Jun 01 | Closing Market Report

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This segment of the Illinois Nutrient Loss Reduction Podcast, featured on the Closing Market Report, examines the agronomic impact of the soil microbiome through an interview with Waypoint Analytical's Dr. Lizzie French. The soil microbiome consists of microscopic organisms—including bacteria, fungi, and nematodes—that cycle nutrients, process crop residues, and build soil structure.

Waypoint Analytical measures this biological activity using DNA analysis to identify the specific functional capabilities of these microbes, such as their ability to fix nitrogen or solubilize phosphorus. French asserts that implementing conservation practices, including cover crops, reduced tillage, and tile drainage management, provides the necessary habitat and carbon inputs to sustain microbial populations and prevent nutrient runoff. By testing and understanding their soil's biological capacity, producers can optimize fertilizer efficiency and potentially reduce nitrogen applications in soils with robust organic matter, though French cautions that maintaining proper soil pH remains the most critical foundational step for supporting biological activity.

- Lizzie French, Soil Biology Manager - Waypoint Analytical, Inc.

Todd Gleason: I'm out of the office today, so no update of the commodity markets. However, we do have the latest edition of the Illinois Nutrient Loss Reduction podcast.

Announce: Todd Gleason services are made available to WILL by University of Illinois Extension.

Todd Gleason: This is episode 81 of the Illinois Nutrient Loss Reduction Podcast. I'm University of Illinois Extension's Todd Gleason. Today we'll explore the role of the soil microbiome in reducing nutrient loss with a couple of folks from Waypoint Analytics. We'll learn about it as we explore the biome and how it interacts with the ecology of the soil. Let's start with Elizabeth French. She goes by Lizzie. Hi Lizzie, thank you for being with us. Tell me about yourself, please.

Lizzie French: I am Dr. Lizzie French. I currently live in Laramie, Wyoming, but I spent a good chunk of my adult life in the Midwest. I got a biology degree at Indiana Wesleyan and then went to grad school at Purdue in the Botany and Plant Pathology department. I started working on projects with tomato pathogens, but then I got really interested in all the other bugs out there in the soil and ended up focusing more on the soil microbiome as a whole, how it interacts with the plant, and how that ends up impacting plant and soil health. I liked it so much I stuck around a couple more years, did a postdoc in a different lab at Purdue, and then ended up moving into the industry. I worked with Nutrien for a few years on soil biology and how we can use it to make agronomic decisions. I moved over to Waypoint about a year and a half ago. I have been loving it and really enjoying the work looking at soil microbes and how we can help make agronomic decisions by having a fuller understanding of what's going on in the soil.

Todd Gleason: Lizzie, on that point, tell me about Waypoint Analytical. What is this organization?

Lizzie French: Waypoint Analytical is one of the largest ag soil testing networks in North America. We have seven different ag labs across the US, and we run probably two million-plus soil samples in a year. We also offer tissue testing, water testing, manure, fertilizer, pathology testing, disease diagnostics, nematodes, and now soil biology testing as well, for looking at the good guys in the soil, not just the pathogenic organisms.

Todd Gleason: We're here today to talk about the soil microbiome. Can you tell me what that is and why it's important?

Lizzie French: The soil microbiome is all the living organisms you can't see in your soil. You've got bacteria, fungi, viruses, protists, and nematodes. There are thousands of different species of organisms, and if you pick up just a spoonful of soil, there's going to be billions of these tiny microscopic organisms living in your soil, making up that soil ecosystem and doing a lot of really important jobs that we don't always think about. They are essential for nutrient cycling, mineralization of nutrients, breaking down residues, and building up soil structure. These are all critical things we need to happen in our soils from both a production and a conservation standpoint.

Todd Gleason: Lizzie, this is about the biology, the mechanics of the soil, the ecology of the soil itself, and how it works together. What do you think creates a healthy soil across the Corn Belt?

