中国南方典型富硒区土壤硒有效性调控与评价

多目标区域地球化学调查发现中国南方酸性土壤的硒含量普遍较高,但其生物有效性一般较低,土壤硒有效性直接关系到富硒土地资源的可利用性,而土壤酸碱度是影响土壤硒生物有效性的重要因素。本文选取福建、海南富硒红壤(pH为3.91~4.98)、富硒水稻土(pH为4.33~5.75),以生石灰、燃煤炉渣为改良剂,分别设置6个实验处理以调控土壤硒生物有效性。结果表明:添加生石灰和燃煤炉渣均能提升南方酸性土壤的pH,上升幅度在1~2个pH单位,从而有利于土壤中硒元素的活化,显著提高了土壤中硒元素的生物有效性;燃煤炉渣用量与其10倍的生石灰对提升土壤硒有效度的效果相当,而燃煤炉渣作为调控物料更为经济、实用,既可以实现炉渣的有效利用,又可以改善土壤结构、提高土壤硒有效度。

Regulation and Evaluation of Selenium Availability in Se-rich Soils in Southern China

The multi-purpose regional geochemical survey presented that the concentration of selenium in acid soil in southern China is generally higher, but the bio-availability of selenium in soil is relatively low, which affects the usage of selenium-rich soil. Seven red soil samples with the range of pH value from 3.91 to 4.98 and 2 paddy soil samples with pH value of 4.33 and 5.75 respectively were collected from selenium-rich areas in Fujian province and Hainan Island. Regulation experiments were implemented to increase the bio-availability of selenium in soil with lime, coal slag as additives by six treatments in the lab. The results are as follows: soil pH can be significantly elevated with 1 to 2 units of pH usually as additives increased, which resulted in the release of selenium from binding states and increase of selenium availability in soil effectively; The usage of coal cinder with 10 times to quicklime have the same effect to promote selenium availability. The coal cinder as a regulation material is more economical and practical. It can not only realize the effective utilization of cinder, but also improve the soil structure and increase the soil selenium availability.