Working Within Our Current System: A Conservation Chat with Eileen Kladivko

Cover kladivko_creditHost Jacqueline Comito sat down with Dr. Eileen Kladivko, Professor of Agronomy at Purdue University and founding member of the Midwest Cover Crops Council (MCCC), for the most recent episode of the Conservation Chat podcast.

Eileen Kladivko’s chat covered many issues areas that she has studied for decades surrounding soil health, cover crops, earthworms and drainage. To start the chat off, Eileen wanted to make something clear: drainage is essential.

“I like to remind people that we wouldn’t be growing crops at all on some of our most productive lands in the Midwest if we didn’t have tile drainage.”

Tile drainage is essential if we want to farm much of the land that we currently farm – especially in Iowa. While there are benefits to tile drainage, a drawback of the system is the movement of nitrate with water that flows out of tile lines and into the surface water. How can we begin to solve this challenge? Mimic nature and the system that we replaced, Eileen suggested.

We’ve got agriculture, we’ve got lots of human beings here, and we want to be productive. We want to mimic nature where we can, but we’re not going back to pre-settlement conditions. That’s impossible. But let’s see if there are some things we can learn from what the vegetation cycles were, and the hydrology cycles, that can help us with our current system.”

Adding cover crops to our current system is one way to address our nitrate challenge and to mimic the natural vegetation cycle that once existed on the land. Cover crops have seen a steady increase in popularity, and for some farmers, the desire to grow something comes naturally.

A subject that Eileen Kladivko is most passionate about is soil health. Soil health is a popular topic because we want our soil to function to full capacity for crop production, but we understand relatively little about the soil biology that can shape the physical and chemical properties of soil. In recent years, the soil health conversation is shifting to research about soil biology. The downside is that soil health research takes time.

“That’s one of the challenges with the whole soil health thing . . . we’re trying to look at some of the commercial soil health tests that are available right now and see which of those might actually be able to detect changes with time in some of our Indiana sites. It’s quite challenging because the tests are quite variable. Soil health does take time to improve, and sometimes those tests just don’t show it over the short term.”

Without lab tests to show short-term gains in soil health, there is one indicator that can give farmers a short-term pat on the back: earthworms! Earthworm populations are highest in systems with limited tillage and high levels of crop residue. Eileen has spent much of her career counting earthworms.

“I didn’t think that was going to be a long-term commitment of mine,” said Eileen. Decades later, Eileen has developed a foundation for research on the physical and chemical properties of soil as they relate to soil health and good soil biology.

What are your chances of having a high earthworm population within a system that includes tillage? Not likely. Switching to no-till and adding a cover crop will increase your chances to see early signs of soil health and good soil biology before other commercial soil health tests are able to show results. Iowa Learning Farms has seen similar results when counting earthworms under different tillage and cover crop systems here in Iowa.

Listen to the full Conservation Chat episode! If you’re on the go, take the Conservation Chat podcast with you – find it on iTunes or search for “Conservation Chat” on the podcast app of your choice!

Julie Whitson

5 Lessons Learned with Rye Cover Crops

Here at Iowa Learning Farms, we’ve been working with cereal rye cover crops since 2008. That’s not nearly as long as our good friend and colleague Tom Kaspar with USDA-ARS, but we can certainly say that, with our partners in the Iowa Cover Crop Working Group, we’ve been exploring and promoting cover crops long before they were cool!

Our longest ongoing study involves the use of cereal rye as a winter cover crop in on-farm trials within corn/soybean cropping systems across the state of Iowa. Over the years, twelve farmers have participated as partners in this project, with each demonstration site featuring field-length replicated strips with a cereal rye cover crop as well as replicated strips without a cereal rye cover crop.

