摘要
盆栽试验研究稻草与紫云英对土壤中外源Cd形态及其生物有效性的影响结果表明 ,添加稻草与紫云英可降低水稻分蘖期潮土和红壤交换态镉含量 ,且二者在不同土壤的影响不同。 2种有机物料在水稻分蘖期固定作用并不稳定 ,随时间的推移 ,氧化锰结合态和紧有机质结合态吸附的镉将随紧有机质的分解和活性锰的还原被释放出来 ,并向交换态镉转化 ,提高Cd的生物有效性。水稻对外源Cd吸收与Cd在土壤中形态密切相关 ,水稻分蘖期稻草与紫云英均可抑制水稻根和茎叶对外源Cd的吸收 ,至成熟期水稻根、茎叶和糙米中Cd含量迅速增加 。
The effects of rice straw and the Chinese milk vecth on the forms of added Cd and its bioavailability in soil were studied in pot experiment. The results indicate that the rice straw and the Chinese milk vecth can significantly reduce the Ex (exchangeable) Cd contents of fluvo aquic soil and red soil in tillering stage. But the influence is different between the soils. The effects of rice straw and the Chinese milk vecth on the forms of added Cd in tillering stage are not stable. From tillering to mature stage, Sob Cd (strong organic bound) and Mn Cd are released and transformed into Ex Cd with the decomposition of strong organic material and reduction of active Mn. The Cd uptake by rice is closely related to the forms of Cd. In tillering stage, these two kinds of organic materials can inhibit the Cd uptake by root and stem of rice. But in mature stage, Cd contents in root, stem and leaf, and grain of rice rise rapidly, which results from the increase of Ex Cd and decrease of Sob Cd.
出处
《中国生态农业学报》
CAS
CSCD
2004年第3期105-108,共4页
Chinese Journal of Eco-Agriculture
关键词
有机物料
外源镉
形态特征
生物有效性
土壤肥力
Rice straw, Chinese milk vecth, Rice, Red soil, Fluvo aquic soil, Cd form, Bioavailability
