Cover Crops: One Piece of the Puzzle in CLL Project

Cover crops are an important tool for helping keep soil, nitrogen and phosphorus in the field – instead of our water bodies. Because they grow outside the typical corn/soybean growing season, cover crops help reduce soil erosion and take up nutrients that could otherwise leave the field. It is also the most popular practice among our Conservation Learning Lab (CLL) farmer partners.

The CLL project is studying the impact of conservation practices implementation at the watershed scale in Floyd and Story County.  The conservation planning process within the watersheds has yielded cover crop contract enrollment of 675 acres and 1,081 acres, respectively, starting this fall covering 50-68% of the crop acres within the watershed.

Cover_crop_April_Berger_FarmThe farmer partners chose to seed either winter cereal rye and oats.  These grass species are easy to establish, relatively inexpensive and are the leading biomass producers in our cover crop research projects – keeping that soil covered (reducing the loss of phosphorus) and taking up nitrogen.

The Iowa Nutrient Reduction Strategy team reviewed cover crop research results from across Iowa and the Midwest and found that cereal rye and oats reduced nitrogen loss by 31% and 29%, respectively.  Similarly, the reduction of phosphorus when adding cereal rye is about 29%, primarily as a result of reduced soil erosion. According to our RUSLE2 calculations, a cereal rye cover crop added to a no-till system can reduce soil erosion by 30-80% and can be even larger when transitioning from a conservation tillage system.

Be sure to keep checking back as we will be providing updates as the cover crops are seeded this fall!

The project is funded by the Iowa Department of Agriculture and Land Stewardship (IDALS) and the United States Department of Agriculture – Natural Resources Conservation Services (USDA-NRCS) of Iowa.

Who Doesn’t Want to See More Cattle on the Rolling Green Pastures of Iowa?

I have a soft spot for beef cattle. I mean, who doesn’t like to see cattle on rolling green fields on a beautiful Iowa summer day? While this pastoral scene can bring tranquility and enjoyment, returning more land to grazing has water quality benefits and social benefits.

gilmorecity1As you know, I spend most my time thinking or talking about the Iowa Nutrient Reduction Strategy (NRS). Most of my presentations are on edge-of-field nitrate reduction practices. My job is to study specific engineering solutions to our water resource issues. Perhaps not all of our problems can be solved through engineering? Radical thought.

When you really look at our nutrient loss issues, the most important factor affecting nutrient loss is that today there are primarily annual row crops where once there was perennial vegetation pre-settlement or diverse crop rotations during the early 1900’s.

These cropping systems have made Iowa an agricultural leader. We are unlikely to see major land use changes in the near future, but I do think there is potential for more
diverse land uses, especially in certain areas in Iowa. One way to diversify would be an March_img_4373increase in pasture and hay land. For this to work, we would need more cattle to forage.

The Iowa NRS Nonpoint Source Science Assessment estimated that grazed pastureland had 85% nitrate-N reduction and 59% P reduction compared to an annual corn-soybean system. Another added value of having greater need for forage by cattle might be that this could greatly improve the potential economics of cover crops. Late fall and early spring grazing could provide some of the forage needs for the cattle.


The infrastructure to increase beef cattle on pasture is not what it once was. We have taken out miles of fence throughout the state and there are substantial labor needs for an integrated livestock-cropping system. On the other hand, adding some diversity to agricultural operations could open up opportunities for young farmers to get back on the landscape.

DSCN0318As we move forward with implementation of nutrient reduction practices, it is important to think about our livestock system and how we might be able to increase the number of cattle on pasture in Iowa. Not only could this benefit our environment and maybe provide more opportunities for young people to get into agriculture, it could also add substantial beauty to our landscape with cattle grazing green pastures.

Matt Helmers

To explore the benefits of pasture-based livestock operations, check out Dr. Helmers’ Conservation Chat or Leopold Center Dr. Mark Rasmussen’s Conservation Chat. Matt Helmers is an Iowa Learning Farms team member and Professor of Agricultural and Biosystems Engineering at Iowa State University. 

Introducing the Iowa Watershed Approach

Today’s guest post was provided by Adam Wilke, ISU Extension and Outreach Water Specialist.

The Iowa Watershed Approach (IWA) is a new five-year project focused on addressing factors associated with flood disasters in the state of Iowa. The IWA project will also provide benefits of improved water quality by implementing conservation practices outlined in the Iowa Nutrient Reduction Strategy.


Assessing Cedar River flood waters, September, 2016. Photo courtesy Brain Powers / DSM Register.

The “HUD Project,” as it is commonly referred, was awarded $96.9 million by the U.S. Department of Housing and Urban Development (HUD). The National Disaster Resilience Competition provided $1 billion to communities that have experienced recent significant natural disasters, including Iowa’s three flood-related Presidential Disaster Declarations in 2013. Iowans remember the devastating floods of 2008 and 1993, and some are still working to repair damage from September 2016 flooding.


Map of Iowa Watershed Approach. Courtesy of Iowa Flood Center.

