Saturated Buffers

Saturated buffers utilize the organic matter in the soil profile of a vegetated filter strip located between a field edge and a stream to remove nitrogen from tile transported water. To accomplish this a control structure is used to divert a portion of the tile flow into a distribution tile that runs parallel to a stream. To view results from ADMC saturated buffer research please click here.

Conventional outlet through a filter strip.
Modified outlet for a saturated buffer.
Setting the stop boards in the control structure
NRCS/SWCS photo by Lynn Betts
Plowing in the distribution line
NRCS/SWCS photo by Lynn Betts
Recently installed distribution line in a buffer to be seeded
NRCS/SWCS photo by Lynn Betts
New growth at saturated buffer site
NRCS/SWCS photo by Lynn Betts

Location

Saturated buffers typically treat drainage systems operating from a single field and on 6 – 12 inch mains. To meet NRCS standards, the site must meet the following:

  • At least 30 feet of perennial vegetation
  • Stable stream banks
  • At least 1.2% soil organic matter
  • No sand lenses or gravel layers in along the length of the distribution line

Footprint

The control structure sits on the main near the field edge in the the filter strip. Typical distribution lines run 5oo to 1,000 feet.

Performance

Recent ADMC monitoring showed that saturated buffers removed an average of 33% of the nitrate load. Research by Iowa State University with the USDA-ARS showed saturated buffers removed an average of 44% of the nitrate load.

Economics

$ 0

Average installation costs of 7 ADMC monitored saturated buffers was $3,600

$ 1

Practice cost per pound of N removed

Financial Assistance

Saturated buffers are eligible for financial assistance through theĀ NRCS EQIP Conservation Practice Standard 604 as well as through the FSA CLEAR initiative. Your state may also have state or private funding available. For more information, please refer to the ADMC Financial Assistance page.

NRCS CPS 604 Saturated Buffers