Comparison of Atrazine Losses in Three Small Headwater Catchments

Abstract

Understanding the processes causing herbicide transport to surface waters is crucial to determine mitigation options to reduce these losses. To this end, we investigated the atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) transport in three agricultural catchments (1.1-2.1 km2) in the watershed of Lake "Greifensee" (Switzerland). In 1999, atrazine application data were recorded for all three catchments. Time proportional samples were taken at a high temporal resolution at the catchment outlets. Extremely wet conditions caused large relative losses from the catchments, ranging between 0.6 and 3.5% of the amount applied. Most of the atrazine load was due to event-driven diffuse losses from the fields. Farmyard runoff contributed less but caused the highest concentrations (up to 31 microg L(-1)) in the brooks. The maximum concentrations due to diffuse losses varied between 1.2 and 8.2 microg L(-1) among the catchments. Despite different absolute concentration levels, the concentration time-series were very similar. It seems that the travel-times within the catchments were mainly controlled by the rainfall pattern with little influence of the catchment properties. These properties, however, caused the relative losses to vary by a factor of 6 between the catchments. This variability could be partly explained by differences in the connectivity of the fields to the brooks and by their hydrological soil properties. A comparison of the losses from the three catchments with those from the entire watershed of Lake Greifensee demonstrated that they were representative for the larger area. Hence, the study results provide a good data set to evaluate distributed models predicting herbicide losses.

Concentrations of dissolved herbicides and pharmaceuticals in a small river in Luxembourg

“…Besides agricultural applications, various herbicides are used in the urban environment e.g. facades and roof protection, garden and roadside weed removal (Blanchoud et al 2004;Botta et al 2009;Leu et al 2005;Skark et al 2004;Wittmer et al 2010). Sometimes the diffuse pesticides input from urban areas via CSO exceeds the annual load of point source emissions by water treatment plants (Taebi and Droste 2004).…”

“…The main sources contributing to contamination of urban storm water runoff are the application of plant protectants on urban surfaces, wet and dry deposition of contaminants from the atmosphere and pollutant allocation from road traffic (Gilbert and Clausen 2006;Greenstein et al 2004;Kim et al 2006;Leu et al 2005). The wash-off effect from contaminated surfaces and the following runoff concentration and in most cases its direct discharging by channels or pipes often leads to high concentrations in urban storm water runoff (Gnecco et al 2005;Krein et al 2007;Van Metre and Mahler 2003).…”

Modeling potential herbicide loss to surface waters on the Swiss plateau

“…Only 3 datasets of monitoring data of atrazine for maize could be used for a plausibility check (Murtensee: 6 years, Greifensee 11 years, subcatchment of Ror 3 years Leu et al, 2005;Stamm et al, 2006;Gomides Freitas et al, 2008)). The averaged loss rates were compared with the averaged FFI weighted by row-cropping intensity of maize in the catchments.…”

“…Herbicide losses are mainly driven by a few discharge events during and shortly after application (Thurman et al, 1991;Leu et al, 2005). This pattern is due to the fact that herbicides are transported to surface waters by fast transport processes, mainly surface runoff and/or preferential flow to tile drains.…”

Structural and metabolic responses of microbial community to sewage-borne chlorpyrifos in constructed wetlands

“…The half-life of chlorpyrifos is usually 60 to 120 days in soil, but it can range from 2 weeks to over 1 year depending on the illumination intensity, soil type, temperature and other factors (Anwar et al, 2009). Long-term usage of chlorpyrifos has caused agricultural non-point source pollution, and increased risk to the quality of aquatic environments (van Dijk and Guicherit, 1999;Spalding et al, 2003;Leu et al, 2005). Accumulation of chlorpyrifos in water bodies could cause potential damage (such as carcinogenicity, neurotoxicity, and reproductive and developmental toxicity) to both aquatic organisms and humans (Jorgenson, 2001;Robles-Mendoza et al, 2009).…”