Every Little Bit Counts

What do you know about earthworms? Before this internship, I knew a few basics: they’re useful for fishing and they live underground. But, what do these small creatures have to do with water quality and soil health? It turns out that they are very good indicators. Today I’m going to touch more on our most recent project for this summer, earthworm counting, and how it has shown me that every little bit of information counts.

Before we start each research project, the other interns and I all sit down with our supervisors and discuss what the projects are and how we’re supposed to go about them. When this project was presented to us, I was more than a bit skeptical about how this could help us. So far, through the two weeks of earthworm counting that we have completed, that skepticism I originally had has faded away.

LEFT: I am looking for the middens within the area of our research point. RIGHT: Cutting the cover crop and removing residue to find the middens.

Earthworm counting is exactly what it sounds like. We head to test plots all over the state to take a look at the number of earthworms within a 19” x 30” frame between the rows of crops, corn or soybeans. We count the middens, the tops of the worms’ holes where the organic matter is pulled into the tunnel, closely examining the soil surface looking for the mounds they leave behind. When we think we found one, we dig with a pair of scissors to look at the underside of the midden and find the tunnel. The main variable that we look at is cover crops – are there observable differences in the number of earthworms between strips with cover crops and those without? Earthworms are very good for our soil and the more we have, the better the soil health of that area is.

One of our other interns, Kaleb, found a midden while we were at a farm in southwest Iowa.

The last time that I went home, my cousin, who is in 6th grade, asked me what some of the projects were that I was working on and I told her that I was doing earthworm counting. She didn’t sound very impressed when that’s what I told her, so I decided to have her complete the experiment herself at home. After about a week of testing the fields at home I had my cousin tell me any conclusions that she came up with. She told me that in the places with cover crops, the number of earthworms was higher than places with no cover crops — which is the same exact results we have been getting in the research plots across the state. But, that wasn’t all. To me, the best part about all of this was that I allowed a 6th grader to conduct an experiment that can provide important information about soil health in about 30 minutes of instructions.

Research can come from anywhere and anything and the impact it can have is limitless. It also appeals to me in that it allows for all generations to be involved with the same issues. You can have a 6th grader counting earthworms to find out more about soil health while at the same time you can have a farmer taking core samples to test for the same thing. Research is a big part of my internship, but it’s also a big part of the future. When understanding complex issues such as soil health, every little bit of information counts, and I’m super excited that I get to experience all of this research firsthand this summer!

Donovan Wildman

Donovan Wildman is participating in the 2018 Water Resources Internship Program at Iowa State University.  Wildman grew up near West Branch, IA (Clear Creek Amana High School). In the fall, he will be starting his sophomore year at Iowa State University, majoring in Agricultural Engineering with an emphasis in Land and Water Resources.

Field Day Recap: Management Matters with Cover Crops!

Cover crops and conservation leases were the theme of an Iowa Learning Farms Women Landowners Cover Crop Workshop held in Marshalltown on June 7.  While cover crops offer numerous benefits out on the landscape, one common theme emerged clearly from the workshop presentations and discussion  — it all comes down to active management when integrating a cover crop.

Allen Burt, who farms 3 miles north of Marshalltown, kicked off the workshop by sharing his experience with cover crops and some of his key management considerations.

He emphasized, “Start with something easy.”  In Burt’s playbook, that means getting oats out on soybean ground as soon as you can in September (drill or broadcast), let them winterkill, and then plant corn into that in the spring.

On corn ground, he suggests starting with cereal rye and a little bit of starter fertilizer (something like a 10-23-23 mix) after the corn is harvested, ideally in early October. The cereal rye will survive over the winter, and then Burt recommends terminating in the spring with glyphosate.

Burt’s recommendations align nicely with the Iowa Learning Farms’ findings, as well, shared at the workshop by Liz Juchems, Conservation Outreach Specialist.

