Elucidating the impact of waste derived biochar on arsenic accumulation and responses in paddy rice (Oryza sativa L.)

Arsenic (As) is a non-essential metalloid, adversely affecting large population across the globe. In recent years, application of biological waste derived biochar for the purpose of crop growth improvement and abiotic stress amelioration has gained attention. The present study aimed to investigate the potential impact of bio-waste derived biochar (at 1, 2.5 and 5% application rate) particularly, kitchen waste biochar (KWB) and temple waste biochar (TWB) on growth, yield and As accumulation in rice plants, grown in As-contaminated soil. The application of KWB and TWB, in soil exhibited an improvement in plant growth, grain yield (3-53%) and harvest index (7-21%) in control and As contaminated soils. Increased activity of antioxidant enzymes was also recorded in rice plants grown in biochar amended soil. KWB and TWB application decreased As concentration in root (6-31%), shoot (25-61%) and grains (32-50%) of rice plant. The maximum decrease in As content in rice grains was found in 2.5% amendment of both the biochar, with 50 and 42.86% decrease in TWB and KWB respectively followed by 1 and 5% biochar amendments. TWB was found more efficient than the KWB in ameliorating As stress. The present findings demonstrated that waste derived biochar can act as a low-cost sustainable method for ameliorating As stress and reducing As accumulation in rice.