Abstract:

A total of 28 samples of plow layer soil (0-25 cm) were collected from vegetable field in Chongqing to assess the total and available soil selenium (Se). The correlations of soil pH, organic matter content, total nitrogen content with total Se and available Se were analyzed. The results show that the soil total Se content in the study area is moderate and the overall average value is 0.22 mg/kg, slightly higher than the national soil background value. The average content of available Se content is 9.31µg/kg, which is at a high level. The variation coefficient of total Se and available Se is 76% and 53% respectively, indicating that there is a significant difference of Se content among the districts and counties in Chongqing. The correlation coefficient between soil total Se and available Se in the study area is 0.84 (P<0.01), which is significantly and positively correlated. Soil total Se and available Se are positively correlated with soil pH, organic matter and total nitrogen. Overall, the vegetable soil in Chongqing has the potential to develop Se-rich vegetables. In the future, the Se content in soil and vegetables could be improved by ameliorating soil acidity and alkalinity, increasing organic fertilizer and reasonably applying nitrogen fertilizer.

Key words: vegetable soil, total selenium, available selenium, influencing factors, correlation analysis, Chongqing