| 不同母质发育土壤Cd环境行为对水分管理模式的响应差异 |
| 摘要点击 1644 全文点击 543 投稿时间：2019-11-28 修订日期：2020-01-14 |
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| 中文关键词 水分管理 土壤母质 Cd 环境行为 土壤性质 |
| 英文关键词 water management parent material Cd environmental behavior soil properties |
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| 中文摘要 |
| 为探明不同母质发育稻田土壤Cd环境行为对水分管理模式变化的响应差异，通过不同的水分管理模式（长期淹水、湿润灌溉和干湿交替），在3种外源Cd水平下（0.5、2.0和5.0 mg·kg-1），对2种母质发育稻田土壤（黄泥田和麻砂泥）进行培养试验，分析了土壤氧化还原电位（Eh值）、pH值、土壤溶液Cd含量及土壤Cd赋存形态等指标.结果表明，不同母质发育土壤pH值和Eh值对水分管理模式变化的响应存在差异，土壤pH值变化率分别为长期淹水：-2.61%（黄泥田）和2.25%（麻砂泥），干湿交替：-1.96%（黄泥田）和0.52%（麻砂泥），湿润灌溉：-4.08%（黄泥田）和-0.52%（麻砂泥），2种母质土壤Eh值与pH值呈极显著负相关；2种母质类型土壤溶液Cd质量浓度随水分管理模式变化规律一致，且该质量浓度麻砂泥高于黄泥田，其均值分别为：1.03 μg·L-1（黄泥田），1.07 μg·L-1（麻砂泥）；水分管理模式对不同母质发育土壤中有机结合态和铁锰结合态Cd含量影响不显著，长期淹水会促进Cd向残渣态转化，且在黄泥田中这一促进作用比在麻砂泥中强.因此，在应用水分管理调控土壤Cd生物有效性的过程中，需根据土壤母质类型区别实施. |
| 英文摘要 |
| To explore the effects of water management mode on Cd environmental behavior in different parent-material-developed paddy soils, two parent-material-developed paddy soils (yellow clayey soil and granitic sandy soil) under three exogenous Cd levels (0.5, 2.0, and 5.0 mg·kg-1) with different water management modes (long-term flooding, moistening irrigation, and wet-dry rotation) were cultured in this study. The soil redox potential (Eh value), pH value, Cd concentration in soil solution, and Cd fractionation were also determined. The results showed that water management mode had different effects on the pH and Eh values of soils developed from different parent materials. The change rates of soil pH value were as follows:long-term flooding:-2.61% (yellow clayey soil), 2.25% (granitic sandy soil); alternation of dry and wet:-1.96% (yellow clayey soil); 0.52% (granitic sandy soil); wet irrigation:-4.08% (yellow clayey soil) and -0.52% (granitic sandy soil). The Eh value of the soils was negatively correlated with the pH value. The influence pattern of water management model on Cd mass concentration of soil solutions in two parent-material soils was consistent. The Cd mass concentration of soil solutions in granitic sandy soil was higher than that in yellow clayey soil. The mean values of Cd concentration were 1.03 μg·L-1 for yellow clayey soil and 1.07 μg·L-1 for granitic sandy soil. Water management mode had no significant effect on the proportions of organic bound Cd or Fe-Mn bound Cd in two different parent-material-developed soils. The long-term flooding mode promoted the transformation of exogenous Cd to residual Cd, and this promotion in yellow clayey soil was higher than that in granitic sandy soil. In conclusion, during the process of regulating soil Cd bioavailability through water management, the role of soil parent materials needs to be considered. |
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