The Water Table
The Water Table
#127 | Cover Crops & No-Till: A Conservationist’s Perspective
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Cover crops and no-till… How will they impact your bottom line? We’re joined by fan-favorite and Conservation Manager, Ruth McCabe, to dig into the benefits and drawbacks of these increasingly popular conservation practices. We're tackling the tough questions: Do cover crops boost yields? How do they affect soil health? Why are these practices being adopted from Iowa to Minnesota and beyond? This is the first of several insightful conversations with Ruth you won't want to miss!
Chapters:
00:00 Welcome Ruth McCabe
01:00 What is going on at Heartland Co-op and Beyond?
04:41 Cover Crops
05:51 Ruth's Experience and a Balanced View of Cover Crops
08:33 Regional Differences in Cover Crop Adoption
11:29 Benefits and Considerations for Cover Crop Use
14:00 The Leaky Root
16:26 Warming up the Soil
18:52 No-till + Cover Crops = So Many Bonuses
20:43 The Learning Curve and Potential Yield Impact of New Practices
22:00 Short-Term Yield Hits, Long-Term Benefits
23:52 Guidance is Key
Related content:
- Episode 82: Getting #%@$ Done in Iowa With Batch and Build…On the Road
- Episode 104: Worldwide Conservation, Water Quality and Woody Harrelson
- Subsurface Drainage and Soil Temps
- Heartland Co-Op
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Ruth McCabe (00:00):
There are a lot of really good things happening in the private lands conservation space and like 3.8 million acres to maybe 4 million acres. I mean, that's no slouch, that's nothing small. Sugary things that feed microbes and fungi in the soil, all incredibly valuable to have in the soil because it builds long-term soil health. As an agronomist, I would say depending on where you farm, you need to adjust your goals. Why are you using the cover crop? Because I remember last year when I drove up here, I saw one cover crop field and on the drive up today I saw seven.
Jamie Duininck (00:36):
Well, welcome back to the Water Table podcast. Today I have one of my favorite guests back with me, Ruth McCabe from Heartland Co-op, Conservation Manager over there in Iowa at Heartland Co-op. And Ruth, you're getting close to being the guest that's on the most, so it depends on what you look at Trey Ellis. I see Trey as a co-host because he takes over for me sometimes, but if that's the case, then a true guest. I think this is your third, maybe fourth appearance on the Water Table?
Ruth McCabe (01:13):
I think it's third, but we should make it a fourth and a fifth and a sixth. This is becoming like a yearly or bi-yearly pilgrimage for me and I'm all about it. It's a gorgeous drive.
Jamie Duininck (01:22):
Great. Well thanks for joining me in studio. I think you've also been in studio. We did a mobile studio once, but a lot of times my guests are not in studio and it's way more fun to sit and have a conversation together than looking at somebody on a screen. So I appreciate you showing up here at what I like to call the global headquarters of the Water Table podcast. So thanks for being here.
Ruth McCabe (01:45):
It's great. It's cool to be in the studio and I'm excited because I like to gesticulate with my hands a lot, so chances are strong that I'm going to knock this water bottle off the table at some point.
Jamie Duininck (01:53):
Nothing wrong with that. I'll start talking to you about some things that are irritating to you if you haven't quite done it yet.
Ruth McCabe (02:01):
Get me fired up.
Jamie Duininck (02:01):
We'll get it done. So what's going on in the world of conservation at the Heartland Co-op? A lot of times what we talk about, the types of things we try to educate people on at the Water Table really collide with what you guys are trying to do, in a good way. And so it's why I think you are a frequent guest here is because the things that you're implementing every day, that you're passionate about, that you're talking about is something that our listeners are listening to the podcast because they want more information on. So that's what I want to do today is just chat about what's going on in your world.
Ruth McCabe (02:42):
Oh man, there's a lot going on. It depends on what avenue you want to take. In the conservation space specifically, there are a lot of really good things happening in the private lands conservation space, which I'm personally very excited about. I work for an ag retailer, so that is very exciting for me and some opportunities there that we could dive into. In the public space there are some changes happening, especially at the federal level, that has turned a lot of federal programming on its ear, turned things upside down so we could go that route if you want it. That's less exciting.
