Effect of monocalcium phosphate on the concentration of cadmium chemical fractions in two calcareous soils in Iran

Abstract

This study has been done to see the impact of phosphorus (P) on the concentration of cadmium (Cd) chemical fractions in two sorts of calcareous soils within the Fars province in Iran. Because of these interactions, we looked at the in fl uence of phosphorus on cadmium fractions. Variables were three levels of Cd (0.0, 30.0 and 60.0 mg kg -1 of soil from CdSO 4. 8H 2 O), three levels of p (0.0, 50.0 and 100.0 mg kg -1 of soil from Ca (H 2 PO 4 ) 2. H 2 O, three levels Incubation time (2, 4 and 8 weeks) and two sorts of soil (clay and sandy clay loam). The randomized completed block design (RCBD) was used for this research. After 2, 4 and 8 weeks of treatments, the sequential extraction procedure was done to determine cadmium concentration in WsEx (Water Soluble and Exchangeable), Sorb (EDTA ex-tractable), MnOx (Manganese Oxides), Car (Carbonate), OM (Organic matter), AFeOx (Amorphous Iron Oxides), CFeOx (Crystaline Fe oxides) and Res (Residual) fractions. The results showed that 69.0 to 71.0% of the added Cd was removed within the WsEx, Sorb and MnOx fractions. Cadmium concentration in Sorb, OM and Res fraction was higher within clay soil while cadmium concentration within WsEx and Car fractions were higher within sandy clay loam soil. Adding P as monocalcium phosphate reduced cadmium concentration within WsEx and Sorb fractions while increased Car, OM and Res fractions. The presence of phosphorus reduces the concentration of Cd in those forms that are easily released into soil solution (WsEx and Sorb) from where they’ll be absorbed by plants and thus decrease cadmium uptake by plants.