Effect of soil texture and zinc oxide nanoparticles on growth and accumulation of cadmium by wheat: a life cycle study

Abstract

Cadmium (Cd) is getting worldwide attention due to its continuous accumulation in agricultural soils which is due to anthropogenic activities and finally Cd enters in food chain mainly through edible plants. Cadmium free food production on contaminated soils is great challenge which requires some innovative measures for crop production on such soils. The current study evaluated the efficiency of zinc oxide nanoparticles (ZnONPs) (0, 150 and 300 mg/kg) on the growth of wheat in texturally different soils including clay loam (CL), sandy clay loam (SCL), and sandy loam (SL) which were contaminated with were contaminated with 25 mg/kg of Cd before crop growth. Results depicted that doses of ZnONPs and soil textures significantly affected the biological yields, Zn and Cd uptake in wheat plants. The application of 300 mg/kg ZnONPs caused maximum increase in dry weights of shoot (66.6%), roots (58.5%), husk (137.8%) and grains (137.8%) in CL soil. The AB-DTPA extractable Zn was increased while Cd was decreased with doses of NPs depending upon soil textures. The maximum decrease in AB-DTPA extractable Cd was recorded in 300 mg/kg of ZnONPs treatment which was 58.7% in CL, 33.2% in SCL and 12.1% in SL soil as compared to respective controls. Minimum Cd concentrations in roots, shoots, husk and grain were found in 300 mg/kg ZnONPs amended CL soil which was 58%, 76.7%, 58%, and 82.6%, respectively. The minimum bioaccumulation factor (0.14), translocation index (2.46) and health risk index (0.05) was found in CL soil with the highest dose of NPs. The results concluded that use of ZnONPs significantly decreased Cd concentration while increased Zn concentrations in plants depending upon doses of NPs and soil textures.

Keywords: Cadmium; Metal bioavailability; Soil texture; Wheat growth; Zin oxide nano.