Iowa’s CREP Wetlands Provide Opportunity to Measure Delivery Scale Impacts

The Iowa Conservation Reserve Enhancement Program (CREP) is a state, federal, local, and private partnership that provides incentives to landowners who voluntarily establish wetlands for water quality improvement.

The goal is to reduce nitrogen loads from croplands to streams and rivers, while also providing wildlife habitat and increased recreational opportunities. Over the past 15 years, about 90 CREP sites have been constructed in a 37 county region in north central Iowa.

For over 10 years Dr. William Crumpton, Iowa State University professor in the department of Ecology, Evolution and Organismal Biology, has been leading the monitoring of 10-15 of the CREP sites to measure their performance.

In a new video released by the Iowa Learning Farms, Dr. Crumpton discusses how CREP wetlands function and the need for long-term delivery scale monitoring with Dr. Matt Helmers, Director of the Iowa Nutrient Research Center.

Here’s a sneak peak of their conversation:

How do CREP wetlands go about removing nitrate?

The primary process is denitrification. Denitrification is carried out by anaerobic bacteria. They use carbon as an energy source and nitrate as an electron receptor instead of oxygen. They denitrify nitrate into N2 gas -which is 80% of our atmosphere.

What factors influence their performance in removing nitrate?

1. The amount of water that goes into the wetland, also known as hydraulic loading rate. This factor is the easiest to adjust to control overall performance. If the wetland is larger, the hydraulic loading rate is smaller and the higher percentage of nitrate that entered the system is removed.

2. Temperature. Denitrification increases with warmer temperatures and slows during the cooler times of the year.

3. Incoming nitrate concentrations. If the incoming concentration is higher more mass of nitrate is removed by the wetland.

What are the habitat benefits of these sites?

The buffer area is about 3x the pool area. For example, a 10 acre CREP pool has a 30+ acre buffer around it. The buffers are seeded with native prairies mixes of grasses and forbs. Because CREP sites are designed to be wet, even in drought years these sites have not gone dry. They provide critical habitat during drought conditions.

These CREP sites are being used for projects like the Conservation Learning Labs led by the Iowa Learning Farms. Why is delivery scale level of monitoring important to helping meet the Iowa Nutrient Reduction Strategy Goals?

Delivery scale monitoring helps determine if plot scale performance results on nitrate and phosphorus reductions from various practices is what can be expected at field-level implementation.

For the CLL sites at least 50% of each watershed has been seeded to cover crops for 3 years. However, the water quality data has not yet shown a significant response. What are some factors that are contributing to the lack of response?

Scale and weather both play a role in the results. The larger system has a longer lag time compared to plot scale research. Continued long term monitoring at the delivery scale is extremely important as weather influences nutrient loading and management decisions. Both 2017 and 2018 weather limited the amount of cover crop growth, likely reducing their nutrient reduction performance. Dr. Crumpton recommends at least 10 years of monitoring to average out the weather influences on the practices performances and account for lag time in the system.

For more information on nitrate reduction wetlands in Iowa and cost-share opportunities for your farm, be sure to check out our recent virtual field day with Susan Kozak, IDALS Soil Conservation & Water Quality Division Director, and Shane Wulf, IDALS Water Resources Bureau Environmental Specialist.

Liz Ripley

August 5 Webinar: Scaling up Oxbow Wetland Restorations for Multiple Benefits

Iowa Learning Farms will host a webinar on Wednesday, August 5 at noon about the benefits of restoring oxbow wetlands.

Learn more about this promising edge-of-field conservation practice, it’s many benefits, potential funding pools, and other exciting up-to-date news on the gaining momentum and enthusiasm around oxbows! Karen Wilke, Iowa Freshwater Specialist & Boone River Project Director for The Nature Conservancy, will spotlight the multiple benefits that oxbow wetland restorations bring for water quality, wildlife, and people by sharing recent research findings and restoration experiences from the field.

