Cover Cropping for Soil Health _ No-Till and Low-Till Strategies

Hey nerds, Farmer Jesse here. Today, let's talk cover crops and how to have a successful go at them, as opposed to, I don't know, like a an accidental planting of weeds. And at the end of this video, I'll give you my latest cover crop fail or pseudo fail. Anyway, you'll see, so let's do it. We learn more from our mistakes than our successes, right? Or at least, hopefully they do. I don't seem to learn anything. Before we get into strategies, let's briefly discuss what I'm talking about when I'm talking about cover crops. Cover crops are plants that you grow for a period of time with no real intention of harvesting them. Now, there are some caveats to that, to not harvesting them, which we'll discuss. But generally, you are growing the cover crop simply to replenish the soil, mulch the soil, provide fodder for beneficials and pollinators, or in some cases to simply hold the soil in place between crops. Done correctly, cover crops can be almost, if not entirely, all that you need for fertility and soil health, i.e. no need for any added amendments, but done incorrectly and they can become a troublesome weed that cools the soil and slows down your season or whatever. That is what we're going to try and help you avoid today. Okay, so there are four absolutely essential questions you need to answer before you plant a single cover crop. First, though, a word from today's video sponsor, our good friends over at Rimmel Greenhouses, who created this, our beloved North Point high tunnel, ridge vent, and all. My name is Bob Rimmel, and I'm the owner and founder of Rimmel Greenhouse Systems. Rimmel Greenhouses would like to thank you as a listener and viewer of their podcasts and videos, and we are a proud supporter of no-till growers. Rimmel support has helped us to create a lot of content, so I hope you will show them some love if you love this channel and our work. Okay, so there are four questions you need to answer before planting a single cover crop seed. Are you ready? Are you note-taking? Maybe note-taking would be a good idea. One, what is your goal with the cover crop? Two, what is the crop that is following the cover crop? Three, how are you going to terminate said crop? And four, how are you going to establish the cover crop you choose? So, let's go through each of those. First up, defining your cover crop goals. Determining what you want out of your cover crop is the first step to determining what the cover crop is going to be. Cover crops can do a lot of different things for soil. Say, your soil is compacted. The right cover crops can help break up compaction layers. Or maybe your soil is deplete in certain nutrients or soil organic matter. Cover crops can help replenish those, too. That said, if your goal is for the cover crop to help mulch, you may have to be more strategic than if your goal is simply to have the cover crop add some nitrogen through a legume, like field peas, which are good for nitrogen fixation, but don't themselves make a good long-term mulch. At least not on their own, because they're just very tender. So, let's get an overview of each goal and how to navigate it. The basic cover cropping rule for compaction is to use cover crops with deep tap roots, such as brassicas, like rapeseed, which no one feels comfortable saying. I have no idea why that continues. Brassica napis. Napseed. Everybody loves naps. Problem solved. Anyway, for decompaction, focus on crops like napseed, daikon or tillage radish, mustards, and brassicas like that. Both the large and fine roots of these crops can dig deep into the soil and help decompact the soil as they grow and then decompose. For nitrogen fixation, using leguminous crops like peas, beans, vetch, annual clovers, and so on, which are often inoculated with rhizobium bacteria, which you purchase separately, is the way to go. If the goal is a mulch, then grasses like rye, wheat, barley, oats, that sort of stuff, plus like sorghum sudangrass and other grain types, are going to give you the best above-ground biomass, as well as a lot of really good below-ground biomass. For pollinators and beneficials, flowering crops like buckwheat in the summer, or Lacey Facilia in the spring, which you have to sow in the late winter in our climate to get it to flower, which is Kentucky's own 6b, I will often throw some sunflowers or zinnias or cosmos into a summer mix, if it makes sense. In terms of goals, there is also biofumigation, biofumigation just meaning to get rid of a certain soil-borne pathogen with plants, using crops like mustards to help control, often like fungal pathogens in particular. That said, for those biofumigant crops to be most effective, the studies generally show that incorporating the residue of the actual plant after chopping it up is the best. So indeed, some sort of light tillage, but also you can just use ground brassicaceous seed meal instead to do that same, have that same effect if you're gonna work it in. And of course, blends of different crop species can not only increase biodiversity within the soil, but sometimes yield of the subsequent crop, according to some studies, and check the notes for some citations on all of this stuff. So what I usually recommend is to focus the majority of your cover crop on your primary goal, and add a few other crops that make sense in terms of your termination strategy for soil health and microbial diversity. Before we get into termination though, we have to talk about question number two. What is your desired crop that you want to plant following the cover crop? If you want to follow your cover crop with, say, like carrots or something you have to directly seed, a multi cover crop like rye may not be the best idea, because even after it's terminated, it