Improving water and soil quality with conservation buffers

Excerpt

What we know about combining practices. In order to characterize what is known about water quality effects of conservation buffers, we'll use three examples of in-field, edge-ot-field, and streamside buffers drawn from our experiences.

In-field buffer practices work best when used in combination with other buffer types and other conservation practices. For example, vegetative barriers may be used in combination with edge-of-field buffers to protect and improve their function and longevity by dispersing runoff and encouraging sediment deposition upslope of the buffer. In March 2001, a new type of in-field buffer-vegetative barriers-was added to the Natural Resources Conservation Service's National Handbook of Conservation Practices (see Table 1). These barriers-sometimes called grass hedges-are narrow (approximately 3 to 6 feet wide) strips of tall, coarse grass. Vegetative barrier grasses have large diameter stems that can withstand greater runoff rates without becoming submerged (Dabney, 2002). These are in contrast to the grasses typically used in grassed waterways. One advantage of this buffer type is it discourages concentrated water flows cutting an ephemeral gully, so sediment will deposit in the field where it can contribute to soil fertility and …