(03:16):
Then there's just in general the changes that come with the seasons. So it's spring in Iowa, very spring. People are planting. It's always very exciting during spring planting season. A lot of folks out terminating cover crops. So even on the drive up here today to be on this podcast with you, I got a couple calls from farmers who had questions on whether they should pull the trigger on terminating their cover crops. So there's a lot of stuff going on.
(03:40):
My team, it had just finished up our survey season. We run a batch and build for saturated buffers and bioreactors, so we could talk about that. So we just surveyed a little over 100 outlets, about 115 outlets across about 70 fields for either saturated buffers or bioreactors, mostly saturated buffers. And so now my team is getting all that data put together and we're going to be sending it over to our engineer to get preliminary designs. So that's very exciting. In my realm, I also work on large scale nutrient treatment wetlands. I'm a part of a few different wetland partnerships in Iowa, and so I've got three or four wetlands right now that are going through various stages of development hopefully for construction starting either later this year or early next spring. So there's a lot of that going on. So just a ton going on in the heartland world. A ton going on in the conservation space. I'll open it up to you. Where do you want to go?
Jamie Duininck (04:34):
Well, let's start with, it's something we kind of briefly talked about a year ago or whenever we last got together, but was cover crops and you kind of mentioned that, so we may as well start there. It's something that I've seen as a real... you tell me, but it feels like that's growing from the 'I' states out different directions, and one being to the north here into Minnesota, because it's something I've noticed a lot more in the last even six months, but for sure the last year is a lot more farmers. I don't know if they've adopted the process or adopted cover crops or if they're just dabbling with the idea of, but there definitely a lot more cover crop talk. You're seeing it on the landscape.
Ruth McCabe (05:22):
Yep. Absolutely.
Jamie Duininck (05:23):
And I just have all kinds of questions about how is that working? Does it work as well in a place like Minnesota as it does where it's warmer, has another 30 days growing season, those kind of questions. Is there any yield hits, all of that stuff. So maybe let's just start a dialogue and I'll keep some questions going.
Ruth McCabe (05:45):
Let's do it. Yeah.
Jamie Duininck (05:48):
You've been involved in cover crops for how long would you say?
Ruth McCabe (05:51):
Oh golly. Oh, man. Oh, I don't want to... Oh, no, I'm going to age myself if I say, but I've probably been working with cover crops either in cover crop research, so I worked for the University of Minnesota and Iowa State University before I jumped into the private sector and then working as a seed salesman for cover crops for a while there, which was a ton of fun, for Minnesota, Iowa, and Wisconsin. And then now doing what I do now. But probably 15 years. Yeah, a little over 15 years.
Jamie Duininck (06:16):
So what's the progression of that been?
Ruth McCabe (06:20):
Oh, it's crazy.
Jamie Duininck (06:21):
It has to just be like you were from a different planet when you first started talking about it.
Ruth McCabe (06:27):
Yeah, because 15 years ago I feel like it was just super weird. A lot of people really had negative ideas about it or negative preconceived notions about cover crops, which to be fair. Look, as a cover crop advocate, I will say there are a lot of reasons to use cover crops and I'm a big fan of them, but there are also reasons to be careful with cover crops and it's okay to criticize cover crops. So some of the negative ideas that people had about them 15 years ago are true. You mentioned they do, can, reduce yield, will reduce yield especially in the beginning and we can talk about that. And there's research that supports that. They also have a million positive benefits, man, which I could go on ad nauseum about. But yeah, early on they were not as popular I'd say 15 years ago.
(07:11):
Now I'm seeing them everywhere. Excitingly. For example, 2023, the fall of '23, Iowa had about 3.8 million acres. And I'm excited to say that we don't have the hard numbers yet, but I know personally from my own company's cover crop sales in '24, they were the highest they've ever been by far, that I was confidently saying, "Well, I'm pretty sure '24 in Iowa is going to be our highest year for cover crop acres yet." And happily it looks like that is going to be the case. So I don't know quite what the number will be, but highest adoption rate yet in the state. And 3.8 million acres to maybe 4 million acres, I mean that's no slouch, that's nothing small. I mean we were at zero acres not 15 to 20 years ago. So even driving here, what I thought was interesting is I decided to count on the way up because I remember last year when I drove up here, I saw one cover crop field and on the drive up today I saw seven.
