The National Natural Science Foundation of China (Program Foundation of Institute for Scientific Research of Karst Area of NSFC-GZGOV( U1612442）)
【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, in-situ 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%, K2O: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. Treatments 12, 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.
韦小了,牟 力,付天岭,李相楹,何腾兵,何 季,滕 浪.不同钝化剂组合对水稻各部位吸收积累Cd及产量的影响[J].土壤学报,2019,56(4):883-894. DOI:10.11766/trxb201810120516 WEI Xiaoliao, MOU Li, FU Tianling, LI Xiangying, HE Tengbing, HE Ji, TENG Lang. Effects of Passivator on Cd Absorption and Accumulation and Yield of Rice as Affected by its Combination[J]. Acta Pedologica Sinica,2019,56(4):883-894.复制