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Potential Efficiency of Riparian Vegetated Buffer Strips in Intercepting Soluble Compounds in the Presence of Subsurface Preferential Flows.

Allaire SE, Sylvain C, Lange SF, Thériault G, Lafrance P - PLoS ONE (2015)

Bottom Line: However, such strips do not intercept all contaminants, particularly soluble ones.Our results demonstrate that the risk of water contamination by soluble contaminants is high in such systems, even when a well-vegetated buffer strip is used.The design of buffer strips should be modified to account for underground bypass, either by using plants that have deep, fine roots that do not favour PF or by adding a filter extending deep underground that can be regularly changed.

View Article: PubMed Central - PubMed

Affiliation: Département des sols et de génie agroalimentaire, Université Laval, Québec City, Quebec, Canada.

ABSTRACT
Buffer strips have been widely recognized as to promote infiltration, deposition and sorption of contaminants for protecting surface water against agricultural contamination. However, such strips do not intercept all contaminants, particularly soluble ones. Although preferential flow (PF) has been suggested as one factor among several decreasing the efficiency of buffer strips, the mechanisms involved are not well understood. This project examines buffer strip efficiency at intercepting solutes when subsurface PF occurs. Two soluble sorbed tracers, FD&C Blue #1 and rhodamine WT, were applied on an agricultural sandy loam soil to evaluate the ability of a naturally vegetated buffer strip to intercept soluble contaminants. Rhodamine was applied about 15 m from the creek, while the Blue was applied 15 m to 165 m from the creek. Tracer concentration was measured over a two-year period in both the creek and the buffer strip through soil and water samples. Although the tracers traveled via different pathways, they both quickly moved toward the creek, passing beneath the buffer strip through the soil matrix. Our results demonstrate that the risk of water contamination by soluble contaminants is high in such systems, even when a well-vegetated buffer strip is used. The design of buffer strips should be modified to account for underground bypass, either by using plants that have deep, fine roots that do not favour PF or by adding a filter extending deep underground that can be regularly changed.

No MeSH data available.


Photos of (A) the general aspect of the field, (B) the buffer strip, (C) Blue and rhodamine application on plot C, and (D) gullies near plot B and interception of particles in the buffer strip grass after the most intense rain during the studied period (Photos: Soil Physics and Hydrodynamic Group, Université Laval).
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pone.0131840.g001: Photos of (A) the general aspect of the field, (B) the buffer strip, (C) Blue and rhodamine application on plot C, and (D) gullies near plot B and interception of particles in the buffer strip grass after the most intense rain during the studied period (Photos: Soil Physics and Hydrodynamic Group, Université Laval).

Mentions: The field (Fig 1A) is a catena with Beaurivage soils, with a well-developed podzol on the top of the hill, a gleyed brunisol on the backslope, and a poorly drained gleysol at the footslope [23] connecting to a small creek that flows year round. Previously forested, the site was cleared about 20 years ago, at which time a small number of artificial drains were installed and tree stumps were buried at various depths. The soil was cultivated with cereals from 2004 to 2006, corn from 2007 to 2008, soya in 2009 and 2010, oats in 2011, alfalfa in 2012, and then again with corn. The slope of the field is about 4% (Fig 1A).


Potential Efficiency of Riparian Vegetated Buffer Strips in Intercepting Soluble Compounds in the Presence of Subsurface Preferential Flows.

Allaire SE, Sylvain C, Lange SF, Thériault G, Lafrance P - PLoS ONE (2015)

Photos of (A) the general aspect of the field, (B) the buffer strip, (C) Blue and rhodamine application on plot C, and (D) gullies near plot B and interception of particles in the buffer strip grass after the most intense rain during the studied period (Photos: Soil Physics and Hydrodynamic Group, Université Laval).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492607&req=5

pone.0131840.g001: Photos of (A) the general aspect of the field, (B) the buffer strip, (C) Blue and rhodamine application on plot C, and (D) gullies near plot B and interception of particles in the buffer strip grass after the most intense rain during the studied period (Photos: Soil Physics and Hydrodynamic Group, Université Laval).
Mentions: The field (Fig 1A) is a catena with Beaurivage soils, with a well-developed podzol on the top of the hill, a gleyed brunisol on the backslope, and a poorly drained gleysol at the footslope [23] connecting to a small creek that flows year round. Previously forested, the site was cleared about 20 years ago, at which time a small number of artificial drains were installed and tree stumps were buried at various depths. The soil was cultivated with cereals from 2004 to 2006, corn from 2007 to 2008, soya in 2009 and 2010, oats in 2011, alfalfa in 2012, and then again with corn. The slope of the field is about 4% (Fig 1A).

Bottom Line: However, such strips do not intercept all contaminants, particularly soluble ones.Our results demonstrate that the risk of water contamination by soluble contaminants is high in such systems, even when a well-vegetated buffer strip is used.The design of buffer strips should be modified to account for underground bypass, either by using plants that have deep, fine roots that do not favour PF or by adding a filter extending deep underground that can be regularly changed.

View Article: PubMed Central - PubMed

Affiliation: Département des sols et de génie agroalimentaire, Université Laval, Québec City, Quebec, Canada.

ABSTRACT
Buffer strips have been widely recognized as to promote infiltration, deposition and sorption of contaminants for protecting surface water against agricultural contamination. However, such strips do not intercept all contaminants, particularly soluble ones. Although preferential flow (PF) has been suggested as one factor among several decreasing the efficiency of buffer strips, the mechanisms involved are not well understood. This project examines buffer strip efficiency at intercepting solutes when subsurface PF occurs. Two soluble sorbed tracers, FD&C Blue #1 and rhodamine WT, were applied on an agricultural sandy loam soil to evaluate the ability of a naturally vegetated buffer strip to intercept soluble contaminants. Rhodamine was applied about 15 m from the creek, while the Blue was applied 15 m to 165 m from the creek. Tracer concentration was measured over a two-year period in both the creek and the buffer strip through soil and water samples. Although the tracers traveled via different pathways, they both quickly moved toward the creek, passing beneath the buffer strip through the soil matrix. Our results demonstrate that the risk of water contamination by soluble contaminants is high in such systems, even when a well-vegetated buffer strip is used. The design of buffer strips should be modified to account for underground bypass, either by using plants that have deep, fine roots that do not favour PF or by adding a filter extending deep underground that can be regularly changed.

No MeSH data available.