中国农业科学 ›› 2005, Vol. 38 ›› Issue (01): 116-121 .

• 土壤肥料.节水灌溉 • 上一篇    下一篇

硅对土壤外源镉活性和玉米吸收镉的影响

杨超光,梁永超,娄运生,豆虎   

  1. 南京农业大学资源与环境科学学院
  • 收稿日期:2004-03-15 修回日期:1900-01-01 出版日期:2005-01-10 发布日期:2005-01-10
  • 通讯作者: 梁永超

Influence of Silicon on Cadmium Availability and Cadmium Uptake by Maize in Cadmium-contaminated Soil

,,,   

  1. 南京农业大学资源与环境科学学院
  • Received:2004-03-15 Revised:1900-01-01 Online:2005-01-10 Published:2005-01-10

摘要: 通过土培试验,研究了外源硅对土壤镉形态组成的影响,以及与玉米吸镉量的关系。结果表明,经0.1和1.0 mmol·kg-1(以CdSO4·8/3H2O加入)镉处理的土壤加入2.0 g·kg-1 硅酸钠(以Na2SiO3·9H2O加入,pH调至6.0)后可显著减轻镉对玉米的毒害,降低玉米吸镉量。加硅处理显著降低土壤中的交换态和铁锰结合态镉量,但显著提高碳酸盐结合态和残渣态镉的量。硅降低镉对玉米毒害的机制之一是硅改变了根外土壤中镉的形态,降低了镉的活性和生物有效性。

关键词: 镉形态组成, 镉毒害, 玉米,

Abstract: Pot experiments were conducted to investigate the influence of silicon on soil cadmium fractionation and cadmium uptake by maize (Zea may L. Nongda 108). The results showed that Cd toxicity in maize treated with Cd at 0.1 or 1.0 mmol·kg-1 (added as CdSO4·8/3H2O) was significantly alleviated by addition of 2.0 g·kg-1 sodium metasilicate (NaSiO3·9H2O) due to the decreased Cd uptake by maize. The ameliorative effect of Si was due to lower exchangeable Cd and Fe/Mn oxide-bound Cd, and higher carbonate-bound and residual Cd in Si-treated Cd-contaminated soils compared with non-Si-treated ones. One of the possible mechanisms of Si-enhancement of resistance to Cd toxicity is that silicate alters the Cd forms in soil, resulting in reduction of Cd bio-availability.

Key words: Cadmium fractionation, Cadmium toxicity, Maize, Silicon