有机肥对镉锌污染土壤的改良效应

Amelioration of Soils Polluted by Cadmium and Zinc by Organic Matter

通过对苗期玉米的盆栽试验，探讨了在镉、锌污染土壤上施入不同量的有机肥并配合淋洗措施后土壤中镉、锌的形态转化、迁移规律和对植物生长的影响及改良效果。结果表明：施入有机肥后土壤中有效态镉、锌的含量明显降低，通过络合淋洗后土壤中镉、锌的总量减少显著，因而能够显著减轻Ｃｄ２＋、Ｚｎ２＋对植物的毒害程度。土壤Ｃｄ２＋为０—１００ｍｇ／ｋｇ时，施用猪粪４５０—６７５ｔ／ｈｍ２，玉米受毒害程度明显降低；土壤中Ｚｎ２＋的浓度为５００ｍｇ／ｋｇ时，增施猪粪２２５—４５０ｔ／ｈｍ２，玉米中锌的含量接近正常值。随有机肥施入量的增加玉米生物量增加也较显著，故在镉、锌污染的土壤上增施有机肥是一种十分有效的改良方法和途径。

This paper reports the amelioration of soils polluted by Cd and Zinc by organic matter and water leaching in a pot experiment using corn seedling as an index crop. The results indicated that the effective cadmium and zinc in the soils were reduced notably after applying organic matter and water leaching. When the added cadmium ranged from 0. 07 to 100mg/kg in soils, the toxicity of cadmium to corn degraded sharply after applying pig excrement at a dosage of 450—675 t/hm2. When the added zinc was at 500 mg/kg, the zinc in the corn approached normality after applying pig excrement at a dosage of 225—450t/hm2, the biological yield of corn was increased significantly. It is a very effective measure to apply organic matter to ameliorate the soils contaminated by cadmium and zinc.