Abstract:

A total of 94 samples of rice and soil were collected in functional zone of grain production in Cixi City, Zhejiang Province. Soil samples were tested for total content and speciation of selenium, pH and organic matter, and rice samples were tested for selenium. The characteristics of selenium in soil and rice were analyzed. According to the standard of Se-rich soil and multivariate correlation analysis theory, the evaluation method which based on total selenium in soil was compared with which based on total selenium, physical and chemical indicators of soil. The results indicated that 22.3% of soil samples and 53.2% of rice samples reached Se-rich standard, while selenium in soil and rice showed moderate variation, proving low-level impact of external factors and same geological background. Otherwise, there were significant differences between the two evaluation me-thods, the evaluation simply based on total selenium in soil commonly omited most of the Se-rich areas, and the Se-rich areas targeted by this method actually had lower rate of Se-rich rice. In comparison, the evaluation method based on total selenium in soil, physical and chemical indicators of soil outperformed the another evaluation method due to its better results of both more Se-rich samples and higher rate of Se-rich rice in targeted areas.

Key words: soil selenium, soil physical-chemical indicators, rice selenium, Se-rich soil evaluation, compara-tive study, Cixi City