Jamie Duininck (08:03):
Well that's it right there. Seven times increase. And that's kind of what I've seen is it's just so much more conversation about it. I don't want to say talk about it, conversation about it, because what I mean by that is people are just more comfortable with it. It isn't anything odd. Everybody knows somebody that's trying to or tried it. I probably should know this, but when you say close to 4 million acres in Iowa, how many acres do you know of tillable land there in Iowa?
Ruth McCabe (08:35):
Yeah, great. Fantastic question. So Iowa's about... These are rough numbers. As a state, we're roughly 36 million acres. Nine to 10 million of those acres are in cities or housing developments or some other kind of production, agriculture that isn't crop. So 26 million acres-ish are in row crop production. So I mean 3.8 million acres, that's a decent percent. Yeah, that's a decent percentage. And when I say as I drove up here, I saw seven fields, I should say. When I crossed the Iowa-Minnesota border and really got north of, we'll say the Minneapolis latitude, that's where I was like, okay, now I'm really going to start counting fields because typically you don't see any cover crops this far north. So that would be where I started to count and saw seven. So I was pretty excited about that. I mean, in Iowa, if you drive through Iowa, you're going to see cover crop fields every which direction. It's nuts. I mean it's real green out there right now.
Jamie Duininck (09:25):
Yeah, and that's another thing that's interesting about the time of the year that it is now, and I think farmers, this is second nature, they understand it, but you go just 50 miles if you're straight south or straight north, it really changes a lot this time of year. And so then you're talking about different crops and how they grow, but specifically since we're talking about cover crops, how it becomes more challenging or different types of crops to actually make it worth it when you plant them in the fall to get any of the root growth and then in anything in the spring. So talk a little bit about that. How is this going to work, especially if you're talking about the Dakotas and Minnesota and farther north as we go along, and what are the challenges going to be with cover crops and what are the benefits in that geographical region?
Ruth McCabe (10:22):
Okay, great question. So I am both one of the biggest advocates for cover crops and also sometimes one of the biggest critics of cover crops. And I hold that middle ground on purpose because I feel like it's very easy to get into an echo chamber where everyone's like, "Oh, cover crops are amazing and if you grow them, your children's children's children will evade cancer." And I don't like these weird promises that are made around something that definitely has drawbacks. As an agronomist I would say, depending on where you farm, you need to adjust your goals. Why are you using the cover crop? So I mean, if you are in a place that's super windy and you're further south, Iowa, you might be using cover crops, especially for spring erosion control. And that's a really good usen, reason to use cover crops. Usen, I just made a word up.
Jamie Duininck (11:07):
Yeah, well.
Ruth McCabe (11:07):
Pretty proud of that.
Jamie Duininck (11:08):
We're usen.
Ruth McCabe (11:08):
Yeah, we're usen. Yeah, right. Yeah, yeah, yeah.
Jamie Duininck (11:11):
So we are usen them.
Ruth McCabe (11:12):
Okay, we trademarked that right here, right? Can we say that? Are we allowed to say that?
Jamie Duininck (11:12):
Yeah.
Ruth McCabe (11:15):
Okay. All right. But the further north you move, I feel like let's adjust our goals. Having a living root in the soil is also really, really valuable. And because soil health, right? So when you have a living plant root in the soil, plant roots are leaky and that's not an accident. They leak stuff, yummy carbon compounds if you will, sugary things that feed microbes and fungi in the soil, all incredibly valuable to have in the soil because it builds long-term soil health. Now this isn't instantaneous, okay? The further north you move in order to really see some of those soil health benefits from using cover crops, you got to do it more than just once, right? It's going to take several years and again, the further north you move, you run into these complications of less of a growing season for these things to grow before you need to crop again in the spring.
