Evaluation of Water Quality Benefits of Prairie Strips in Iowa. Contract Number: AG-3151-P Iowa State University

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1 Evaluation of Water Quality Benefits of Prairie Strips in Iowa Contract Number: AG-3151-P Iowa State University PI: Matt Helmers Quarterly Report January March 2017 Objectives: The specific objectives are to estimate 1) the impacts of integrating variable width contour strips within row-cropped agricultural landscapes, and 2) the impacts of maintaining contour strips on CRP fields returning to crop production - on reducing erosion and sediment, nitrogen, and phosphorus leaving fields. Progress: Project Status While primarily funded with leveraged support, groundwater monitoring is being conducted at all prairie strips sites. Progress was made on the groundwater data summarization in the first quarter of Groundwater graphs displaying depths of water below ground surface are listed in Figures 1-8. Measurements do vary among sites, but generally groundwater tends to be shallower in the control sites when compared to the treatment sites. Available groundwater nitrate analyses were also graphed, and are listed in Figures There doesn t seem to be an obvious consistent pattern with respect to nitrate concentrations and location of groundwater wells. However, the Armstrong site is one of our most well developed sites as far as prairie strips is concerned, and relative nitrate concentrations there reflect a pattern we would expect to see, where nitrates are reduced from the top of the prairie strip to the bottom and concentrations at the top of the prairie strip are similar to the control site. Groundwater data will continue to be collected as prairie vegetation continues to establish to evaluate whether we see changes in time. Laboratory analysis on runoff samples is continuing. We have located a site just south of Marshalltown, Iowa for monitoring cool season buffer strips. Construction of monitoring structures will be done in the second quarter of this year with monitoring the watersheds beginning shortly thereafter. Established sites are being readied for monitoring as soon as temperatures allow deployment of equipment. Next steps: Second quarter of 2017 Continue working on data summarization. Install field equipment for upcoming monitoring season. Construct and install equipment at cool season buffer strip site south of Marshalltown. Outreach Activities 1. March 23, 2017 Presentation on Water quality summary of prairie strips research at Prairie Strips training event in conjunction with the Iowa Water Conference in Ames, IA (25 attendees)

2 2. February 17, 2017 Presentation on Practices to improve soil health and water quality at Soil Health Conference in Ames, IA (55 attendees) 3. February 9, 2017 Presentation on Iowa Nutrient Reduction Strategy at Watershed Conference in Dubuque, IA (75 attendees) 4. January 4, 2017 Presentation on Evaluation of prairie strips for water quality improvement at State Soil Conservation Committee meeting in Des Moines, IA (15 attendees)

3 Figure 1: Groundwater depths below ground surface at Armstrong site near Lewis, Iowa.

4 Figure 2: Groundwater depths below ground surface at Eastern Iowa Airport site, Cedar Rapids, IA.

5 Figure 3: Groundwater depths below ground surface at Guthrie site, near Ames.

6 Figure 4: Groundwater depths below ground surface at McNay site, near Lucas, Iowa.

7 Figure 5: Groundwater depths below ground surface at Rhodes site, near Rhodes, Iowa.

8 Figure 6: Groundwater depths below ground surface at Spirit Lake site, Spirit Lake, Iowa.

9 Figure 7: Groundwater depths below ground surface at Whiterock Conservancy site, near Coon Rapids, Iowa.

10 Figure 8: Groundwater depths below ground surface at Worle site, near Ames, Iowa.

11 Figure 9: Groundwater nitrate concentrations at Armstrong site, near Lewis, Iowa.

12 Figure 10: Groundwater nitrate concentrations at Eastern Iowa Airport site, Cedar Rapids, Iowa.

13 Figure 11: Groundwater nitrate concentrations at Guthrie site, near Ames, Iowa.

14 Figure 12: Groundwater nitrate concentrations at Rhodes site, near Rhodes, Iowa.

15 Figure 13: Groundwater nitrate concentrations at Worle site, near Ames, Iowa.