Determining the Spatial Distribution of Some Heavy Metals and Their effects on Soybean Yield at Sari Region

This study aimed to investigate the possibility of heavy metals contamination in the soil next to MDF factory located in Sari, Mazandaran province, Iran and their effects on soybean yield.

Accordingly, in an area of 3600 square meters 32 soil samples from 16 points (0-15 and 15-30 cm) and 48 plant samples were collected. After transferring the samples to the laboratory, absorption of heavy metals in the soil was measured. Also, the correlation between the yield and yield components with heavy metals were determined.

Distribution map of heavy metals and stepwise regression results showed that the cadmium significantly affected the number of unfilled pods per plant. When Cd increased, the number of unfilled pod increased as the rate of 0.5 per unit. In addition, a significant interaction existed between cadmium and iron for the 1000 grain weight. Accordingly, the maximum 1000 grain weight (131 g) was observed at the areas with the lowest concentration of cadmium and iron. Also, overlapping of distribution map of Zn and the number of unfilled grain per plant indicated that this parameter mainly controlled by Zn. Hence, the number of unfilled grain per plant increased as the rate of 0.53 per unit of Zn in the soil.

In conclusion, determining distribution map of heavy elements and overlapping with the yield and yield components not only help to identify contaminated areas and effective factors on spread of heavy metals into the soils but also help to evaluate their consequence effects on plant performance.