Wilke has worked for The Nature Conservancy for the past seven years to research, promote, and restore oxbow wetlands for improved water quality, floodwater storage, and wildlife habitat across Iowa. She hopes webinar attendees will leave with a sense of hope for the future, excitement for the possibilities, and a sense of purpose for moving forward.

To participate in the live webinar, shortly before 12:00 pm CDT on August 5:

Click this URL, or type this web address into your internet browser: https://iastate.zoom.us/j/364284172

    Or, go to https://iastate.zoom.us/join and enter meeting ID: 364 284 172 

Or, join from a dial-in phone line:

    Dial: +1 312 626 6799 or +1 646 876 9923

    Meeting ID: 364 284 172

The webinar will also be recorded and archived on the ILF website, so that it can be watched at any time. Archived webinars are available at https://www.iowalearningfarms.org/page/webinars.

A Certified Crop Adviser board-approved continuing education unit (CEU) has been applied for, for those who are able to participate in the live webinar. Information about how to apply to receive the credit (if approved) will be provided at the end of the live webinar.

Hilary Pierce

August 6 Virtual Field Day: Increasing Wetland Opportunities with Iowa Department of Agriculture and Land Stewardship

Iowa Learning Farms, in partnership with the Iowa Department of Agriculture and Land Stewardship (IDALS), Iowa Nutrient Research Center, and Conservation Learning Group, is hosting a free virtual wetland field day on Thursday, Aug. 6 at 1 p.m. CDT. Join us as we explore new wetland program opportunities and a wetland under construction with Susan Kozak, IDALS Soil Conservation & Water Quality Division Director, and Shane Wulf, IDALS Water Resources Bureau Environmental Specialist.

The Iowa Conservation Reserve Enhancement Program (CREP) is a state, federal, local, and private partnership that provides incentives to landowners who voluntarily establish wetlands for water quality improvement. The goal is to reduce nitrogen loads from croplands to streams and rivers, while also providing wildlife habitat and increased recreational opportunities. Over the past 15 years, about 90 CREP sites have been constructed in a 37 county region in north central Iowa.

To accelerate the installation of wetlands across the state to help meet the Iowa Nutrient Reduction Strategy goals, the Iowa Water Quality Initiative offers flexible, cost-share funding to help install wetlands in areas that do not meet CREP program requirements. To date, more than 30 additional wetlands are set to be begin construction in the next two or three years.

Keokuk County wetland under construction.
Photo credit: landowner Denny Lyle

To participate in the live virtual field day at 1:00 pm CDT on August 6th, click here or, join from a dial-in phone line:

    Dial: +1 312 626 6799 or +1 646 876 9923

    Meeting ID: 914 1198 4892

The field day will be recorded and archived on the ILF website so that it can be watched at any time. The archive will be available at https://www.iowalearningfarms.org/page/events.

Participants may be eligible for a Certified Crop Adviser board-approved continuing education unit (CEU). Information about how to apply to receive the credit (if approved) will be provided at the end of the live field day.

Liz Ripley

June 24 Webinar: Environmental Performance of Wetlands Receiving Non-Point Source Nutrient Loads: Benefits and Limitations of Targeted Wetland Restorations

Iowa Learning Farms will host a webinar on Wednesday, June 24 at noon about the potential targeted wetland restorations have to reduce agricultural nutrient loads.

William Crumpton speaks to a water quality field day group at a CREP wetland in Pocahontas County

Over the past 15 years, over 90 wetlands have been restored through the Iowa Conservation Reserve Enhancement Program (CREP) with the explicit goal of intercepting and reducing non-point source nitrate loads. William Crumpton, Professor at Iowa State University, will summarize results from 15 years of work on Iowa CREP wetlands, including nutrient removal, GHG emissions, and hydrology. The research presented in this webinar is one of the largest and longest running projects of its kind and helps to clarify the potential benefits and limitations of targeted wetland restorations. The research methods are also being used to monitor the impact of in-field practice changes through the Conservation Learning Lab project.

