Hyperaccumulator Oilcake Manure as an Alternative for Chelate-Induced Phytoremediation of Heavy Metals Contaminated Alluvial Soils.

The ability of hyperaccumulator oilcake manure as compared to chelates was investigated by growingCalendula officinalisL for phytoremediation of cadmium and lead contaminated alluvial soil. The combinatorial treatment T6[2.5 g kg−1oilcake manure + 5 mmol kg−1EDDS] caused maximum cadmium accumulation in root, shoot and flower up to 5.46, 4.74 and 1.37 mg kg−1and lead accumulation up to 16.11, 13.44 and 3.17 mg kg−1, respectively at Naini dump site, Allahabad (S3). The treatment showed maximum remediation efficiency for Cd (RR = 0.676%) and Pb (RR = 0.202%) at Mumfordganj contaminated site (S2). However, the above parameters were also observed at par with the treatment T5[2.5 g kg−1oilcake manure +2 g kg−1humic acid]. Applied EDDS altered chlorophyll–a, chlorophyll–b, and carotene contents of plants while application of oilcake manure enhanced their contents in plant by 3.73–8.65%, 5.81–17.65%, and 7.04–17.19%, respectively. The authors conclude that Calendula officinalis L has potential to be safely grown in moderately Cd and Pb-contaminated soils and application of hyperaccumulator oilcake manure boosts the photosynthetic pigments of the plant, leading to enhanced clean-up of the cadmium and lead-contaminated soils. Hence, the hyperaccumulator oilcake manure should be preferred over chelates for sustainable phytoremediation through soil-plant rhizospheric process. [ABSTRACT FROM AUTHOR]