Saturated buffers store water within the soil of field buffers, by diverting tile water into shallow laterals that raise the water table within the buffer and slow outflow. Early results for saturated buffers indicate that they can be very effective for removing nitrate from tile drain water before it is discharged into surface waters by diverting a fraction of the tile flow through riparian buffers as shallow groundwater. As a consequence of the diversion, saturated buffers could also help reduce the peak flow in streams, acting as detention structures that delay discharge and flatten the stream hydrograph, although little research has occurred on their potential ability to temporarily store water.
Understanding the Practice and its Benefits
- Leopold Center for Sustainable Agriculture Farming for Untroubled Waters: Reconnecting Tiles and Buffers by Dan Jaynes (3 minutes, May 2011)
- Iowa Farm Bureau. Conservation Q&A: Saturated Buffer (3 minutes, August 2015)
- Presentation at Illinois EPA Non-Point Source Pollution Workshop. Nitrogen Reductions with Saturated Buffers, by Steve Baker (2012)
- 2 page Fact Sheet Highlighting Demonstration Sites in Hamilton and Story County, Iowa, Leopold Center for Sustainable Agriculture. Success Stories in Sustainable Agriculture: Saturated Buffers by Arlene Enderton (2013)
- PowerPoint outlining water quality benefits and site selection. Saturated Buffers: Beyond the Drawing Board, by Nathan Utt (2013)
- 2 page Saturated Buffer Fact Sheet. USDA Natural Resources Conservation Service Iowa (2015).
- Conservation Corner: Saturated Buffer by Successful Farming @ agriculture.com. Installation video of a saturated buffer to remove nitrates from tile drainage (2 min.).
- A new nitrate reduction practice called saturated buffers by The Des Moines Register. Explanation of the practice by Dan Jaynes (2 min).
- Iowa Learning Farm. Saturated Buffers in Tile Drained Landscapes for Nitrate Removal, by Dan Jaynes (42 minutes, June 2014)
- Midwest Ag Drainage Water Management webinar series, organized by Iowa State University. Saturated Buffers by Dan Jaynes and Dan Perkins (1 hour, October 2015)
NRCS Practice Information
- NRCS Interim Conservation Practice Standard; Vegetated Subsurface Drain (Iowa)
- Looker, D. 2015. New Tool Cheaply, Efficiently Captures Nitrates. Successful Farming Magazine.
- Kershner, L. 2015. Negligible nitrate escapes. Farm News.
- Eller, D. 2015. Buffer strips key to reducing nitrates in Iowa water. The Des MoinesRegister.
- Morrison, L. 2014. Saturated Stream Buffer Test. Corn and Soybean Digest.
- Morrison, L. 2012. Buffer Booster: Cut Nitrates by Routing Tile Water Through Grass Buffer. Corn and Soybean Digest.