title: Impact of agronomic practices on arsenic accumulation and speciation in rice grain.
abstract: Rice is a major source of dietary arsenic (As). The effects of paddy water management, straw incorporation, the applications of nitrogen fertilizer or organic manure, and the additions of biochar on arsenic accumulation and speciation in rice grain were investigated under field conditions over four cropping seasons in Hunan, China. Treatments that promoted anaerobic conditions in the soil, including continuous flooding and straw incorporation, significantly increased the concentration of As, especially methylated As species, in rice grain, whereas N application rate and biochar additions had little or inconsistent effect. Continuous flooding and straw incorporation also increased the abundance of the arsenite methyltransferase gene arsM in the soil, potentially enhancing As methylation in the soil and the uptake of methylated As by rice plants. Intermittent flooding was an effective method to decrease As accumulation in rice grain.
authors.affiliation: Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Ministry of Agriculture Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Ma
authors.affiliation: Changsha Research Station for Agricultural & Environmental Monitoring and Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China.
authors.forename: Jianlin
authors.initials: J
authors.lastname: Shen
authors.affiliation: Changsha Research Station for Agricultural & Environmental Monitoring and Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China.
authors.forename: Jinshui
authors.initials: J
authors.lastname: Wu
authors.affiliation: Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Ministry of Agriculture Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Ministry of Agriculture Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Qirong
authors.initials: Q
authors.lastname: Shen
authors.affiliation: Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Ministry of Agriculture Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK. Electronic address: Fangjie.Zhao@njau.edu.cn.
authors.forename: Fang-Jie
authors.initials: FJ
authors.lastname: Zhao
mesh_terms: D001151:Arsenic / Q000032:analysis*; D002681:China; D005308:Fertilizers; D055868:Floods; D008745:Methylation; D009584:Nitrogen / Q000378:metabolism; D012275:Oryza / Q000737:chemistry* / Q000378:metabolism; D018514:Plant Structures / Q000737:chemistry / Q000378:metabolism; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D005308:Fertilizers; D012987:Soil; D012989:Soil Pollutants; D001151:Arsenic; D009584:Nitrogen
keywords: Arsenic; Arsenic methylation; Arsenic speciation; Contamination; Rice