Sun Tong, Fu Yu-Tong, Li Ke, Xu Ying-Ming, Sun Yue-Bing
Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture and Rural Affairs(MARA), Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China.
College of Resources and Environment, Northeast Agricultural University, Harbin 150030, China.
Huan Jing Ke Xue. 2020 Jul 8;41(7):3426-3433. doi: 10.13227/j.hjkx.202001065.
Field experiments were conducted to investigate the effects of Mn-based modified rice husk biochar on soil organic carbon, aggregate structure, mass load, and the content of available Cd in aggregates. The results showed that the concentration of soil organic carbon increased gradually with additional modified biochar, resulting in a 3.2%-32% increase compared with the CK. Modified biochar improved the composition structure and stability of soil aggregates, and increased the amount of large aggregates (5-8 mm and 2-5 mm), while micro-aggregate production was inhibited (≤0.25 mm). Compared with the CK, mean weight diameter (MWD), geometrical mean weight (GMD), and soil aggregate structural body () of the soil aggregates increased by 15.1%-20.3%, 8.1%-22.4%, and 0.43%-7.6%, respectively. Cd was preferentially enriched on small aggregates, and the mass loading of Cd in soil aggregates increased gradually with decreasing particle size. The distribution factor of Cd showed significant enrichment in the 0.5-1 mm and 0.25-0.5 mm grain sizes, whereas it showed a clear loss in particle sizes of 5-8 mm and 2-5 mm. The addition of modified biochar reduced the content of DTPA-Cd in soil aggregates, causing 7.6%-15.1%, 15.6%-24.3%, 3.6%-13.8%, and 11.6%-13.7% reductions in 5-8, 2-5, 0.5-1.0, and 0.25-0.5 mm particle sizes, respectively. In general, modified biochar not only has a favorable optimizing function on the structure of soil aggregates, but also decreases the content of available Cd in different sizes of soil aggregates, increasing its significance in the remediation of Cd-contaminated soil.
开展田间试验，研究锰基改性稻壳生物炭对土壤有机碳、团聚体结构、质量负荷以及团聚体中有效镉含量的影响。结果表明，随着改性生物炭添加量的增加，土壤有机碳含量逐渐升高，与对照相比增加了3.2% - 32%。改性生物炭改善了土壤团聚体的组成结构和稳定性，增加了大团聚体（5 - 8毫米和2 - 5毫米）的数量，同时抑制了微团聚体（≤0.25毫米）的产生。与对照相比，土壤团聚体的平均重量直径（MWD）、几何平均重量（GMD）和土壤团聚体结构体（）分别增加了15.1% - 20.3%、8.1% - 22.4%和0.43% - 7.6%。镉优先富集在小团聚体上，土壤团聚体中镉的质量负荷随粒径减小而逐渐增加。镉的分配系数在0.5 - 1毫米和0.25 - 0.5毫米粒径处显著富集，而在5 - 8毫米和2 - 5毫米粒径处明显亏损。添加改性生物炭降低了土壤团聚体中DTPA - Cd的含量，在5 - 8、2 - 5、0.5 - 1.0和0.25 - 0.5毫米粒径处分别降低了7.6% - 15.1%、15.6% - 24.3%、3.6% - 13.8%和11.6% - 13.7%。总体而言，改性生物炭不仅对土壤团聚体结构具有良好的优化作用，还降低了不同粒径土壤团聚体中有效镉的含量，在镉污染土壤修复中具有重要意义。
