title: Biochar amendment immobilizes lead in rice paddy soils and reduces its phytoavailability.
abstract: This study aimed to determine effects of rice straw biochar on Pb sequestration in a soil-rice system. Pot experiments were conducted with rice plants in Pb-contaminated paddy soils that had been amended with 0, 2.5, and 5% (w/w) biochar. Compared to the control treatment, amendment with 5% biochar resulted in 54 and 94% decreases in the acid soluble and CaCl2-extractable Pb, respectively, in soils containing rice plants at the maturity stage. The amount of Fe-plaque on root surfaces and the Pb concentrations of the Fe-plaque were also reduced in biochar amended soils. Furthermore, lead species in rice roots were determined using Pb L3-edge X-ray absorption near edge structure (XANES), and although Pb-ferrihydrite complexes dominated Pb inventories, increasing amounts of organic complexes like Pb-pectins and Pb-cysteine were found in roots from the 5% biochar treatments. Such organic complexes might impede Pb translocation from root to shoot and subsequently reduce Pb accumulation in rice with biochar amendment.
authors.affiliation: College of Resource and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
authors.forename: Honghong
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Soil and Environmental Sciences, National Chung-Hsing University, Taichung, 10402, Taiwan.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Resource and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Agricultural Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Shanli
authors.initials: S
authors.lastname: Wang
authors.affiliation: College of Resource and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.|Department of Agricultural Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Mingkuang
authors.initials: M
authors.lastname: Wang
authors.affiliation: College of Resource and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
authors.forename: Tuanhui
authors.initials: T
authors.lastname: Xie
authors.affiliation: College of Resource and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
authors.forename: Guo
authors.initials: G
authors.lastname: Wang
mesh_terms: D001682:Biological Availability; D002606:Charcoal; D007501:Iron / Q000378:metabolism; D007854:Lead / Q000378:metabolism*; D012275:Oryza / Q000378:metabolism*; D012987:Soil
chemical_list: D012987:Soil; C540010:biochar; D002606:Charcoal; D007854:Lead; D007501:Iron