宁夏青铜峡农耕土壤硒含量分布特征及其影响因素分析

通过对青铜峡市农耕表层土壤和水稻全硒含量的测定，分析了青铜峡市农耕土壤硒含量分布特征及水稻子实硒含量影响因素。结果表明，表层土壤硒元素含量在0.057~0.95 mg·kg^-1之间，平均值为0.226 mg·kg^-1，83.55%的农耕土壤达到足硒水平（0.175~0.40 mg·kg^-1），其中连湖农场土壤硒元素含量均值最高，树新林场最低。不同土壤类型土壤硒元素含量表现为灌淤土 > 潮土 > 粗骨土 > 盐土 > 灰钙土 > 新积土。相关分析结果表明，影响研究区土壤硒元素含量的因素主要是土壤pH、有机质、铁氧化物、锰和CEC。此外，水稻子实硒含量不只受土壤全硒含量的影响，而且与土壤pH、有机质等因素密切相关。

Distribution characteristics of selenium in cultivated soil and its influencing factors in Qingtongxia City of Ningxia

The study determinated cultivated surface soil and rice total selenium and analyzed the main influencing factors of selenium distribution characteristics in soil and rice of cultivated soil in Qingtongxia. The results showed that the range of total selenium content in surface soil of farm was 0.057~0.950 mg·kg^-1, the average value of calculation was 0.226 mg·kg^-1, 83.55% of the cultivated soil reached the level of sufficient selenium(0.175~0.40 mg·kg^-1), and the soil in Lianhu farmland was the highest average, and Shuxin tree farm was the lowest. The contents of selenium in different soil types were as follows:irrigation silting soil > moisture soil > skeleton soil > saline soil > sierozem > fluvent soil. The correlation analysis showed that soil pH, organic matter, ferric oxide, manganese and CEC were the main factors affecting the soil selenium content in the research area. In addition, the selenium content in rice grain not only correlated with soil total selenium content, but also closely related to soil pH, organic matter and other factors.