Latest / The Illinois Nutrient Loss Reduction Podcast / Episode 38 | Soil Soldiers: Microbes fighting for your soil health
Transcript
- Episode 38 | Soil Soldiers: Microbes fighting for your soil health 00:00:06:13 - 00:00:38:02 Todd Gleason This is the Illinois Nutrient Loss Reduction Podcast. Episode 38 Soil Soldiers Microbes fighting for your soil health. I'm University of Illinois Extension's Todd Gleason. Today we'll talk about microbes and the communities of microbes that are working within soil to improve its health. That of the plant and the water quality. Stacy Zuber will help us kick things off. She's the Illinois state soil health specialist with the Natural Resources Conservation Service, or NRCs. 00:00:38:04 - 00:00:49:09 Todd Gleason I caught up with her and asked her to tell us a little bit about herself, and then to explain just exactly what soil health might mean and why it's important to farmers and landowners. 00:00:49:11 - 00:01:10:13 Stacy Zuber All right. I am Stacy Zuber. I am the Illinois soil health specialist with the USDA Natural Resources Conservation Service. So really, my job is working on promoting soil health across the state and really trying to promote cover crops and no till and other conservation practices. 00:01:10:14 - 00:01:12:16 Todd Gleason How do you define soil health? 00:01:12:18 - 00:01:48:02 Stacy Zuber The official definition for for soil health is the continued capacity of a soil to function as a vital living ecosystem for plants, animals, and humans. And I really think from that definition, the most important parts of that are really that we're looking at soil functions, we're looking at the processes that are happening within that soil, and then the living ecosystem component of that is a really huge part of it, because a lot of those functions and processes are really being done by the living organisms within the soil, our microbes and macro fauna and different types of organisms within that ecosystem. 00:01:48:07 - 00:01:55:16 Todd Gleason Why is it that farmers, landowners should care about those living microbes, should care about the ecosystem? 00:01:55:21 - 00:02:10:03 Stacy Zuber Within the soil, you know, we get a lot of benefits from from the soil that it provides to us. Having to do with nutrient cycling and having to do with capturing water and being able to store that water within the soil. 00:02:10:06 - 00:02:40:03 Stacy Zuber We want to prevent erosion. There's a lot of different functions within that soil that are really important for for the productivity. Our crop crop production for farmers is really dependent on the functions within that soil. So we really want to support them as much as possible. And the best way to do that, or one of the best ways to do that, is by having a soil microbial community that can really effectively do those processes and functions. 00:02:40:08 - 00:02:55:29 Stacy Zuber And so we want to make sure that we're giving them the best environment for them to live in. And we're feeding them and giving them a fuel so that they are able to, do those functions for us and make that soil more productive and more beneficial for the farmer. 00:02:56:02 - 00:03:01:12 Todd Gleason What kind of microbes might we encounter in the soils of Illinois, and what are their roles? 00:03:01:13 - 00:03:23:03 Stacy Zuber Well, we have bacteria. We have fungi. And that, you know, those are the, I guess, the ones that most people think of first and foremost within the soil. And a lot of what their roles are as decomposers is where they are breaking down plant residues. They are breaking down, the root exudates that the plants are giving off. 00:03:23:05 - 00:04:17:12 Stacy Zuber They're cycling nutrients, through those. So those are our smallest that are out there. Then there's other organisms like protozoa and nematodes that are really involved in population regulation, where they are actually acting as predators and grazers within the soil, where they will eat those smaller organisms, the, the bacteria and fungi. And so that is really important for cycling of nutrients because as those organisms, as protozoa, the nematodes, consume the bacteria and fungi, they are actually cycling nutrients and nutrients like nitrogen that are stored within those bacterial cells, those one fungal cells, when they get eaten by the protozoa or nematodes, some of that nutrients gets released back out into 00:04:17:12 - 00:04:45:23 Stacy Zuber the soil. It some of it gets left over the the predators don't use all of it up. And so then that is released into the soil. And often that's happening right around the plant roots. So there's this process is called priming. There's a priming effects where the plant roots actually can give off, sugars and fruit exudates that attract the bacteria and predators will follow them and cycle and consume the, the bacteria. 