The organic sorghum base in Maoba Town of Renhuai City was taken as the research object to study the geochemical distri-bution and occurrence form characteristics of soil selenium.The results showed that soil selenium content in sorghum base ranged from 0.24 to 1.35 mg/kg,with an average of 0.50 mg/kg,which was 1.72 times of the national soil background value.Se-enriched soil was widely distributed in the study area,accounting for 50％of the total area.The main chemical forms of soil selenium were organic-sul-fide bound and elemental selenium,accounting for 57.14％.The contents of Fe-Mn oxide bound selenium,exchangeable-carbonate bound selenium and residue selenium were not much different,accounting for 14.21％,14.19％and 12.70％,respectively.The water-soluble selenium was the lowest(1.76％).The sum of water-soluble selenium and exchangeable-carbonate bound selenium was rela-tively high(15.95％),which indicated that the bioavailability of soil selenium was strong,and it was easy to be absorbed and utilized by plants,and was beneficial to the cultivation and production of Se-enriched crops.The content of total selenium and various forms of selenium in soil was positively correlated with organic matter,indicating that the increase of organic matter was beneficial to the accu-mulation of selenium in soil.Soil pH was significantly positively correlated with water-soluble selenium content,but weakly negatively correlated with total selenium and other forms of selenium content.It was confirmed that selenium mainly existed in the form of sele-nate under alkaline conditions,which improved the bioavailability of selenium.Therefore,the sorghum base in the study area had a high level of selenium enrichment,a large distribution area,and a strong bioavailability of selenium,which provided a good land re-source condition for improving the quality of sorghum Hongyingzi,and developing local Se-enriched characteristic agricultural products.
sorghum base soilseleniumgeochemical distributionoccurrence formsSe-enriched soil evaluationMaoba Town,Renhuai City
维普
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