highlighting potential shifts in bioavailability. Plant growth parameters responded positively to biochar but negatively to excessive boron. Soil EC increased by 47% under 8% biochar, underscoring the need for careful application to avoid salinity issues. Biochar and boron application rates can promote soil nutrient bioavailability and chickpea growth, and restrict heavy metal accumulation in plants. However, high applications limit plant growth due to intense heavy metal accumulation and ion imbalances in the plant. The application of 2% biochar and 1 mg kg− 1 boron are considered optimal because it enhances nutrient uptake, minimizes heavy metal accumulation, and maintains low salinity risk.