Sprinkler irrigation of rice fields reduces grain arsenic but enhances cadmium

Eduardo Moreno-Jimenez*, Andrew A. Meharg, Erik Smolders, Rebeca Manzano, Daniel Becerra, Javier Sanchez-Llerena, Angel Albarran, Antonio Lopez-Pinero

*Corresponding author for this work

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

Previous studies have demonstrated that rice cultivated under flooded conditions has higher concentrations of arsenic (As) but lower cadmium (Cd) compared to rice grown in unsaturated soils. To validate such effects over long terms under Mediterranean conditions a field experiment, conducted over 7 successive years was established in SW Spain. The impact of water management on rice production and grain arsenic (As) and cadmium (Cd) was measured, and As speciation was determined to inform toxicity evaluation. Sprinkler irrigation was compared to traditional flooding.

Both irrigation techniques resulted in similar grain yields (similar to 3000 kg grain ha(-1)). Successive sprinkler irrigation over 7 years decreased grain total As to one-sixth its initial concentration in the flooded system (0.55 to 0.09 mg As kg(-1)), while one cycle of sprinkler irrigation also reduced grain total As by one-third (0.20 mg kg(-1)). Grain inorganic As concentration increased up to 2 folds under flooded conditions compared to sprinkler irrigated fields while organic As was also lower in sprinkler system treatments, but to a lesser extent. This suggests that methylation is favored under water logging. However, sprinkler irrigation increased Cd transfer to grain by a factor of 10, reaching 0.05 mg Cd kg(-1) in 7 years. Sprinlder systems in paddy fields seem particularly suited for Mediterranean climates and are able to mitigate against excessive As accumulation, but our evidence shows that an increased Cd load in rice grain may result.

Original languageEnglish
Pages (from-to)468-473
Number of pages6
JournalScience of the Total Environment
Volume485-486
Early online date16 Apr 2014
DOIs
Publication statusPublished - 01 Jul 2014

Keywords

  • Food safety
  • Arsenic speciation
  • Water management
  • Cadmium
  • Toxicity
  • Rice
  • ORYZA-SATIVA L.
  • WATER MANAGEMENT
  • SOIL
  • ACCUMULATION
  • SPECIATION
  • EXPOSURE
  • AMENDMENTS
  • SYSTEMS
  • PLANTS
  • MAIZE

Cite this

Moreno-Jimenez, E., Meharg, A. A., Smolders, E., Manzano, R., Becerra, D., Sanchez-Llerena, J., Albarran, A., & Lopez-Pinero, A. (2014). Sprinkler irrigation of rice fields reduces grain arsenic but enhances cadmium. Science of the Total Environment, 485-486, 468-473. https://doi.org/10.1016/j.scitotenv.2014.03.106