摘要
在温室中利用土壤分层试验,模拟不同土层镉污染对水稻吸收镉的影响。结果表明,在任一生育期中,表层土壤(0—10cm)未污染的水稻体内各器官镉含量都明显低于表层污染的土壤;随着表层土壤中镉污染程度的增加,水稻体内镉含量逐渐增加;表层土壤未污染时,随着深层土壤(10—20cm)污染程度的加重,水稻地上部镉含量有增加的趋势,但当表层土壤污染时,随着深层土壤镉污染程度的增加,地上部各器官镉含量的差异不明显。当表层土中镉浓度为5mg·kg-1时,水稻籽粒中的镉含量为0.264mg·kg-1,超过国家粮食卫生标准(0.2mg·kg-1);表层土壤未污染时,即使当深层土壤镉浓度为10mg·kg-1时,水稻籽粒中镉含量仅为0.032mg·kg-1,低于国家粮食卫生标准。
It has been found that cadmium in rice shoot increased with top-soil (0—10 cm) free of pollution, when the metal content increased in subsoil. Howe ver, as top-soil was polluted, with top of pollution of the metal increased, ca dmium in rice shoot was insignificantly higher than the control, suggesting tha t cadmium in rice shoot was mainly originated from the top of soil.During ripeni ng stage, the contents of Cd in rice grain were influenced by the different cont ents of Cd in the soil profile in comparison with the control having 0.005 mg· kg-1. As the Cd concentrations in the top-soil increased, the metal in grains were significantly enhanced. For example, if the metal content in the soil was 5 .0 mg·kg-1, its content in grain accessed to as high as 0.264 mg·kg-1, a lready exceeding the maximum acceptable concentration (0.2 mg·kg-1). In contra st, if the top-soil was not polluted by the metal, the less possibility of poll ution of Cd for the grain took place, even in the case of heavily polluted subso il. We have discovered from our test that when the top-soil had little Cd, the grain just had 0.032 mg·kg-1 of Cd, even the subsoil contained as high as 10 m g·kg-1 of Cd. From the mentioned above, it may be concluded that the Cd pollut ion in rice grain was mainly from the contamination of the pollutant in top-soi l, rather that in subsoil.
出处
《农业环境保护》
CSCD
北大核心
2002年第3期221-224,共4页
Agro-Environmental Protection