00:04:45:23 - 00:05:11:24 Stacy Zuber And then that left over nutrients is right there by the plant roots, which is, a really interesting way that we have that interaction between plants and microbes. So those are really the what we're focused on for the microbes, those smaller ones, there's a number of other ones out there. But I do want to point out on the nematodes, it's important, you know, sometimes they get a bad name because there are some that are pathogenic, and problematic for, for crop producers. 00:05:11:27 - 00:05:25:29 Stacy Zuber But there's a lot of them out there, the vast majority of them that are actually very beneficial for cycling of nutrients. And we really want them out there because they do a lot of those functions, a lot of those processes that are really important for for productive soils. 00:05:25:29 - 00:05:30:14 Todd Gleason Can anything be done to expand or maintain the microbes communities? 00:05:30:21 - 00:06:06:12 Stacy Zuber So the key thing with being able to increase the microbial diversity within our soil is thinking about them as living organisms. You know, just like us, they need a habitat or a home to live in. Something that supports them gives them the right temperature, the right moisture, the right soil pH. They need food to eat. So we want to basically the best way to do that is to make it so that it's very, conducive, a very supportive for them to, to survive in that soil and thrive so we can protect the environment. 00:06:06:12 - 00:06:28:10 Stacy Zuber So we want to protect the soil structure. So if we can minimize disturbance of the soil, if we can have a soil cover by whether that's by having, residues remaining on the surface or by adding cover crops in there that can provide a living cover on the soil surface, you know, during the normal bare time of the year. 00:06:28:12 - 00:07:08:29 Stacy Zuber So we want to make sure we're protecting that habitat for them. So that gives them a place where they are able to, to live. And then we also want to feed them and we want to give them not just one type of food. We want to give them a, wide variety of foods. And we can do that by incorporating more, different crops into our crop rotation and maybe by also adding more diversity into our into our system, by adding cover crops and having, you know, a mix of cover crops can really help as well, because all of those different types of, plant species within the soil are going to give 00:07:08:29 - 00:07:38:02 Stacy Zuber off different types of fruit exudates and different types of food. And so when we have, more diversity in the plants that we're incorporating, that can create a lot more diversity in the food sources and that supports a wider variety of microbes. And then another way we can do that is by integrating livestock. If we add more above ground animals and into those systems, they're also making a different type of food source for those microbes. 00:07:38:07 - 00:07:44:04 Stacy Zuber And so then that also helps create a more diverse microbial community. 00:07:44:11 - 00:08:05:15 Todd Gleason Stacy Zuber is the Illinois state soil health specialist with NRCS. Angela Kent, as it happens, is a professor of natural resources and environmental sciences at the University of Illinois who's been studying how to maintain and expand those microbial communities, the ecology of the environment in which they thrive. 00:08:05:17 - 00:08:10:07 Todd Gleason I asked her to tell us a little bit about the research she's been doing. 00:08:10:10 - 00:08:36:17 Angela Kent Sure. So my group is interested in studying microbial contribution to the nitrogen cycle quite often. And in particular, we want to help agricultural systems have sustainable nitrogen cycling processes. And what we've zeroed in on is the, the, the contribution of the plant host as an ecological driver of the microbiome and its functions. 00:08:36:19 - 00:09:08:05 Angela Kent So we're exploring different plant genotypes to see to what extent, they, control the recruitment of microbes with, beneficial or detrimental, nitrogen cycling processes. And of course, we want to increase the beneficial nitrogen cycling processes like nitrogen fixation. And we want to decrease, nitrogen cycling processes that, detract from environmental health, things like nitrification and denitrification in ag systems. 00:09:08:08 - 00:09:40:17 Angela Kent So some of the exciting research that we have going on right now is the realization that in corn, we have perhaps bred out some of these sustainable nitrogen cycling processes. So we went back to, we went back in time and looked at teosinte maize’s ancestor, and discovered that, that teosinte can't actually suppress nitrifiers and denitrifiers, so can suppress these detrimental, nitrogen cycling processes. 00:09:40:20 - 00:10:10:20 Angela Kent And, and that has been lost in modern baselines. And so one of the things that we're doing is we discovered the genomic regions in teosinte that contribute to those, those processes, and we're trying to move those into modern maize. So we have some near isogenic lines that contain those, those genomic regions that, suppress detrimental, nitrogen cycling processes by microbes. 