Cadmium Accumulation in the Soils and Wheat and Barley Plants Irrigated by Sewage (Case Study: Qods City)

Sewage, as a permanent source of agricultural water, in addition to supplying some of the water needs of the agricultural sector, contributes to saving and sustaining water resources in the country. The aim of this research was to investigate the accumulation of cadmium in soil and seed of wheat irrigated by refined sewage, and the barley crops irrigated by a mixture of unrefined sewage and well water in Qods city. For this purpose, nine samples of each irrigation treatment, 60 samples of wheat and barley (30 samples from each plant) and 30 soil samples in the each plant (from a depth of zero to 20 cm) were randomly collected to evaluate the physical and chemical properties of incoming water. The results showed that the amounts of electrical conductivity, biological oxygen demand, chemical oxygen demand and cadmium concentrations were more in the mixture of well water and unrefined water than the refined water. The mean of Cadmium concentration in wheat and barley grains was 0.018 and 0.012 mg/kg, respectively, and there was no significant difference between the Cadmium concentrations in the seeds of the two plants. The mean of cadmium concentrations in the soil of wheat and barley were respectively 0.070 and 0.058 mg/kg, which does not indicate a significant difference in this regard between the soils of the two plants. The results of the bioconcentration factor in wheat and barley seeds (0.020 and 0.242, respectively) showed that the ability of the barley plant to extract cadmium was higher than the wheat plant, but none of them demonstrated an ability to extract Cadmium with a coefficient higher than one.