土壤干湿交替促进硒酸盐的还原作用

采集不同类型的新鲜土壤，经处理获得其风干、烘干的样品，重新潮湿后，加入一定量的Na2SeO4溶液，进行了培育实验（incubationexperiments）。实验结果表明，随着土壤干燥程度的增加，硒酸盐还原作用的速度也随之加快。这进一步证实，作为一种地球化学营力的土壤干湿交替，通过对土壤水势（soilwaterpotential）、微生物群落等的影响，间接地促进了硒酸盐还原作用，因而成为硒生物地球化学循环的驱动力之一。

ACCELERATION OF SELENATE REDUCTION BY ALTERNATIVE DRYING AND WETTING OF SOILS

Different types of fresh soil were collected.Solutions of Na2SeO4 were added to fresh,airDried and oven-dried soils for incubation experiments.The experimental results showed that seleNate reduction rates increased with increasing drying degree of soils,indicationg that alterative drying-rewetting of soils,as a geochemical stress,would accelerate indirectly selenate reduction by affecting soil water potential,microbial colony,etc.Therefore,alternative drying-rewetting of soils may be one of the driving forces for biogeochemical cycle of selenium.