Iowa Conservation Reserve Enhancement: Landowner Guide to CREP, October 2009

Strategically located and designed wetlands constructed through the Iowa CREP are one of the most promising off-site strategies for reducing surface water contamination. Research conducted at Iowa State University has demonstrated that targeted wetlands have the potential to remove 40-90% of the nitrate in tile drainage from upper-lying croplands. The effect of wetlands on watershed scale nitrate reduction is largely determined by the fraction of the watershed’s total nitrate load that the wetlands intercept