生物质炭对根际土壤中镉形态转化及水稻镉累积的影响

发布时间：2018-10-18 16:34

【摘要】：采用盆栽试验和Tessier连续形态分析方法,研究了不同镉污染水平下(1.0、2.5、5.0 mg·kg-1),施入不同量的生物质炭(0.0、2.5、5.0、10.0 g·kg-1)对根际与非根际土壤中镉形态转化及水稻镉累积的影响。结果表明,(1)施入生物质炭后,根际与非根际土壤中镉的有效性降低。施入生物质炭后,根际与非根际土壤可交换态、碳酸盐结合态、铁锰氧化物结合态以及有机物结合态镉最大可分别降低34.64%和28.15%、49.27%和63.82%、34.58%和24.59%、60.04%和49.00%,残渣态镉最大可分别增加14.79%和16.57%。10.0 g·kg-1生物质炭处理影响效果最显著。在不同处理下,镉形态变化显著且根际与非根际之间的变化呈显著性差异。中低镉污染水平下,施入生物质炭,根际与非根际土壤中镉形态变化趋于一致但镉形态含量存在差异。高镉污染水平下,生物质炭引起根际与非根际土壤中镉形态变化但不显著。(2)施入生物质炭可显著降低水稻各部分镉含量且水稻根部镉含量大于地上部镉含量。在不同镉污染程度下,不同施入量生物质炭处理与对照相比,地上部、根部镉含量最大可分别降低42.51%、22.86%;根部镉含量最大是地上部的2.63倍。10.0 g·kg-1生物质炭对水稻各部分镉含量降低效果最明显。
[Abstract]:Pot experiment and Tessier continuous speciation analysis were used to study the effects of different amounts of biomass carbon (0.02.55.0g kg-1) on cadmium transformation and cadmium accumulation in rhizosphere and non-rhizosphere soil under different cadmium pollution levels (1.0 ~ 2.5g / 5.0 mg kg-1). The results showed that: (1) the availability of cadmium in rhizosphere and non-rhizosphere soil decreased after applying biomass charcoal. After the application of biomass charcoal, the exchangeable and carbonate bound forms of rhizosphere and non-rhizosphere soil were observed. The maximum reduction of Fe and mn oxide bound and organic bound cadmium were 34.64% and 28.15%, 49.27% and 63.82% and 24.590.04% and 49.00%, respectively. The residual cadmium content increased by 14.79% and 16.570.10.0 g kg-1, respectively. Under different treatments, the morphological changes of cadmium were significant and there were significant differences between rhizosphere and non-rhizosphere. Under the medium and low cadmium pollution level, the changes of cadmium forms in rhizosphere and non-rhizosphere soil tended to be the same, but there were differences in cadmium speciation content when biomass charcoal was applied. Under the high cadmium pollution level, biomass carbon caused the change of cadmium form in rhizosphere and non-rhizosphere soil, but it was not significant. (2) applying biomass charcoal could significantly reduce the cadmium content of rice, and the CD content in the root of rice was higher than that in the aboveground. Under different levels of cadmium pollution, the aboveground parts were treated with different amounts of biomass carbon, compared with the control. The maximum cadmium content in roots was decreased by 42.51% and 2.63 times as much as that in aboveground parts, respectively. 10.0 g kg-1 biomass charcoal had the most obvious effect on the reduction of cadmium content in rice.
【作者单位】：云南农业大学资源与环境学院;
【基金】：国家自然科学基金项目(41301349) 云南省应用基础研究计划项目(2013FB043)
【分类号】：X53;X56

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