کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4410898 1307568 2011 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Transport modes and pathways of the strongly sorbing pesticides glyphosate and pendimethalin through structured drained soils
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
پیش نمایش صفحه اول مقاله
Transport modes and pathways of the strongly sorbing pesticides glyphosate and pendimethalin through structured drained soils
چکیده انگلیسی

Leaching of the strongly sorbing pesticides glyphosate and pendimethalin was evaluated in an 8-month field study focussing on preferential flow and particle-facilitated transport, both of which may enhance the leaching of such pesticides in structured soils. Glyphosate mainly sorbs to mineral sorption sites, while pendimethalin mainly sorbs to organic sorption sites. The two pesticides were applied in equal dosage to a structured, tile-drained soil, and the concentration of the pesticides was then measured in drainage water sampled flow-proportionally.The leaching pattern of glyphosate resembled that of pendimethalin, suggesting that the leaching potential of pesticides sorbed to either the inorganic or organic soil fractions is high in structured soils. Both glyphosate and pendimethalin leached from the root zone, with the average concentration in the drainage water being 3.5 and 2.7 μg L−1, respectively. Particle-facilitated transport (particles >0.24 μm) accounted for only a small proportion of the observed leaching (13–16% for glyphosate and 16–31% for pendimethalin). Drain-connected macropores located above or in the vicinity of the drains facilitated very rapid transport of pesticide to the drains. That the concentration of glyphosate and pendimethalin in the drainage water remained high (>0.1 μg L−1) for up to 7 d after a precipitation event indicates that macropores between the drains connected to underlying fractures were able to transport strongly sorbing pesticides in the dissolved phase. Lateral transport of dissolved pesticide via such discontinuities implies that strongly sorbing pesticides such as glyphosate and pendimethalin could potentially be present in high concentrations (>0.1 μg L−1) in both water originating from the drainage system and the shallow groundwater located at the depth of the drainage system.


► Glyphosate and pendimethalin leached through structured soil in high concentrations.
► Transport of particle-bound pesticide accounted for only 13–31% of observed leaching.
► Particle-bound pesticide was transported solely by vertical transport in macropores.
► Dissolved pesticide was also transported laterally via discontinuities in the soil.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemosphere - Volume 84, Issue 4, July 2011, Pages 471–479
نویسندگان
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