Immobilization of chromium bioavailability through application of organic waste to Indian mustard (Brassica juncea) under chromium-contaminated Indian soils.

Industrialization results in production of large volume of wastewaters, and disposing of them become a serious problem. The wastewaters may have range of heavy metals, which have an impact on soil and plant health. The objective was to evaluate the influence of farm yard manure (FYM) and pressmud (PM) applications on Indian mustard growth and chromium (Cr) uptake in tannery effluent irrigated Cr-contaminated soil. Soil was collected from the tannery effluent irrigated fields (chromium contaminated) of Shekhpura village of Kanpur, India. A pot culture experiment was carried out by growing Indian mustard (Brassica juncea) var. RH 749 on the Cr-contaminated soil with application of different levels and combinations of FYM and PM (at 0, 2.5, and 5 g kg each). Biomass yield, Cr uptake, bioconcentration factor (BCF), transfer factor (TF), transfer efficiency (TE), and Cr removal indices were examined. Higher doses of FYM and PM resulted in reduction of Cr concentrations in shoot (6.60 to 2.50 µg g) and root (27.27 to 9.43 µg g); and absorption in plant tissues and had improved total dry matter yield (14.56 to 30.94 g pot). The use of FYM and PM had a substantial (p ≤ 0.05) impact on phytoremediation parameters like BCF (0.128 to 0.045), TE (59.61 to 64.51%), and Cr removal (0.65 to 0.51%). Combined application of FYM (5 g kg) and PM (5 g kg) had enhanced the dry matter yield of shoot (12.51 to 26.40 g pot) and root (2.05 to 4.54 g pot) and reduced the Cr uptake (138.54 to 108.79 mg pot) than the individual amendment addition of FYM (138.52 to 135.89 mg pot) and PM (126.02 to 130.52 mg pot). Combined application of FYM (5 g kg) and PM (5 g kg) could be beneficial for remediation of Cr-contaminated areas for cultivation of crops.