00:10:10:22 - 00:10:42:10 Angela Kent And then the other aspect that we're interested in is, working with Fred Vilas Lab. We're interested in microbial inoculant that, promote soil health and, and, soil nitrogen provisioning. So, nitrogen fixers, but then, also some, other additives that contribute to soil health and, and then we're, we've done an experiment in the field, the summer where we're stacking some of these traits that we have or inoculating with nitrogen fixing microbes. 00:10:42:10 - 00:10:58:00 Angela Kent And then, we are, helping to keep that nitrogen in the rhizosphere by, adding, those inoculants to the nitrification inhibiting corn. So we want to provision nitrogen and keep it in the field. 00:10:58:03 - 00:11:04:27 Todd Gleason How do you see this research being utilized moving forward in the crop breeding area? For selection. 00:11:05:00 - 00:11:12:04 Angela Kent So we, we have, a crop breeder collaborator who is, very, very interested and very on top of that. 00:11:12:07 - 00:11:35:14 Angela Kent But we're actually funded in part by the, Illinois Nutrient Research and Education Council, which is funded by, corn growers. And so we have specific objectives that were of interest to them. So we we're, making test crosses right now where we're making hybrids that contain the genomic regions that, lead to the suppression of nitrification and denitrification. 00:11:35:14 - 00:11:53:16 Angela Kent We're going to make sure that these, capabilities don't depress yield, because we know that that's important, too. And that was that was a, concern of the of the corn growers, when this project was reviewed. So, so, you know, we're moving right to yield trials pretty soon here next summer. 00:11:53:19 - 00:11:57:29 Todd Gleason Do you have any advice on how to improve and maintain soil microbes? 00:11:58:01 - 00:12:15:23 Angela Kent Crop rotation is really important. And I think, anything they can do for, adding organic amendments would also boost the yield to, cover crops to help, help retain nutrients. Also would be would be pretty beneficial as well. 00:12:15:27 - 00:12:20:20 Todd Gleason Well, some of that to do list is fairly simple, like crop rotation and other things on the list. 00:12:20:20 - 00:12:48:03 Todd Gleason Not so simple. Angela Kent from the University of Illinois is doing some research to try to figure out what else can be done and how effectively and efficiently it can be incorporated into modern farming operations. Operations, in fact, like Terry Davis, who's from Roseville, Illinois, he's been no tilling for 35 years. And in fact, he says he does work to maintain the microbial communities within his soils. 00:12:48:07 - 00:13:18:29 Terry Davis Yes. We have been, by the usage of, reduced tillage. We've made the addition of cover crops into our rotations to help accelerate that. And, we have modified the timing and application of fertilizers, to try to, allow the microbial populations to, to thrive as much as possible. 00:13:19:01 - 00:13:27:07 Todd Gleason But let's talk a little bit about the soil improvements you think you've seen over time since you started with the conservation practices? 00:13:27:09 - 00:13:31:11 Todd Gleason For instance, what were the first things that happened after you went no till? 00:13:31:13 - 00:13:55:26 Terry Davis The first thing I noticed was the and that was a detriment at the time. The tie up of nutrients as the soil made that transition from oxidation of nutrients through tillage to biological activity, releasing nutrients from the soil profile. 00:13:55:29 - 00:14:01:06 Todd Gleason And once that was completed, did it release those back for the crop to use? 00:14:01:08 - 00:14:37:08 Terry Davis Yes, we did get everything back over the years. It took about three years for that to occur. I learned a lesson from that and have since then when running New Farm ground, taking the opportunity to do some, inline tillage to continue to loosen that sole profile up, but not to turn that soil profile over so that, we allow the oxidation of the organic matter to happen through biological activity rather than through mechanical tillage. 00:14:37:11 - 00:14:41:02 Todd Gleason Anything change in the way water flows to the soil profile? 00:14:41:09 - 00:15:07:20 Terry Davis Yes. Water infiltration has improved immensely. Water profile, moisture retention has improved significantly. To the extent that the in a bigger rain event like I had this last weekend, which in my area right here, we had between three and a half and six inches of rain, over a 48 hour period. 