The IWA focuses on nine watersheds throughout the state, representing varying soil types, topographic regions, and land uses. These watersheds were prioritized as regions that have been most impacted and distressed from previous flood events and have unmet recovery needs. The IWA is a vision for both rural and urban resilience, and three cities (Storm Lake, Coralville, and Dubuque) are priority areas for the project.

Previous efforts to address flooding impacts were piloted through the Iowa Watersheds Project in five watersheds throughout the state in 2010. By 2016, over 65 constructed practices—such as ponds, wetlands, and terraces—have been completed.


Road damage from Cedar River flood, June 2008. Courtesy Iowa Dept. of Transportation.

The theme of year one is “The Iowa Watershed Approach: A Visions for Iowa’s Future Under Changing Hydrologic Conditions.” Climate science indicates that annual average precipitation in Iowa has trended upward over the last 100 years and extreme precipitation events (more than 1.25 inches per day) have increased throughout the state. University of Iowa research of 774 U.S. Geological Survey stream gauges found an upward trend in frequency of flooding throughout the Central U.S. over the past 50 years. This has contributed to crop loss and destruction of infrastructure, such as homes, roads, and bridges.

The IWA will work to achieve six specific outcomes:

  1. Reduce flood risk
  2. Improve water quality
  3. Increase flood resilience
  4. Engage stakeholders through collaboration and outreach/education
  5. Improve quality of life and health, especially for susceptible populations
  6. Develop a program that is scalable and replicable throughout the Midwest and the United States

The IWA focuses on innovative in-field and edge-of-field practices to reduce flood potential and decrease nutrient concentration in surface water. The practices include:

• Wetland Construction                              • Farm Ponds
• Storm Water Detention Basins              • Terraces
• Sediment Detention Basins                    • Floodplain Restoration
• Channel Bank Stabilization                    • Buffer Strips
• Saturated Buffers                                       • Perennial Cover
• Oxbow Restoration                                     • Bioreactors
• Prairie STRIPS


Courtesy ISU Extension and Outreach.

The IWA project creates Watershed Management Authorities (WMA) and these organizations allow for a broad range of stakeholders—including scientists, state agencies, counties, municipalities, farmers, and citizens—to organize and work towards the common goals of flood reduction and water quality improvement. Some watersheds, such as the Middle Cedar, have established WMAs, while others are beginning the formation process.

Stream gauges will provide data for the Iowa Flood Center to conduct hydrological assessments in each watershed and allow researchers to assess risks associated with flooding and water quality, including developing and evaluating future scenarios to maximize results from project resources.

WMA will use these findings to best select eligible subwatersheds at the HUC 12 (Hydrologic Unit Code) scale and prioritize implementation of constructed projects. Stakeholder inputs, watershed plans, and hydrological assessments will guide the WMAs in selecting the most beneficial practices and appropriate locations.


Courtesy ISU Extension and Outreach.

This project combines the strengths and efforts of Iowa State University Extension and Outreach, the Iowa Nutrient Research Center, and the Daily Erosion Project by the Iowa Water Center to achieve these goals. The IWA is a new way to think about the movement of water across the Iowa landscape. One of the most important pieces of completing such a large and complicated project is to ensure stakeholder engagement throughout the project. We look forward to hearing your questions, thoughts, and concerns as we all seek the common goal of reducing flood disaster and ensuring water quality for generations to come.

Adam Wilke

Help Celebrate Cover Crop Week with #FarmersCoverIowa!

aerial-vs-hagie-plot_-hagie-seedingLed by Iowa Department of Agriculture and Land Stewardship and CleanWaterIowa, we are joining the celebration of Cover Crop Week.

Cover crops are a great way to improve soil health and protect water quality. Many Iowa farmers are adding cover crops to their crop rotations so soil stays covered when the fields are not growing other crops. Cover crops also improve soil organic matter and slow water runoff.

The Iowa Nutrient Reduction Strategy research summary indicated an average 31% reduction in nitrate (N) concentration with use of a rye cover crop and a 28% reduction with an oat cover crop. The living cover crop will reduce soil erosion and phosphate (P) loss by about 29%, when planted in late summer or early fall.

Share your photos and experiences with cover crops with #FarmersCoverIowa!

For more information on adding cover crops to your farmland, visit our resources page today and follow us on Twitter and Facebook.

Liz Juchems

Wetlands and Water Quality

Wetlands are often viewed as filters, or kidneys of the landscape, and that’s for good reason as they have great potential for improving water quality!  Today let’s dig in and investigate how wetlands help to improve water quality and the mechanisms at work to make that happen.

Wetlands can be strategically placed to improve water quality through the removal of nutrients, specifically nitrate, like the wetlands in the Conservation Reserve Enhancement Program (CREP). Water enters these nutrient removal wetlands coming from a series of tile drains, often carrying a substantial load of nitrogen in the form of nitrate.

As water moves slowly through the wetland, microbes breathe in and consume nitrate (NO3), the way humans use oxygen when we breathe and respire, converting the nitrate to inert N2 gas (comprising 80% of the atmosphere).  This process is called denitrification. In turn, cleaner water is sent downstream. 


