Legume Species for Cover Crop Mixes: What Each One Does

0:00 Let's get into legumes, plant family of Fabaceae, and it's not just for faba beans. All of the legumes are in this plant family.

0:12 And we might ask why legumes. Well, first of all, and many of you I'm sure would say, because of nitrogen. They fix, or they have the ability to pull atmospheric nitrogen out of the air and produce this nitrogen in the nodules in the roots for following cash crops. So we'll get into some of the individual species, how much nitrogen they can make, and different things like that, but that is one of the biggest benefits of legumes. I knew that, but I also utilized ChatGPT and that's what that said too, so now it's confirmed.

0:49 High protein forage content. So if we're talking about C to N ratio or just some high quality forage for cattle for hay, legumes can play a great role in that. We'll get some of that with some specific species. I guess I just already mentioned the lower C to N ratio, but not only for forage content but also for the ability to decompose quicker. The C to N ratio is really important when you're thinking about a mix or just a cover crop, you know, if it's an individual species or a mix, it might depend on your soil. If you have a really high functioning, high biological soil, you might be able to crank the seed to N ratio up, which would essentially mean just a higher ratio of grasses and maybe lower or not as many legumes or brassicas, that type of thing. But if you're just starting out and your organic matter and some other things aren't functioning as high as you would like to see, it might be a smarter spot to start out with a lower C to N ratio, which might mean a little bit higher ratio of legumes. Often times and that way you don't have lasting residue.

1:55 You want some lasting residue but not too much where it just doesn't decompose for years. So something to balance—not a perfect answer there, it's a little bit nuanced, but something to keep in mind that legumes have the lower C-to-N ratio, and then in mixes they're often a good fit for weed suppression. Hairy vetch is a great option for weed suppression as well as some other legumes.

2:22 Speaking of hairy vetch, very exceptional at nitrogen fixing—probably the best. I was going to say one of the best, probably the best at fixing nitrogen. And I should say the best reliable option for fixing nitrogen because its cold tolerance is so high that you can get it to reliably overwinter and fix a lot of nitrogen in the spring if you plant it say here in the fall.

2:45 Yeah, ability to fix you know upwards of 200 lbs per acre of nitrogen—is that going to happen every year? Probably not. If you only put 8 to 10 lbs an acre, are you going to fix 200 lbs? Probably not. But even if you fix 100 or 150, that's some money, that's some economics of cover crops at play there. So hairy vetch exceptional at fixing nitrogen.

3:06 Yeah, I mean this area, even up north of Nebraska, hairy vetch is going to overwinter no problem. Good weed suppressor—I mentioned that a little bit. Now I wouldn't want, you know, if I was full on going for weed suppression, I'm not just going to throw hairy vetch out there. I'm going to probably start with cereal rye, but I'd probably throw some hairy vetch in there. It can get a pretty thick stand. I've tried running through kind of our plots of hairy vetch and I didn't make it out without tripping. It's viny, it covers the ground.

3:42 Good part of a weed suppressing mix I would say, and then it pairs well with cereal rye. Speaking of rye, it pairs well in the sense that it shares kind of similar maturity days, and it roller crimps decently well with rye in the spring. Timing is everything with roller crimping so a little bit nuance there. There's not a silver bullet approach, but the potential is there to roller crimp it along with rye and have pretty decent termination.

4:09 And even if you're not roller crimping for termination, it does still pair well with cereal rye, just if you're spraying it out, decomposing, releasing that nitrogen before a corn crop for example. So it pairs well with rye, which is the most common cover crop, so that's an added bonus of hairy vetch. Common vetch is not as exceptional as hairy vetch in a lot of areas, but it does have some benefits. It's a lot cheaper than hairy vetch, and so if you're planting in the spring and you don't need the cold tolerance that hairy vetch has, common vetch might only have a cold tolerance of 10 degrees.

