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environexpbot125_42.pdf 1.24 MB ( 限定公開 )
言語
英語
著者
Makino, Tomoyuki
Arao, Tomohito
内容記述(抄録等)
The Codex Committee adopted a maximum level of 0.2 mg kg^<-1> for inorganic arsenic in polished rice at the 37th Session of the Commission (Codex Alimentarius Commission, 2014). It is thus necessary to establish agronomic management practices for reducing the accumulation of As in rice grain even in Asuncontaminated soil. We examined the effect of the application of different kinds of iron (Fe) materials on As uptake in rice plants grown in bottomless concrete frames filled with soil collected from an area surrounding a formerly As-polluted region. We assessed the concentration and speciation of As in soil solution throughout the rice cultivation period. Application of Fe materials had a significant effect on the concentration of arsenite, arsenate, inorganic As (sum of arsenite and arsenate) and total As, in the soil solution. The concentration of these forms of As in soil solution treated with Fe materials was significantly lower than the control. The lowest concentrations of As were observed in the plot to which a metal Fe powder composed mainly of a zero-valence Fe was applied throughout the rice cultivation period. The application of metal Fe powder and Fe oxide material composed mainly of ferrihydrite significantly reduced the amount of available As in the soil. The amount of acid ammonium oxalate extractable Fe was significantly increased by the application of metal Fe powder and Fe oxide material compared to that of the control and converter furnace slag. Concentrations of all forms of As in soil solution showed a significant positive correlation with the amount of available As and a significant negative correlation with the amount of acid ammonium oxalate extractable Fe in soil; this indicated that the increase of acid ammonium oxalate extractable Fe by application of Fe materials retarded the release of As from the soil solid phase to soil solution by fixing As and Fe. The concentrations of arsenite, dimethylarsinic acid (DMA), the sum of As species, and total As in grain with applied metal Fe powder and Fe oxide material were significantly lower than the control, reflecting the concentration of soluble As species in soil solution. These results strongly suggest that the application of metal Fe powder and Fe oxide material effectively reduced As accumulation in rice grain, making it a promising agronomic management practice for reducing the risk of As accumulation.
主題
Arsenic
paddy field
Iron materials
silicate
掲載誌名
Environmental and experimental botany
125
開始ページ
42
終了ページ
51
ISSN
00988472
発行日
2016-02-04
DOI
DOI公開日
2016-12-06
NCID
AA00637364
出版者
Elsevier B.V
資料タイプ
学術雑誌論文
ファイル形式
PDF
権利関係
© 2016 Elsevier B.V. All rights reserved.
著者版/出版社版
出版社版
業績ID
e29878
e31615
部局
生物資源科学部 附属生物資源教育研究センター