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[00:00:00] Mike Howell: The dirt with me, Mike Howell, an eKonomics podcast where I present the down and dirty agronomic science to help grow crops and bottom lines. Inspired by economics.com farming’s go-to informational resource. I’m here to break down the latest crop nutrition research use, and issues helping farmers make better business decisions through actionable insights. Let’s dig in.
[00:00:39] Mike Howell: Well, hello again everyone. Welcome back to the Dirt. Spring is in full swing across most of the country. Everybody’s getting corn planted and we’re even getting a little bit of cotton planted down in the south. Everything is moving on quite nicely today. I thought we would bring in a guy that’s been on the program a time or two already.
He’s kinda new in North Dakota, but he’s been working for quite a long time. We’ve got Brady [00:01:00] Gale here with us today, and we wanted to have a little discussion about cover crops. Brady, welcome back to the Dirt.
[00:01:05] Brady Goettl: Happy to be here, Mike. I enjoy doing these talks as much as possible, so I’m glad you reached out to have me talk about cover crops again.
[00:01:12] Mike Howell: Well, we’re glad you’re here. First off, if you would introduce yourself to our listeners. I’m sure we’ve got some new listeners since you were on last time, and wanna make sure everybody knows who you are and what you do.
[00:01:21] Brady Goettl: For sure. Yeah. My name is Dr. Brady Goettl. I work for North Dakota State University as the extension soil fertility specialist.
Mike mentioned that I’m new in this position, but I’ve been around North Dakota for about five years now. Previously working in a research role and prior to that, spent some time working in private industry as a crop consultant and nutrient management planner. So I’ve covered a lot of different jobs in the egg world and I’m happy to be here. I enjoy doing it and really enjoy working with producers.
[00:01:48] Mike Howell: Brady cover crops is a topic that is in all the press these days. You look at the farm press and you see it everywhere. People are talking about regenerative agriculture and soil health, and this goes hand in hand [00:02:00] with that. I saw you give a presentation about it back during our winter meetings and thought it would be great if we covered the topic of cover crops today.
Make sure everybody’s on the same page on this. Before we get started, let’s talk a little bit about what we mean by the term cover crops. What exactly is a cover crop?
[00:02:16] Brady Goettl: Just like most things in the SOA Health field, everybody has a little bit different definition of it In my mind, in a nutshell, a cover crop is just something that we’re gonna grow in the field, not necessarily with the goals of harvesting, but with the goals of somehow improving our infield practices or preventing erosion, that type of thing.
Up in North Dakota, cover crops are really common as a way to try to prevent wind erosion from occurring. There’s a whole host of other benefits we can get from these crops, but we’re not going out and harvesting them.
[00:02:44] Mike Howell: Brady, what type of species of plants are we growing for cover crops?
[00:02:47] Brady Goettl: There’s a whole host of things that we can grow as cover crops, and fortunately, a lot of the crops that we’re growing as a cash crop on our farm can also be used as cover crops in certain scenarios up here in North Dakota.
Unfortunately, we don’t have a [00:03:00] terribly long growing season. So we’re fortunate to use quite a bit of winter rye. It’s a very cold, hardy, it’s airable to stand up to some of our North Dakota winters. Otherwise, if we start moving farther south within the country, that really opens up a lot of opportunities for other species, especially legume type cover crops, both the annual and perennial clovers.
As we start looking at some of the different grass crops as well, outside of winter rye, potentially looking at some of the wheat crops, otherwise getting into millets and all that type of things. Broadleaf crops such as sun hemp. Really the opportunities are endless and continually there’s new species that are being used or being evaluated for their benefit as a cover crop.
[00:03:40] Mike Howell: Brady, you mentioned the benefits here several times and mentioned a couple of the benefits, but are cover crops something that everybody should be utilizing? You know, if we read just a popular press these days, it sounds like that’s something that everybody should be doing. It’s a no brainer. What’s your opinion on that?
Should everybody be planting cover crops?
[00:03:57] Brady Goettl: I think there’s a lot of different benefits to cover crops and [00:04:00] there’s definitely one or another benefit that could fit into everybody’s operation, but cover crops are just like every other tool that we’ve got in our toolbox as farmers, sometimes it’s gonna work, sometimes it’s not.
