贵州省黔南州耕地土壤硒地球化学特征及富硒资源评价OA

Through investigation of farmland soil,crops and their supporting root systems in Qiannan Pre-fecture,a total of 49281 surface soil samples and 975 crops and their supporting root systems soil samples have been collected throughout the prefecture.Se element in the soil and crops has been mainly analyzed.It is showed that the variation range of selenium content in cultivated soil in Qiannan Prefecture is 0.02～19.20mg/kg,with an average content of 0.57mg/kg.Its background value is higher than that of cultivated soil in Guizhou province and national surface soil background value.The selenium content in cultivated soil is mainly significantly affected by the parent rock of the soil,and soil type,land use mode,and pH have a certain impact on it.The designated area of selenium rich cultivated land soil resources is over 3700km2,and accounts for over 72％of the evaluated land area in Qiannan Prefecture.The selenium rich cultivated land soil resources in the entire prefecture are mainly concentrated in Fuquan city,Weng'an county,Chan-gshun county,Longli county,Guiding county and Huishui county.Qiannan Prefecture has a rich variety of selenium rich agricultural products,with a selenium rich rate of over 80％for bulk crops,such as corn,high calcium apples,prickly pears,pomelo peels,chili peppers,tomatoes,lettuce,and purple king grapes.The average enrichment coefficient of selenium in soil by crops in the entire state is less than 7％.It is indicated that the selenium content level in crops is also influenced by factors,such as soil physico-chemical properties,selenium occurrence forms,crop types,and different parts of crops.This study will provide geochemical data support for the development of selenium rich industry and agricultural planning in Qiannan Prefecture.