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In our eight years of on-farm cover crop demonstrations, what have we learned?  Here are our Top 5 takeaways regarding cereal rye cover crops:

1. Rye cover crops are largely yield neutral.
In the vast majority of this study (55 of 59 site-years), farmers found that a properly managed cereal rye cover crop had little to no negative effect on corn and soybean yields. Soybean yield actually increased in 7 site-years and corn yield increased in 2 site-years. There can be a learning curve up front, but in the long run, this study’s findings dispel the myth that rye negatively impacts crop yields (especially corn yields) in the following season.
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2. Cover crops require active management.
Additional considerations/management factors when using a rye cover crop include seeding rate and method in the fall, and then cover crop termination and adjusting planter settings to accommodate additional residue in the spring. In the few cases of this study where crop yields were negatively impacted, farmers identified insufficient cover crop termination and improper planter settings as reasons for the few years where there were crop yield reductions.

3. Spring growth is key to realizing rye’s benefits.
Unlike winter wheat, oats, radishes and turnips, cereal rye survives over winter and continues its growth into the spring months. Large amounts of spring over crop biomass can be produced – variable to location and termination date.
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4. Soil health is hard to define and even harder to measure.
Five years into the study, we found no measurable differences in soil health variables (soil organic matter, total carbon, total nitrogen, pH, infiltration and runoff) between the strips with and without the cereal rye cover crop at individual locations. A much greater intensity of sampling and additional time (years) may be required to quantify significant changes. Plus many of Iowa’s soils have relatively high levels of organic matter to begin with, so detecting very small changes can be challenging.

5. Earthworm numbers have increased with a cereal rye cover crop. Looking at the common nightcrawler (Lumbricus terrestris), our 2016 midden count data indicate a statistically significant difference of 38% more earthworms with a cereal rye cover crop. Earthworms can serve as tangible, early biological indicators of soil health.
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These findings and more will be highlighted at ISU’s Soil Health Conference coming up later this week. Stop by and see our poster, and let’s talk cover crops – we hope to see you there!

Ann Staudt

 

Additional information on our work with rye cover crops:

ILF Cover Crop Research webpage
Additional ILF Cover Crop Resources
Earthworms, Cover Crops and Soil Health

The Iowa Cover Crop Working Group is a collaboration of Iowa Learning Farms and the following organizations:

  • Practical Farmers of Iowa
  • Iowa State University Extension and Outreach
  • Iowa Dept. of Agriculture and Land Stewardship
  • USDA-Agricultural Research Service, National Laboratory for Agriculture and the Environment
  • USDA-Natural Resources Conservation Service
  • Midwest Cover Crops Council

Funding for this demonstration project has been provided by Iowa’s State Soil Conservation Committee, Iowa Department of Agriculture and Land Stewardship, Leopold Center for Sustainable Agriculture, Iowa State University Extension Water Quality Program, and NRCS Conservation Innovation Grant 69-6114-15-005.

Earthworms serve as Indicator of Soil Health

A friend of the farmer, gardener, and angler alike, the earthworm may help to unlock the secrets of the soil by serving as an early indicator of soil health!  Anecdotally, farmers have expressed benefits to using cover crops and noted improvements to their soil, but quantifying changes in soil health can be complex to measure (and require years of intensive sampling). That’s where earthworms come into play!

Thanks to funding from a USDA-NRCS Conservation Innovation Grant, the Iowa Learning Farms team is studying the common nightcrawler, Lumbricus terrestris, and investigating its population dynamics in agricultural ecosystems.

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In particular, we are conducting midden counts at seven sites across the state (6 on-farm demonstration sites, 1 research site), all managed as a no-till corn/soybean rotation.

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Within that system, we are evaluating earthworm populations on side-by-side strips with and without cereal rye cover crops.  Read more about the study in our earlier blog posts Guest Blog: Digging for Worms and Midden Madness.

What have we found?

The midden counts conducted in June 2016 indicate that on each site, strips with a cereal rye cover crop have comparable or higher earthworm counts than those without a cereal rye cover crop …

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Looking at all sites together across the board, we see statistically significant differences between the strips with a cereal rye cover crop and those without. Based upon this preliminary data set, we are seeing 38% more earthworm middens with a cereal rye cover crop!

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If you’d like to learn more, I just gave a webinar earlier in the week on this topic. The archived webinar can be viewed on the Iowa Learning Farms webinar page (along with all of our previous webinars). Click on the November 16 webinar to view Earthworms and Cover Crops: Unlocking the Secrets in Soil!

