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

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).

Effects of agricultural management on chemical and biochemical properties of a semiarid soil from central Spain

“…The enzymatic activity values, more influenced by soil depth (16-67% of variance) than by tillage system (11-37% of variance), were lower than those obtained for agricultural soils from temperate humid zone of NW Spain (Díaz-Raviña et al, 2005;Mahía and Díaz-Raviña, 2007;Mahía et al, 2011) but lied in the reported range for other Spanish soils in the semiarid and arid zones (Madejon et al, 2007;Madejon et al, 2009;Melero et al, 2012). Higher values were exhibited by the 0-5 cm layer of soil samples with higher organic matter content, which seems to indicate that the main soil property determining biochemical properties levels is the organic matter content.…”

Ageing of atrazine in manure amended soils assessed by bioavailability to Pseudomonas sp. strain ADP

“…Other studies have also found a higher degree of atrazine as well as triazine amine ageing in topsoils compared to subsoils (Kruger et al 1997;Hang et al 2005;Godskesen et al 2005), which has been related to a larger fraction of organic matter in A horizons (Chung and Alexander 2002). Bound residues of atrazine have been found to be present in the fraction with highest organic matter content in several studies (Barriuso and Koskinen 1996; Loiseau and Barriuso 2002;Hang et al 2005;Mahía and Díaz-Raviña 2007). In the present study, the carbon contents were 2.58 % in the A horizon and 0.19 % in the C horizon (Table 1).…”

Laboratory Degradation Studies of 14C-Atrazine and -Isoproturon in Soil from Sugarcane Cultivated Fields Under Kenyan Tropical Conditions

“…This has also been observed in some of the halogenated phenylura herbicides such as methabenzthiazuron, diuron, metobromuron and monuron (Berger 1999). As result some of the compounds most frequently used such as atrazine and isoproturon are frequently detected in surface and ground waters (Yassir et al 1999;Mahia and Diaz-Ravina 2007;Sørensen et al 2003).…”