4:47 When we're talking about cold tolerances, I think Colton on some of his slides has some cold tolerances. Again, I keep saying these things are nuanced, but going back to what we talked about earlier today, it's more of an art, not an exact science. And so it's going to depend on a lot of variabilities. It depends on the year, depends on snow cover. Is it actually 10 degrees exactly that common vetch is going to cold kill? Maybe some years, maybe it'll be zero degrees but you have good snow cover, common vetch might survive, or 15 degrees it might shoot it out. So there's some variability in there, but bear with me: common vetch will not reliably over winter.

5:25 Maybe this far down south sometimes, but not as reliable as hairy vetch, but a cost-effective option maybe for spring planting, different things like that. Decent nitrogen fixer but not going to fix as much nitrogen as hairy vetch, but can still fix 75, 100, maybe 125 pounds, which is what we've seen with some tests. Then it's a fairly fast growing and it's widely available and cost effective, so there's common vetch for you—it's a common option.

5:57 Spring peas—spring forage peas—we really like these. Excellent forage, they grow very quick. They pair well with oats and other species. One of the most common spring mixes we do in March, April is spring oats and spring peas, then maybe you add a flare of something else in there too. That's one of our favorite things to do in the spring. Good biomass, good forage, good quality, fairly cost-effective option. Spring peas are 20, 25 cents cheaper than winter peas often times, so not as much cold tolerance as winter peas but a little faster growing and a little bit more cost effective.

6:50 We'll stay on forage peas. What I wanted to mention also was—I said there a spring variety, but even like spring oats that Davis was talking about, spring oats, spring peas, common vetch—probably more commonly planted in the spring, but they're often times a good option for the fall as well. They grow quicker than their winter variety counterparts, but they might not over-winter sometimes. That's not a bad thing—get plant some in first of September.

7:21 Have it grow for a couple months. It might die out but you're going to give you some quicker growth, so that might serve its purpose. So winter varieties are not only for fall and winter. Spring varieties are not only for the spring. That's just kind of something to think about there and not put them in a box.

7:38 But we'll move on to winter peas. Good fall and winter forage option, similar to winter peas, but like I said they don't grow quite as fast, but a very good option. And then they are more cold tolerant than spring peas. Mentioned that already. I will say with the cold tolerance on winter peas, that is definitely nuanced. It depends on how deep that you plant those winter peas. They can be pretty darn cold tolerant if you plant them, you know, two to three inches deep in the ground.

8:06 That doesn't work as well with a diverse mix because you don't want to plant clovers or turnips or even some oats, you know, three inches deep in the ground. But if you're able to plant your winter peas separately and you really want them to overwinter, especially if you're north of I-70, if you're in Nebraska, you can get some winter peas to over winter if you plant them deep enough. Around here it's probably more reliable. You can plant them still an inch deep and they may overwinter. I would say most years.

8:33 Easier to terminate than hairy vetch. Just not as vigorous in a lot of ways. A good nitrogen fixer. On average, probably a little bit less nitrogen fixed than hairy vetch, although we have seen winter peas in some tests fix over around 200 pounds per acre of nitrogen. Not going to claim that every year for you, but a very good nitrogen fixer, to say the least.

9:03 Lentils have less biomass than vetch. I think I had it on notes but I don't have my notes up here with me. I feel like often times vetch and peas are just always talking down to lentils and they're always saying anything you can do, I can do better. And to be honest, I might not disagree with the winter peas and hairy vetch kind of smack talking lentils. They're a great option, but anything lentils can do, probably something else can do a little bit better.

9:31 But I don't know, sometimes it's helpful to have a nice role player kind of on an NBA team. You can't just have five Superstar teams. We've seen how that works and even gets us in trouble in the Olympics sometimes when people don't just know their role and play good defense, spot up threes, that type of thing. I feel like that's sometimes how lentils are. They're not the breadwinner of the mix, but they play a good role.

