Determining the Cadmium Accumulation in Maize (Zea mays L.) and Soil Influenced by Phosphoric Fertilizers in Two Different Textured Soils

Abstract

Non-nutritive metals, especially cadmium (Cd), are present in P fertilizers; the long-term application of these P fertilizers leads to Cd build-up in the soil. The current study aims to evaluate the impacts of P sources and rates on the growth of maize (Zea mays L.) and the bioavailability of Cd. Twelve treatments including rock phosphate 4 g kg−1 (RP1); 8 g kg−1 (RP2); 12 g kg−1 (RP3)); single super phosphate 333 mg kg−1 (SSP1); 444 mg kg−1 (SSP2); 555 mg kg−1 (SSP3); di-ammonium phosphate 130 mg kg−1 (DAP1); 174 mg kg−1 (DAP2); 218 mg kg−1 (DAP3); mono-ammonium phosphate 115 mg kg−1 (MAP1); 154 mg kg−1 (MAP2); 193 mg kg−1 (MAP3) in two soil textures (sandy and clayey) were assessed. Results revealed that all P sources significantly influenced the plant growth and yield characteristics of maize (p ≤ 0.05). In both soil textures, P in soil and plant, plant growth and yield characteristics were maximized by MAP and DAP. Cadmium build-up in soil and uptake was also significantly (p ≤ 0.05) affected by P sources, levels, and soil texture. It was observed that Cd build-up in soil and uptake by plants boosted with increasing P levels. Maximum Cd concentration in plant root and shoot was found with SSP3, and its concentration in soil increased with MAP3, whereas the concentration was higher in sandy texture. The study concludes that type of P fertilizer should be determined based on texture and human consumption of the crop to avoid Cd toxicity.