Remediation of Phytotoxic Effect of Chromium by Different Amendments in Rice-Wheat Sequence

A pot-house experiment was carried out at Micronutrient Project, AAU, Anand to study the effect of Cr levels (0, 10, 20, 40, 80 and 160 mg/kg soil) in presence and absence of amendments (FYM and gypsum) on rice and wheat under rice-wheat sequences on coarse loamy soil with three replications under factorial completely randomized block design. The experimental results indicated the rice grain yield gradually decreased due to direct effect of Cr while residual effect was found beneficial up to Cr20 which improved grain yield of wheat by 15.09 per cent over control. Similarly, rice and wheat grain as well as straw yield were also found enhanced due to direct and residual effect of FYM and gypsum over their corresponding control. The Cr content in grain and straw of rice and wheat significantly increased with increase in Cr levels due to both direct and residual effect of Cr. The highest Cr content was recorded in straw followed by grain in both the crops. The application of farm yard manure (FYM) and gypsum significantly decreased Cr content of rice and wheat grain and straw due to direct and residual effect. The direct and residual effect of gypsum and FYM decreased Cr content of rice grain by 21.31 and 28.30 per cent over corresponding control. The Cr application increased DTPA-Cr of the soil due to direct and residual effect after rice and wheat. The application of amendments significantly decreased DTPA-Cr in the soil after both rice and wheat in the soil over control. The findings, in general, indicated that the toxic effect of Cr on crop could be mitigated more effectively with FYM application and reduce risk of health hazards for human beings and animals. However, the regular monitoring for soil quality is necessary for managing Cr pollution in the soil.