Hu Xue-Fang, Tian Zhi-Qing, Liang Liang, Chen Jun-de, Zhang Zhi-Min, Zhu Xiang-Min, Wang Shi-Kun
Chinese Academy of Agricultural Engineering, Beijing 100125, China.
Key Laboratory of Agro-Products Postharvest Handling, Ministry of Agriculture, Beijing 100121, China.
Huan Jing Ke Xue. 2018 Jul 8;39(7):3409-3417. doi: 10.13227/j.hjkx.201711084.
Using selected sepiolite (SEP) and biochar (BC) as contrasts, we investigated the effects of a new cross-linked modified chitin (CC) on the bioavailability of Pb and Cd in soils, the yield of rice, and the absorption and accumulation of Pb and Cd in different parts of rice plants in a field environment. We hope this study provides the basis for the application of this material to improve soil fertility, and a direction for further soil improvement studies. A field experiment was carried out in 2015-2016 on selected Pb- and Cd-contaminated rice fields in Linghai, Liaoning. The changes in soil pH and available Pb and Cd in the soil were analyzed after the rice was harvested(October 2016). The effects of different treatments on the growth traits and yield of rice, the absorption of Pb and Cd by rice roots, stems and leaves, and grains were compared. The results showed that adding 167-333 kg·hm CC could increase the soil pH value by 0.36-0.45 units, decreasing the contents of available Pb and Cd in the soil by 46.39%-64.01% and 29.73%-43.24% respectively (<0.05). This treatment significantly reduced the Pb and Cd contents in all parts of rice (<0.05) compared to conventional fertilization; Pb and Cd contents in different parts of rice were significantly reduced (<0.05) by 16.09%-38.14% and 21.22%-31.38% in the root, 19.17%-46.92% and 25.66%-45.34% in the stem and leaf, and 29.47%-58.25% and 44.75%-64.02% in the grain, respectively. The treatment of adding 333 kg·hm CC (CC-2) reduced the contents of Pb and Cd in rice grains to 0.2041±0.011 mg·kg and 0.1922±0.021 mg·kg, respectively, which were lower than or close to the limit values of Pb and Cd in rice (0.20 mg·kg) as per GB 2762-2005. Compared to conventional fertilization, SEP treatment, and BC treatment, without adding any amendments, the yield per mu of rice under CC treatment increased by 33.6-47, 27.6-44, and 8.67-34.77 kg, respectively. The effect of CC-2 treatment on yield was the most obvious; the yield of rice per mu increased by 47 kg, and the yield increase rate was 8.59%. The ability of CC to repair soil contaminated by Pb and Cd and to reduce the contents of Pb and Cd in rice was not weaker than that of SEP and BC. The CC treatment also controlled the migration and redistribution of Pb and Cd in soil-rice systems, and significantly increased the yield of rice. It has good potential to ensure the safe production of rice.
以选用的海泡石（SEP）和生物炭（BC）作为对照，我们研究了一种新型交联改性甲壳素（CC）对田间环境下土壤中铅（Pb）和镉（Cd）的生物有效性、水稻产量以及水稻植株不同部位对Pb和Cd的吸收与积累的影响。我们希望本研究为该材料应用于提高土壤肥力提供依据，并为进一步的土壤改良研究指明方向。2015 - 2016年在辽宁凌海选定的受Pb和Cd污染的稻田进行了田间试验。在水稻收获后（2016年10月）分析了土壤pH值以及土壤中有效态Pb和Cd的变化。比较了不同处理对水稻生长性状和产量、水稻根、茎、叶及籽粒对Pb和Cd的吸收的影响。结果表明，添加167 - 333 kg·hm CC可使土壤pH值升高0.36 - 0.45个单位，土壤中有效态Pb和Cd含量分别降低46.39% - 64.01%和29.73% - 43.24%（P<0.05）。与常规施肥相比，该处理显著降低了水稻各部位的Pb和Cd含量（P<0.05）；水稻不同部位的Pb和Cd含量在根中分别显著降低（P<0.05）16.09% - 38.14%和21.22% - 31.38%，在茎和叶中分别降低19.17% - 46.92%和25.66% - 45.34%，在籽粒中分别降低29.47% - 58.25%和44.75% - 64.02%。添加333 kg·hm CC处理（CC - 2）使水稻籽粒中Pb和Cd含量分别降至0.2041±0.011 mg·kg和0.1922±0.021 mg·kg，低于或接近GB 2762 - 2005规定的水稻中Pb和Cd的限量值（0.20 mg·kg）。与常规施肥、SEP处理和BC处理相比，不添加任何改良剂，CC处理下水稻每亩产量分别增加33.6 - 47、27.6 - 44和8.67 - 34.77 kg。CC - 2处理对产量的影响最明显；水稻每亩产量增加47 kg，增产率为8.59%。CC修复Pb和Cd污染土壤以及降低水稻中Pb和Cd含量的能力不弱于SEP和BC。CC处理还控制了Pb和Cd在土壤 - 水稻系统中的迁移和再分配，并显著提高了水稻产量。它在确保水稻安全生产方面具有良好潜力。
