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Measurement of residues and simulation of the movement of atrazine in deeper soil layers after long‐term application in agriculture
Author(s) -
Wagner Bernhard,
Schewes Robert,
Maidl F. X.,
Fischbeck Gerhard
Publication year - 1995
Publication title -
zeitschrift für pflanzenernährung und bodenkunde
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 0044-3263
DOI - 10.1002/jpln.19951580404
Subject(s) - atrazine , soil horizon , groundwater , sorption , soil science , pesticide , chemistry , dispersion (optics) , environmental science , environmental chemistry , groundwater recharge , hydrology (agriculture) , agronomy , soil water , geology , geotechnical engineering , biology , physics , adsorption , aquifer , organic chemistry , optics
The herbicide atrazine [2‐chloro‐4‐ethylamino‐6‐isopropylamino‐1,3,5‐triazine] was applied to corn at recommended rates over a period of 18 years until 1988. The investigated field was sampled down to a depth of 10 m in 1989 and 1991. In both years residues of atrazine were determined down to 10 m depth by HPLC‐analysis of soil extracts in concentrations of up to 12 μg/kg. Batch‐experiments were conducted to establish sorption isotherms of various soil layers. Numerical simulations of the migration of atrazine, based on the Richards‐equation and the convection‐dispersion‐equation with first‐order degradation were performed and compared to the measurements. Depth‐dependent distribution of atrazine residues could be roughly reproduced by calculations, but the calculated depth‐profiles of atrazine concentrations varied strongly within the variability of the sensitive parameters. The deterministic model used was therefore not able to predict the amount of pesticide residues in groundwater recharge precisely.