title: Incorporating rice residues into paddy soils affects methylmercury accumulation in rice.
abstract: Paddy fields are characterized by frequent organic input (e.g., fertilization and rice residue amendment), which may affect mercury biogeochemistry and bioaccumulation. To explore potential effects of rice residue amendment on methylmercury (MMHg) accumulation in rice, a mercury-contaminated paddy soil was amended with rice root (RR), rice straw (RS) or composted rice straw (CS), and planted with rice. Incorporating RS or CS increased grain MMHg concentration by 14% or 11%. The observed increases could be attributed to the elevated porewater MMHg levels and thus enhanced MMHg uptake by plants, as well as increased MMHg translocation to grain within plants. Our results indicated for the first time that rice residue amendment could significantly affect MMHg accumulation in rice grain, which should be considered in risk assessment of MMHg in contaminated areas.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People's Republic of China. Electronic address: ahuzhk@126.com.
authors.forename: Huike
authors.initials: H
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People's Republic of China; Environmental and Life Sciences Program (ENLS), Trent University, Peterborough, Ontario, Canada. Electronic address: zhonghuan@nju.edu.cn.
authors.forename: Huan
authors.initials: H
authors.lastname: Zhong
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People's Republic of China. Electronic address: 1079057085@qq.com.
authors.forename: Jialu
authors.initials: J
authors.lastname: Wu
mesh_terms: D000383:Agriculture / Q000379:methods; D018533:Biomass; D002523:Edible Grain / Q000737:chemistry / Q000254:growth & development; D008767:Methylmercury Compounds / Q000032:analysis* / Q000737:chemistry; D012275:Oryza / Q000737:chemistry* / Q000254:growth & development; D018517:Plant Roots / Q000737:chemistry / Q000254:growth & development; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D018505:Waste Management / Q000379:methods
chemical_list: D008767:Methylmercury Compounds; D012987:Soil; D012989:Soil Pollutants
keywords: Bioaccumulation; Bioavailability; Methylmercury; Paddy field; Straw return