A consultant I work very closely with says cover crops are like a pair of players. They can do a lot of really great things, but. Sometimes you just need a hammer. So to say that everybody across the country should be doing cover crops. That’s a hard statement to make, but I definitely think there’s opportunities or benefits that every operation could gain from ’em if it fits within their crop rotation and also their other management strategies.
[00:04:33] Mike Howell: Let’s get into a little bit of these benefits. We’ve mentioned this a couple of times already. What are some of the benefits to growing cover crops?
[00:04:40] Brady Goettl: When I think about my path into soil health and soil fertility, it really started out with controlling soil erosion. So always at the top of my mind, how can we use cover crops in order to prevent both wind and water erosion?
I think that’s one of the number one benefits that we can gain from covered crops. If we think about all of our annual cropping systems, we [00:05:00] harvest that crop. If we are doing fault tillage, for example, now we’ve significantly reduced our residue cover. But if we could go back out with a cover crop, help to hold some of that soil in place, that’s really the number one benefit I see in my mind.
Now we’ve planted that cover crop to try to control erosion. What other benefits are we gaining from that here in the Red River Valley of North Dakota? Generally in the spring, the conditions can be fairly wet. We can start having delayed planting because of saturated conditions if we have that established cover crop that survive through winter, so that cereal rye that I mentioned earlier.
That can help take up some of that water, provide better traffic ability. That’s kind of a secondary benefit from that. In addition, as we think of the people that are very involved in the soil health for soil health principles, specifically, having that living route, helping to increase biodiversity, some of those things aren’t necessarily measurable on the farm, but our benefits nevertheless, when we think about a healthy soil and promoting a healthy environment, a lot of the benefits I focus on are more on the agronomic side of things, and then of course the discussion on how can cover crops help change the amount and the rates of fertilizer that we need in some of our fields. Are we getting a benefit from that? Is it a drawback? That’s a big point of discussion.
[00:06:15] Mike Howell: You just said the magic word drawbacks, and we’ll get into the other side of the story here in just a minute, but.
I’m gonna show my age. Just a second before we move on. You mentioned using cover crops to help control erosion. And I’m old enough to remember the Soil Conservation Service and their big campaign, the hot program, hold our Top Soil, and that was one of the big components of that was always have something on top of that soil to keep that erosion from happening.
[00:06:37] Brady Goettl: Certainly, and like I said, that’s always been a big point in my career up to this point is let’s hold that top soil where it needs to be, and a cover crop is a good glue for making sure that happens.
[00:06:47] Mike Howell: So we mentioned the drawbacks. Talk about some of the drawbacks or concerns a grower may have about putting in cover crops.
[00:06:52] Brady Goettl: Having a little bit of a farming background myself and working on the dairy farm growing up, there’s just not a lot of time to go around [00:07:00] in some of these infield management practices. So in my mind, one of the biggest drawbacks to cover crops is just the extra work and effort it’s gonna take to plant that in most cases.
Is that outweighed by the benefits we’re getting from it? In my mind, I think so, but also it’s another pass across the field, more wear and tear on equipment, and then also the cost aspect of it, depending on the species you’re wanting to use as your cover crop. We could be as high as 30 to $40 per acre of seed input, depending on fava bean.
Some of those legumes are quite a bit more expensive, but if we play our cards right, we could really put in a very inexpensive cover crop. I’ve done a fair amount of research up here in North Dakota looking at using volunteer small grains as a cover crop. Barley, for example. Unfortunately, the nature of that beast is to have a fair amount of seed coming outta the back of the combine.
No matter how well calibrated our combine is, when we harvest barley, we end up losing quite a bit out of the back. So if we manage that volunteer, we can have essentially a zero cost cover crop, and that’s where I start seeing a lot of the [00:08:00] benefits from it. As we potentially go out there, do one pass of herbicide to control the broad leaves, and then allow that volunteer crop to grow.
We can get our surface cover that we’re hoping for from an erosion. Standpoint, we’ve now extended the season that that living root is in the soil. Instead of that barley being harvested in August and then having nothing until the following this year, it’s looking like May before we’re gonna have anything growing in the ground again, we can definitely extend that.
