南疆焉耆盆地土壤-小麦系统硒耦合关系及生物有效性

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

为研究土壤-小麦系统硒的关联性,采集南疆焉耆盆地小麦主要种植区小麦及对应根系土样品,通过相关分析、多元逐步线性回归方法,探讨土壤、小麦中Se含量及形态,查明影响小麦中硒的主要控制因素。结果表明,强有机质结合态硒(SOM-Se)和残渣态硒(Re-Se)是土壤硒的主要赋存形态,占土壤总Se含量的65.15%;土壤中硒受土壤风化程度、土壤质地和有机质含量影响明显;小麦籽粒中硒主要以有机硒形式存在,无机硒仅占全Se含量的6.39%,小麦硒的可给性高;土壤总Se含量可以很好地指示小麦Se含量水平,水溶态硒(Sol-Se)、离子交换态硒(Ex-Se)为有效硒的重要指标。基于土壤总Se、B、SOM构建的小麦硒吸收模型,可解释小麦吸收硒67%的方差。结合实际生产,给出了研究区高效富硒(含硒)小麦判别标准。据此编制富硒土壤高效利用区划图,有效地支撑了焉耆盆地富硒小麦标准化管理和面粉加工,提高了富硒土壤划定的科学性和实用性。

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.