土壤中硒的形态

３种江苏省土壤，即潮盐土，灰潮土和黄棕壤原土硒和外加硒的形态分布研究结果表明，原土硒主要分布在残渣态Ｆ５上，３种土壤的Ｆ５的百分含量均达全量硒的８０％左右，而外加硒经４个培养后相对均匀地分布于可溶态Ｆ１（黄棕壤例外），交换态Ｆ２、氨水提取态Ｆ３和残渣态Ｆ５上，２种处理下硒形态分布与土壤ＰＨ值，粘粒和游离氧化铁含量有一定关系，ＰＨ值是潮盐土≈灰潮土＞黄宗壤，粘粒及游离氧化铁含量是黄棕壤＞潮盐土＞灰质

Speciation of Selenium in Soils

The distribution of natural and applied selenium(Se)species in three kinds of soil,i.e.,tide-saline soil(C),gray tide-soil(G)and yellow brown soil(Y),in Jiangsu province was studied. The results show that the naturally occurred Se species were mainly distributed as residual species (F5),and F5 ineach of the three kinds of soil accounted for about80% of total Se species. After an incubation for 4months, the applied Se species were relativelyhomogeneous to be distributed as soluble species(F1)(except in Y),exchangeable species(F2),aqueous ammonia extractable species(F3)andresidual species(F5).With two differenttreatments,the distribution of Se species was foundto be in some relation to soil pH value, glutinousgrains and free iron oxide levels.The soil pH valuewas in such an order as C=G>Y;the levels ofglutinous grain and free iron oxides:Y>C>G;thepercentage levels of F1 and F2:C=G>Y;and thepercentage levels of F3 and F5:Y>C>G.