(12:04):
And then will they even grow? Does it get cold too quickly? Is it too dry? Are they even going to grow if you plant them that late and you don't typically get late fall rains, is it even going to grow? If you're looking at the Dakotas, for example, they don't get anywhere near as much rain as say Iowa does. Again, financially is it justified? My advice there would be narrow down the cover crops you're selecting from. My favorite cover crop, though many people don't like it, is cereal rye. In the cover crop world, it's very boring, but to me it is just an MVP. It'll grow through anything. It'll grow through a nuclear holocaust. Let's not test that theory, but I'm pretty sure it will. And it can grow in really short growing seasons and it's very aggressive and it can grow with very little moisture. So I feel like it works everywhere.
(12:51):
The thing is, if you have a shorter growing season and you need to get in in the spring ASAP to terminate, especially ahead of corn, maybe you're only using cover crops ahead of your beans, your bean years, maybe you're just only using it every other year if you rotate or if you are growing it ahead of your corn, oh, do you have starter on your track? Do you have starter on your planter so that you can make sure that your corn is getting that early shot of nitrogen because rye can be aggressive for nutrients in the spring. But again, the further north you move, I would see it more as growing something in the soil as opposed to necessarily growing something above soil. Now, if you're somebody who's really concerned about above ground erosion control, get some oats in.
(13:30):
Maybe the further north you move, you try seeding early, like in season, like in standing crops. For example, we have a Hagie high clearance cover crop interseeder and we start seeding cover crops in August so we're getting them into the standing canopy. That has a ton of benefits, especially for the people who do want to terminate early in the spring so that they have control over their fields so their fields can dry up and stuff. Getting those things to grow earlier by seeding them into standing crops can help. Now I know I just rattled off a bunch of ideas and benefits and some drawbacks all at once, so that was a little muddled. So I'll stop and give you a chance to...
Jamie Duininck (14:03):
Yeah, there's a lot there. But one of the questions I had right away that isn't totally on what you just shared, but you'll know the answer so I'm asking is, what does just different root systems do for the soil? So you're talking about the leaky root, that it creates other microorganisms and different things in the soil that's good for soil health. But just the fact that you have a corn root, a soybean root, a corn root, a soybean root, you're on a rotation and now you're adding in oats and cereal rye and whatever else, those different root systems, what do they do for the soil? My assumption is that's really good for aeration.
Ruth McCabe (14:46):
It can be, yeah.
Jamie Duininck (14:47):
But what else is the benefit?
Ruth McCabe (14:49):
Yeah, absolutely. Great question. Every plant wants something different from the microbial populations that are in the soil around their roots. So microbes and fungi. To break it down simply, oh, break it down simply, oh man, what a good pun. Oh, sorry. If there's any microbiologists that are listening to this, they'll laugh. But anyway. But to keep it simple, these microbial populations in the soil make nutrients more available to plant roots. And every plant has a different profile of nutrients that they need or that they need access to that's different from other plants.
(15:22):
So rye secretes certain compounds that like a mustard, like a radish will not secrete and vice versa. So they give off compounds that are different. So every plant gives off a different compound. Humans should eat a variety in their diet. We should eat vegetables and fruit and meat and carbohydrates and whatnot. Well, plants, every plant gives off something different and they need something different from the soil. So they're growing different microbes in the soil around their roots, so they have access to that. What does that do for your corn and soybeans? Well, it means that the microbial populations that live in the soil are kept thriving even after you've harvested your soy or your corn. Because the thing is you're only growing those plants for five, six months out of the year maybe, four months out of the year, and then the rest of the year you've got nothing growing in that soil. So a lot of those microbial populations are just going to go stagnant.
(16:11):
And so if you keep something in the soil, say over winter, like a rye root for example, it is going to keep those microbial populations firing all winter long. I mean, they might slow down because it's cold, but it's going to keep them firing earlier in the spring. You just have access to that many more say nutrients in the soil when you do plant your corn and your soybeans, that's the idea. That's kind of the rationale. And I'll also say that it's a positive and a negative, but when you have a cover crop in the soil that overwinters, then in the spring you have this plant that is actively warming up the soil just a little bit faster.
