Cover crops key to N retention + soil health, especially before soybeans

How can we increase nitrogen retention and soil health in Iowa’s corn and soybean cropping systems? There is not just one single quick fix, but Dr. Mike Castellano, William T. Frankenberger Professor of Soil Science and Associate Professor in the Department of Agronomy at Iowa State University, made the strong case for cover crops in last week’s Iowa Learning Farms webinar.

Castellano framed the webinar with a discussion of nitrogen budgets. As he put it, we don’t typically think about financial management without a budget – nutrient management is the same way! He then explored the potential of cover crops, especially cereal rye, to aid farmers in retaining nitrogen (via the cover crop plant biomass) and building soil organic matter. Watch the full archived webinar on the Iowa Learning Farms website:

OR, if you’d like the CliffsNotes version, here are the Top 5 key take home points that jumped out at me…

cc-top5takehomepoints-iiAgain, you can check out the full presentation on the Webinar Archives page of the Iowa Learning Farms website.

Save the date…
The next Iowa Learning Farms webinar will be Wednesday, October 19 at 1:00 p.m., featuring our own Dr. Matt Helmers. He will be addressing common questions and misconceptions regarding cover crops, drainage, and more … think Mythbusters meets water quality! It’s sure to be a lively conversation.

Ann Staudt


Cover Crop Webinar to Focus on Soil Health and Nitrate Retention

As fall cover crops go into the ground, many farmers have questions about how to best manage cover crops and achieve benefits such as soil health and nitrate retention. Dr. Mike Castellano will share his research on how cover crops can best be managed to maximize benefits during the Iowa Learning Farms’ monthly webinar on Wednesday, September 21 at 1 p.m.

corn_in_rye_small“Future gains in crop production and environmental quality will require a systems approach that integrates many disciplines,” Castellano said. To achieve this vision, Castellano uses expertise in soil science and ecosystem ecology to work with a broad range of scientists, managers and policy makers.

Castellano is the William T. Frankenberger Professor of Soil Science and Associate Professor in the Department of Agronomy at Iowa State University. He has a PhD in Soil Science from The Pennsylvania State University.


Log on as a guest shortly before 1:00 p.m.:

If you can’t participate live, watch the archive of today’s webinar (along with all of ILF’s past webinars) on our website:

Julie Whitson


Conservation practices in the Black Hawk Lake watershed improve water quality


Michelle Soupir presenting at Black Hawk Lake Field Day Sept. 15, 2016

Note: Today’s guest blog was written by Michelle Soupir, Leigh Ann Long, Katherine van der Woude.  They are conducting a monitoring and research project in Black Hawk Lake watershed in Sac County.  Michelle presented at our Iowa Learning Farms field day on September 15th in Lake View. It was a great chance to share with area folks what they have been learning about water quality in the small streams feeding Black Hawk Lake and we wanted to share it with you too!


We have been collecting water samples from three subwatersheds in the Black Hawk Lake watershed since March 2015, and the data we have clearly shows the positive impact that conservation practices have on water quality.


Katherine van der Woude collects samples from their automated samplers and meets a new amphibian friend near Black Hawk Lake.

One part of our work is comparing two subwatersheds with similar soils and of similar size, about 450 acres each.

Subwatershed 12 has various conservation practices implemented over nearly all of its area including: cover crops, terraces, nutrient management plans and CRP on both sides of the stream near where we collect our samples.  The second location, subwatershed 11 has only about 25% of the subwatershed in conservation practices. See map below.


2015 was a wet year with nearly 35 inches of rainfall in the watershed, compared to a long term average of 20 inches.  Much of the extra rainfall came as highly intense storms, which has an impact on soil erosion and nutrient movement.

From the site with fewer practices (11), average nitrate loading in 2015 was 153 lbs/ac, while the site with lots of conservation practices (12) had an average load of 115 lbs/ac.  This calculated to about a 33% increase in nitrate load from the site without conservation practices.

Total phosphorus loads were also higher from the site without conservation practices (11) at approximately 2.7 lbs P/ac., with 92% of the losses occurring during storm events.  Two-thirds of those total P losses came from a single storm event in June 2015 that delivered 4.1” rainfall in 2 ½ days.  In the subwatershed 12, the average total P loads were nearly half of those from the site with fewer practices.

