典型土壤不同提取态Cd与水稻吸收累积的关系

发布时间：2018-06-27 03:00

本文选题：土壤类型 + 镉　；参考：《环境科学》2017年06期

【摘要】：用盆栽试验方法研究典型土壤不同提取态Cd(TCLP-Cd和土壤溶液-Cd)及其与水稻吸收累积的关系.选取典型水稻土红黄泥(第四纪红色黏土母质发育)和紫泥田(紫色砂页岩母质发育的紫泥田),添加外源Cd梯度为0、0.5、1、2、5、10mg·kg~(-1),进行水稻盆栽试验,研究水稻不同生育期土壤pH、土壤溶液Cd(SSE-Cd)、TCLP提取态Cd(TCLP-Cd)及水稻各部位Cd积累量变化.结果表明,水稻生育期红黄泥SSE-Cd范围为0~2.50μg·L~(-1),平均0.57μg·L~(-1),而紫泥田浓度范围为0~1.60μg·L~(-1),平均0.48μg·L~(-1);红黄泥TCLP-Cd范围为0~0.25 mg·kg~(-1),平均0.10 mg·kg~(-1),而紫泥田为0~0.2mg·kg~(-1),平均0.07 mg·kg~(-1).随着水稻生育期的延长,土壤溶液Cd及TCLP提取态Cd均不同程度降低,且红黄泥高于紫泥田.TCLP提取态Cd与土壤溶液Cd呈显著正相关.随着外源Cd浓度的增加,水稻植株Cd累积量逐渐增加.土壤溶液Cd与米Cd、TCLP提取Cd与米Cd及水稻植株Cd累积量均呈极显著正相关.两种不同母质土壤环境容量差异很大,紫泥田土壤中Cd安全阈值是红黄泥的2.06倍,且两种土壤水稻Cd吸收累积差异明显,因而不同母质土壤Cd污染治理可能需要不同的措施.TCLP提取Cd与水稻Cd累积量相关性更高,提取量更大,可以准确评价土壤中Cd的生物有效性.
[Abstract]:Pot experiment was used to study the relationship between different extractable forms of CD (TCLP-CD) and soil solution (Cd) in typical soils and their relationship with rice uptake and accumulation. The pot experiment of rice was carried out by selecting typical paddy soil red yellow mud (Quaternary red clay parent material development) and purple mud field (purple mud field with purple sand shale parent material development) and adding exogenous CD gradient of 0 ~ 0. 5 ~ 1 ~ 1 ~ 2 ~ 2 ~ 2 ~ (10 mg 路kg ~ (-1). The changes of soil pH, soil solution CD (SSE-CD) and TCLP extractable CD (TCLP-CD) and CD accumulation in different parts of rice were studied at different growth stages of rice (Oryza sativa L.). The results showed that the range of SSE-CD in red and yellow mud was 0 ~ 2.50 渭 g / L ~ (-1), with an average of 0.57 渭 g / L ~ (-1), while that in purple mud was 0.60 渭 g / L ~ (-1), with an average of 0.48 渭 g / L ~ (-1), and that in red and yellow mud was 0.0.25 mg / kg ~ (-1), with an average of 0.10 mg / kg ~ (-1), while that in purple mud was 0.07 mg ~ (-1) and 0.0.25 mg / kg ~ (-1) in red and yellow mud. With the prolongation of rice growth period, CD in soil solution and CD extracted by TCLP decreased to different degrees, and red yellow mud was higher than that in purple mud field. TCLP extract CD was positively correlated with CD in soil solution. With the increase of exogenous CD concentration, CD accumulation in rice plants increased gradually. CD in soil solution was significantly positively correlated with CD accumulation in rice and rice plants. The CD safety threshold in purple mud soil was 2.06 times higher than that in red yellow mud, and there was significant difference in CD uptake and accumulation between the two soils. Therefore, different measures may be needed to control CD pollution in different parent soils. CD extraction by TCLP has a higher correlation with CD accumulation in rice and can accurately evaluate the bioavailability of CD in soil.
【作者单位】：中南林业科技大学环境科学与工程学院;
【基金】：国家科技支撑计划项目(2015BAD05B02) 农业部财政部重大专项(农办财函[2015]38号) 湖南省重点学科建设项目(2006180)
【分类号】：X53;X56

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