(16:45):
I can't tell you how many times I've been driving down the highway in the spring and I have stopped and taken these pictures where on one side of the road there's a field of cover crops and it is green, and you can tell that that soil is warmed up because across the road is a field that doesn't have cover crops, and there is still a ton of snow. So I mean, it's just the slightest little bit of difference.
(17:09):
On the flip side, I just said it's a positive and a negative, right? On the flip side, I've seen fields where you have all this biomass in the spring from a cover crop, and if it doesn't get terminated timely for one reason or another, now you have all this biomass that's laying there holding in a bunch of moisture. If you have heavy wet soils, that's the last thing you want when you want to get in and plant. So again, they're a double-edged sword. So I love cover crops, but I want people to walk into them with eyes wide open.
Jamie Duininck (17:34):
So that creates more questions. And one of them is just around when you say it warms of soil up just a little bit more, that's a big deal, right?
Ruth McCabe (17:43):
Oh, yeah.
Jamie Duininck (17:45):
I mean, if you're three degrees warmer and it gives you, I don't know, I'm just shooting from the hip here, but maybe four or five days of germination sooner, that could be...
Ruth McCabe (17:46):
Game changer.
Jamie Duininck (17:59):
4 or 5% more.
Ruth McCabe (18:02):
Yeah, absolutely. Well, so in 2019, in Iowa anyway, 2019 was an infamously wet year. We just had rain that did not stop. In Nebraska, there was tons of flooding, a lot of cows died. There was a lot of cattle deaths. It was really traumatic. And in Iowa, we just had rain that just wouldn't stop. And what I found really fascinating was I had farmers who had fields of rye, and they were like, those were the only fields that I didn't have to do prevent plant on, because that rye soaked up that moisture in a way that allowed me to get out there and plant. And they couldn't in any of the fields that they didn't have rye on. Again, double-edged sword because in drier springs rye will soak up all that moisture and now you're trying to plant into cement.
Jamie Duininck (18:44):
So is there a correlation between no-till and cover crops? Do people cover crop into no-till quite a bit.
Ruth McCabe (18:54):
Yep. Cover crops and no-till go along really well together. And that dynamic is changing and I'm watching it not necessarily in a judgmental way or in a sad way, I'm just kind of watching it like, "Well, this is fascinating," and it's changing because of the changes in resistance level of many weeds to glyphosate, for example. And so as people maybe are moving to strip-till or they're moving to disking or something to try to do a little bit more control in their soil, they're still using cover crops, which I think is really still appropriate. I mean, I know that cover crops and no-till have gotten along really well over time, but there's no reason why you can't use cover crops and tillage. Traditionally, they're best friends, but I'm seeing more and more people who are turning to tillage who are also still using cover crops, and I think that's fantastic.
Jamie Duininck (19:41):
How about no-till and it's just a stand alone? In this region I'm seeing more of it than I have.
Ruth McCabe (19:48):
Yeah, I was excited to see no-till just coming up here. Again, I saw lots of no-till fields that I didn't see last year.
Jamie Duininck (19:52):
And for me, I like it for a number of reasons when I'm an outdoorsman and I think it's good for the wildlife. I think it's good for the soil, hold the soil back, and I think it's good for drainage.
Ruth McCabe (20:04):
Oh yeah, yeah.
Jamie Duininck (20:05):
I know it is. So that's why I'm saying that a little bit sarcastically, but it is. But all those things together are really important for our landscape and holding the soil where it's supposed to be on the field.
Ruth McCabe (20:17):
Yeah. Keeping the soil in place, that's my big goal or my big ulterior motive with conservation practices. So I mean, I love cover crops, they're great, but if somebody tells me that they're going to do no-till, but they're not going to use cover crops, I'm like, that's fantastic. How can I help you? That's great. Yes, perfect decision. You do you. At the end of the day, the goal is to get conservation practices on the landscape. No-till has all kinds of benefits that are separate, obviously, from cover crops.
Jamie Duininck (20:45):
Over your career I'm sure you've seen a lot of farmers that have adopted these practices, many different practices, but we've kind of been talking about no-till and cover crops here. But as they adopt those, what kind of learning curve just on average do you see? Is it pretty quick where they're really satisfied with the results and that they didn't see a yield hit or does it take time on average?
