【摘要】 为筛选出能有效抑制水稻各部位吸收积累Cd及提高产量的有机和无机材料钝化剂组合,选取贵州存在稻米镉超标的水稻土,以水稻盆栽试验研究15种钝化剂组合对土壤中可交换态Cd、水稻各部位吸收积累Cd及稻谷产量的影响。结果表明:施用15种钝化剂组合使土壤pH上升0.25～1.04,土壤阳离子交换量增加2.65%～50.96%,土壤有机质上升0.22%～17.20%,土壤可交换态Cd含量降低5.21%～20.56%;水稻根系、秸秆、稻壳和糙米中Cd含量分别降低6.66%～45.58%、12.88%～49.76%、27.15%～59.79%和12.85%～68.62%,稻谷产量增加20.59%～62.14%,水稻根、秸秆、稻壳和糙米富集系数范围分别为1.01～1.67、0.16～0.28、0.12～0.22和0.09～0.24,根系对Cd的富集能力最大。施用生石灰+钝化剂1+鸡粪、生石灰+钝化剂2+鸡粪、生石灰+钝化剂3+鸡粪和生石灰+钝化剂4+鸡粪4种钝化剂具有较好的降Cd效果,均使糙米中Cd含量低于0.2 mg·kg^-1,符合国家食品污染物限量标准,且其增产作用又明显。该结果可为贵州山区稻田Cd污染土壤改良及安全利用提供科学依据。更多还原

【Abstract】 【Objective】As a toxic heavy metal element, Cd（Cadmium） pollution of the soil is a global threat to human health. Compared to the other heavy metals, Cd is easily absorbed by roots and transported to tender shoots of plants and accumulated therein, thus contaminating the edible parts of a variety of crops. Rice（Oryza sativa） is liable to absorb Cd from soil and store it in grain. Therefore,Cd pollution in paddy soil is becoming an increasingly serious problem in China. In view of the current situation of soil Cd pollution in China, i.e. low in pollution level and extensive, in pollution area, insitu remediation technology has become one of the hot spots in the study on remediation of heavy metal contaminated farmland soil in China. Therefore, this study is oriented to explore effects of Cd pollution passivators, organic and inorganic, on Cd adsorption and accumulation and yield rice as affected by combination of the paasivator.【Method】Paddy fields that yielded rice with Cd exceeding the standard for food safety in Guizhou Province were selected as research object, and soils were collected from the fields to cultivate rice in a pot experiment, which was designed to have 15 treatments, that is, Treatment 1（L as quicklime）; Treatment 2（M as chicken manure）; Treatment 3（D1 as Silicon-sulfhydryl ≥45% in effective ingredient）; Treatment 4（D2 as mixture of CaO≥20%, SiO2 4%, K2 O:4%, MgO 5%, S 2%, free water 8%and organic carbon 8%）, Treatment 5（D3 as mixture of CaO 24%, SiO2 3%, free water 8% and organic carbon 8%）; Treatment 6（D4 as mixture of CaO 30%, SiO2 35%, MgO 5%, Fe（OH）2 3 %, free water 5% and organic carbon 8 %）; Treatment 7（L+M）; Treatment 8（L+D1）; Treatment 9（L+D2）; Treatment 10（L+D3）;Treatment 11（L+D4）; Treatment 12（L+D1+M）; Treatment 13（L+D2+M）; Treatment 14（L+D3+M）; and Treatment 15（L+D4+M）. At the end of the exchangeable Cd content in the paddy soil, Cd content in root,straw, husk, and brown rice and rice yield were measured and analyzed in attempt to screen out the most effective treatment to mitigate Cd hazard and increase rice yield.【Result】15 treatments increased soil pH by 0.25～1.04, soil CEC by 2.65%～50.96% and soil organic matter by 0.22%～17.20%. and reduced exchangeable Cd content by 5.21%～20.56% in the soil. And they reduced Cd content in root, straw,husk and brown rice by 6.66%～45.58%, 12.88%～49.76%, 27.15%～59.79%, and 12.85%～68.62%,respectively, while increasing rice yield by 20.59%～62.14%. Cd enrichment coefficient of rice root, straw,husk and brown rice varied in the range of 1.01～1.67, 0.16～0.28, 0.12～0.22 and 0.09～0.24, respectively.Obviously root was the highest in Cd enrichment capacity. It was found in this experiment that Cd bioconcentration factor（BCF） of root, straw, husk, brown rice varied in the range of 1.01～1.67, 0.16～0.28,0.12～0.22 and 0.09～0.24, respectively, All the findings illustrate that root is the highest in Cd enrichment capacity, and the application of the 15 kinds of passivators reduces Cd accumulation in rice. Treatments12, 13, 14 and 15 or the application of L+D1+M, L+D2+M, L+D3+M, L+D4+M are the most effective in reducing Cd content in various rice organs and increasing rice yield. What is more important is that, the above four treatments keep Cd content in brown rice below 0.2 mg·kg^-1, which meets the requirement set in the National Food Standards（GB 2762-2017）.【Conclusion】In a word, the passivators of L+D1+M,L+D2+M, L+D3+M and L+D4+M can reduce Cd absorption and accumulation in different parts of rice, and increase rice yield. The findings may provide a certain scientific basis for the improvement and utilization of Cd-polluted paddy soil and ensure safe production of rice in mountainous areas of Guizhou Province.更多还原