Journal of
Soil Science and Environmental Management

  • Abbreviation: J. Soil Sci. Environ. Manage.
  • Language: English
  • ISSN: 2141-2391
  • DOI: 10.5897/JSSEM
  • Start Year: 2010
  • Published Articles: 311

Full Length Research Paper

Biodegradation and dissipation of 14C-carbofuran in clay soil from Loukkos perimeter, Northwestern Morocco

BENICHA Mohamed 1*, MRABET Rachid 2 and AZMANI Amina 3
1Laboratory of Pesticides residues, UR research on nuclear techniques, environment and quality, Regional Center of Agronomic research, 78, Bd Mohamed Ben Abdellah, 90010 Tangier, Morocco. 2Regional Center of Agronomic research, 78, Bd Mohamed Ben Abdellah, 90010 Tangier, Morocco. 3University Abdel Malik Essaadi, Faculty of Science and Technology, Ancienne Route de l'Aéroport, Km 10, Ziaten. BP: 416. Tanger – Maroc.
Email: [email protected], [email protected]

  •  Accepted: 21 November 2011
  •  Published: 22 December 2011

Abstract

Mineralization and dissipation of 14C-ring labeled carbofuran (2, 3-dihydro-2, 2-dimethylbenzofuran-7-yl-methylcarbamate), one of the highly toxic N-methyl carbamate pesticides,  in an untreated Vertisol Moroccan soil used for sugar beet cultivation was studied under laboratory conditions over a period of 63 days. The experiment was conducted in flooded and non-flooded conditions. Carbofuran mineralization was determined by monitoring the 14CO2production from soil amended with U-ring14C-carbofuran. Under both conditions, higher mineralization rates of 14C-carbofuran were observed. The extent of mineralization being more in moist (19.2%) than in flooded conditions (12.4%). In both conditions, the soil extractable pesticide residues decreased with time, while the bound residues gradually increased. The extractable 14C-activity disappearance rate was much higher in flooded than in non-flooded conditions. At the end of the experiment, 15.8% and 31% of applied dose were recovered as extractable residues under flooded and moist conditions respectively. Soil bound residues were formed to the extent of 33.3% of the applied dose in flooded soil, while 29.1% was formed in non-flooded soil. The amount of the organic volatiles was much higher in flooded condition (18.2%), as compared to 5.6% in non-flooded soil. The main degradation product formed was carbofuran phenol.

 

Key words: Carbofuran, mineralization, degradation, volatilization, 14C, biodegradation.