Exploring the distribution and enrichment regularities of Se(Selenium) in groundwater -soil-crop from a same space is a way to know the distribution and regularity patterns of Se under various environmental factors influence. This paper collected soil samples of 0~20 cm and 0~18 m, groundwaters in irrigation area, rice and corn seeds. Then samples were measured mass fraction and mass concentration of Se and relative elements in different media. Statistical analyses were used to acquire Se distribution and enrichment pattern. Results show that Se distribution histogram appears 2 mass fraction peaks among 0.10~0.25 mg?kg-1and 0.40~0.50 mg?kg-1, respectively in top soils. Correlation analyses show that Se in top soils has negative relationship with Al2O3 and Cr, positive relations with P, Hg and Mn (P<0.001). In soil profiles, Se accumulated at 0~100 cm and 7~11 m depth, while the predominant enrichment layer is 0~100 cm. The dominating chemical speciations of Se in different depths are strong organic combined state, humic combined state and residual state, those account for 87.3% of the total Se concentration with concentration decrease as the deep down. Se in groundwater has a mean concentration of 0.337×10-3 mg?L-1, and mainly exists as Se (VI), accounting for about 95% of the total result from easily dissolved but hardly absorbed. Se concentrations in rice seeds correlate with them in top soils (r=0.646, P=0.002), while they are no correlation between Se in corn seeds and in top soils (r=0.124, P=0.593). In Se-rich top soils of the studying area, the ratio of Se enrichment in rice seeds is 43%, and with the soil class of Se content being from marginal to abundant, the increment of Se concentration in rice seeds is 1.30 times of it in corn seeds.%探索同一空间下土壤-地下水-农作物中Se(Selenium)的分布规律和不同介质间Se的富集规律,以期为科学认识同环境中不同元素和指标对Se的分布及富集的影响作用提供理论依据.通过在富Se地区采集0~20 cm表层土壤样品、0~11 m深层土壤剖面样品、浅层灌溉用地下水样品以及主要农作物水稻和玉米籽实,采用统计分析方法分析了研究区不同介质中Se的分布规律、富集规律及影响因素.结果表明,研究区表层土壤中Se质量分数均值为0.311 mg?kg-1,直方图表明其在0.10~0.25 mg?kg-1和0.40~0.50 mg?kg-1处有2个明显峰值;相关分析表明表层土中Se质量分数与Al2O3和Cr呈负相关,与P、Hg和Mn呈正相关(P<0.001);Se在土壤剖面深度为0~100 cm以及7~11 m两个层位上富集,在0~100 cm富集作用更显著;不同深度土壤中Se主要赋存形态为强有机态、腐殖酸结合态和残渣态,三者最大可占总量的87.3%,且随着深度下降而迅速下降;研究区浅层地下水中Se质量浓度均值为0.337×10-3 mg?L-1,主要以Se(Ⅵ)存在,占总Se的95%,主要原因是Se(Ⅵ)溶解性、迁移性强且不易被吸附;水稻籽实Se与表层土Se质量分数相关性显著(r=0.646,P=0.002),玉米籽实与表层土Se质量分数无显著相关性(r=0.124,P=0.593);研究区富Se地块的水稻籽实富Se率为43%,土壤Se质量分数等级由边缘(0.125~0.175 mg?kg-1)至丰富(>0.40 mg?kg-1),水稻籽实Se的质量分数增量是玉米籽实的1.30倍.
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