Accumulation efficiency of sunflower for lead and cadmium along with sustainable crop productivity under soil stress

Abstract

By nature coastal saline soils having several constraints in crop production in addition to that of heavy metals contamination deteriorate the soil productivity. To restore these contaminated soils, various remediation techniques in practices must be revamped. The present study was conducted to enhance the accumulation of heavy metals lead and cadmium in sunflower and improve the crop productivity using organic and inorganic soil amendments along with NPK fertilizers in completely randomized design. Soil samples were admitted to estimating soil physico chemical properties and DTPA extractable lead (Pb) and cadmium (Cd) and plant samples analyzed for DTPA extractable Pb and Cd concentrations under ICP-OES. The physico-chemical properties and DTPA extractable Pb and Cd concentrations were significantly influenced by amendments. Sunflower exhibited significant differences concerning accumulation of Pb and Cd against amendments tested along with higher biomass production. Higher shoot and root concentration of Pb(0.72,0.81 and 0.94,0.97 mg kg-1) and Cd (1.78, 2.32 and 0.35,0.32 mg kg-1)were recorded in the treatment RDF + EDTA, which was followed by RDF + Potassium humate and RDF + Zeolite application at 45 DAS and at harvest. Remediation efficiency of sunflower increased by application of RDF + EDTA through enhanced solubility of Pb and Cd in soil and thus increased Pb and Cd accumulation in root and shoot of sunflower. Whereas, the application of RDF+ FYM or press mud reduced the bioavailability of Pb and Cd in soil and thus restricted the accumulation of Pb and Cd by sunflower. Further, application of NPK fertilizers maintained the availability of nutrients and enhanced the yield of sunflower. The application of EDTA along with NPK fertilizer enhanced the bioaccumulation of lead and cadmium by sunflower without yield loss. Since, there is a possibility to cause leaching of HMs to ground water by EDTA. Hence, RDF plus Potassium humate or Zeolite can be recommended for lead and cadmium removal by sunflower in coastal saline soils with no loss in crop productivity.