The Illinois Nutrient Loss Reduction podcast explores efforts to reduce nutrients in Illinois waterways from agricultural runoff to municipal wastewater with host Todd Gleason and producers Rachel Curry and Nicole Haverback with University of Illinois Extension.
Read the blog at extension.illinois.edu/nlr/blog.
This is the Illinois Nutrient Loss Reduction Strategy Podcast Episode 70: Constructed Wetlands for Water Quality Insights and a Farmer Perspective. I'm University of Illinois Extension's Todd Gleeson. We'll begin today with Jill kostell. She's with the Wetlands Initiative. I asked her to tell us a little bit about herself and what she does at the initiative.
Jill Kostel:Yes. I'm the water resources program director. I have a background in civil and environmental engineering, and I manage our smart wetlands program at the Wetlands Initiative. And the Wetlands Initiative is a non for profit located here in Illinois. We design, restore, and create wetlands.
Jill Kostel:We do this work through innovation, collaboration, and using sound science to improve water quality, habitat for plants and wildlife, and our climate.
Todd Gleason:What's the difference between a constructed wetland and what the Wetlands Initiative does?
Jill Kostel:Yeah. The majority of the work that we do is what we called wetland restoration. And with a restored wetland, your goal is to restore the natural hydrology and native vegetation in a former wetland that was either drained, farmed, or otherwise modified it doesn't have its hydrology and its plant life anymore. And the purpose of this practice is really to restore wetland functions, habitat, and diversity to something similar to what was its original condition before being modified. A constructed wetland is an engineered ecosystem that could be built anywhere but on a former wetland.
Jill Kostel:It is essentially an artificial wetland ecosystem designed to mimic a natural wetland's ability to clean water. In this case, the wetlands are cited to intercept a tile main and designed to provide the optimal conditions needed for the wetland processes to remove excess nutrient as much as possible. And in this case, our main goal is nitrate removal since tile drainage is responsible for most of our agricultural nitrate load in our streams and lakes. But I would say because we are using native vegetation and developing this shallow emergent marsh, they can also provide valuable wildlife, waterfowl, and pollinator habitat. And this constructed wetlands is what we do through our smart wetlands program.
Todd Gleason:When you're thinking about wetland restoration, how do you know if a wetland was there previously?
Jill Kostel:We can tell by the soils. Wetland soils have specific characteristics, and those characteristics stay even if the hydrology or the water levels have been modified. They've been drained off. Those soil characteristics remain, and that's one of the ways we identify, former wetland is looking at the soils.
Todd Gleason:In the case of the wetland that you've been working with farmer Rex Newton on, and we'll hear from him in just a bit, Is that a restored or a constructed wetland?
Jill Kostel:That is a constructed wetland for cropland tile drainage treatment, which is the official conservation practice name. And so that was designed specifically to intercept a number of tiles. We put them two tiles. That means they were coming through their property and joined them into one tile, and that goes directly into the wetland. Wetland processes occur.
Jill Kostel:That water stays in there for a while. Wetlands are doing all the awesome things that they do, and then we have a structure at the end that controls the water levels, and then the water eventually then, goes right back out into the creek it would've gone to, directly if it wasn't intercepted by the wetland. And the water leaving the wetland has a lot less nitrate than it did coming into the wetland.
Todd Gleason:Do you verify that through, sampling or some other form?
Jill Kostel:Yes. We have monitored, two other constructive wetlands. But, yeah, we've done watering. They're actually quite easy to monitor because you can just monitor and take a water sample of what's coming into the wetland and what's leaving the wetland, and you'll see a difference in the concentration and the load. So we can estimate how much we're we're removing.
Jill Kostel:Now the wetland, that will be, monitoring will begin on that this year. So we'll have a better sense of how well that wetland is working. But in general, constructed wetlands, if they're designed correctly and sized correctly, we expect at least a 50% nitrate removal. Some of our wetlands move up to 80-90% of the nitrate coming in.
Todd Gleason:And how do they do that? Is it just captured by the plants? Does it stay put? Is it removed in some other form?
Jill Kostel:Yes. We are really relying on the, microbes that are, living in the sediment and on the plants within the wetlands. Plants do take up nutrients to grow, but those plants also die so they can release some of those nutrients back into the water column. But the process that's really sustainable is the ones done by the microbes, which is converting that nitrate into a nitrogen gas. So the microbes will do there if there's nitrate, and there's a they will breathe the nitrate in in the absence of oxygen.
Jill Kostel:So you wanna have a little bit of an anaerobic layer in the wetland. And then the carbon from the plants and the sediment is what provides them their energy to do that work. So if you have carbon, you have nitrate, and you have microbes, they will keep on, removing nitrate forever. It's a very sustainable process.
Todd Gleason:What considerations should farmers and landowners keep in mind when considering a wetland for their properties?
Jill Kostel:Well, we wanna make sure we have somewhere where there's a tile main that we can intercept. Feel like somewhere between 30 to 200 acres of tile drainage, is a good size for these. It doesn't take too much land out of production because we want the wetland treatment area to be at least 1% of the drainage area captured, and then, therefore, the total project size is closer to 5%. So we like those odd corners or areas that may be slightly wet or hard to farm. Those are kind of the best, areas to put it.
Jill Kostel:But they also have to really consider that this is a we don't say permanent practice, but we are excavating. We are digging, you know, essentially a pond and not filling it up. We only have about two at maximum two feet of water in these wetlands because that's the ecosystem that removes the best, is best for removing nitrogen. So we have to you know, and the other thing we have to consider that it's a capital cost. You know, this is not of all the tile treatment practices, this is probably the most expensive one.
