Buffers

Conservation buffers are strips of permanent vegetation that are meant to intercept nutrients and sediment carried by surface water. They do that by slowing down surface water and allowing plants to take up and use the water and nutrients. Buffer strips in agricultural fields can help mitigate water pollution by keeping nutrients, sediments, and pesticides in the field. Buffers also make great wildlife habitat and help protect biodiversity. 

NRCS states that if buffers are installed properly, they can: 

  • Remove up to 50% or more of nutrients and pesticides
  • Remove up to 60% or more of certain pathogens
  • Remove up to 75% or more of sediment

There are many conservation programs that can help with the cost of buffers, including the Conservation Reserve Program (CRP), Environmental Quality Incentives Program (EQIP), the Conservation Stewardship Program (CSP), and the Conservation Reserve Enhancement Program (CREP) for land in the 100-year floodplain. 

Buffers can take many forms:

Riparian forest buffers

A riparian forest buffer is a corridor of trees and/or shrubs planted adjacent to a river, stream, wetland, or water body. Riparian buffers protect the soils alongside streams from floods, trap sediment and harmful chemicals, and provide shade and woody debris for the river or stream ecosystem. They must be sufficiently wide (usually 15 to 100 feet). Plants must be tolerant of extended periods of flooding and have moderate to aggressive root and crown spread to establish quickly. 

See the NRCS Practice Standard for a riparian buffer here. 

Saturated buffers

We have a whole page devoted to saturated buffers here. 

Filter strips

Filter strips are strips of grass, trees, or shrubs that remove nutrients from runoff by filtration, deposition, infiltration, or plant uptake before they can enter water bodies, which protects water quality. The vegetative strip moves row crop operations further from a stream. 

Michigan has a really nice fact sheet about filter strips here. 

See the NRCS Practice Standard for a filter strip here. 

Grassed waterways

Grassed waterways are shaped to establish a natural drainage-way that prevents gullies from forming by safely conveying water flowing from the field. The vegetation acts as a filter, absorbing some of the chemicals and nutrients in runoff water. The grass cover prevents gully erosion by holding sediment in place.

Iowa has a really nice fact sheet about grassed waterways here.

See the NRCS Practice Standard for grassed waterways here. 

Contour grass strips

Contour grass strips are strips of perennial vegetation alternated with wider cultivated strips that are farmed on the contour.

Read all about contour buffer strips here and here.

See the NRCS Job Sheet for a contour grass strip here. 

Field borders

Field borders are strips of perennial vegetation (native or introduced grasses) that are established at the edge or around the perimeter of a field. They control sheet, rill, gully, and wind erosion, and provide wildlife and pollinator food and cover. 

Read all about field borders here.

See the NRCS Job Sheet for a field border here, and the Practice Standard here.