Water management of alternate wetting and drying reduces the accumulation of arsenic in brown rice - as dynamic study from rhizosphere soil to rice.
Ecotoxicol Environ Saf
; 185: 109711, 2019 Dec 15.
Article
en En
| MEDLINE
| ID: mdl-31574369
ABSTRACT
There have been no controlled systematic studies on the dynamic variation of As in soil - soil porewater - root surface (Fe plaques) - rice plant system under alternate wetting and drying (AWD) irrigation. Therefore, effects of continuous flooding (CF) and AWD treatments (2F2D 2-day flooding followed by 2-day drying; 7F2D 7-day flooding followed by 2-day drying) on the migration of As from soil to brown rice were studied. Results indicated that As contents in brown rice of AWD treatments (0.03-0.17â¯mg/kg) were 43.3%-85.0% lower than CF (0.20-0.30â¯mg/kg). AWD irrigation promoted the transformation of Fe and associated As in rhizosphere soil from highly active forms (H2O and HCl-extracted Fe-bound As) to stable states (oxalate and DCB-extracted Fe-bound As), which decreased the release of As from rhizosphere soil. The dynamic variation of As contents in porewater was described by a dissolution factor (DF) which decreased significantly in AWD treatments and had a significant positive correlation (R2â¯=â¯0.83; Pâ¯<â¯0.05) with As contents in brown rice. In addition, contents of Fe and associated As on the root surface were about 17.1% and 11.0% higher in AWD treatments than in CF treatment, respectively, and the transfer factor (TF) of As from root surface into root was 22.7% lower in AWD treatments than in CF. In summary, AWD irrigation reduced As contents in porewater through decreasing availability of As in rhizosphere soil; and AWD also reduced the transfer of As into rice roots through promoting As sequestration by Fe plaques on root surface.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Arsénico
/
Oryza
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Suelo
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Contaminantes del Suelo
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Rizosfera
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Riego Agrícola
Idioma:
En
Revista:
Ecotoxicol Environ Saf
Año:
2019
Tipo del documento:
Article
País de afiliación:
China