The downfall of trying to use some of those volunteer cover crops is in most cases, they’re not going to survive the winter or barleys or wheats, that type of thing. So it’s gonna be a very false specific. Some of the other drawbacks to cover crops, we can use them to manage water, but in certain years they can actually take up too much water and we can actually see a water deficit from that being really on top of that management.
Potentially if you have a over wintering cover crop to go back through and terminate that quite early in the spring to make sure it doesn’t use up. Too much water in certain years, and then greater discussion being had [00:09:00] now about are we creating green bridges for different diseases or different insect pests to carry through.
That’s a little bit out of my realm as a soil scientist, but it’s definitely a bigger discussion that’s being had right now as. Pest pressure continues to increase. Are we creating another way for certain pests to move into our small grains crops specifically if we’re very heavily relying on small grain cover crops?
[00:09:25] Mike Howell: Brady, you mentioned cost, and I know some places have some government assistance that can help you overcome that cost. Do you know a lot about that? Does North Dakota have government assistance programs to help out with that?
[00:09:36] Brady Goettl: Through the NRCS, there are pretty good programs for farmers who are interested in planting cover crops.
Additionally, some of the soil conservation services, both in North Dakota and then also on the Minnesota side of things as well in the Red River Valley, are also offering cost share programs for cover crops. So I think for the folks that are interested in doing cover crops, there’s a lot of good resources out there to help either financially launch [00:10:00] that or offer technical assistance to try to get this off the ground.
[00:10:03] Mike Howell: I know that cost assistance varies depending on your location. I’ve heard some places talking about they will cover nearly a hundred percent of it and some, it’s really negligible how much they will cover. So check with your local government agencies and make sure what’s gonna happen in your part of the world.
It may benefit you to put out some of these cover crops economically. Brady. One thing you didn’t mention, and I kind of wanted to throw it out there. Here in Mississippi, our environment is just a little bit different than what yours is there in North Dakota. You talked about these cover crops may or may not survive the winter.
Here in the South, we can plant just about anything and it’s gonna survive through the winter. It may not be the best quality in the world, but it’s gonna make it through the winter. We have a little issue with resistant weeds. We’ve got resistant pig weeds, we’ve got resistant grass species, Italian rye grass is a big one that comes to mind, and we have had to make a change in our production systems where we put out residual herbicides in the fall after we get the crop removed.
It’s gonna be really tough to make these cover crops successful if you’re putting out herbicides in the fall. Any ideas how we make it overcome that, or what’s your thinking on that situation?
[00:11:08] Brady Goettl: I think that’s a tough situation is my thinking on it. There’s been work done along the line of thinking of interceding cover crops.
So if we’re interceding cover crops in corn, for example, we know there’s certain herbicides that won’t damage certain cover crop species. So I think that’s one avenue of, depending on the residual herbicides that are being used, potentially there are cover crops that. Could overcome that to a certain extent.
Otherwise, just like I mentioned before, it really depends on what the goals are. If managing those weeds is the number one goal, the potential to use cover crops might get pushed down the road a little bit more. Otherwise, I know there’s been lines of thinking on using cover crops as a form of weed control as well.
If we can put up. A very high biomass cover crop, and then using tools like roller crimpers and that type of thing to create a mat of residue on the surface, potentially we could forego [00:12:00] those herbicide applications. And what do the economics look like for that? Potentially trying to manage that cover crop and roll it.
Maybe less expensive and equally effective as herbicide applications, but it just comes down to the management herbicide. Applications are a surefire way to kill weeds, but cover crops leave a little bit more up to chance.
[00:12:19] Mike Howell: I wouldn’t even go quite that far anymore with some of our weed resistance. I don’t think we have a surefire way, but I do think we could benefit from cover crops if we can figure out how to get ’em into the mix and keep ’em alive during that winter season.
I think it’s something we need a lot more research on, especially down here in the south.
[00:12:35] Brady Goettl: Certainly.
[00:12:35] Mike Howell: Brady, you mentioned that you’re a soil fertility expert, and that’s one of the things I wanted to talk about with cover crops. Do we need to add fertility for these species that are growing? Do we need to fertilize these cover crops?
