水稻土镉形态分布特征及其生物效应研究

发布时间：2018-03-16 15:32

本文选题：水稻土　切入点：镉形态　出处：《西南农业学报》2017年02期 　论文类型：期刊论文

【摘要】：作物籽粒中镉来源于土壤,土壤中镉形态的含量与作物吸收量密切相关。本文旨在找出作物籽粒中镉与土壤镉形态之间的相关性,探究小麦/水稻籽粒中镉的来源,为阻断镉吸收提供理论依据。采用调查采样方法,对成都平原镉污染区冲积性水稻土耕作层土壤镉形态及对应的作物秸秆和籽粒镉含量进行了测试分析,研究镉超标水稻土不同形态镉的分布特征及其生物效应。结果表明:水稻土不同形态镉的平均含量高低排序为:铁锰氧化物结合态残留态水溶交换态有机质结合态碳酸盐结合态,各形态分布极不均衡,生物可利用形态所占比例较大。铁锰氧化物结合态镉与土壤pH值呈极显著正相关(r=0.712**,P0.01)。小麦、水稻籽粒与秸秆中镉含量均呈极显著正相关,相关系数分别为0.854**(P0.01)和0.872**(P0.01)。小麦秸秆和籽粒中镉含量与土壤中水溶交换态镉呈极显著正相关(r=0.677**和0.867**,P0.01),与其他形态相关性不显著;水稻籽粒中镉含量仅与土壤中水溶态镉含量呈显著正相关(r=0.573*,P0.05),与其他形态相关性不显著。镉污染区水稻土种植水稻和小麦农产品的镉含量超标风险较大。
[Abstract]:Cadmium in crop grains is derived from soil, and the content of cadmium forms in soil is closely related to crop uptake. The purpose of this paper is to find out the correlation between cadmium forms in crop grains and soil cadmium forms, and to explore the sources of cadmium in wheat / rice grains. In order to provide theoretical basis for blocking cadmium absorption, the cadmium morphology of cultivated layer of alluvial paddy soil and the cadmium content of crop straw and grain in CD contaminated area of Chengdu Plain were measured and analyzed by the method of investigation and sampling. The distribution characteristics and biological effects of cadmium in different forms of paddy soil were studied. The results showed that the average content of cadmium in different forms of paddy soil was in the order of iron and manganese oxide bound residual water-soluble exchangeable organic matter binding. Carbonate bound state, The distribution of various forms was very uneven, and the proportion of bioavailable forms was large. There was a very significant positive correlation between Fe and mn oxide bound cadmium and soil pH value, and there was a very significant positive correlation between CD content in wheat, rice grain and straw. The correlation coefficients were 0.854 (P 0.01) and 0.872 (P 0.01), respectively. There was a very significant positive correlation between the cadmium content in wheat straw and grain and the water-soluble exchangeable cadmium in soil, but there was no significant correlation between CD content in wheat straw and grain and water soluble exchange cadmium in soil. The CD content in rice grain was only positively correlated with the soluble CD content in soil, but not in other forms.
【作者单位】：四川省农业科学院土壤肥料研究所;重庆市长寿区农业委员会;大英县农业局;
【基金】：四川省科技支撑计划项目(2014NZ0008,2015NZ0108) 四川省农业科学院公益性项目(2016GYSH-024)
【分类号】：S153;S511;S512.1

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