College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, PR China; Joint International Research Laboratory of Agriculture and Agri-product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225127, PR China.
College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, PR China.
Chemosphere. 2022 Mar;290:133349. doi: 10.1016/j.chemosphere.2021.133349. Epub 2021 Dec 21.
Biochar has been practically used as a soil conditioner in degraded or contaminated soils. Whether biochar would simultaneously affect soil micronutrient bioavailability in heavy metal-contaminated soils warrants research. A 90-d incubation of rice straw biochar with either Pb- or Cd-contaminated soils was conducted to investigate the biochar effect on Fe, Mn, Cu and Zn bioavailability. Biochar amendment decreased the DTPA-extractable, acid extractable and reducible Pb and Cd but increased the oxidizable and residual Pb and Cd. It decreased the DTPA-extractable Fe by 73.8% and 23.1% but increased the DTPA-extractable Mn by 9.8% and 44.3% in the neutral and acidic soil, respectively. The lower Fe availability was attributed to the liming effect and the increased numbers of oxygen-containing groups and organic-mineral phases of biochar over time. Biochar amendment increased soil bacterial richness and diversity in both soils. Rice straw biochar can effectively immobilize heavy metals and reduce soil Fe bioavailability but increase Mn bioavailability, which would potentially affect soil micronutrient fertility and productivity.
生物炭已实际用作退化或污染土壤的土壤改良剂。生物炭是否会同时影响重金属污染土壤中的土壤微量元素生物有效性，值得研究。通过 90 天的培养，用 Pb 或 Cd 污染的土壤与水稻秸秆生物炭进行了培养，以研究生物炭对 Fe、Mn、Cu 和 Zn 生物有效性的影响。生物炭的添加降低了 DTPA 可提取、酸提取和可还原 Pb 和 Cd，但增加了可氧化和残留 Pb 和 Cd。它分别降低了中性和酸性土壤中 DTPA 可提取 Fe 的 73.8%和 23.1%，但增加了 DTPA 可提取 Mn 的 9.8%和 44.3%。Fe 的生物有效性较低归因于生物炭随时间推移的石灰化效应以及含氧基团和有机-矿物相数量的增加。生物炭的添加增加了两种土壤中的土壤细菌丰富度和多样性。水稻秸秆生物炭可以有效地固定重金属并降低土壤 Fe 的生物有效性，但增加 Mn 的生物有效性，这可能会影响土壤微量元素的肥力和生产力。
