Effect of applied chromium and amendments on dry matter yield and uptake in maize-Indian mustard rotation in soils irrigated with sewage and tubewell waters

Screen house study was conducted to determine the effects of farmyard manure (FYM) and lime on the growth and chromium (Cr) accumulation of maize and Indian mustard in artificially contaminated soils. One of the soils received sewage irrigation (SWI) and the other tubewell irrigation (TWI) and both were treated with Cr at 0 to 320 mg kg⁻¹ soil. Maize and Indian mustard were grown for 45 and 50 days, respectively. The results revealed that there was linear reduction in dry matter yield (DMY) of maize with increasing level of chromium irrespective of the amendment. Application of both FYM and lime reduced the magnitude of reduction with Cr contamination. At 320 mg Cr kg⁻¹ level, application of FYM improved the maize yield by 1.2% in TWI and 4.4% in SWI soil over control and mustard yield by 15% and 23.5%, in respective soils over control. The application of lime at the same level decreased the maize yield in both soils but increased the mustard yield by 1.5% in TWI and 11.9%, in SWI soils over control. The Cr content and uptake in maize and Indian mustard increased linearly and significantly at all levels of applied Cr in both the soils. The significant increase in Cr uptake was observed up to 80mg kg⁻¹ in both the crops but the uptake was more pronounced in mustard than in maize. The toxic effect of Cr on crops could be alleviated more effectively with FYM than with lime application.