重庆市蔬菜地土壤硒含量及其影响因素分析

采集重庆市28份蔬菜地耕作层土壤(0~25 cm),测定土壤全硒和有效硒含量,并对土壤pH、土壤有机质含量、土壤全氮含量与全硒和有效硒相关性进行分析。结果表明,研究区土壤全硒含量适中且总体均值为0.22 mg/kg,略高于全国土壤背景值,有效硒含量平均值为9.31 µg/kg,处于高水平,且全硒及有效硒的变异系数分别为76%和53%,说明各区县间硒含量差异较大。相关性分析表明,研究区土壤全硒与有效硒的相关系数为0.84(P<0.01),呈极显著正相关,土壤全硒及有效硒与pH、有机质及全氮之间均呈正相关。总体而言,重庆市蔬菜地土壤具有发展富硒蔬菜的潜力,今后可从土壤酸碱改良、增施有机肥、合理施用氮肥3个方面进行管理,提高土壤及蔬菜中硒含量。

Selenium Content of Vegetable Soil in Chongqing and Its Influencing Factors

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.