秸秆及生物炭添加对猪粪沼渣施肥水稻重金属积累的影响

发布时间：2018-10-23 21:22

【摘要】：秸秆还田在重金属污染稻田中被广泛应用并日益推广,其对土壤中重金属生物有效性和水稻重金属吸收积累产生的影响不容忽视.本研究选用因连续10年以上施用生猪沼渣沼液而导致重金属超标的水稻土,通过盆栽试验研究了不同的秸秆还田方式(直接还田或生物炭还田)与用量(0、1%、2%、4%和8%)对水稻重金属吸收积累的影响.结果表明,长期施用沼渣沼液可导致土壤重金属富集,其中,铜(Cu)、锌(Zn)和镉(Cd)含量高于国家土壤环境质量二级标准;秸秆或生物炭添加提高了水稻根或茎叶中重金属的截留,降低了籽粒中的积累;秸秆还田对于水稻Cu的吸收积累控制效果显著,添加1%、2%、4%和8%的秸秆分别使糙米中的Cu含量降低了35%、51%、64%和71%;生物炭添加对于控制水稻Cd的吸收积累效果显著,1%、2%、4%和8%生物炭添加量分别使水稻Cd的积累降低了21%、33%、36%和35%.对于Zn的吸收积累,两种还田方式均具有显著的控制效果;但在As污染稻田,秸秆直接还田应慎重,因为秸秆添加可显著提高糙米中As的积累.通过对比不同的秸秆还田量对控制糙米中重金属积累的效果,同时考虑该区域重金属的污染状况和还田成本,推荐在该施肥区域实施2%的秸秆直接还田.该研究将为水稻安全生产与农业废弃物循环利用提供理论与实践指导.
[Abstract]:Straw returning is widely used and popularized in heavy metal polluted paddy fields, and its effect on the bioavailability of heavy metals in soil and the accumulation of heavy metals in rice can not be ignored. In this study, Paddy soils with heavy metals exceeding the standard were selected as a result of the application of biogas liquid from pig residue for more than 10 years. Pot experiments were conducted to study the effects of different straw returning methods (direct or biochar returning) and the amount of straw returning (0 1% and 8%) on heavy metal uptake and accumulation in rice. The results showed that long-term application of biogas residue biogas liquid could lead to the enrichment of heavy metals in soil, among which the contents of Cu, (Cu), Zn (Zn) and CD (Cd) were higher than those of the national secondary standard of soil environmental quality, and the addition of straw or biochar increased the interception of heavy metals in rice roots or stems and leaves. The effect of straw returning to field on Cu absorption and accumulation in rice was significant. The addition of 4% and 8% straw reduced the Cu content in brown rice by 35% and 71%, respectively, and the addition of biochar had a remarkable effect on controlling the absorption and accumulation of Cd in rice, and the accumulation of Cd in rice decreased by 21 33 36% and 35 5% respectively by adding 4% and 8% biochar, respectively. For the absorption and accumulation of Zn, the two returning methods had significant control effect, but in As polluted paddy field, the direct return of straw to the field should be cautious, because straw addition could significantly increase the accumulation of As in brown rice. By comparing the effects of different amount of straw returning on controlling the accumulation of heavy metals in brown rice, considering the pollution of heavy metals and the cost of returning to the field, it was recommended that 2% straw should be directly returned to the field in the fertilized area. The research will provide theoretical and practical guidance for rice production safety and agricultural waste recycling.
【作者单位】：中国科学院生态环境研究中心土壤环境研究室;中国地质大学地球科学与资源学院;浙江省嘉兴市农业科学研究院;
【基金】：浙江省自然科学基金(No.LY15D010001) 浙江省嘉兴市科技计划(No.2014AZ21001)~~
【分类号】：X173

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