will be challenging to sow anything into it. You may instead want something that does not create a heavy mulch, such as legumes and other, you know, broadleaf plants, that will either break down or can just be lightly raked off the surface before you sow. If you want to transplant thousands of lettuce plants, you may make the same sort of decision, because transplanting into a thick mulch is a lot of work. On a small scale, fine. On a large scale, that's a lot of work. If you're following a cover crop with something like tomatoes though, as we often do, then a mulching cover crop might be ideal. You might want that extra weed suppression, even if it means digging the holes for the tomato transplants requires a little extra work. Pulling that mulch aside and then digging a hole. Crop planting is perhaps beyond the scope of this particular video, but one of the biggest mistakes I see in cover cropping is when someone writes me in March or April freaking out that they are ready to plant their crop, but their rye or, you know, whatever cover crop it is, is still very short and not ready to be terminated. That comes from choosing the wrong cover crop for the following cash crop. And your options, if you goof on this, and that's okay, and you need that bed right away, are basically just tillage. Just know that I give an extensive amount of detail about cover cropping in the Living Soil Handbook, which, when you purchase it from no-till-growers.com, you also help support these videos. Again, answering these questions before you plant a cover crop is key, but so too is doing a little crop planning. Kind of can't do one without the other. It's like kind of like talking about peas and oats without making a holland oats joke, which I'm gonna resist doing. Probably. Essential question number three. How are you going to terminate your cover crop? Let's say you want to use a rye and vetch and crimson clover cover crop. It's a personal favorite of mine. Well, depending on your climate, that mix will likely not fully die over winter. So you will have to have a plan for how to kill it in the spring and also plan to not be able to plant into that area until later in the spring or early summer. For us, we usually can't terminate a cover crop like that and get the amount of mulch we want until late May. Meaning, if we wanted to plant early tomatoes into a cover crop like that, it would be tough to do so without tillage. As early as other people in the area usually plant their first field tomatoes around the 1st of May. Our cover crop's just not quite ready at that point. So, of course, make sure you consider those things. But anyway, back to the killing of the cover crop. On a small scale, you have a lot of no-till options. For one, you can smash the cover crop down either with a T-post like this or some other heavy object and then cover it with a tarp for a few warm weeks. The weeks have to be warm and or sunny or the tarp will not terminate. Like, you can't just throw a tarp over something in the, you know, February or March and expect much of it in most climates. And, you know, most of the United States at least. Now, you can use clear plastic for solarization for this if you don't have an opaque tarp. But watch the end of this video for, well, a warning about that. Also, to terminate a grain-based cover crop, you can wait all the way until the milk stage and then crimp it down with something very heavy, usually a specifically designed crimper. But if your timing is right, you can also use the stomp method or a very heavy pallet or in our case a power arrow with the BCS or whatever makes sense for you. The idea is to crimp the stem so the plant can no longer send energy to the seed that it wants to form. That term milk stage, that's when the plant is at its most vulnerable right before producing viable seeds. You do not want it to go past the milk stage where you may just plant some more of that grain. Let's do a quick milk stage breakdown because it's important and I don't know of many videos that really get into explaining it. But first, and let's use rye since I have footage of it and but this applies to all grains really, rye begins flowering when it is still relatively short, but the days are growing longer and warmer. For us, this usually happens in mid-April or so. Then the rye flower stalk will continue to get very tall and you will notice yellow things, things, yeah, I'm trying to be botanically accurate. You'll notice the yellow little yellow things hanging off of the seed head. That's the flowering stage and you will start to see pollen as you tap the seed head. When the, at this stage when you feel the seed head, it will feel crunchy, but you will not feel any seeds. Once those seeds, seed heads start to feel harder and fuller is when you're getting into milk stage. At this point, you should be able to squeeze the seed head with a dirty fingernail and a little liquid will pop out. That's go time. At this stage, milk stage, you can terminate a cover crop given your equipment is effective enough without tarping. I like having vetch in my rye mix as well because although it doesn't make a great mulch, it does help pin that rye down after you crimp it. Now winter is another nice way to kill a cover crop, cold weather. Crops that are sensitive to frost like summer cover crops or crops that are mildly sensitive like peas and oats can be killed by planting them early enough. We usually shoot for no later than like mid-September here in Kentucky, zone 6b again. So that the plant can put on enough biomass to cover the soil when it dies after a few hard frosts. Now one note of caution about peas and oats, if you don't plant them early enough to put on a fair amount of biomass, they may not die over the winter. Short peas and oats can