My Account: Log In | Join | Renew
Search
Author
Title
Vol.
Issue
Year
1st Page

Abstract

 

This article in JEQ

  1. Vol. 36 No. 3, p. 826-831
     
    Received: Nov 2, 2006
    Published: May, 2007


    * Corresponding author(s): mdiazr@iiag.cesga.es
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2134/jeq2006.0477

Atrazine Degradation and Residues Distribution in Two Acid Soils from Temperate Humid Zone

  1. J. Mahía and
  2. M. Díaz-Raviña *
  1. Departamento de Bioquímica del suelo, Instituto de Investigaciones Agrobiológicas de Galicia (CSIC), Avda Vigo s/n, Apartado 122, E-15780 Santiago de Compostela, Spain

Abstract

Mineralization of atrazine and formation of extractable and non-extractable “bound” residues were followed under laboratory conditions in two contrasting soils (organic C, texture, and atrazine application history) from northern Spain. The soils, a Humic Cambisol (MP) and a Gleyic Cambisol (G) were incubated with labeled atrazine (ring-13C atrazine) at field application dose and measurements were made at different time intervals during 3 mo. Fate and behavior of atrazine along the incubation showed different patterns between the two soils, the time taken for degradation of 50% (DT50) being 9 and 44 d for MP and G soils, respectively. In MP soil, with 40 yr of atrazine application and lower organic C and clay content, more than 89% of U-13C-atrazine added was mineralized after 12 wk, with most mineralization occurring within the first 2 wk. G soil, with 10 yr of atrazine application, exhibited a more progressive U-13C-atrazine mineralization, reaching 54% of initially added atrazine at 12 wk. Hydroxyatrazine and deisopropylatrazine were the metabolites founded in the extractable fraction, demonstrating that both chemical and biological processes are involved in atrazine degradation. Soil G showed during all the incubation times an extractable residues fraction greater than that in MP soil, indicating a high potential risk of soil and water contamination. Rapid microbial degradation through s-triazine ring cleavage was proposed to be the main decomposition pathway of atrazine for the two soils studied. Bound residues pool also differed notably between soils accounting for 9 and 41% of initially added atrazine, the higher values shown by soil with higher organic matter and clay content (G soil).

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2007. American Society of Agronomy, Crop Science Society of America, Soil Science SocietyASA, CSSA, SSSA