湖南镉污染农田土壤钝化后两个品种水稻的生长效应

On the effects influencing the growth of the two rice varieties due to Cd contaminated soil passivation in Hunan

采用盆栽试验,考察镉污染农田土壤在添加不同含量ME钝化剂的条件下,不同品种水稻中镉分布规律及水稻生长效应。结果表明,添加ME钝化剂能提高土壤pH值,降低土壤中镉有效态含量,表现为分蘖期,湘晚籼13和岳优712品种土壤有效态镉质量比与空白比较分别降低了10%~13%和24.3%~45.7%;成熟期与空白比较分别降低了6.8%~15%和11.5%~21.8%。添加ME钝化剂能明显降低水稻植株、稻壳及糙米中镉质量比,湘晚籼13品种最大降幅分别为78.6%、80.9%及46.8%;岳优712品种最大降幅分别为59.2%、64.7%及79.5%。岳优712品种糙米中镉富集系数低于湘晚籼13品种。综合ME钝化剂对土壤有效态镉的钝化效果、水稻吸收重金属的抑制效应及水稻的生长效应,初步确定0.5%（质量分数）ME钝化剂处理优于1%。

The article is to devote itself to the study of the effects of ME deactivator on the distribution of Cd in two varieties of rices and those on the rice growth in the typical Cd-polluted farmland by doing a pot-cultivating experimental test. In our test, we have been engaged in an exploration and tracing activities of the effects of ME deactivator on the soil pH value, available Cd in the polluted soil at the rice tillering and maturing stages, in addition to Cd contents in the different parts of the two varieties of rice and their growing plant. The results of our experiments reveal that, first of all, the addition of the deactivator can help to increase pH value of the soil and reduce the effective Cd content in the soil. For example, at the tillering stage, Cd contents of the soil for planting rice species Xiangwanxian 13 and that of Yueyou 712 can be reduced by a percentage of 10%- 13 % and 24.3%-45.7% as compared with those of the blanks; At the maturing stage, Cd contents tend to decrease by 6.8%-15% and 11.5%-21.8%. Moreover, we have also found that adding ME deactivator can help to reduce significantly Cd content in the rice plant, the rice husk and the brown rice of Xiangwanxian 13 by 78.6% , 80.9% and 46.8% at most, respectively, while reducing Cd content of Yueyou 712 by 59.2% , 64.7% and 79.5% at most. Statistical- ly speaking, the distribution of Cd content in each part of the rice can be stated in a descending order shown below： plant 〉 husk 〉 brown rice. Furthermore, we have also found that Cd accumulation factor of the rice species known as Yueyou 712 tends to be lower than that in Xiangwanxian 13. What is more, when adding ME deactivator to the two species of rice, Cd enrichment factors have been found decreased significantly as compared with the blanks. The results show that Cd enrichment factor of the brown rice of Xiangwanxian 13 can be reduced maximally by 47.3% and that of Yueyou 712 can be reduced maximally by 80%. And, the last but not the least, considering the passivation effect of the soil available Cd, heavy metal absorption inhibitory and rice growth effect, the passivation effect of 0.5% ME treatment is better than 1%.