Edge-of-Field Conservation Practices that Work

Whole farm conservation best practices aren’t limited to in-field practices like no-tillage, strip-tillage, cover crops and extended rotations. A suite of edge-of-field conservation practices, like those pictured below, can help improve water quality in the state by managing the loss of nitrogen from cropland.

Based on 2012 and 2017 United States Department of Agriculture Census of Agriculture data, approximately 50% of Iowa cropland has subsurface drainage. While this drainage makes it possible to farm previously wet soils, it also carries dissolved nitrogen from farm fields to the streams, rivers, lakes, wetlands, and other surface waters of the state.

Excess nitrogen in water leads to local, regional, and national-level alterations to aquatic ecosystems resulting in decreased water clarity, increased algal growth, and oxygen shortages that cause fish kills and reduce diversity. Excess nitrogen also harms drinkable water supplies. Concentrations above the 10 mg/L NO3-N drinking-water standard established by the United States Environmental Protection Agency are not uncommon in Iowa.

Edge-of-field practices such as treatment wetlands, bioreactors, saturated buffers, and controlled drainage can significantly reduce the amount of nitrate-nitrogen that leaves drainage networks. On average, nitrate-nitrogen is reduced by:

  • 52% with treatment wetlands
  • 53% with saturated buffers
  • 43% with bioreactors
  • 32% with controlled drainage

While edge-of-field practices have the potential to remove large amounts of nitrate-nitrogen, there is no one practice that works well at all sites. A combination of appropriate practice implementation and high adoption rates is needed to meet the nitrogen reduction goals of the Iowa Nutrient Reduction Strategy that calls for the reduction of nutrient loadings to the Gulf of Mexico by 45% over the coming decades.

Over the next five weeks, we’ll be exploring different edge-of-field practices and the decision trees to help identify which practice(s) will work best for your system.

-Liz (Juchems) Ripley

Iowa’s Water Quality Challenge

On Wednesday, Iowa Learning Farms hosted a webinar about the efforts and progress being made toward reducing agricultural losses of nitrogen and phosphorus.

Laurie Nowatzke, Measurement Coordinator for the Iowa Nutrient Reduction Strategy at Iowa State University, explained:

  1. How does nutrient loss occur in Iowa agriculture?
  2. Which practices reduce nutrient loss?
  3. Are these practices being adopted?

Nowatzke explained that agricultural losses of nitrogen and phosphorus mainly occur in two different ways: soil and phosphorus loss through erosion from surface runoff and loss of nitrate-nitrogen and some dissolved phosphorus through subsurface drainage. In-field and edge-of-field practices have been designed and are being adopted by farmers and landowners to reduce these losses.

These practices can be used to meet the nutrient reduction goals set forth in the Iowa Nutrient Reduction Strategy. The Strategy lays out several different scenarios in which the goals can be reached through different combinations of practices and the necessary adoption rate for each scenario. One of these scenarios is shown in the figure below, with the current estimated adoption rate also shown.

More widespread adoption of these practices (in this combination of practices or in the other scenarios) will be needed to reach the nutrient reduction goals of the Iowa Nutrient Reduction Strategy.

Nowatzke shared the following resources for more information:

More information about the progress toward Iowa’s water quality goals can be found in the forthcoming 2018-19 Annual Progress Report of the Iowa Nutrient Reduction Strategy. Last year’s report can be found here.

Watch the full webinar here!

Be sure to join us next week, on May 6, when  Ross Evelsizer, Watershed Planner & GIS Specialist at Northeast Iowa RC&D, will present a webinar titled: “Multi-Cropping as a Profitable Soil Health Solution“.

Hilary Pierce

Iowa’s Water Quality Challenge: Efforts and Progress in Reducing Agricultural Nitrogen and Phosphorus Loss

Iowa Learning Farms will host a webinar on Wednesday, April 29 at noon about the work that is being done in Iowa to reduce losses of agricultural nitrogen and phosphorus, as well as the progress that has been made.  

What are the drivers of nutrient loss and water quality impacts in Iowa? To what extent are agricultural conservation practices being used in Iowa to address these concerns? This webinar will explore these questions, describe the wide variety of data sources available, and present findings from the forthcoming Annual Progress Report of the Iowa Nutrient Reduction Strategy. Laurie Nowatzke, Measurement Coordinator for the Iowa Nutrient Reduction Strategy at Iowa State University, will share how Iowa’s water quality efforts are tracked, the latest findings, and where participants can find additional resources about these efforts.

“There are many programs and initiatives working toward reducing nutrient loss in Iowa. This project uses data to show the current status and outcomes of those efforts, and it aims to provide Iowans with timely information regarding water quality improvement,” said Nowatzke. She works for the College of Agriculture and Life Sciences to evaluate Iowa’s progress in meeting water quality goals, research Iowa farmers’ conservation practice adoption, and track statewide use of water quality improvement practices in agriculture.

To participate in the live webinar, shortly before 12:00 pm on April 29:

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

Chatting with Secretary Mike Naig

If you missed our February webinar with Iowa Secretary of Agriculture Mike Naig, you are in luck! You can listen to the conservation with Dr. Jacqueline Comito on Episode 52 of the Conservation Chat.

