Effect of chemical fertilizer on cadmium uptake by sugarcane grown in contaminated soil

Abstract

Background and Objective: Heavy metal especially Cd contamination to agricultural soil is one of the most serious environmental problems globally. Sugarcane grown in the contaminated area may absorb Cd and this may be dangerous for human consumption on the long run as it may be carcinogenic. Chemical fertilizer is used to increase the crop production and its application could affect to the level of Cd accumulation in plants. Thus, this study was conducted to study the effect of chemical fertilizer application on the Cd accumulation levels in both soil and sugarcane. Materials and Methods: The effect of 16-16-8 NPK fertilizer on the cadmium (Cd) uptake by sugarcane grown in Cd-contaminated soil was investigated in this study. The LK92-11 sugarcane seeds were cultivated in soil containing 58.3 mg total Cd (TCd) kg-1 soil to which 16-16-8 NPK fertilizer was subsequently applied at 0 (control), 31.25, 62.5 and 125 g m-2 at 1 and 5 months of cultivation. Soil and sugarcane samples were collected for Cd analysis after 2, 4, 6 and 8 months of cultivation. After harvesting, the soil and sugarcane split into the underground stems, roots, bagasse, leaves and juice were separately analyzed for their TCd content. Results: The highest TCd accumulation in the soil occurred with a fertilizer application dose of 125 g m-2 but with the lowest available Cd concentration. In contrast, the application of fertilizer at 31.25 g m-2 resulted in the highest Cd accumulation level in the roots (22.61, 21.50, 20.17 and 19.01 mg kg-1 at 2, 4, 6 and 8 months, respectively) followed by the underground stems>bagasse>leaves>juice. Conclusion: This study recommends the application of 16-16-8 NPK fertilizer at 31.25 g m-2 to Cd-contaminated soil because this concentration resulted in the greatest reduction in the TCd level in the soil (15.0%).