Please direct all questions and comments to Dr. Christian De Kimpe Buffer zones and shelterbelts Despite the careful use of inputs and soil conservation practices, some potential contaminants may still leave agricultural fields. To prevent them from entering waterways, they can be trapped in buffer zones at the edge of the fields or in locations in the landscape where runoff occurs. Buffer zones are areas or bands of natural or planted vegetation located between agricultural land and water bodies.
Impoundments receiving drainage waters from agricultural land can also function as buffer zones.
The efficiency generally increases with strip width. Similar results were reported for forested buffers 10 to 60 metres wide. Buffer zones are effective in filtering out sediments when the water flow is shallow and uniform, but concentrated flow tends to reduce this effectiveness. Riparian trees and shrubs have also been shown to anchor stream bank soils and help stabilize eroding gullies. This stability reduces the amount of sediment entering water from stream bank erosion.