Lizzie French: You need those three components together. You need to have the soil structure that allows you to have good air and water infiltration. The soil biology plays a role in that where you've got microbes producing sticky glues that help build that soil structure. You need the chemistry; you have to be able to grow a crop. That's what soil health is in production agriculture. You have to be able to grow a crop, and you want your grandkids to be able to grow a crop too. You need to have the chemistry there to be able to grow that crop. The biology piece interacts with all of that. You need to have a healthy, thriving community of microbes that are able to cycle those nutrients into available forms that are helping to build that soil structure, and all of those things affect each other. You can't pull them apart to understand them; you have to look at them as a whole to get an idea of the system. When talking about the Midwest, corn, and soy, having sufficient levels of the nutrients needed to build those crops, having solid soil structure, and then having high levels of soil biology that are able to make those nutrients available and keep that soil structure where it needs to be.

Todd Gleason: Getting to making the nutrients available, and keeping them in place. How is it that you measure a microbiome? What happens, and are there good things and bad things about it?

Lizzie French: There are lots of ways to measure. The thing most people are probably familiar with is something like the Haney test where you're getting a respiration metric. That is a 40,000-foot view of how much overall microbial activity exists. Are they living and breathing? That is a great high-level metric, but it doesn't tell you specifically what those microbes are doing and what they're capable of doing in your soil. With our test, we're looking at the DNA of the microbes in the soil. When you do a nutrient extraction, you have a specific process where you separate out those nutrients and then analyze them on an instrument. We're doing the same thing, but we are finding the microbes in the soil, taking their DNA, and then specifically looking at that DNA and saying, "How many of you are nitrogen fixers? How many of these microbes can solubilize phosphorus? How many of you are mycorrhizal fungi that are going to help extend the root system and help that crop acquire more nutrients?" That's what we're able to answer using DNA analysis: who is there and what those microbes are actually capable of doing in the soil.

Todd Gleason: On the microbiomes, are they capable of keeping nutrients, particularly nitrogen and phosphorus, in place, and if that is true, do they lock them in place so that they're not usable by the plant as well?

Lizzie French: That's a great question. Microbes need nitrogen and phosphorus too for their survival. There are two ways they help keep it in the soil. The first one, they keep it in their biomass. When those microbes are growing, yes, they do temporarily lock up those nutrients so that they're not available. Microbes have much faster lifecycles than we do or that plants do. Within a short amount of time—days or weeks—those nutrients that have been vacuumed up into the microbial biomass become available again as they go through their lifecycle. You have other organisms in the soil, like protists, that are tiny little lions keeping the population of the antelope in check on the soil savanna. They go out and eat those bacteria and then make that nitrogen available again for the crop. That's the first mechanism.

The second one, which most people are more familiar with, is through building up organic matter. That microbial biomass, those dead microbes, become part of the organic matter. Those microbes are important; they break down residues, keep that carbon in the soil, and a lot of those nutrients are locked up into that carbon. As you build up organic matter and mineralize some to make new nutrients available, it's a cycle that microbial activity keeps going where it is able to retain nutrients in the organic matter and make them available again for the crop.

Todd Gleason: That's Lizzie French. She's a Soil Biology Manager at Waypoint Analytics. You're listening to the Illinois Nutrient Loss Reduction podcast. So
Lizzie, you're maintaining that it's important to understand how soil biology interacts with fertilizer management. How can a producer improve the biology to reduce fertilizer needs? What are the biggest opportunities?

Lizzie French: From a big picture perspective, it's any practices you can implement. This part gets rebranded every 10 years or so, but it's still the same principles. Your microbes need food and they need housing. From a soil health perspective, that's protecting your soil structure by minimizing tillage as much as possible. That prevents breaking up those fungal networks that spread throughout the soil to help your crop get to nutrients, and it helps protect the soil structure and housing for those bacteria.

Todd Gleason: I'm going to break in here for just a moment because tomorrow on this program you'll hear a different podcast, the Weather Realness podcast, and they too will talk about soil structure, but in terms of dust storms and the importance of that soil structure and tillage to dust storms. Now, let's continue with the Illinois Nutrient Loss Reduction podcast here on Illinois Public Media's Closing Market Report.

Lizzie French: And then you need to feed them. Whether that is through organic inputs like manures or composts that provide carbon to the soil, or cover crops that keep a living root in the soil for a longer period of the year, all of those practices build up populations of microbes and help you do more with the fertilizer you're adding. You soak up that fertility into the microbial biomass you're feeding. If phosphorus is getting tied up in your soil, you have microbial activity that can help bring it back into solution, versus if you have lower levels of biological activity where you'll need to apply more fertility to get the same result in your crop.