[00:12:47] Brady Goettl: In most cases, when we think about growing a cover crop, we’re not really gonna want to go add additional fertilizer to ’em. We’re hoping that the cover crop can use some of the residual fertilizers that are there, especially when we start thinking about [00:13:00] nitrogen fertilizer here in North Dakota and across most of the upper Midwest and Great Plains.
Grass covered crops are king. They’re going to need nitrogen, but we can use that as a tool to try to capture some of that and potentially prevent it from leaching out from the system or volatilizing. If we have a wet year. When we start thinking about P and K uptake, it gets a little bit more cloudy.
There those discussions being had about, do we want to actually take up a lot of phosphorus potassium into above ground biomass? Is that opening the door for potential losses? And there’s a few schools of thought on that, and right now the literature is a little mixed in opinion on is it really best management to try to sequester some of that and cover crop biomass.
[00:13:43] Mike Howell: Let’s focus in on nitrogen just a little bit. A lot of people think cover crops and they automatically think about a legume cover crop because they’re assuming that that’s going to add nitrogen back to the soil and they won’t have to put out as much nitrogen fertilizer in the subsequent crops. Is that necessarily the case, or how does this work?
[00:14:00] Brady Goettl: I think it really depends on where you’re at in the world. Up here in North Dakota. Again, we just don’t have a long enough growing season to have a really successful legume cover crop up here. If we’re trying to plant something after the harvest of a cash crop, even if it has legume, we’re not gonna put on enough biomass to see any meaningful difference in the amount of nitrogen fertilizer that will have to apply the next year.
As you go farther south and potentially can have a very high biomass legume cover crop, certainly we could see reductions north of 40 pounds per acre of nitrogen fertilizer if we have a really nice successful clover or other legume cover crop. It depends on where you’re at and then. What did that year allow you to put on for biomass?
[00:14:41] Mike Howell: Talk a little bit about the nutrient cycling in the soil and in the cover crops. If these cover crops are taking up the nutrients, how long is it gonna take before those nutrients are available for the next year’s crop? Are we gonna be tying anything up and causing a problem that way?
[00:14:55] Brady Goettl: For that, I like to give my favorite extension answer.
It depends. The school of thinking for a long time really related back to the carbon nitrogen ratio. If we had a low enough CN ratio, we could assume that N is gonna be mineralized. We’ll see it available immediately that next season if we have a really high CN ratio. I think very mature cover crops, things that have reached physiological maturity are gonna have a high CN ratio and potentially tie up some of that nitrogen going into next season.
Through the research that’s been done here in North Dakota, Minnesota, Wisconsin is what I focus on most is there’s more to it than just CN ratio. If we start thinking about legume crops, for example, in general, those are gonna have a fairly low carbon nitrogen ratio. We’ll probably see a benefit of those next year.
Where I’m at in the world, we’re not really able to grow enough, like I said before, to make a meaningful difference. If we start thinking about small grain cover crops, the rise, the volunteer barley, like I mentioned before, those can still fall in CN ratio below that 25 to one is [00:16:00] kind of that cutoff we’ll think about for and mineralizing or and being immobilized, but we’re not necessarily seeing a benefit from that immediately the next year.
Research that myself and Dave Franzen, a previous soap fertility specialist here at NDSU worked on from 2021 to 2024. We looked at growing a small grain cover crop and then tracking and demanded crops after that to see if there has been any benefit from those cover crops. The first year, we didn’t see any difference, good or bad, whether or whether or not we had a cover crop.
From the standpoint of following crop yield, we know that we got a benefit from it from the standpoint of erosion control and increasing ground cover. Then as we start going in those same trials the second year, the third year, we start seeing small differences between the crop response, where there was cover crop.
Potentially. We’re starting to see some of that end mineralized two or three years down the road, but again, it’s in small amounts. We’re not necessarily seeing huge benefits from it. Even [00:17:00] though a successful cover crop can have anywhere between 40 and 80 pounds of nitrogen in it, and just the above ground biomass, we’re not immediately just seeing 40 or 80 pound reduction in nitrogen demand.
It’s kind of a mixed bag there. We’re not necessarily seeing we need to apply additional nitrogen fertilizer to overcome that uptake, but we’re not necessarily seeing a benefit from it either.