Jill Kostel:However, it's also one of the most cost effective practices given the amount of nitrate these wetlands can remove and as well as their longevity with very low maintenance. The good thing is that we currently have farm well programs that can provide financial assistance to help you know, offset some of those costs in installing a wetland. All wetlands pay a very major role in reducing nutrients, even, you know, restored wetlands, constructed wetlands. Wetlands are often referred to as nature's kidneys as they can clean, you know, purify water by removing the pollutants. And so restored or constructed wetlands can do this.
Jill Kostel:Constructed wetlands, we are just designing it such that we're really trying to optimize that nutrient removal.
Todd Gleason:Jill Kostell is with the Wetlands Initiative. She mentioned a farm that they've been working on putting in a constructed wetland that's operated by Rex Newton. I spoke with him as well. I started by asking Rex to tell me just a little bit about himself and his operation.
Rex Newton:Oh, boy. Well, I started farming in '75, so this is gonna be my fiftieth year. In the early eighties, I started dabbling with no till because NRCS office had a planner that they were letting us use to demonstrate. So I did some strips and what have a yielded challenge, I guess you'd call it. And I'll be darned, the no till was about a little over six bushel better.
Rex Newton:I thought, well, that's not bad. So I've started growing there with a no till and the attachments back in that era weren't all the greatest. Milletail was kind of in the back burner. So I've grown that and I've seen benefits from it. The one landlord is pretty conservation minded, so he's the one that put the wetland in.
Todd Gleason:Why is it you wanted to put the wetland in?
Rex Newton:I'd say it was both of us, but I left it up to the landlord to make the decision because I had gone to a meeting that Jill spoke at, and I thought, well, this is interesting. So I approached the landlord and told him we ought to look into this whether we do anything or not. So that's when Jill and Jean come out to our farm and visit with him and he got interested in it and that's come to happen. We got one in there. It drains 60 acres of tile.
Rex Newton:And I think the wetland is 2.8 acres. But we also got pollinator plot and stuff like that around it too. So it was pretty easy sell really mainly because he's he's pretty conservation minded. And we've grown that and now we're concentrating on nutrient management with cover crops, six years of cover crops. And strip till I started doing some of that about four years ago.
Rex Newton:And Todd, we've never In 1982 was the last year of moldboard plowed and it was a disaster because 'eighty three ended up being a drought year and that corn, corn on corn moldboard plowed me 56 bushel to the acre. And then across the road, I no tilled corn on bean stubble, and it made a 125 bushel of the acre. So that was another selling point to change my operation.
Todd Gleason:From the farmer's perspective after the fact, is there much management that has to be done with the wetland? Do you have to care for it very much?
Rex Newton:Well, not so far. I mean, they get a person that comes in and and checks on it and tries to manage the species of weeds that we don't want. Right now we've got some cattails and I'm sure that's from the seed bank. When you dig down that deep, why you're gonna get some seeds from way back. So we're gonna start sampling the water coming in and the sampling of the water going out.
Rex Newton:And that way I got some real stats that I can use on both sides. I got corn and soybeans and I'd like to take some out of those tile lines to test. So I even got a comparison there. One side will be corn and one side will be beans. So then I'll have nitrogen on one side of the creek to test and then cover crop on the corn stalks going to beans on the other side.
Rex Newton:So I'm kinda excited about seeing how that's gonna prove to me whether I'm doing the right thing or not. I feel like the science is telling me I'm doing the right thing. So I feel comfortable there, but I think this would be more of a more of a selling point, so to speak.
Todd Gleason:Yeah. So if you take tile line samples out of out of the cornfield, out of the wetland field, and then out of the soybean field, plus if you were able to convince them to pick up samples prior to your cornfield, after the cornfield, but before the wetland out of the out of the creek, and then before and after the soybean field, you'll have a whole lot of data to show what really is happening across the board. What's across the board. On all three on all three of your fields, and then what's what the total load is coming out, and what it looked like and what it looked like going in too. Fantastic.
Todd Gleason:That's that's really good stuff. I hope that, I hope that that's that's able to take place. Any advice for farmers, and landowners who are considering adopting a wet land. I mean, you were there, I'm sure, as they were building it, trying to figure out where to place it, those sorts of things. What do you suggest?
Rex Newton:Well, you gotta be patient for one thing. Because it seemed like it took so long for the seeds to get started and stuff like that. Your pollinators plots and then you have invasive weeds you got to control. As far as the soil and work that they did, that was fine. And then starting to see how it was going to really work was kind of fun to me because I'd go down there and look and started seeing some different birds and I don't know my bird names, species, but they were different.
Rex Newton:And then the Monarchs showing up. It just kind of gives you a good sense that this has got to be good. And like I said, if I get some test results on the nitrates and stuff that it is removing, it'll be that much more rewarding, I'm hoping. So basically it helps, Todd, when you've got a landlord that's interested in saving the soil for the next generation.
Todd Gleason:Rex Newton is a conservation minded farmer from Marshall County, Illinois that has been working with his landowners to improve their properties, in this case by deploying a constructed wetland. We also talked today on this episode 70 of the nutrient loss reduction podcast with Jill Kostell from the Wetlands Initiative. She was working with Rex and the property owner to put the constructed wetland into place. You've been listening to the Nutrient Loss Reduction Podcast from the University of Illinois. It is produced in conjunction with Rachel Curry and Nicole Haverback.
Todd Gleason:I'm Todd Gleason.