00:15:07:22 - 00:15:34:06 Terry Davis And where normally you get into tilled farmland this time of year, that the surface will seal over and that water will shed off where the no till fields, that water usually stays on the fields and you see some see some ponding that you might not have saw otherwise just because that water is not leaving the field. But, but staying or. 00:15:34:06 - 00:15:43:21 Todd Gleason No, it has to do with, root penetration and the stability of the size of the aggregate of the soil. 00:15:43:27 - 00:16:13:28 Terry Davis Both of those, we have noticed a significant increase in soil aggregate size, and we have much more infiltration due to earthworm activity producing, on an average, 20 to 30 burrows per square foot. So we have a very poor sponge like, soil surface now, which allows that water to infiltrate rather runoff, that large events like this. 00:16:13:28 - 00:16:26:10 Terry Davis And it, takes that profile 24, 48 hours to be able to filter that water down through the profile. Whereas before, it just ran off. 00:16:26:12 - 00:16:28:25 Todd Gleason Has your need for inputs changed? 00:16:28:25 - 00:16:44:16 Terry Davis It has over the years. My nitrogen usage, is the main objective that we have, tried to work with, my phosphorus and potassium levels on my own ground. 00:16:44:16 - 00:17:13:24 Terry Davis And the family farm, were in pretty good shape before I made the conversion. So I hadn't had to make many changes there. And I rented farm ground, even low rental, well rated rental farms that we found that basically, putting on a maintenance plus maybe about, 10 to 15% extra has been adequate to completely satisfy the needs of of the growing crop that year. 00:17:14:00 - 00:17:21:23 Todd Gleason You. Yeah. More than three decades of experience with no tell. How long have you been introducing cover crops into the farm? 00:17:21:25 - 00:17:50:11 Terry Davis Cover crops began six years ago. Was my first foray into purposely seeding a fall crop for the sole purpose of cover crop. With the determination of termination in the spring. We had been planning some wheat previously, but, and then double cropping beans behind it, but, its purpose had not been there as a cover crop per se, but as a cash crop at that time. 00:17:50:18 - 00:18:05:00 Todd Gleason Did it change or, make additional improvements or possibly things that didn't go as well with water infiltration, stability of the soil, need for pesticides, the earthworms and such. 00:18:05:06 - 00:18:49:25 Terry Davis As I said, with the addition of the cover crop. Now, we experienced this year, I'm getting such a good soil coverage in the spring due to the increased soil residue that staying on the surface, that the cover crop on top of that is creating a mat of vegetation decaying on the soil surface, which unfortunately, in a spring like this year, means call cold surface temps and the germination of the soybean crop, especially, I did note the differences in that the spring, just 00:18:49:27 - 00:19:15:27 Terry Davis a few degrees temperature change, had a little frost damage one evening, around Mother's Day. And that was solely caused by, the the soil surface being covered. It the heat didn't radiate back up off the soil surface as readily as it did off of, tilled fields and some neighboring fields. Did fare better than I during it. 00:19:16:00 - 00:19:43:11 Terry Davis Time period or even my own fields. I'd see spots where we had removed the cover, turning traffic and just bare soil. But, the beans did fare better through that. Just a few few hours of cold weather made a difference, to those this year. But I think we'll get it back this summer, because those same soils are going to remain cooler this summer. 00:19:43:11 - 00:19:49:08 Terry Davis When we get into the the high heat. And that will reduce the stress level on the plants late summer. 00:19:49:10 - 00:19:56:22 Todd Gleason Given your experience, what are the things that producers should do to improve soil microbial health? 00:19:56:22 - 00:20:25:02 Terry Davis First thing, reduce the number of trips off the field with the mechanical tillage. Secondarily, to speed up the process, sizing of the residue, early on, it seems to be a benefit, long term, the reduction in the nitrification products I've seen has made a big difference in my microbial activity. 00:20:25:05 - 00:20:45:25 Terry Davis As I said, I do time my nitrogen application rather than in the fall. But in the spring, just ahead of planting, we lay down what we think is going to be needed and then come back in, side dress, depending on what we think the season is going to give us as far as increased opportunities for yield. 00:20:45:28 - 00:20:48:26 Todd Gleason Terry Davis is a farmer from Roseville, Illinois. 00:20:48:26 - 00:21:11:29 Todd Gleason He's been no tilling for some 35 years. You've been listening to the Illinois Nutrient Loss Reduction podcast. This has been episode 38 Soil Soldiers Microbes Fighting for Your Soil Health. The program is produced in conjunction with Illinois Extension Watershed Outreach associates, Jennifer Jones and Rachel Curry. I'm Illinois Extension's Todd Gleason.