• 中文核心期刊
  • CSCD来源期刊
  • 中国科技核心期刊
  • CA、CABI、ZR收录期刊

不同调控措施对土壤-水稻系统中镉累积与转运的影响

Effects of Control Methods on Bioconcentration and Translocation of Cadmium between Soil and Rice Plants

  • 摘要:
      目的  探讨不同调控措施对稻田土壤-水稻系统中重金属镉的累积与转运的影响。
      方法  通过田间试验对几种污染源控制措施(沉降截源、清洁水灌溉、稻草还田/离田)及施用石灰对污染区醴陵及益阳农田系统中重金属的影响进行研究。
      结果  与稻草还田对照处理相比,除施用石灰外,其他处理对土壤中镉的有效性影响并不显著。施用石灰能明显降低污染土壤中镉的有效态含量和水稻中镉的累积量。与对照相比,石灰处理下土壤中镉的弱酸提取态含量最低,而秸秆离田处理下土壤中弱酸提取态镉含量最高,且可还原态镉向弱酸提取态镉进行了转化。分析水稻各部位的镉富集与转运系数表明,施用石灰、沉降截源及清洁水灌溉等调控措施可降低水稻地上部位镉的富集系数,减少水稻对重金属的累积量,且施用石灰处理与截断大气源处理最高可分别降低水稻籽粒中镉含量40%与8%。
      结论  在污染区农田施用石灰、控制大气源、净化农田灌溉水,同时将污染秸秆移除农田等措施,可有效降低水稻镉的积累量,有助于实现污染农田土壤安全利用和水稻的安全生产。

     

    Abstract:
      Objective   Effects of various pollution control methods on Cd accumulation and transport between contaminated soil and rice plants grown on the land were analyzed.
      Method   Field experiments were conducted on the contaminated lots at Liling and Yiyang of Hunan Province to investigate the effects of various control measures, including eliminating atmospheric Cd deposition, cleansing land by irrigation, and removing contaminated spent straws from field, as well as applying lime on soil, along with returning cut rice straws to land as control (CK).
      Result   Other than the lime application, the tested methods yielded no significant effects on Cd in soil in comparison to CK. Lime significantly neutralized Cd in soil and reduced the heavy metal content in rice grown on the lot. Compared with CK, the acid-extractable Cd in soil was lowest under the lime treatment and highest with straws removal, which also resulted in partial conversion of the reducible Cd to the acid-extractable fractions. The lime application, atmospheric pollution cutoff, or irrigation with groundwater could lower the Cd bioconcentration and accumulation in the aboveground rice tissues. For instance, a reduction on Cd in rice grains of approximately 40% by the lime application or 8% by the atmospheric interception was achieved.
      Conclusion  The treatments on Cd contaminated soil by lime application, deposition prevention, water cleansing, or straw removal could reduce in varying degrees of heavy metal accumulation in rice improving safety of the food consumption.

     

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