黑龙江省海伦市农耕区土壤硒分布特征及影响因素

Distribution Characteristics of Selenium Cultivated Soil and Its Influencing Factors in Hailun County of Heilongjiang Province

海伦市是黑龙江省耕地面积最大的县市,为了研究海伦市农耕区土壤硒的分布特征及影响因素,在海伦市农耕区采集了15 608件0~20 cm表层土壤样品和976件150~200 cm深层土壤样品,分析了土壤全硒含量、形态等土壤化学指标。结果表明,表层土壤硒元素含量在0.02~0.87 mg·kg^-1之间,平均含量0.29 mg·kg^-1,93.87%的农耕土壤为足硒土壤,4.99%的土壤为富硒土壤,几乎不存在硒潜在不足和缺硒土壤,无硒中毒地区。不同土壤类型的硒元素平均含量由高到低依次为水稻土>黑土>草甸土>风沙土>暗棕壤。相关分析结果表明:影响研究区土壤硒含量的主要因素是土壤pH、有机质和成土母质,土壤中硒元素赋存形式以有机结合态为主,土壤总硒、有机质、pH也是影响硒有效性的主要因素。

Heilongjiang Province is considered to be a region with severe selenium deficiency in China,and the distribution of selenium in soil is extremely uneven.Large-scale selenium-enriched soil was first discovered through agricultural geological surveys in recent years.Through the statistical analysis of soil selenium content in the farming area of Hailun County,the distribution characteristics and influencing factors of soil selenium were discussed,which provided a scientific basis for rational development of local selenium-rich resources.15,608 surface soil samples of 0-20 cm depth and 976 deep soil samples of 150-200 cm depth were collected in the study area,and chemical indicators such as total selenium content and selenium morphology were analyzed.The soil selenium content in the study area was evaluated according to the national selenium-enriched soil standard.The selenium content in the surface soil was between 0.02-0.87 mg·kg^-1 with the average content 0.29 mg·kg^-1.93.87%of the soil was selenium-sufficient soil,and 4.9%of the soil was selenium-rich soil.There was almost no potentially selenium deficient or deficient soil.The average content of selenium in different soil types from high to low:paddy soil>black soil>meadow soil>aeolian sandy soil>dark brown soil.Relevant analysis results showed that the main factors affecting soil selenium content in the study area were soil pH,organic matter and soil parent material.The main forms of selenium in soil were organic-bound forms.Total selenium,organic matter and pH were also the main factors affecting the selenium availability.