关键词: 硒, 化学行为, 控制因素, 闭蓄性硒

Abstract: The content and controlling factors of association forms of selenium in soil have been studied in the major soils in China by Jackson's procedure separating soil phosphonous.The results show that in acid conditions, the oxides or minerals of Fe, Al, Mn are main factors controlling selenium chemical behaviour in soils, and the action of Ca, Mg, K is not significant. But in alkaline condition, the compounds or minerals of Ca, Mg, K are main factors controlling unenveloped selenium in soil,with the oxides minerals of Fe,Al,Mn controlling the enveloped selenium. P, Si not only take part in the selenium fixation in soil and affect the selenium utilization by plant in complex anion. but also affect the selenium cycle in soil in the form of compounds and minerals.The staustic correlation between association selenium and other elements such as Cr, V , Sr, Ba, Co, Cu, Ni was not found in all the studied soils.

Key words: selenium, chemical behaviour, controlling factors, enveloped selenium