title: Arsenic mobility and bioavailability in paddy soil under iron compound amendments at different growth stages of rice.
abstract: Iron (Fe)-based solids can reduce arsenic (As) mobility and bioavailability in soils, which has been well recognized. However, to our knowledge, there are few studies on As uptake at different growth stages of rice under Fe compound amendments. In addition, the formation of Fe plaques at different growth stages of rice has also been rarely reported. Therefore, the present study was undertaken to investigate As mobility and bioavailability in paddy soil under Fe compound amendments throughout the whole growth stage of rice plants. Amendments of poorly crystalline Fe oxides (PC-Fe), FeCl2+NaNO3and FeCl2reduced grain As by 54% ± 3.0%, 52% ± 3.0% and 46% ± 17%, respectively, compared with that of the non-amended control. The filling stage was suggested to be the key stage to take measures to reduce As uptake. At this stage, all soil amendments significantly reduced As accumulation in rice plants. At the maturation stage, PC-Fe amendment significantly reduced mobile pools and increased immobile pools of soil As. Besides, PC-Fe treatment promoted the transformation of Fe fractions from dissolved Fe to adsorbed, poorly crystalline and free Fe oxides. Moreover, significant positive correlations between soil Fe fractions and As fractions were found. Accordingly, we hypothesized that Fe compound amendments might affect the concentration distribution of Fe fractions first and then affect As fractionation in soil and its bioavailability to rice plants indirectly. The formation of Fe plaques varied with growth stages and different treatments. Significantly negative correlations between mobile pools of As and Fe or As in Fe plaques indicated that Fe plaques could immobilize mobile As in soils and thus affect As bioavailability. Overall, the effect of the soil amendments on reduction of As uptake varied with growth stages and different treatments, and further research on the key stage for reducing As uptake is still required.
authors.affiliation: Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, China; Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou 510632, China.
authors.forename: Huan-Yun
authors.initials: HY
authors.lastname: Yu
authors.affiliation: Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, China.
authors.forename: Xiangqin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, China. Electronic address: cefbli@soil.gd.cn.
authors.forename: Fangbai
authors.initials: F
authors.lastname: Li
authors.affiliation: Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.affiliation: Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, China.
authors.forename: Chuanping
authors.initials: C
authors.lastname: Liu
authors.affiliation: Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: College of Agriculture, Guangxi University, Nanning 530005, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Lei
mesh_terms: D000327:Adsorption / Q000187:drug effects; D001151:Arsenic / Q000032:analysis / Q000378:metabolism*; D001682:Biological Availability; D002681:China; D002523:Edible Grain / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D004784:Environmental Monitoring; D005290:Ferric Compounds / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D012275:Oryza / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*
chemical_list: D005290:Ferric Compounds; D012987:Soil; D012989:Soil Pollutants; D001151:Arsenic
keywords: Arsenic bioavailability; Arsenic fractionation; Fe fractions; Fe plaques; Soil amendments