Ann Staudt

This material is based upon work supported by the Natural Resources Conservation Service, U.S. Department of Agriculture, under NRCS Conservation Innovation Grant 69-6114-15-005.

ILF Webinar Digs into Earthworms and Soil Health

The common nightcrawler, Lumbricus terrestris, is a deep-burrowing worm species that is found in many Iowa crop fields. The presence of nightcrawlers can serve as one indicator of the overall soil health in Iowa’s agricultural ecosystems. Ann Staudt, Assistant Manager of the Iowa Learning Farms, will discuss ILF’s recent research that analyzes the relationship between earthworm populations, cover crops and overall soil health.

midden1While soil health can be difficult to quantify, earthworms are a very tangible early indicator of soil health, long recognized by farmers and gardeners as being beneficial organisms in the soil ecosystem. Staudt hopes that this research will teach us more about the connections between earthworm populations and soil health in a cover crop versus no cover system, and that earthworms can be a simple, straightforward indicator of soil health.

Staudt is an environmental engineer who actively blends scientific knowledge and creative expression through her work and teaching. Staudt holds her MS degree in Environmental Engineering from the University of Notre Dame and BS degree in Chemical Engineering from Iowa State University.

Log on as a guest shortly before 1:00 p.m.: https://connect.extension.iastate.edu/ilf/

If you can’t participate live, watch the archive of today’s webinar (along with all of ILF’s past webinars) on our website: http://www.extension.iastate.edu/ilf/page/webinars

Julie Whitson

August ILF Webinar: Cover Crops with Tom Kaspar

ILF’s August Webinar features none other than Tom Kaspar, Plant Physiologist at the USDA-ARS National Soil Tilth Laboratory in Ames, IA and USDA Collaborator/Professor with the Agronomy Department at Iowa State University.

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Tom Kaspar digs up some of the cover crop roots in his long-term research plots.

Tom discusses his research on Cover Crops in terms of their proven benefits, such as erosion control, soil health, and reduction in nitrate loss.  But Tom also reminds us that we have just scratched the surface of our knowledge, pondering the possibilities of better adapted species, further experimenting with mixtures, and a better understanding of the precise effects upon yield.

Watch this webinar (and catch up on ones you’ve missed here.)

You can also read about getting started with cover crops and if you missed Tom Kaspar on the Conservation Chat, listen here!

-Ben Schrag

Guest Blog: Digging for Worms

Today’s guest blogger is Iowa Learning Farms/Water Rocks! student intern Megan Koppenhafer.  Originally hailing from Williamsburg, IA, Koppenhafer is entering her junior year at Iowa State University, where she is double majoring in Environmental Science and Community and Regional Planning.  Growing up on a farm, she spent a lot of childhood days in the outdoors, and she is really thankful for having a summer job that also allows her to spend much of her working time outdoors!

As a child, whenever I would go fishing at summer camp I would dig in the soil after a good rain looking for worms to use as bait. I remember madly tearing under the mulch in the playground or in the soft sod next to the sidewalk. It was like finding a slimy treasure each time. I had the pleasure of watching my own campers’ joy in finding the worms last summer when I worked at a camp in Iowa City.

This summer I found myself enjoying my first couple of weeks of the internship but longing for more of the same contact with the soil that I’d had as a camper and camp counselor. Summer just feels like the time to do that kind of thing! There’s something about digging in the soil that makes you feel like you are accomplishing something.

Megan Koppenhafer, Ben Schrag, and Jessica Rehmann searching the soil for evidence of earthworms at research plots west of Ames.

Megan Koppenhafer, Ben Schrag, and Jessica Rehmann searching the soil for evidence of earthworms at research plots west of Ames.

This past week I began a new research project that would allow me to play in the soil like the days of old. So with four others, two interns and two full-time staff members, we embarked to count earthworm middens.

A clear shot of an “un-capped” earthworm hole; the little clump of soil and residue to the right is the midden.

A clear shot of an “un-capped” earthworm hole; the little clump of soil and residue to the right is the midden.

