Conservation Chat 38: Go Deep with Earthworms

WebEpisode 38 of the Conservation Chat digs in deep to talk about earthworms, why they matter, where they thrive and what they can tell us about soil health. The chat features two heavy-hitters of earthworm research related to cover crops: Ann Staudt who leads research on the relationship between night crawlers and cover crops with the Iowa Learning Farms and Dr. Tom Kaspar, a plant physiologist who is also considered to be “the grandfather of cover crop research” in Iowa.

To study earthworms, you must be able to count them. In the earthworm literature, there are four common ways that researchers have approached the counting of earthworms:

  1. Excavate an area of soil to find and count the earthworms
  2. Use a mustard solution or wasabi to chemically extract the earthworms, drawing them to the surface
  3. Apply an electrical current to the soil surface and electrically extract the earthworms, drawing them to the surface
  4. Count middens (well-defined clumpy mounds that an earthworm leaves behind on the soil surface). This is the only method of counting earthworms in which earthworms are not harmed!

Iowa Learning Farms took the latter route and decided to count middens (pictured on the left). Ann Staudt wanted to study whether there were observable differences in the population of nightcrawlers (a type of earthworm) in corn and soybean fields with and without a cereal rye cover crop. The research was completed in fields that had side-by-side cover crop and no cover crop strips. The research found that there were 38% more nightcrawlers in the strips that contained cover crops!

Results

RyeThis research is unique, as very little research has been done about earthworm populations within corn and soybean systems. And, there is much more research that can be done related to earthworms in a corn and soybean system. Future research could include looking at cover crop growth related to earthworm populations, how earthworm populations may respond to different types of cover crop species and mixes, and even nutrient ability in a crop field related to earthworm tunnels, which some literature cites as “hot spots of nutrients.”

The podcast gets down to the heart of why earthworms matter. We often talk about why soil health is important, but it can take many years to detect indicators of soil health with current tests and methods. Ann Staudt suggests that earthworms may be a “reverse canary in the coal mine” for soil health:

“In some ways, it’s like a reverse canary in the coal mine. It’s showing us some of the positive benefits perhaps earlier than we’re seeing it in a lot of the other parameters that we’re trying to measure.”

There is one particularly unique benefit of earthworms that is not commonly considered. Dr. Kaspar explains:

“In [a no-till system], earthworms are basically tilling the soil for you. They’re creating these burrows or holes . . . the nightcrawler in particular is the only worm that produces a relatively vertical hole that goes from the surface down as deep as five or six feet, depending on the soil. . . Those holes allow water and air to enter the soil, which is really important and they provide a pathway for roots to go deeper into the soil.”

This last point is particularly important in a corn and soybean cropping system with tight spacing between plants. In order for crop roots to grow and have a greater ability to access water and available nutrients deeper into the soil profile, they must grow down. Earthworm tunnels can help crop roots do just that.

Listen to the most recent episode of the Conservation Chat with Ann Staudt and Dr. Tom Kaspar! You can now listen in a variety of ways:

Like the podcast? You can help us out by sharing with a friend! Do you agree that earthworms could be a mascot for life in our soil?

Julie Winter

Iowa Learning Farms Webinar to Explore Lessons Learned from Using Cover Crops to Reduce Nitrate Losses

DSCN0571Even with excellent nutrient management, nitrate losses from corn and soybean fields can occur because these cash crops only grow and take up nitrate and water for five months of the year. Cover crops like winter rye can be an effective strategy for reducing nitrate losses to groundwater or tile drainage because they can take up water and nitrate during the period between harvest and planting of the next year’s crop.

Dr. Tom Kaspar, Plant Physiologist at the USDA-ARS National Laboratory for Agriculture and the Environment, will share his lessons learned over his storied career researching the use of cover crops and no-till to improve water quality and soil health in corn and soybean production systems.

DATE: Wednesday, December 13, 2017
TIME: 12:00 noon
HOW TO PARTICIPATE: Log on as a guest shortly before 12:00 p.m.:
https://connect.extension.iastate.edu/ilf/

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: https://www.iowalearningfarms.org/page/webinars.

Julie Winter

Cover crop researcher Tom Kaspar receives Spencer Award

Congratulations to our friend and collaborator, Dr. Tom Kaspar, on receiving the Spencer Award for Sustainable Agriculture yesterday!

Long regarded as the grandfather of cover crops here in the state of Iowa, USDA-ARS plant physiologist Tom Kaspar is certainly one of the leading voices on cover crops across the Midwest.  He was one of the “founding fathers” of the Midwest Cover Crops Council, and his collaborative work over the years has investigated and documented the benefits and challenges of cover crops in corn and soybean cropping systems, ranging from impacts on water quality, soil health, nutrient cycling, and more.

We are grateful to Tom for serving as a guest speaker at countless Iowa Learning Farms field days and workshops over the years, sharing his findings with farmers, landowners, and other ag partners across the state. We are also grateful for his efforts in guiding the work of the Iowa Cover Crop Working Group, including our long-term on-farm rye study and our study of earthworms and cover crops.

Kaspar has amassed years of experience investigating not only soil health and cover crops, but also connections with no till, minimum tillage, climatic variations, disease, pathogens, and more. To hear some great perspectives from the man himself, check out Episode 6 of the Conservation Chat podcast, in which host Jackie Comito talks cover crops with Dr. Tom Kaspar.

Kaspar was also featured in our August 2015 Iowa Learning Farms webinar, presenting on Reaching the Full Potential of Cover Crops in Iowa.  Stay tuned to the blog, as well — we’ll be highlighting some of Kaspar’s cover crop findings here in the next week or so.

In the meantime, congratulations to Tom for an honor that is very well deserved!

Ann Staudt

 

Register today for the Midwest Cover Crops Council 2017 Annual Meeting

The Iowa Learning Farms and Iowa Cover Crop Working Group (ICCWG) encourage you to register for the Midwest Cover Crop Council Annual Meeting March 14-15, 2017 in Grand Rapids, MI.

Registration, agenda and sponsorship information is now available online.  Early registration is encouraged, as prices go up after January 31, 2017!

The Midwest Cover Crop Council was first organized in 2006 and includes representatives from twelve states and Ontario, Canada. Representing Iowa is our very own ICCWG member Tom Kaspar with USDA-ARS and Andy Lenssen, Iowa State University.  Since its inception the organization has grown into a community that facilitates the sharing of cover crop knowledge within the Midwest and beyond.

While you are registering for the conference, be sure to check out their updated website. The goal of the update was to organize resources more consistently and enhance search capabilities to help users find information more quickly. Additionally, the new website is mobile responsive, meaning it will switch to a mobile-friendly design when viewed on a phone or tablet.

Liz Juchems

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.

Kaspar_digging_cover_crops_blog

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