9:56 So I wouldn't plant them by themselves, but I would throw them in a mix. They're fairly cost effective for how many seeds per pound there are, and a little bit goes a long ways with that. But yeah, less biomass, smaller seed size, so that can be kind of a nice thing sometimes. Pretty cold tolerant, especially the winter lentils. There's spring and winter lentils as well, but yeah, pretty cold tolerant. And then yeah, not recommended as a monoculture. That was my spiel on lentils.

10:24 Fava beans, also called fava beans or horse beans. I just learned that last night. I knew fava beans and then broad beans, so lots of different names for fava beans. We stick with fava beans. I don't know if we have a huge reason why, but fava beans, they're all the same thing.

10:48 Large seed size, so sometimes doesn't work well in a mix. Well, I should say sometimes it doesn't work going through your no-till drill, so that's something to be aware of. They can be quite a bit larger than even like spring peas or soybeans, that type of seed size. They can be double, triple the size of that pretty easily. There are some smaller-seeded varieties, not as widely available as I would like to see. So that's something to be aware of. That's one of the main reasons they're not as widely adopted as you think they might be for some of the benefits they have.

11:19 Very, very good nutrient cycling. I would say a lot of that reason is because they grow very quick, so that's a nice benefit to faba beans. Quick-growing nitrogen fixer, and so we had a question earlier today on the panel, you know, some spring options, any success growing cover crops in the spring if you don't have time to plant rye or vetch in the fall? If you're in that situation, and even before corn, I think there's some scenarios where you could plant some faba beans in the spring in March and still have quite a bit of nitrogen fix before a cash crop, before you need to plant corn. So that can be an option as well. Thinking of faba beans, quick-growing biomass as well, not so much of the forage, but for some nitrogen and biomass, I would say.

12:06 All right, I'm going to get to some individual clovers, but first I'm just going to talk about clovers broadly. So here's a picture of some crimson clover, but clovers in general, great pollinators, attract the beneficial insects, kind of fun to see pretty flowers out there. So we have them obviously in a lot of our pollinator mixes. So it serves a great purpose just with that great forage for wildlife.

14:15 We've liked having the Kentucky Pride on hand and yeah probably the cheapest, whether it's Kentucky Pride or other varieties, probably one of the cheapest clovers out there. And so a good option for a lot of different scenarios.

14:27 Clovers—I should have said when I was just talking broadly on clovers—this is one that goes long ways and you don't need to put, you know, five or 10 pounds an acre of clover with, you know, five or six or eight different species. You know, two, three, one, two, three pounds can go a long ways in a mix, especially with fixation balanza Clover, very small seeded. Now all clovers are small seeded compared to peas, but even within the compounds of clover, fixation Clover is pretty small seed, so definitely a little bit goes a long ways with fixation Clover.

15:01 But excellent cold tolerance. It has more cold tolerance than most other clovers, and so a lot of people have had some good success planting Clover along with rye and hairy vetch or along with hairy vetch to fix some nitrogen. And then it also—I think I had this in the note—great nitrogen fixer. I guess I didn't have it in my note, I apologize. It also is a good one for roller crimping. It's got more of a hollow stem than other clovers, and so, like I said, when it's paired with hairy vetch or rye or both, you can roller crimp it or easy to terminate before corn.

15:39 So some organic corn producers are using fixation Clover with vetch for fixing a lot of nitrogen. But fixation Clover also has a lot of benefits with food plots, with grazing, with interseeding, so it's been a fun one, kind of a high demand product. Great things out of the fixation balanza Clover. Those were all cool season species. Now we're going to jump into.

16:06 Warm season species and there's just a few of these so I guess I'm doing pretty good on time. Cow peas are probably the most common warm season legume that we sell probably for a variety of reasons. It's very, very heat tolerant. Now obviously all of these warm season species are going to be more heat tolerant than the cool season species, but even with the warm season species, cow peas are very heat tolerant. Most of them are grown for seed in Georgia, and so just their climate and their environment is just highly ready for whatever we can throw at them for our summers.