And finally, enormous differences were observed between the total suspended solids; 2,900 lbs of soil per acre were lost from subwatershed 11, but less than 89 lbs/ac were lost from the site with many conservation practices.  Again, most of the soil losses came from storm events.

Another way to look at it:

These results show what a tremendous difference conservation practices can make and how important it is to use many different approaches to meet water quality goals.

For more information on the Black Hawk Lake Watershed Water Quality Project follow them on Facebook and Twitter. Questions about the monitoring project can be directed to Michelle Soupir at

A Cy-Hawk Collaboration on Conservation

With the entire state of Iowa picking sides as the Cyclones and Hawkeyes meet on the gridiron tomorrow, the Iowa Learning Farms team helped to showcase an outstanding collaboration between the two “teams” with a field day last evening at the Eastern Iowa Airport in Cedar Rapids!

dscn1158cIt was an absolutely beautiful evening, with 70 people in attendance to learn about how the Eastern Iowa Airport is implementing a number of innovative conservation practices on its land, in collaboration with the University of Iowa’s Biomass Fuel Project and Iowa State University’s STRIPS project. Our field day was situated right between the field sites for these two projects, and it was great to see the support of the airport, the City of Cedar Rapids, and the two universities – a truly collaborative effort, and a definite win for conservation!

Cedar Rapids mayor Ron Corbett kicked things off, emphasizing the power of collective action for good – whether it be through sandbagging to save the City of Cedar Rapids’ final drinking water well in the floods of 2008, or working together on efforts to implement unique conservation practices on the ground to benefit both water quality and water quantity.

ISU’s Emily Heaton then jumped right in to lead a discussion and answer people’s questions about the use of giant miscanthus as a potential bioenergy crop. Giant miscanthus has been planted on 63 acres of the airport’s property, and is being harvested for use in the University of Iowa’s Biomass Fuel Project. Several area farmers are also growing miscanthus to supply the U of I with this feedstock.



dscn1139cField day attendees had many questions for Heaton about planting, growing, and harvesting the miscanthus – see a sampling of the outstanding questions below!

  • What are the water quality benefits (nutrient reductions) with miscanthus?
  • What is the water use of miscanthus? Does it reduce runoff?
  • What are the habitat/wildlife benefits of growing miscanthus?
  • How long does miscanthus remain viable?
  • Do you need to harvest it annually?
  • How does miscanthus tolerate extemes – flood and drought?
  • What are the production costs of miscanthus – seed, fertility program, etc.?
  • What does it do for the character of the soil?
  • When is the best planting window for miscanthus?
  • How does miscanthus compare in terms of energy content to other fuel sources?
  • How much is it worth when you harvest it?
  • If I want to plant some of this miscanthus on my farm, where do I get seed?

dscn1150cISU’s Lisa Schulte Moore was up next, highlighting the other “on the ground” practice at our field day site – prairie strips!  The idea behind prairie strips is to transition approximately 10% of a row cropped landscape to strips of perennial prairie vegetation, reaping benefits for soil health, water quality, and biodiversity. Schulte Moore emphasized the important steps in establishing and maintaining the prairie strips, and with proper care, the amazing disproportionate benefits these strips can offer.

We also heard from the University of Iowa’s Ingrid Gronstal-Anderson and Ben Anderson, talking about the University of Iowa’s sustainability goals with these projects and how the U of I power plant is working to integrate different bioenergy feedstocks into their energy stream.

dscn1175cFinally, Eastern Iowa Airport Director Marty Lenss wrapped things up by praising the collaborative nature of this work, just as the sun was setting and giving us a spectacular show across the western horizon. No matter which side you’ll be cheering for in tomorrow’s football game, this is one outstanding collaboration that we can all celebrate!

Ann Staudt


This just in – Iowa Learning Farms launches a new website!

Accessing conservation information and upcoming field day details just became a lot easier with the launch of our new Iowa Learning Farms website –


The new site is mobile device friendly to access information on the go or in the field. Don’t worry if you have your favorite links saved, they will continue to work and redirect to the new site (if they don’t please let us know so we can get that fixed asap!).