Ruth McCabe (21:12):
That's a great question. It's been all over the map. Here's the typical story and then I'll tell you how there's all these exceptions to this, but there's a learning curve and you'll usually hear people say three to five years. That's what you'll hear people throw around, sometimes as much as seven years, where your soils are changing, especially when you switch to no-till. There's all kinds of stuff that happens with your soil that needs to adjust, that needs to change. There's all sorts of things that need to shift when you switch to no-till, and the research really supports this in the upper Midwest especially. I know in Iowa, and I've read some studies that also look at shifting to no-till say in Minnesota, and it's similar, but you can expect a yield hit for your first few years when you switch to no-till. And this isn't just unique to the upper Midwest.
(21:56):
I mean this is in other countries too, so this is worldwide. This is just an issue that you deal with. You're going to lose yield for the first few years, and there's a variety of reasons for that. When you use cover crops as well, it's the same thing. And there's research that supports this. Again, in the first few years when you switch to cover crops, you're probably going to have a yield hit, and that happens for a variety of reasons. It happens because you're new to cover crops and you don't understand how timely you need to be with spring termination if it's an overwintering cover crop. You may have gone too heavy with the seeding rate and now you have all this carbon on your soil surface that you didn't traditionally have before, and so now maybe you didn't use enough nitrogen in the fall or something, and so your soils need time to break that down.
(22:39):
So then your corn takes a yield hit, that's a big one. Or your equipment is not adapted to planting into the residual trash that's left from having a cover crop. So you get a lot of hairpinning and there's just a lot of things that can happen with cover crops that can cause you to lose yield in the first few years while you learn your system, while you learn the capabilities of your machinery, your own patience in the spring, and it's similar stuff with no-tills. You just got to learn and you're going to learn by losing yield and that stinks.
(23:11):
If you work with an agronomist who's really familiar with these practices, then your learning curve might be a little less steep because maybe that... No, for sure. For example, if you work with me, hey, I'm going to give you really conservative advice. The thing about farmers, and I love this about farmers, is they are just like "whole hog or none, man." They're like, "I'm going in. When I decide on something, I am diving in." I have some farmers that are conservative. They'll start small, but a lot of my farmers are like, "I'm all in on this." And I'm always the one who's like, "Whoa, whoa, whoa, whoa. Slow down, slow down. I want you to have a good experience with this."
(23:40):
So I'm going to be really conservative with my suggestions so that people have a good experience in their first few years so that it's not as painful so that they stick with it. Because what you hear about, and I've seen this too, as a farmer who makes the decision to go all in, they don't have somebody giving them guidance, somebody who has experience doing this saying, "Hey, you might not want to try that." Or, "Hey, it's going to be 50 degrees the next three days. You need to get out there and terminate that stuff now because it's going to be rainy and cold next week, and that stuff's not going to die if you try terminating it next week." Just somebody who has this experience.
(24:09):
They don't have that person, so they get for example, classic case, rye gets out of control on them in the spring. It's two and a half, three feet tall before they finally get it killed. Then they got to go try to plant corn into that, and they take a huge hit to their yield because there's all this nitrogen tie-up because it takes forever for the rye to decompose enough that that nitrogen's available to the corn. It's just this whole thing. So there can be steep learning curves or less steep learning curves. My advice is work with an agronomist who has experienced transitioning in those systems so that your learning curve is a little less steep.
(24:38):
But my one thing... I'll just finish with this. I am a conservationist. We work in the conservation space, and I go to all these meetings, very exciting meetings, lots of energy where you go to these conservation conferences and everybody's talking about how amazing no-till and cover crop were for their operations, and their yields are through the roof and their ROI is amazing. And it's like, "Yes. And how many years have you been doing it and you've been tracking those numbers?" And come to find out, "It's been 15 years since I adopted these practices and now everything is fantastic." And it's like, "Okay, yes." Once you get to that stage and you're experienced with these practices, you're going to be loving all the benefits from them. But there is a growth curve there and you're glossing over that.
Jamie Duininck (25:20):
Thanks for joining us. Tune in for the next episode of our conversation with Ruth McCabe.
