Effects of Ammonium Chloride Fertilizer and its Application Stage on Cadmium Concentrations in Wheat ( Triticum aestivum L.) Grain

AbstractChloride (Cl) in saline soil increases the cadmium (Cd) concentration in crops. Here, we conducted a field experiment to investigate changes in Cd concentrations in wheat grain after the application of the Cl-containing fertilizer ammonium chloride (NH4Cl), with the aim of reducing its potential health risk. Effects of the application stage of NH4Cl fertilizer and leaching treatment (i.e., heavy rainfall) were also investigated in field and pot experiments. Both field and pot experiments showed that the Cd concentration of wheat grain was higher with NH4Cl fertilizer than with ammonium sulfate or urea fertilizers. Grain Cd concentration in wheat fertilized with NH4Cl at the tillering–jointing and flowering stages in the field experiment was 0.223 mg kg–1, which was about 1.5 times higher than that fertilized with urea. This finding is important because, in Japan, compound fertilizers containing NH4Cl are commonly used in fields for wheat cultivation. NH4Cl fertilizer application at the tillering–j...