Research & Development Center for Grasses and Environment, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, People's Republic of China.
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China.
Environ Sci Pollut Res Int. 2017 Oct;24(28):22340-22352. doi: 10.1007/s11356-017-9854-z. Epub 2017 Aug 11.
Biochar produced from rice straw (RC) and maize stalk (MC) was amended to the heavy metal-contaminated soil to investigate the effects of different biochar feedstock and particle size (fine, moderate, coarse) on the accumulation of Cd, Zn, Pb, and As in Brassica chinensis L. (Chinese cabbage). The concentrations of Cd, Zn, and Pb in shoot were decreased by up to 57, 75, and 63%, respectively, after biochar addition (4%). Only MC decreased As concentration in B. chinensis L. shoots by up to 61%. Biochar treatments significantly decreased NHNO-extractable concentrations of Cd, Zn, and Pb in soil by 47-62, 33-66, and 38-71%, respectively, yet increased that of As by up to 147%. Amendment of RC was more effective on immobilizing Cd, Zn, and Pb, but mobilizing soil As, than MC. A decrease in biochar particle size greatly contributed to the immobilization of Cd, Zn, and Pb in soil and thereby the reduction of their accumulations in B. chinensis L. shoots, especially RC. Increases in soil pH and extractable P induced by biochar addition contributed to the sequestration of Cd, Zn, and Pb and the mobilization of As. Shoot biomass, root biomass, and root system of B. chinensis L. were enhanced with biochar amendments, especially RC. This study indicates that biochar addition could potentially decrease Cd, Zn, Pb, and As accumulations in B. chinensis L., and simultaneously increase its yield. A decrease in biochar particle size is favorable to improve the immobilization of heavy metals (except As). The reduction in Cd, Zn, Pb, and As levels in B. chinensis L. shoots by biochar amendment could be mainly attributed to a function of heavy metal mobility in soil, plant translocation factor, and root uptake.
生物炭由稻草（RC）和玉米秸秆（MC）制成，并添加到重金属污染土壤中，以研究不同生物炭原料和粒径（细、中、粗）对小白菜（ Brassica chinensis L.）中 Cd、Zn、Pb 和 As 积累的影响。添加生物炭（4%）后，植株中 Cd、Zn 和 Pb 的浓度分别降低了 57%、75%和 63%。只有 MC 降低了小白菜地上部 As 的浓度，达 61%。生物炭处理显著降低了土壤中 NH4NO3 可提取态 Cd、Zn 和 Pb 的浓度，分别降低了 47-62%、33-66%和 38-71%，而 As 的浓度则增加了 147%。与 MC 相比，RC 更有效地固定 Cd、Zn 和 Pb，但活化了土壤中的 As。生物炭粒径的减小极大地促进了土壤中 Cd、Zn 和 Pb 的固定，从而减少了它们在小白菜地上部的积累，尤其是在 RC 中。生物炭添加引起的土壤 pH 值和可提取 P 的增加有助于 Cd、Zn 和 Pb 的固定和 As 的活化。生物炭添加增强了小白菜的地上部生物量、根系生物量和根系系统，尤其是 RC。本研究表明，生物炭添加可能降低小白菜中 Cd、Zn、Pb 和 As 的积累，同时增加其产量。生物炭粒径的减小有利于提高重金属（除 As 外）的固定性。生物炭添加降低小白菜地上部 Cd、Zn、Pb 和 As 含量的主要原因是土壤中重金属的移动性、植物转运因子和根系吸收。