Put simply, these wetlands are strategically designed and placed to allow the natural microbiology to happen – the microbes are doing all of the heavy lifting! These nitrate removal wetlands are ideal locations for denitrification to occur because they provide saturated anaerobic soil conditions, and the system is supplied with a source of nitrate from agricultural drainage water. Aquatic plants and wetland soils provide surfaces on which those microbes live, in addition to providing organic carbon to help maintain growth and metabolism of the denitrifying microbes. Strategically designed and sited wetlands can reduce nitrate loads to downstream water bodies by 40-70%.

Hear more about this process from Dr. Bill Crumpton and others in our award-winning video Incredible Wetlands:

Sediment Capture
Wetlands can also improve water quality by slowing the flow of water and capturing sediment, if the contributing water is coming from overland flow.  When the velocity of water slows down, as in wetlands, sediment is unable to stay suspended.  Think of it like a salad dressing with herbs and spices … when you give it a good shake, it gets well mixed throughout, but after letting it sit for some time, the herbs/spices sink to the bottom.

The same thing happens in wetlands.  When the speed of the water slows down, the suspended sediment (soil) particles gradually settle to the bottom where wetland plants hold the accumulated sediment in place, again sending cleaner water downstream.


Role of Wetlands in Nutrient Reduction Strategy
Iowa’s Nutrient Reduction Strategy lays out several different scenarios of conservation practices in which the targeted 45% reduction in nitrogen and phosphorus can be achieved.  Wetlands play a really key role in reaching those goals, particularly on the nitrogen side of things!  One of the combined scenarios of practices calls for ~7,600 wetlands strategically placed for nitrate removal.  There are currently 77 CREP wetlands across the state of Iowa, with others in the works.


The amount of human and financial capital to reach these goals is huge, but we continue to make forward progress in increasing the number of wetlands acres (see last week’s blog post, Wetlands: By the Numbers, for more information about ongoing wetlands restoration efforts).

Check out our previous posts celebrating American Wetlands Month:

Stay tuned next week for the fun tools and techniques we use to help teach young people about the amazing benefits of wetland ecosystems on our landscape!

Ann Staudt

January 2016 Webinar Recap: Talking about the Iowa Nutrient Reduction Strategy with Dr. John Lawrence

Did you miss our latest webinar?  You can view archived versions of all Iowa Learning Farms webinars here.  Iowa Learning Farms webinars are also available for download through iTunes.


Iowa Learning Farms kicked of the 2016 webinar series with a chat with Dr. John Lawrence, Associate Dean of the College of Agriculture and Life Sciences at Iowa State University (ISU) and Director of the Iowa Nutrient Research Center and ISU Extension and Outreach (ISUEO) Agriculture and Natural Resources program area.

Dr. Lawrence and ILF Program Director, Dr. Jacqueline Comito, spoke about the Iowa Nutrient Reduction Strategy and the difficulties of defining and measuring success as Iowa works to reduce nutrients to Iowa waters and to the Gulf of Mexico.  Dr. Lawrence heads the Iowa Nutrient Research Center, which has played an integral role in assessing scientific approaches that target the scope, scale, and practices laid out in the Iowa Nutrient Reduction Strategy.  To reduce nutrients, Dr. Comito and Dr. Lawrence spoke about the need to get more creative and motivate farmers to implement practices that could reduce nitrogen and phosphorus loss.

The conversation covered important information about next steps for Iowa if we cannot “push the needle” each year and improve our water quality.  Watch the webinar here.  If you enjoy listening to podcasts, you can find many Iowa Learning Farms webinars available for download.  Take a look at our webinar archive and see what you might be missing.

Julie Whitson

Today’s Webinar: Bioreactors in the Spotlight

It’s Webinar Wednesday – tune in this morning at 9:00am for perspectives on bioreactors and their potential for benefiting water quality. This month’s Iowa Learning Farms webinar will coincide with the Midwest Ag Drainage Water Management series, thus the change of time from our usual afternoon webinar time slot.

With a focus on denitrifying bioreactors, today’s webinar is structured to provide both the perspective of the research/extension specialist and the farmer/practitioner. The featured speakers include Dr. Richard Cooke, Associate Professor in the Department of Agricultural Engineering at the University of Illinois at Urbana-Champaign and Chad Ingels, Iowa State University Extension and Outreach watershed specialist and northeast Iowa farmer. Subsurface bioreactors have garnered a large amount of interest across the Midwest for their potential role in whole-farm nutrient management; they are highlighted as a key edge-of-field practice for reducing nitrogen export in the Iowa Nutrient Reduction Strategy.

To Recap…
What: “Bioreactors and Water Quality” Webinar
When: Wednesday, September 16 at 9:00am
Where: (Select “Enter as a Guest” button)
Why: Learn more about denitrifying bioreactors, an emerging edge-of-field practice with great potential for nitrate reduction in subsurface drainage water

If you can’t participate live, watch the archive of today’s webinar after the fact (along with all of ILF’s past webinars) on the ILF Webinars page.

Ann Staudt