survive the winter in climates like ours and then you'll have to terminate them in the spring kind of like the rye. If you have a strong enough mulching or flail mower or alternatively a scythe, weed eater or man eater, you can use that too. But mowing crops is more risky in terms of them bouncing back. So I usually suggest pairing that with a tarping for a few weeks. Mowing will also reduce the mulching effect. For more on cover crop termination, in fact, watch this video here. Sometimes YouTube doesn't put the card up here, which just makes me look ridiculous, which I gotta admit is kind of a solid gag. Touche YouTube. Final question. How are you going to establish the cover crop that you chose? Directly seeding a cover crop with a seeder is always going to give you the best, most even germination. If you can't direct seed with a seeder, broadcast the seed and then lightly rake and press it into the soil with some sort of roller if you can. A barrel of water is fine, whatever you've got. Seed to soil contact is essential for good cover crop establishment and germination. You just want the seed to be covered in soil in some fashion. It doesn't have to be deep, it just needs to be covered. And if it's dry, you should water it in. It's not just going to germinate on its own. It does need those other things. Broadcasting the seeds onto the surface, say for clovers, which do fairly well in that scenario, is a good way just to feed the birds and not feed your soil. The soil will have to be prepared in some way, like any other crop. You cannot just sow a cover crop into like a weedy bed or a pasture and expect much out of it. Some quick hitter tips here before I get to my fail. Inoculate your seed in whatever way that makes sense for you. That could be rubbing the seed with compost before spreading it. It could be priming it, as explained in this video. It could be both. Also, if the cover crop is not doing too hot, it just doesn't look good, give it a compost tea spray or two. Don't hesitate to treat your cover crop like a cash crop because how well your cover crop does is indicative of how well your subsequent crop will do. Also, I haven't talked about buckwheat much in this video. I love buckwheat, but I never sow buckwheat at the same time as other summer cover crops. I either use it solo or with something like mung beans, which grow fairly fast, or I sow it in a week later after I've sowed my original cover crop. So if I sow sorghum-sudangrass, I'll wait a week and then sow my buckwheat because buckwheat will just outrun everything. Lastly, for the quick hitters, I will mix in vegetable seeds sometimes, but just be mindful if you're gonna do this. You don't want to say add squash seed to a cover crop where you intend to plant squash later because it may inadvertently propagate a squash plant disease. But I will occasionally mix in salad turnips and kale into fall cover crops as a fodder crop. I like just mixing in a few things that I can harvest a little of. My mentor Eric Smith at Bug Tussle Farm used to just sow a whole field of like turnips and collards and kales and mustard greens and daikons as a cover crop and we'd go in there and just like harvest lightly off of them in the late fall. You know, all the way until it was really cold. It was kind of a cool use of space. It wasn't always the most efficient thing, but it was like a crop that you got out of your cover crop and especially on a small scale that makes a lot of sense. Okay, stay tuned until after the credits for my latest cover crop fail, but like this video if you liked this video. If you are not subscribed to this channel, make sure to hit the subscribe button. If you are subscribed, you're awesome. Want some ways to support these videos? You can buy a hat or a copy of the Living Soil Handbook from notillgrowers.com. You can join our Patreon page or just simply hit the Super Thanks button. Otherwise, super thanks for watching. We'll see you later. Bye. Okay, so I have used solarization to kill cover crops in the past, but I actually did it a few times. But I've never really loved the results, but it had been a while and I'm on a new farm. This cover crop here was still in the flowering stage when I needed to terminate it. So I was like, let's give solarization another shot. Why the heck not? Well, we're about to find out why the heck not. We crimped it down, which got a little messier than usual because I think the flowering stage for some reason made the rye bind in our clobber method a little more than usual where we run the power harrow, but just really high above the surface, thus clobbering the cover crop. Anyway, once the crop was down, we threw an old greenhouse plastic over top and pinned it down as well as we could. We left that for a relatively sunny week. And what we found underneath was indeed the cover crop was terminated or at least mostly terminated, but the soil was completely dry down to about a foot. I mean completely. The plastic had fully dehydrated the entire area. Now the explanation I have for why the moisture was not retained by the plastic is that this plot is on a slight slope. So what I imagined happened here is that all of the moisture was evaporated out and then moved up to the top highest corner where it just sort of escaped out of a loose end of the plastic. So in theory, a lot of good microbial work we did growing the cover crop was completely destroyed by the plastic. We had to really saturate the space to plant the tomatoes and we're looking at 10 dry days coming up here at least. So if you're going to solarize, make sure not to do so on a slope and pin the thing down on every edge thoroughly so it's essentially airtight or just maybe, I don't know, use the black tarp or another method instead. Now, for my walk of shame, bye.