There are great resources available on our website including how-to videos, a field day planning guide, and free publications on cover crops, no-till, strip-till, wetlands and many more! You can also find an Iowa Learning Farms farmer partner near you to ask questions or share ideas.

Stay up to date with upcoming events, webinars and recent news on our website and be sure to follow us on Facebook and Twitter!

Liz Juchems


Chatting about river ecology, restoration, and policy

Labor Day weekend is just around the corner… planning to spend any time out on one of Iowa’s rivers?  The latest episode of the Conservation Chat podcast features an interview with Molly Hanson, Executive Director of the nonprofit river advocacy group Iowa Rivers Revival.

Listening to this podcast, you will quickly hear how Hanson’s energy and enthusiasm runneth over – she is extremely passionate about the environment, ecology, and education … oh, and turtles, too!

ConservationChat-Hanson(angle)Iowa Rivers Revival is a statewide advocacy group, working to restore Iowa’s river ecosystems to a healthier state of functioning. That may be through streambank stabilization work, in-stream work, and/or dam modification/mitigation. River restoration also involves working with citizens across the state – talking with farmers and landowners about in-field conservation practices, and working with urban residents to build awareness of issues like stormwater.

“Rivers are conveyor belts of water and soil – that’s what they are, and they’re constantly moving both of those things.”

Hanson comes to IRR from the naturalist/county conservation world, and it’s clear that education also continues to be a passion of hers.

“The education, especially of kids, is such a key piece. They’ve gotta get out there and see it for themselves and have their ‘aha’ moment … then they’re way more likely to care and to take care of it. Science teachers, mentors, family, grandparents: we’ve got to get kids outside!”

So I mentioned turtles earlier …  One of Hanson’s other projects has involved working with IRR and other conservation groups to push for new legislation to protect four different species of aquatic turtles (snappers, spiny softshell, smooth softshell, and painted turtles).  Many of these turtles are being commercially harvested and sent overseas, with no protected seasons or catch limits in our state. Hanson helped to champion a bill that will put regulations in place to help protect these species – every species has an important role to play in terms of biodiversity and overall ecosystem health!

Tune in to Episode 23 of the Conservation Chat to hear more of this engaging conversation with Molly Hanson! Download or play this podcast and others at

Ann Staudt

Seeding Cover Crops: ILF Hits the Field

The Iowa Learning Farms team has been busy in the last few weeks seeding our cover crop demonstration sites across the state. Now is the time to seed if you want to seed into a CC planting windowstanding cash crop prior to harvest. Seeding into a standing crop will allow the cover crop to establish and will provide more benefits prior to winter. Aerial seeding, overseeding, and broadcast seeding work well for seeding into a standing crop. You can also drill cover crop seed after harvesting your cash crop.

We seeded our test plots using hand broadcast seeding. Hand broadcast seeding is a great option if you have a small amount of space to seed. It’s especially useful if you’re just getting your feet wet with cover crops and want to test out a strip or small area in your field.

Seed packetsWe weigh our seed ahead of time so that we can seed at a rate of one million seeds per acre. Each envelope shown here will seed one 50 foot row in our test plot. For seeding rate guidance, see our Cover Crops in Iowa Seeding Rate Guide and Cover Crop Seeding Rate Calculator.

Our test plots have a corn/soybean rotation. For plots currently in soybeans that will be going into corn, we seed single species oats, a mix of oats with radish and hairy vetch, or no cover crop.For plots currently in corn that will be going into soybeans, we seed single species rye, a mix of rye with rapeseed and radish, or no cover crop.

All seeds combined 2

From left to right: single species oats, oats mix, single species rye, and rye mix

In the field, we seed 50 foot rows by hand. One person holds a tape measure and stays at the beginning of the row. Another person takes the end of the tape measure with them and walks backwards, using a consistent shaking pattern to distribute the seed evenly throughout the 50 foot row. Seeding ends when the tape hits 50 feet. Liz has perfected that consistent shake over the years.

We seed all of our plots in this way, traveling up and down the rows.

We hope that these fields will green up just like they have in past years. This is our fourth year seeding cover crops at these locations. Check out our results of the project so far with this publication from the Northeast Research Farm.

Julie Whitson