“The Iowa Nutrient Reduction Strategy includes a wide range of in-field and off-field practices, but will likely require restoring thousands of wetlands targeted to intercept and reduce nitrate loads from cultivated cropland,” said Crumpton, who studies wetland processes and functions, including the dynamics of energy flow and nutrient transformation in wetlands, the fate and effects of agricultural contaminants in wetlands, and the role of restored and constructed wetlands in watershed hydrology and water quality.

Wetland restored to intercept and reduce nonpoint source nutrient loads from approximately 950 hectares of cultivated cropland in Palo Alto County, Iowa

“I hope participants will better understand the effects of targeted wetland restorations on water quality and hydrology and thus appreciate the potential benefits and limitations of this practice in Iowa’s agricultural landscapes,” Crumpton said about Wednesday’s webinar.  

To participate in the live webinar, shortly before 12:00 pm CDT on June 24:

Click this URL, or type this web address into your internet browser: https://iastate.zoom.us/j/364284172

    Or, go to https://iastate.zoom.us/join and enter meeting ID: 364 284 172 

Or, join from a dial-in phone line:

    Dial: +1 312 626 6799 or +1 646 876 9923

    Meeting ID: 364 284 172

The webinar will also be recorded and archived on the ILF website, so that it can be watched at any time. Archived webinars are available at https://www.iowalearningfarms.org/page/webinars.

A Certified Crop Adviser board-approved continuing education unit (CEU) has been applied for, for those who are able to participate in the live webinar. Information about how to apply to receive the credit (if approved) will be provided at the end of the live webinar.

Hilary Pierce

Wetland Ecosystem Services: How Wetlands Can Benefit Iowans

On Wednesday, Iowa Learning Farms hosted a webinar about the importance of wetlands in Iowa. Kay Stefanik, Assistant Director of the Iowa Nutrient Research Center, described what makes a wetland a wetland, the different types of wetlands found in Iowa and the ecosystem services that wetlands provide.

Wetlands need to have saturated soils or standing water for enough of the year that hydric soils and hydrophytic vegetation establish. The hydric soil of wetlands is different than that of upland areas. Upland soils will have water and oxygen gases in the pore spaces between the soil particles, while wetlands soils will have water in its pore spaces, with either very little or no oxygen gas. The figure below shows the different in the pore spaces of upland and wetland soils (Raven P.H. et al. 2011. Biology, 9th edition). Finally, wetlands feature hydrophytic vegetation (water plants), which can grow in these saturated soil conditions.

Stefanik described four common types of wetlands that naturally occur in Iowa. Prairie potholes are found predominantly in the Des Moines Lobe and are depressions that collect water during wet periods of the year. Riverine wetlands occur near streams or rivers on floodplains or as oxbow (old meanders of a stream channel that have been cut off from the main channel over time) wetlands. Fens are typically groundwater fed and feature low vegetation. Emergent marshes have herbaceous vegetation, open water areas and algae.

Throughout the entire state of Iowa, about 89% of the original wetlands have been removed or lost as land use has changed. In the Des Moines Lobe region, which used to be known as the “1000 Lake Region”, 99% of the wetlands have been lost. This loss of wetlands matters to us all, due to the ecosystem services that wetlands provide.

To learn more about these ecosystem services that wetlands can provide, watch the full webinar here!

If you want to learn more about wetlands in Iowa, tune in to the Celebrating Iowa’s Wetlands Virtual Field Day on May 28.

Please join us on May 27 for a webinar with Paul Miller, Urban Conservationist at the Iowa Department of Agriculture and Land Stewardship (IDALS), titled “The Importance of Urban Conservation and Useful Stormwater Management Practices for Homeowners”.

Hilary Pierce

May 28 Virtual Field Day: Celebrating Iowa’s Wetlands

Iowa Learning Farms, in partnership with the Iowa Nutrient Research Center and Conservation Learning Group, is hosting a free virtual wetland field day on Thursday, May 28th at 1pm CDT.  