[00:17:23] Mike Howell: Brady, we’ve talked quite a lot about cover crops and the benefits and maybe some of the potential drawbacks. Is there anything else you think we need to cover before we wrap this up?
[00:17:31] Brady Goettl: I think the biggest thing that comes to mind is just remembering what are your goals for growing that cover crop. We’re not just planting it for the sake of growing a cover crop, but if we know we’re trying to do it for erosion control or we know that we’re trying to.
Reduce weed pressure, or we want to provide potential grazing opportunities if we have cattle in our system. I think knowing what our goals are for the cover crop is really essential to having a successful cover crop. Knowing what our goals are is gonna allow us to decide, one, how much we can spend. On that cover crop, if we know there’s going to be a monetary benefit at the end of it, we can potentially spend more on seed.
It can help us with the variety selection and then just also the timing for management. Anytime somebody calls me and asks about growing a cover crop, the first question always is, what are your goals? ’cause once we have a goal, then we can actually make a plan from there.
[00:18:20] Mike Howell: Hard to know how to get to the end if you don’t have a roadmap to get there.
[00:18:24] Brady Goettl: Certainly.
[00:18:24] Mike Howell: Great advice, Brady. Well, we really appreciate you taking time to visit with us today. Listeners, thanks for tuning in and if you will hang around for just a moment. We’ll be right back with segment two. Farming Isn’t Farming without questions and now. There’s a place to go for answers at economics.
An entire team of agronomists is waiting and ready to help for free. No question is too big or too small. Visit Nutrien-ekonomics.com and submit your question with the ask an agronomist feature.
Listeners, welcome back for Segment two. I’m really enjoying doing this segment with you this year. As you know, we are asking our agronomist questions of the week and for our ask an agronomist question today, we have Lyle Cowell with us. Lyle, welcome back to the dirt and remind everybody who you are and what you do.
[00:19:15] Lyle Cowell: Thanks for having me back, Mike. It’s always great to be on the dirt. Lyle Cowell. I’m the agronomist for Canada for Nutrien Wholesale.
[00:19:19] Mike Howell: This week, our question has to do with soil salinity, and that’s something that I haven’t had a lot of experience with, but I’m getting more and more questions about it. Even down here in the southeast part of the United States, it seems to be getting to be more and more of a problem.
But our question today is, what is soil salinity and what types of crops will do best in these situations?
[00:19:40] Lyle Cowell: Well, Mike, it’s something that we deal with a lot in Western Canada on the prairies, and it relates to just the high level of soluble salts in the soil. We could think of it as too much of a good thing because a lot of the salts in Western Canada are sulfates.
So we may have not just tens or hundreds of pounds of sulfate, but thousands of pounds of sulfate. These salts are iron pears. It might be magnesium sulfate, might be the dominant salt in our soil. There are regions in North America where it would be perhaps less value or less useful salts, such as sodium chloride, or perhaps other more harmful salts.
But in the end, it’s just an excessive level of salts. And these salts are predominantly being carried by groundwater. And as the groundwater moves up or down in the soil, you have these salts also moving up or down into the routing zone and into the germination layer of these top soil. And what do you do about it?
Well, there’s a wide range tolerance of crops into salinity. There are annual crops that have good tolerance to salinity crops like barley have better. Tolerance to salinity. Sugar beets are known to have a good tolerance to salinity. The problem is that annual crops have a time, time germinating on an annual basis in saline soils, and so we often then rely on forages.
Forages often have very high tolerance to salinity, plus they only have to germinate once that critical point in the growing cycle of a crop. Some manual crops can handle it, but in the end, in the ad theory, it’s often the salt tolerant forage.
[00:21:12] Mike Howell: Well, that’s some great advice on soil salinity. Listeners, we appreciate you tuning in this week.
If you have questions about anything we’ve talked about today, you can always visit our website. That’s Nutrien-ekonomics.com. Until next time, this has been Mike Cowell with the Dirt. Hey, guys, if you like what you heard today, do us a favor and share this podcast with someone else. It could be your neighbor, your friend, your crop advisor, or whoever you think would enjoy it.
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