Se coupling relation and biological effectiveness study of the soil-wheat system in Yanqi Basin, southern Xinjiang

Wheat is an important grain crop in southern Xinjiang.Samples of wheat and corresponding root soil were collected from the main planting areas of wheat in Yanqi Basin of southern Xinjiang in order to study the correlation of Se in the soil-wheat system.Correlation analysis and multiple stepwise linear regression were used to find out the main controlling factors of Se in wheat by study of the content and Se speciation in soil and wheat, and the results show that strong organic matter bound Se (SOM-Se) and residual Se (Re-Se) are the main existing forms of Se, accounting for 65.15% of total Se in soil.The content of Se in soil is highly impacted by the degree of soil weathering, soil texture and organic matter.Organic Se is the mainly form in wheat, and inorganic Se accounts for 6.39%, which shows that Se in wheat is of high availability for human beings.The total Se in soil can indicate the content of Se in wheat, and water-soluble Se (Sol-Se) and ion-exchange Se (Ex-Se) are important indexes of Se available.The regression models based on total Se, B, SOM can explain the variance of 67% of Se in wheat.The standard of high effective Se-rich (Se-containing) wheat in the study area are given in combination with the factor of actual production, and the zoning map of high-efficiency utilization of Se-enriched soil is made, which supports the standardized management of Se-enriched wheat and flour processing, and improves the scientificity and practicability of Se -enriched soil delineation.