From fens to oxbows to prairie potholes, each wetland has a role to play. Within a row crop system, these areas offer an opportunity to improve water quality and field profitability when allowed to function as wetlands rather than cropped areas. The wetland plants also provide a great habitat for a variety of pollinators.

May is American Wetlands Month and to celebrate, the event will take you on a tour of the diversity of wetlands found in Iowa. The event will include video footage from a variety of wetlands in north Central Iowa and live interaction with Kay Stefanik, Iowa Nutrient Research Center Assistant Director and Adam Janke, Iowa State University Assistant Professor and Extension Wildlife Specialist. Together they will discuss how these sites were formed, identify features that make each wetland unique – including the wildlife and plants, and answer questions from attendees on how farmers and landowners can work with and around the wetlands.

“Most people are familiar with created wetlands used to treat agricultural runoff but may not know that natural wetlands benefit us too”, says Stefanik, a wetland and aquatic ecologist who has studied plants and nutrient cycling in freshwater ecosystems. “Natural wetlands improve water quality, help to retain floodwaters and potentially minimize downstream flooding, as well as provide critical habitat for plants and animals.”

“Because of the diverse geologic history of Iowa’s landscapes, we have a large variety of interesting and unique wetland types found throughout the state” says Janke, whose research has focused on understanding how birds use different types of wetlands. “The area in north-central Iowa we are featuring during this virtual field day is really remarkable for the diversity of wetland types it has within a small geographic area.”

Make plans to join us and participate in the live field day. Shortly before 1:00 pm CDT on May 28th, click this URL, or type this web address into your internet browser: https://iastate.zoom.us/s/315189792

Or, join from a dial-in phone line:

    Dial: +1 312 626 6799 or +1 646 876 9923

    Meeting ID: 315 189 792

The field day will be recorded and archived on the ILF website, so that it can be watched at any time. The archive is available at https://www.iowalearningfarms.org/page/events.

A Certified Crop Adviser board-approved continuing education unit (CEU) has been applied for, for those who are able to participate in the live webinar. Information about how to apply to receive the credit (if approved) will be provided at the end of the live field day.

Liz Ripley

May 20 Webinar: Wetland Ecosystem Services: How Wetlands Can Benefit Iowans

May is American Wetlands Month and Iowa Learning Farms will host a webinar on Wednesday, May 20 at noon about the importance of wetlands in Iowa.

Wetlands are important for all life in Iowa, due to the many ecosystem services they provide, such as water quality improvement, flood control and wildlife habitat. Since European settlement, Iowa has lost almost 90% of its wetland habitat, making it imperative that we both protect the wetlands that are left and find ways to create and restore critical wetland habitat. Kay Stefanik, Assistant Director of the Iowa Nutrient Research Center, will highlight the importance of wetlands and will introduce the different types of natural, created and restored wetlands that can be found in Iowa.

“I hope that webinar participants will take away a greater appreciate for wetlands in Iowa, as well as a desire to better protect wetland ecosystems from future harm,” said Stefanik, whose expertise is in wetland and aquatic ecology, where she has studied vegetation succession in created and restored wetlands, as well as nutrient cycling.

To participate in the live webinar, shortly before 12:00 pm CDT on May 20:

Click this URL, or type this web address into your internet browser: https://iastate.zoom.us/j/364284172

    Or, go to https://iastate.zoom.us/join and enter meeting ID: 364 284 172 

Or, join from a dial-in phone line:

    Dial: +1 312 626 6799 or +1 646 876 9923

    Meeting ID: 364 284 172

The webinar will also be recorded and archived on the ILF website, so that it can be watched at any time. Archived webinars are available at https://www.iowalearningfarms.org/page/webinars.