16:39 Very good forage, drought tolerant, good forage. We put them in a lot of grazing mixes at 4 lb, 5 lb, sometimes 8 lbs per acre with a few pounds of sorghum or millet, different things like that. And you got yourself a pretty darn good warm season grazing mix going. Cow peas are a great fit for that. I mentioned interseeded mixes, they're good option for interseeded mixes just because they vine up. Sometimes you'd want that, they vine up the corn stocks or whatever it might be in that situation. And if they're not vining up something, they can vine out, and so a pretty good ground cover, fixing pretty decent biomass, and offering some decent weed suppression as well.

17:28 Anything else to say on cow peas? Probably not. But one of our favorite warm season legume options is mung beans. Mung beans are a little smaller seed size than cow peas, a lot of similarities that mung beans share with cow peas. They're almost like, sometimes we say kind of the cousin of cow peas. Mung beans are a little bit smaller seed size but about the same cost per pound, but you only need half as much.

17:56 It's a little bit more cost effective. You could argue there's a shorter season for sure. I should be clicking with one talking, shorter maturity time so sometimes that can be an advantage but something to be aware of. So that's probably more times an advantage of cowpeas having a longer maturity time so they don't seed out, they stay higher forage content for a longer period of time for grazing or haying. But mung beans will grow pretty quick and offer a lot of the benefits I would say of cowpeas—less regrowth than cowpeas but still offer some good regrowth and then fast establishment.

18:37 So yeah, mung beans and sunchoke—so cowpeas, mung beans, and sunchoke are kind of the three staples I think. This is my last species I could have included fenugreek, that's kind of a small, that's kind of a fun warm season species that we've been playing around with this year that a lot of people have been excited about, offering some really good benefits. Probably should throw soybeans on here as it's a widely adapted cover crop, although you want to be careful if soybeans are in your rotation. But there are some good varieties of forage soybeans out there. Yeah, cowpeas, mung beans, and sunchoke is what we're talking about today.

19:11 So sunchoke you can see the yellow flower there—great for pollinating and for attracting some beneficial insects and things like that. High nitrogen fixer, high nitrogen fixer. Fast I would say. Sun hemp I would say more so than cowpeas can fix more nitrogen faster, I guess I kind of just repeated myself there. But good option for that as a warm season legume, deep rooted, much deeper rooted than a cow.

19:45 Pea or a mung bean or probably any other warm season legume. So if you're trying to break some compaction up, put some, yeah, some sunflowers or if it's the right time some radishes or other grass species for sure. For compaction you definitely want to have some grass species in there. But if it's in the summer, sunflower would be a great option to think about. That's also one thing to be careful of—not having too out of balance. So if you're planning, well, I suppose it's probably more of how long you let it grow more than how many pounds per acre you plant of sunflower. You just don't want it to get away from you because if it gets mature and has enough space to grow, it can get pretty woody, pretty stocky, pretty hard to control. You might have too much residue there that might cause some problems. Even stocky enough to like pop some tractor tires I've seen before. So something to be aware of—not concerning if you're terminating or grazing or haying or whatever you want to do with it early enough, but just something to be aware of with sunflower.

20:47 Hemp is deep rooted, decent biomass. I think there's a person there standing, and I don't think she's super short, so you can see the height of sunflower there. We love it for some of the deer mixes, although sometimes we're like, I think there's too much sunflower in these deer mixes—I can't see the deer. If you're a hunter, so yeah, some pros and cons I guess, but we like sunflower for its biomass. And I already mentioned the speed, or the fast and tall growth. And so those are some benefits of sunflower. Yeah, decent cost for how much you need in a mix. And again, I would just say point back to talking to one of us or going on the Smart Mix calculator for some of the ratios and rates. You know, there's all sorts of things that you can pick up on, but you know, you might plant 10 lbs of cowpeas in a mix, but you wouldn't want 10 lbs of sunflower in a mix. You might only do two, three, or four—that type of thing. Some rules of thumb we have there. But yeah, with that, I could have shared some more species like I mentioned, but we'll end there. And those were some of the legume species. And so with that, thanks for the time to share.