Buffer Strips: Common Sense Conservation

Buffer strips are strips of land in permanent or semi-permanent vegetation designed to intercept pollutants and manage other environmental concerns.

Buffer strips are a part of a larger group of vegetative conservation structures known as buffers. Buffers include: contour grass strips, filter strips, riparian buffers, grass waterways, cross wind trap strips, shelter-belts, field windbreaks, alley cropping, and vegetative barriers.

Buffer strips remove sediment, nutrients, pesticides, sediment-attached contaminants and animal waste from agricultural runoff. Benefits of grass buffer strips include uptake and transformation of soluble contaminants by soil microbes and grass. To enhance buffer strip effectiveness, fertilizers, pesticides, or animal wastes should not be applied to the filter strip area.

Strategically placed grass buffer strips can reduce loss of sediment, nutrients, and pesticides from cropland. When coupled with good crop management, reduced tillage, soil testing, nutrient management, integrated pest management, and cover crops, buffer strips will assist farmers who desire a measure of economic and environmental sustainability in their operations. Buffer strips can also improve water quality of streams and lakes and enhance wildlife habitat.

Buffer strips work by slowing the movement of runoff water, trapping sediments suspended in the runoff water and enhancing infiltration of the runoff water within the buffer strip. They also trap fertilizers and pesticides that are adsorbed to soil sediment and reduce the amount of soil lost to wind erosion during periods of strong winds. If properly established and maintained, grass filters have the capacity to remove the following from surface runoff:

• 50% or more of the nutrients and pesticides
• 60% or more of certain pathogens
• 75% or more of sediment.

Results from Studies at Blackland Research Center

Atrazine is a widely used herbicide, but concerns about pesticide contamination of surface water associated with off-target losses of atrazine threaten its continued use.

Contour buffer strips, designed to remove sediment, chemicals and organic material transported in surface runoff, were established on nine watersheds at Blackland Research Center (BRC) to determine the efficiency of grass filter strips in reducing non-point source runoff losses of atrazine in surface runoff. Results from the studies at BRC have shown that bermudagrass and wheat buffer strips can reduce atrazine concentrations in surface runoff.

The summary of results from BRC watershed studies over several years (1992-1999) include:

1. Buffer strips reduce total runoff by increasing infiltration
2. Grass buffer strips remove atrazine from runoff
3. Buffer strips reduce sediment losses
4. Establishing buffer strips on the contour increases effectiveness
5. Grass waterways may be needed to channel water down slope on large fields.

Benefits of Contour Buffer Strips on the Blackland Prairie

1. Reduce sediment losses due to erosion
2. Reduce losses of agricultural chemicals
3. May be utilized for hay
4. Provide wildlife habitat
5. Wheat strips can be harvested for grain

The following programs offer economic incentives for installing and maintaining buffers:

• Continuous Sign-up Conservation Reserve Program (CRP)
• Environmental Quality Incentives Program (EQIP)
• Wildlife Habitat Incentives Program (WHIP)
• Wetlands Reserve Program (WRP)
• Stewardship Incentives Program (SIP) and
• Emergency Watershed Protection Program (EWP)

National Conservation Buffer Initiative

In April 1997, USDA officially launched the National Conservation Buffer Initiative and pledged to help landowners install 2 million miles of conservation buffers by the year 2002.

Agricultural producers and other landowners that install buffers can improve soil, air, and water quality; enhance wildlife habitat; restore biodiversity; and create scenic landscapes. Through the assistance of several other governmental and private industry partners the NRCS takes the lead in encouraging farmers, ranchers and other landowners in understanding the economic and environmental benefits of installing and maintaining buffers.

Partial funding for this brochure and buffer strip research provided by USEPA