The newest episode offers a shorter version that highlights discussion topics like the challenge of scaling up to meet the Iowa Nutrient Reduction Strategy Goals and the need for federal, state and private partnerships to reach the goals.

Be sure to subscribe today and catch up on all the great episodes on your favorite device. You can also stream the podcast and webinar from our website.

Liz (Juchems) Ripley

February 5 Webinar: A Conservation Chat with Secretary Naig


Sec. Naig headshot 19

Iowa Learning Farms will host a webinar on Wednesday, February 5th at 12:00 p.m. with Iowa Secretary of Agriculture Mike Naig.

The webinar will feature Dr. Jacqueline Comito, Iowa Learning Farms Program Director, and Secretary Naig discussing conservation, water quality and the Secretary’s vision for Iowa.  They will also discuss the Iowa Nutrient Reduction Strategy and how Iowans are working to meet the nitrogen and phosphorus loss reductions outlined in the Strategy. Webinar participants will be able to submit questions for Secretary Naig during the webinar through the Zoom Webinar software.

Don’t miss this webinar!
DATE: Wednesday, February 5, 2020
TIME: 12:00 p.m.
HOW TO PARTICIPATE: visit www.iowalearningfarms.org/page/webinars and click the link to join the webinar

More information about this webinar is available at our website. If you can’t watch the webinar live, an archived version will be available on our website:

Hilary Pierce

Overview of the Iowa Nutrient Research Center


Are you curious about the role of the Iowa Nutrient Research Center (INRC) and the projects that the INRC has supported and is currently involved with?

Kay Stefanik, Assistant Director of the INRC, discussed the Center and some of the impacts from research projects funded by the INRC, as well as its current activities, in a short webinar on Wednesday. Watch the webinar here!INRC Graphic

Be sure to also check out the upcoming seminar series that is being launched by the INRC! The first seminar will be next Wednesday, January 22 – see below for more information.

INRC Seminar

And  join us next month, on February 5, when Jacqueline Comito will sit down with Mike Naig, Iowa Secretary of Agriculture, for a Conservation Chat!

Hilary Pierce

Saturated Buffer Helping Improve Water Quality Near Walcott

ILFHeaderIMG_0035Mike Paustian returned to the family’s heritage farm in 2008 which encompasses nearly 1,400 acres and a 1,200 sow farrow-to-finish hog operation. In addition to using no-till and minimum tillage, the Paustian’s began adding cover crops to hold soil in place, while scavenging nutrients from the soil and fall applied manure. Their goal is to build long term soil health and organic matter in their fields and improve water quality. They have used primarily cereal rye and oats on about 600 acres for over seven years.

Taking the next step to reduce nitrate loss from their farm, the Paustians installed a saturated buffer just north of their home in the summer of 2018 and are using drone technology to monitor the performance of their farm and conservation practices.

These practices were on full display at our field day last night as the Paustians shared their experiences and efforts to help improve water quality and soil health.

IMG_0003Kay Stefanik, assistant director of the Iowa Nutrient Research Center, set the stage with an overview of the Iowa Nutrient Reduction Strategy and demonstrated how nitrate test strips can be used by farmers and landowners to check their local water quality. These test strips can provide a nitrate and nitrite concentration result in just 30 seconds and should be used multiple times throughout the year to provide a more accurate representation of the system. These strips are available through ISU County Extension offices or by contacting Jamie Benning, Iowa State Water Quality Manager.

After a short walk to the saturated buffer, Keith Schilling and Matthew Streeter, Iowa Geologic Survey, guided us through the installation process and ongoing monitoring of the site. Supported by an Iowa Department of Agriculture and Land Stewardship grant, they are collected data through 2020.

Results from the first year of data indicate that the nitrate concentration leaving the saturated buffer is <2 mg/l whereas the control is measuring an average of over 20 mg/l. With good infield management of nutrients and the addition of cover crops, there is little nitrate entering the buffer and the soil microorganisms are then able to efficiently remove nitrate that does enter the system and release it as N2 gas.

IMG_0029Using their sampling gear, we were able to use a nitrate test strip and take a quick measurement during the field day. The strip revealed about 2 mg/l – consistent with the results from the on-going monitoring.

Back at the shop, Mike provided a quick demonstration of how he is using drone technology to monitor crop and conservation practice performance to help guide management choices for their operation. Using software to analyze the imagery, he was able to observe how his cereal rye cover crop fared during the very wet spring.

IMG_0041“It is clear on this map (lower left corner) where we ran out of manure two years ago. There is less rye growth in that area and we can now adjust our management decisions to help improve our system,” noted Mike. “Another result of using the drones, is our decision to use a tractor with tracks next spring on a field that showed signs of compaction.”

Whether you have access to drone technology or pick up some nitrate test strips from your local Extension office, you can use these tools on your farm to better inform your decisions and seek technical help from your NRCS office to help make some changes to your system to help improve the long term productivity of your farm.

If you are interested in hosting or attended an upcoming field day, feel free to reach out at 515-294-5429 or ejuchems@iastate.edu.

Liz Juchems