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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.


Related in: MedlinePlus

Sampling scheme and distribution of Blue and rhodamine in two series of measurements in the buffer strip soil in November 2011.The absence of Blue circles at spots corresponding to the sampling scheme indicates no Blue detection. Circle size indicates tracer concentration.
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pone.0131840.g006: Sampling scheme and distribution of Blue and rhodamine in two series of measurements in the buffer strip soil in November 2011.The absence of Blue circles at spots corresponding to the sampling scheme indicates no Blue detection. Circle size indicates tracer concentration.

Mentions: The tracers were already present deep in the buffer strip a year after their application (Fig 6), and were even more concentrated six months later (Fig 7). The tracers reached at least 0.8 m depth in the middle of the buffer strip and more than 1.2 m depth close to the creek 6 months after their application.


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)

Sampling scheme and distribution of Blue and rhodamine in two series of measurements in the buffer strip soil in November 2011.The absence of Blue circles at spots corresponding to the sampling scheme indicates no Blue detection. Circle size indicates tracer concentration.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0131840.g006: Sampling scheme and distribution of Blue and rhodamine in two series of measurements in the buffer strip soil in November 2011.The absence of Blue circles at spots corresponding to the sampling scheme indicates no Blue detection. Circle size indicates tracer concentration.
Mentions: The tracers were already present deep in the buffer strip a year after their application (Fig 6), and were even more concentrated six months later (Fig 7). The tracers reached at least 0.8 m depth in the middle of the buffer strip and more than 1.2 m depth close to the creek 6 months after their application.

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.


Related in: MedlinePlus