What are earthworm middens, you may ask? These are indicators of holes which are inhabited by nightcrawlers, and specifically, the midden is the mound of soil and plant matter over the hole. The Iowa Learning Farms group was looking for ways to detect changes in soil health in a way that would be easy and inexpensive to carry out. Because earthworms are a good indicator of soil health, we are counting middens to see if there is a correlation between the number of earthworms in crop fields related to the presence or absence of cover crops (in this case, cereal rye).

We are counting middens at 5 farms around the state this June. One of these is a research farm and the others are on farmers’ land, which are long term rye sites. The counting only happens once a year and it happens in June because the corn/soybean crops are still small enough to see the ground without much difficulty, and the cover crop residues are still present. This means the worms have fresh food to chow down on!

When we step onto the field we are armed with a PVC frame, clipboard, pen, and scissors. Typical plots with and without cover crops are below:

Soybean plot with cereal rye residue

Soybean plot with cereal rye residue (June 2, 2015)

Soybean plot without cereal rye ( June 2, 2015)

Soybean plot without cereal rye ( June 2, 2015)

We spend about 10 minutes with each frame as we carefully scrutinize the soil for middens:

Carefully examining the soil for signs of earthworm activity in a  soybean plot with cover crops.

Carefully examining the soil for signs of earthworm activity in a soybean plot west of Ames (June 2, 2015)

Each field site includes multiple replicated strips with cover crops/no cover crops, and we count 4-5 frames in every individual plot.

I can’t help but remember how imperfect our science was back in those camp days. I now have the secret to getting the perfect fish bait, but alas, not a fish to feed them to! That’s okay though, I am happy to leave the worms in the soil doing what they do best, making the soil a better place for the plants that grow there.

Megan Koppenhafer

Lance Henrichs: My internship so far…

I am one of seven student interns this summer so I will introduce myself. I am Lance Henrichs and I am going into my third year of college at Iowa State. I grew up on a farm in south central Iowa, New Virginia specifically. We raise around 600 acres of row crops and a herd of about 30 beef cows. Since I came from a farming background, fourth generation of farmers, I realized how important Iowa and its natural resources are to everyone at a young age. I decided to come to Iowa State University my senior year of high school for some sort of agriculture program. After about a year I found the Agricultural Systems Technology degree and choose the option of bio-systems management. I soon found out that in my program I needed an internship to graduate. That is when I began looking and found Water Rocks!

This internship has been a learning experience from the start. I felt pretty confident coming into this since I had grown up on a farm that had done many conservation practices, but I have learned so much more thus far. We have attended seminars on cover crops, soil health, and have participated in the Iowa Learning Farms’ webinars. I have had my eyes opened to how much more is needed than no-till and crop rotations. There are many pieces to the clean water and healthy soils puzzle. There is no “one time/fix all” solution. There are many tools that each producer can use to reach the goals of the Iowa Nutrient Reduction Strategy, but no one practice alone will get us there. So, with this increasing knowledge and my connections to farms through friends and family, I am going to try to convince agricultural producers to do more than they currently are.

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Pulling the mound off of a worm burrow at the ISU Ag Engineering and Agronomy Research Farm

This summer has been busy for me, with field work, project work, and events. My main individual project that I have for the summer is researching if there is a relationship between cover crop presence and earthworm presence, specifically lumbricus terrestris (nightcrawlers). I have been researching how they operate and what they do for our soils. In a nutshell, worms are bio-indicators of good soil health. From there I measured their presence by counting mounds on the soils. Since the nightcrawler is a worm that tends to live in one single burrow during its lifespan, it is easily counted by finding its burrows. To feed, these worms pull crop residue over the burrow and slowly pull it into the hole, creating an easily visible mound to count.

As this summer carries on, I hope to be able to continue learning and reaching out to people. I want to be a resource to many people and answer their questions best that I can. Aside from the many two and a half hour car rides, this internship has been a wonderful learning and teaching experience. Thank you to the Water Rocks! and Iowa Learning Farms members for granting me this experience!

Lance Henrichs