Todd Gleason: How important, Lizzie, are conservation practices in this soil biome and the ecology of the soil? You mentioned cover crops; I also want to know about reduced tillage or waterways that move water through and out of the soil, or even tile.

Lizzie French: All of the above. With tillage, you don't see huge increases in soil biology as a result of reducing it, but it maintains what you have. Adding in other practices like cover crops or applying organic inputs builds that soil biology. Waterways are interesting. I live in Wyoming, so we have the opposite problem of not enough water. In Illinois and the Midwest, where you have too much water sometimes, tile drainage is an important component of managing a part of the soil microbiome that leads to nitrogen losses. Nitrification and denitrification are processes that happen entirely because of microbial activity. You have microbes converting ammonia to nitrate. If you have a lot of rainfall, that nitrate can leave through your waterway, or it can be denitrified by another group of organisms converting it back into air. You've completely lost your nitrogen out of your soil that way. Those are all microbes you can manage through tile drainage, applying a nitrification inhibitor, or splitting your nitrogen application so there isn't so much food for the microbes to get rid of at one time.

Todd Gleason: I want to narrow this down. There's a large portion of the Corn Belt from Western Illinois up through parts of Iowa and Minnesota which has similar soils. How should they manage their soil biome?

Lizzie French: It's much easier to answer this question for the Southern Plains of Texas because the soil there needs all the help it can get. The area from Illinois to Minnesota tends to have high organic matter and really good soils. We typically see relatively high levels of overall soil biology, even in conventionally managed fields, because you've got a lot of food there for your microbes. If you have four or five percent organic matter, you're going to have a lot of biological activity. In those cases, the conservation piece is crucial because if you're not keeping that soil where it is, you're not going to maintain that microbial activity.

Todd Gleason: When we talk about soil biology interaction and fertilizer management, how can a producer improve the biology to reduce fertilizer needs?

Lizzie French: Implementing conservation and soil health practices builds up those levels. If you have a soil biology test and it's telling you that you already have good levels of soil biology and organic matter, you might consider dialing back that nitrogen fertility. You are likely not going to see a yield loss if you have that organic matter and soil biology to mineralize. I hesitate to make a hard and fast recommendation for how much to dial back because that depends on rainfall, but it is something to consider. With the current cost of fertility, this information can help you feel more confident about your decision to dial back if you have the capability to provide those nutrients from microbial activity.

Todd Gleason: What is it that you would like to leave with farmers? What should they understand about the soil biome and the test you provide at Waypoint?

Lizzie French: Whether you've realized it or not, you've been farming your microbes this whole time. They are a huge component, and it's a big blind spot if you don't know your levels of soil biology. I encourage folks to take a look, try a few samples across a field with yield variability, and understand if a low-yielding area is a biological limitation. It helps you think through how to use fertilizer efficiently when you have all the information available.
Todd Gleason: Anything I didn't ask that I should have, or any final comments?

Lizzie French: The big thing we did not talk about is pH. If your soil is very acidic, soil health practices might help a little bit, but you're still going to be limited by that pH in terms of biological activity. It is one of the biggest drivers of soil biology. If your soils have become acidified over time, that's your first step. Manage that first, and then work on the other components to build up soil health.

Todd Gleason: Lizzie French is a Soil Biology Manager. She works for Waypoint Analytical and joined us for the Illinois Nutrient Loss Reduction Podcast. You may find that on our website at willag.org under the podcast tab. You're listening to the Closing Market Report from Illinois Public Media. Be sure to stay with us tomorrow when the Weather Realness podcast will take up the dust storms that have become more prevalent in Illinois. We'll be joined by Trent Ford, State Climatologist from the Illinois State Water Survey. We'll discuss the dust storms and the climate behind what's taking place in the State of Illinois. Tune in tomorrow afternoon for the Closing Market Report for a special edition. You can find our programming online at willag.org where the agricultural economist, the animal scientist, and the crop scientist right here on the Urbana-Champaign campus of the U of I post a brand new article to the website daily. You can also listen to the Closing Market Report and Commodity Week directly from the website at willag.org. I'm Extension's Todd Gleason.