Juchems also shared findings about yield impacts following cover crops. Farmer-partners working with cereal rye reported that in 59 of 63 site-years, strips with cover crops were yield neutral compared to strips without a cover crop – no negative impact on corn and soybean yields. The only significant yield declines were in the first two “learning” years of this long-term study, when producers faced challenges regarding spring termination and planter adjustments to accommodate the additional residue from the cover crop. Over time, those management challenges were overcome to realize cover crop success.

Interwoven with the presentations was an earthworm midden counting hands-on demonstration, as well as lively discussion and dialogue from the 25 people in attendance, including area landowners, operators, and conservation/ag professionals.

One producer in attendance brought up, “The #1 problem in farming today is soil erosion.”  Another producer added to that, commenting that a close second in terms of challenges today is the perception of “This is the way we’ve always done it,” acknowledging there can be some resistance to new practices like cover crops, despite the benefits to reducing erosion, benefitting soil structure, etc.

Charles Brown, Farm Management Specialist with Iowa State University Extension and Outreach, noted, “When you talk about using cover crops, it’s a different management practice – you can’t just do the same thing you’ve always done.”  He shared with the group his own experience with growing cover crops, as well as numerous suggestions for landowners and operators to work together to integrate cover crops into a written conservation lease.

Farmer Allen Burt emphasized, “As a producer, my message for you is, ‘Get out there and try it!  If you have the right attitude, you can do it! … Cover crops are a small investment to make things better in the long run.”

Ann Staudt

This workshop was put on as a partnership of Iowa Learning Farms and Marshall Co. Farm Bureau.

Learning about the Water Cycle – Across the Ocean!

During the first part of January, I had the opportunity to travel abroad before returning to the Water Rocks! team. As part of a lifelong dream realized, I took a class with the University of Iowa, called the India Winterim trip, and my section was focused on Water Poverty in Rural India. The class combined my favorite place on Earth (India) with my favorite topic on Earth (water quality). As an added bonus we had the opportunity to learn about strategies for dealing with saline soils from some of the smartest scientists in the field.

Our class partnered with an NGO called the Sehgal Foundation, a group who is doing a lot of work with rural communities in the Nu district (formerly the Mewat district) near New Delhi. While our class was there we had the incredible opportunity to help Sehgal do some wider scale sampling and design work with them.

Our team included Sehgal scientists, engineers and volunteers along with University of Iowa students and professors.

Sehgal serves as the Extension and Outreach department for this district and many others. They educate people on sustainable farming practices and seek to improve water quality for drinking and irrigation purposes.

Drip irrigation in a test plot by the Sehgal radio site.

Our team during the debrief of our tasks for the class. Photo courtesy of Amina Grant.

 I was excited to go out in the field and collect data because with a background in Environmental Science, I felt like I would be the most useful outside. I also wanted to be out in the 70 degree weather!

Our class exploring our site for the first time next to the Aravali Hills.

Being out in the field, I had the opportunity to work with Sehgal water monitors to locate sites and take water salinity samples. Sites were often a bit of a scavenger hunt as wells run dry during the years we are not there or become dysfunctional for a variety of reasons. We worked with the local water monitors to line up our sites to the ones they had been using as best as possible. Then we used a tool called the Solinst to measure water temperature, conductivity and depth.

Me, using the Solinst to take readings. Photo courtesy of Amina Grant.

We went out to the field on three different occasions. My classmates and I worked to efficiently sample as many sites as we could, while making sure we were being accurate about the sites we were testing. It really tested my coordination skills to try and pay attention to what everyone was doing and end up with usable data. I definitely gained some skills in data management because along with my conductivity readings, my friend and classmate Amina Grant had to collect her own samples and that required an entirely different set of numbers to be recorded.

Amina found a Daphnia (small water creature) in one of the wells she was testing. 

We were hoping our measurements would add to the body of knowledge Sehgal and the local volunteers have been building about the water over time. We understood that our measurements were only a small piece of the puzzle, but hopefully some answers can be gained as a result of our cumulative efforts.

Sehgal test plots provide alternative methods for sustainable agriculture in the region. In the back, you can see the drinking water filtration system.

