天津盐碱荒地农垦过程对土壤环境中微量元素的影响(水田)

Impact of Microelements in Soil During Reclamation of Salt-Alkaline Badlands in Tianjin (Paddy Soil)

以天津盐碱荒地农垦过程为例,分析了盐碱荒地农垦为水田种植水稻后土壤环境中微量元素的变化特征。结果表明,随着垦殖年限的增加,Cd、As、Hg元素大量富集在0—20cm土壤中,其原因与污水泡田相关;Cu、Zn、Mn等植物生长必需的元素在20—40cm的土壤中的含量高于0—20cm土壤中的含量,与0—20cm土壤中这些元素有一部分已经被植物吸收有关,B的含量在0—20cm中较高,与人工施肥有关。污水灌溉仍是农业生产中土壤微量元素变化的主要影响因素。

Changes of microelements in paddy soils during reclamation of salt-alkaline badlands in Tianjin is evaluated in the present investigation. The results showed that a significant accumulation of Cd, As, Hg and so on in 0-20 cm of the paddy soil occurred after reclamation, because the soil had been dipped in with polluted water. It has been also shown that Cu, Zn, Mn and B that are necessary for plants in the layer of 20-40 cm were higher than that in 0-20 cm. This may be due to removal of the elements in later layer by plants. However, B content was higher in the layer of 0-20 cm, probably the contribution fromartificial fertilization. It may be concluded that irrigation using sewage on the paddy field was a main reason affecting the change of microelements in the soil.