酸雨区不同用地类型土壤有效态Cd含量季节变化及关键影响因子

发布时间：2018-01-01 14:33

本文关键词：酸雨区不同用地类型土壤有效态Cd含量季节变化及关键影响因子　出处：《环境科学》2017年09期 　论文类型：期刊论文

【摘要】：探明污染土壤重金属有效态含量的季节变化特征及其敏感影响因子,对农业生产过程中减低重金属生态风险具有重要的参考价值.研究于湘江中下游典型Cd超标农业小流域中选取稻田、旱作蔬菜地、丘陵林地这3类主要用地类型,分析不同用地类型Cd活性的季节变化特征及其与土壤基本理化参数的关联.为期1 a的原位监测结果显示,研究区为典型酸雨区,雨水p H值呈现冬、春季节低于夏、秋季.稻田土壤总Cd含量显著高于旱作蔬菜地,菜地显著高于林地,3种用地类型土壤总Cd含量季节特征相似,均为夏秋季节略低于冬春两季.3种用地类型Cd有效态季节变化与总Cd含量无明显的相关性,稻田土壤有效态Cd含量在5~9月的作物生长季明显低于其他月份,而菜地和林地则恰好相反.稻田土壤Cd有效性的最关键影响因子为Eh,呈显著正相关,与土壤p H负相关,菜地土壤与土壤TOC明显负相关,而林地土壤Cd有效性与水溶性有机碳、TOC呈现明显的正相关关系.研究可为Cd超标土壤污染阻控与农业安全生产提供一定的数据参考.
[Abstract]:The seasonal variation characteristics and sensitive factors of the available heavy metal contents in contaminated soils were investigated. It has an important reference value for reducing the ecological risk of heavy metals in the agricultural production process. The selection of paddy field and dry vegetable land in the typical CD exceeding standard agricultural small watershed in the middle and lower reaches of Xiangjiang River were studied. The seasonal variation characteristics of CD activity of different land types and their correlation with soil physical and chemical parameters were analyzed. The study area is typical acid rain area, Rain Water pH value is winter, spring season is lower than summer, autumn. The total CD content of paddy soil is significantly higher than that of dry vegetable land, vegetable land is significantly higher than forest land. The seasonal characteristics of total CD content in the three land use types were similar, and there was no significant correlation between the seasonal variation of CD available state and the total CD content in summer and autumn seasons, which was slightly lower than that in winter and spring. 3. The available CD content in paddy soil was significantly lower than that in other growing seasons from 5 to September, while that in vegetable land and woodland was opposite. The most important factor affecting CD availability in paddy soil was Eh. There was a significant positive correlation between CD availability and soil pH, a negative correlation between vegetable soil and soil TOC, and a significant correlation between CD availability and water-soluble organic carbon. The study can provide some data reference for the prevention and control of CD excess soil pollution and agricultural safety production.
【作者单位】：湖南农业大学资源环境学院;中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室;
【基金】：国家自然科学基金项目(51409101) 湖南农田重金属污染来源及灌溉水处理研究与示范项目(湘财农指[2016]130号)
【分类号】：X517;X53
【正文快照】： 长沙410125)土壤重金属超标已成为当代社会最为关注的全球性环境污染问题之一[1,2],我国近2×107hm2农田存在不同程度的重金属超标问题,其中以西南地区的重金属超标问题尤为严重[1,3,4].湖南是我国著名的有色金属之乡,多数有色以及稀有金属矿产的采冶均集中分布在湘江流域内,

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