A Certified Crop Adviser board-approved continuing education unit (CEU) has been applied for, for those who are able to participate in the live webinar. Information about how to apply to receive the credit (if approved) will be provided at the end of the live webinar.

Hilary Pierce

Can I add or improve a wetland on my farm?

To celebrate American Wetlands Month, I wanted to highlight how important they are here in Iowa and share how the Whole Farm Conservation Best Practices manual can helps match your goals with the right edge of field practice – like wetlands! Several types of wetlands can be used in agricultural settings, depending on your objectives.

Wetlands are crucial to meeting our Iowa Nutrient Reduction Strategy goals of reducing nitrogen and phosphorus losses. Beyond acting like a filter cleaning the water, these wetlands act like sponges absorbing and storing water aiding in both times of flooding and drought. Lastly these wetlands are incredible habitats to migratory and endangered species.

Considering improving and adding a wetland?

Some must-have pieces of information for determining if a wetland could be a suitable edge-of-field practice for the site include a soils map, profitability maps, and knowledge of relationships to district infrastructure if the site is in a drainage district. The decision tree below is a great place to start the planning process.

If the primary goal of a wetland is for water quality improvements, treatment wetlands help to remove nitrogen through conversion of nitrate-nitrogen to nitrogen gas by microbial activity and through plant uptake. Ideally, treatment wetlands should have a pool footprint greater than or equal to 1 percent of the watershed area to be treated. The topography of the site should allow for a drop in elevation from the tile outflow to the surface of the standing water in the wetland to prevent backflow of water into the tile drain system.

Additional land is needed to allow a diverse buffer of wetland vegetation to develop around the shallow water pool. If the wetland footprint is in an area that could experience high sediment flow, a sedimentation basin or other structure will need to be considered. It is also important that treatment wetlands remain fish-free to reduce sediment disturbance and prevent unwanted loss of sediment, phosphorus, and nitrogen from the system.

If the primary goal is to provide additional wetland habitat, identifying low-profitability wet zones within the field can reveal locations that could be planted in perennial wetland vegetation.

Be sure to tune in to our upcoming events featuring wetlands:

-Liz (Juchems) Ripley

Wetland Ecosystem Services: How wetlands can benefit Iowans.

Kay Stefanik | Assistant Director, Iowa Nutrient Research Center

              Iowa was once a mosaic of prairies, wetlands, rivers, and forests.  Today, Iowa looks drastically different as agriculture now dominates the landscape.  Fertile prairie and wetland soils, which are ideal for row crop agriculture, have paved the way to a booming agricultural industry and led to Iowa being one of the top corn and soybean producing states in the country. 

              While agriculture is vital to the regional economy, all things in life come with trade-offs.  The rise of agriculture came at the expense of nature. Of Iowa’s natural ecosystems, wetlands have been particularly hard hit.  Prior to European settlement, wetlands made up almost 4 million acres of Iowa’s landscape.  Today, there are only about 422,000 acres of wetlands remaining; this is an 89% loss in wetland habitat.   

              At this point, you may be wondering “why does wetland loss matter”?  When a wetland is lost, we do not just lose a physical space.  We also lose the wetland’s ecosystem services – the essential direct and indirect benefits that nature provides to humans.  Even though wetlands are much harder to find today, the wetlands that do exist are still providing a variety of ecosystem services.  These ecosystems services include:

  • Flood prevention
  • Water quality improvements through nutrient and sediment removal
  • Wildlife habitat
  • Recreational opportunities
  • Food and fiber

              I am in no way implying that sides need to be taken, that it is agriculture or nature.  What I am suggesting is that not only can agriculture and nature coexist, but that nature can be used to improve agriculture.  By protecting wetlands already on the landscape, as well as strategically creating and restoring wetland habitat, we can increase the impacts of wetland ecosystem services.  Of interest in Iowa are the ability of wetlands to help with flood prevention and to improve water quality. 

