Effect of rice straw biochar on the bioavailability of cadmium in soil to Indian Mustard (Brassica juncea L. czern.) in relation to cadmium spiking

Abstract

A screenhouse experiment was conducted to study the effect of four rates of rice straw biochar (0, 1, 2 and 4%) on the bioavailability and accumulation of cadmium (Cd) by Indian mustard (Brassica juncea) in sewage water irrigated soil artificially spiked with Cd. Immobilization of Cd by rice straw biochar was assessed on the basis of DTPA-extractable Cd in soil and its content in shoots of Indian mustard. The results revealed a linear decrease in DTPA-Cd with the addition of rice straw biochar. Addition of biochar at the highest level (4%) decreased the mean Cd content in soil and in plant by 38.1 and 60.1%, respectively. Biochar addition increased dry matter yield (DMY) of Indian mustard and maximum yield increase of 19.3% was observed at 2% addition. The increase in DMY was decreased to 2.6% at 4% addition of biochar. The study indicated that rice straw biochar can be used as a remediation measure for contaminated sites and may prove to be a viable option for managing agricultural residues.