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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.


Blue and rhodamine concentration in the creek in 2011 and 2012.
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pone.0131840.g004: Blue and rhodamine concentration in the creek in 2011 and 2012.

Mentions: Mean rhodamine concentration in the creek was similar during both years, but its concentration peaks were higher in 2011 than in 2012 (Table 4). Maximum rhodamine concentration reached 13.6 x 10−3 mg L-1 and 3.47 x 10−3 mg L-1 during rain events in 2011 and 2012 (Table 4). The maxima were respectively 13 and 3 times higher than the mean concentrations in 2011 and 2012. The tracer was almost always detected in the creek, being found as frequently in 2011 as in 2012 (Fig 4). When rhodamine was detected in high concentrations, Blue was also detected, but its concentration did not follow that of rhodamine.


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)

Blue and rhodamine concentration in the creek in 2011 and 2012.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0131840.g004: Blue and rhodamine concentration in the creek in 2011 and 2012.
Mentions: Mean rhodamine concentration in the creek was similar during both years, but its concentration peaks were higher in 2011 than in 2012 (Table 4). Maximum rhodamine concentration reached 13.6 x 10−3 mg L-1 and 3.47 x 10−3 mg L-1 during rain events in 2011 and 2012 (Table 4). The maxima were respectively 13 and 3 times higher than the mean concentrations in 2011 and 2012. The tracer was almost always detected in the creek, being found as frequently in 2011 as in 2012 (Fig 4). When rhodamine was detected in high concentrations, Blue was also detected, but its concentration did not follow that of rhodamine.

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.