              Flooding has become a major issue throughout Iowa over the last decade.  Wetlands placed along streams and rivers have the potential to capture surface runoff before stormwater reaches the stream and can also act to hold water from a river that spills over its banks.  This holding capacity prevents some of that floodwater from being immediately transported downstream.  By holding floodwater in place, downstream fields and developed areas may be spared from extreme flooding events and severe economic loss. 

              In addition to flood prevention, wetlands also help to improve water quality.   Wetlands receiving surface runoff can reduce phosphorus concentrations through the settling out of soil particles in the water column. The settled-out phosphorus becomes trapped in the wetland sediment and thus held on the landscape.  Wetlands that receive water with high dissolved nitrogen concentrations, usually ground water or tile line water, can reduce nitrogen through microbial conversion to nitrogen gas.  This nitrogen gas is then lost to the atmosphere, which is already about 78% nitrogen.  The ability of wetlands to reduce nitrogen and phosphorus can help us meet the 45% nutrient reduction goal laid out in the Iowa Nutrient Reduction Strategy.

              These wetland ecosystem services – flood prevention, water quality improvement, wildlife habitat, recreational opportunities, food, and fiber – give wetlands both instrumental and intrinsic value.  Wetlands have great potential to benefit the lives of all Iowans, but only if wetlands are allowed to exist in Iowa’s landscape.

Kay Stefanik

@kay_stefanik (Twitter)

Conservation Best Practices Manual Available for Free Download

The Conservation Learning Group has published the Whole Farm Conservation Best Practices Manual to aid farmers in selecting conservation measures appropriate for their farms.

Designed primarily for farmers just starting out through three years of adopting conservation practices, the manual provides a broad range of information that could be beneficial to any producer. The manual is available for free download or in hard copy from the ISU Extension Store.

Covering in-field topics including tillage management, cover crops and diverse rotations, and edge-of-field practices such as wetlands, bioreactors, saturated buffers, controlled drainage and prairie strips, the manual provides detailed information regarding implementation and expected outcomes.

In addition, it includes comprehensive graphical decision tools to aid farmers in determining the best approaches for each area on their farm.

“A primary goal in producing this manual is to help farmers succeed with conservation practices based on the vast array of ongoing research and field studies conducted at Iowa State and beyond. We’ve heard from farmers across the state that sometimes it’s difficult to navigate discrepancies between different research reports and recommendations regarding conservation and water quality practices. With this manual, we’ve pulled together the most important parts from the rich sets of research on cover crops and other conservation efforts in Iowa and presented them using consistent language in an easy-to-use graphical format.”

Mark Licht, assistant professor and extension cropping systems specialist at Iowa State and CLG member

The manual was developed based on numerous meetings and working groups among stakeholders, researchers, agency representatives and communications specialists, who worked together to provide a comprehensive resource for farmers. The content was also presented to farmers at multiple events, prior to public release, to gather feedback on usability and the graphical decision tools included.

“This manual will be an excellent tool for our conservation planners to utilize as they work with farmers to adopt these management practices. I was involved in the working groups which discussed the best strategies for farmers who are new to these practices. It’s our hope with this advice that they will be successful early in the adoption of these practices both agronomically and from a conservation standpoint.”

Kevin Kuhn, resource conservationist for the USDA Natural Resource Conservation Service

Conservation Learning Group will continue to evaluate responses to the manual and update it with emerging information and data from research projects.

“This is not meant to be a static guide. As our experiences and knowledge base grow, we will continue to communicate with producers and provide the best advice we can to maximize their successes with conservation practices.”

Mark Licht

The manual was developed in cooperation with the Iowa Soybean Association, Iowa Agriculture Water Alliance and Practical Farmers of Iowa, and with the support and input from multiple local, state and federal organizations.

This manual is a joint publication of Iowa State University and USDA-Natural Resources Conservation Service, supported by the Natural Resources Conservation Service, U.S. Department of Agriculture, under number 6000004181.


Liz (Juchems) Ripley