The water challenges in the Nu district are different than ours because their main problem is poor water quality and soil quality due to salinity. But the same principles of hard work, long days, and an interdependency on the water cycle bind across oceans and cultures.

Megan Koppenhafer

 

It’s alive! Scientists get closer to identifying what lives in our soil

Iowa Learning Farms has been spreading the word about soil health, and its preservation, for over a decade, and Iowa farmers have long touted the benefits of soil health for crop growth. Now, the importance of soil is gaining an even wider audience when earlier this year researchers from the University of Colorado-Boulder published findings of a study leading to the first global atlas of soil bacterial communities.

Researchers at the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado-Boulder published their study in the January issue of the highly respected journal, Science. Analyzing 237 soil samples from eighteen countries across six continents of varying climates, the researchers discovered that 2% of soil bacteria—about 500 species—accounted for nearly half of the soil bacterial communities found worldwide!

Images of soil bacteria from the dominant Proteobacteria and Actinobacteria phylotypes courtesy of MicrobeWiki.

While scientists have long known that soil bacteria make up a substantial percentage of earth’s living biomass, contributing to plant productivity, carbon cycling, and nutrient availability, the immense numbers and diversity of soil bacteria (total counts are estimated to be in the tens of thousands!) have kept them from fully understanding soil bacterial distribution and function. The CIRES study is a major breakthrough in soil science as it documents the most abundant and dominant types of soil bacteria found worldwide.

CIRES researchers believe this discovery sets up a “most wanted list” of soil bacteria, as it points to which bacteria should be targeted in future studies seeking to understand soil microbes and their contribution to soil fertility and ecosystem functioning. The next step is to begin categorizing these dominant bacteria into groups of co-occurring bacteria and habitat preferences, resulting in data that the CIRES group hopes will shed more light on the function of certain groups of bacteria, eventually leading to agricultural applications.

The full journal article from Science can be viewed at A global atlas of the dominant bacteria found in soil.

Brandy Case Haub

 

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

Webinar highlights cover crop, water quality connections

In case you missed it, this past week’s Iowa Learning Farms webinar offered an excellent overview of the research findings related to the potential of winter cover crops to reduce nitrate leaching in corn and soybean cropping systems. Dr. Tom Kaspar, plant physiologist with the USDA-Agricultural Research Service, shared results from numerous studies that show the ability of cover crops to reduce nitrate concentrations and loads in tile drainage water.

The press headlines about nitrates and water quality are seemingly ubiquitous, and Kaspar provided solid data that help to paint a complete picture of the challenges and opportunities. Our land uses have changed dramatically, and over the past 60-70 years, our cropping systems have likewise changed dramatically with significant reductions in small grains, hay and perennial vegetation.  With corn and soybeans having a 7-month brown gap when they are not actively uptaking nutrients, that leaves a significant amount of time with nutrients vulnerable to leaching.

However, Kaspar’s research clearly demonstrates that cover crops help transition that brown gap to a green gap, providing the ability to “capture” nutrients in the soil that would otherwise be vulnerable to leaching loss. One of Kaspar’s long-term research studies in central Iowa found that rye cover crops in a corn-soybean cropping system reduced nitrate concentrations in tile drainage water by 57%. Additional studies by Kaspar and collaborators around the state found nitrate reductions of anywhere from 20% to 40%. This variability is expected, with different amounts of cover crop growth, weather, rainfall, soil types, tile systems, and field histories.

Kaspar also pointed out that it takes quite some time for nitrate to move through the system – there is a noticeable lag effect.  For instance, Kaspar and collaborators found that nitrate concentrations in subsurface tile drainage continued to decrease through the summer, long after spring cover crop termination.

Check out the full webinar, Lessons Learned from Using Cover Crops to Reduce Losses of Nitrate for 15 Years, on the Iowa Learning Farms webinar archives page.  And to hear more perspectives from Dr. Kaspar, tune in to Episode 06 of the Conservation Chat podcast!

Ann Staudt

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