Spring Cover Crop Termination: Timing, Methods, and What Works

0:00 This is Davis with Green Cover and I'm here with my colleague Zach down in Kansas and it's April 10th, so where I'm at in Nebraska and where Zach is at in southeastern Kansas, things are probably looking a little bit different as far as greenup and the overall growth of cover crops right now. And so we just wanted to have the conversation. People are starting to get their planters out and switch to their commodity or their cash crops. Obviously, we've got a cover crop to terminate, and so we wanted to have a conversation about that today.

0:34 So Zach, as you think about the topic broadly of termination, what are the different factors that you think we need to be discussing? Yeah, when we think about termination, you know there are lots of different factors that we can discuss, but I think for our audience today we should just keep it simple and maybe like what time frame should I terminate my rye or my cover.

0:57 Crop, what other species do I have in there to terminate and deal with, because not everything is going to terminate equally. And then what is my moisture, what is my basically what's my context of my cash crop or my commodity that I'm going in. And just kind of get ready for that, and then you know to go into that methodology of what am I going to use, am I going to use herbicide, am I going to use some tillage, some roller crimping, mowing, grazing, you know, just bouncing it off of all different options.

1:31 Absolutely yeah, and the topic of termination in general and especially as we think about the method that we're going to use, it's important to think about this spring as we make that decision and execute that plan right now. But it's also really wise to be thinking about that well in advance of the next time you're going to be planting a cover crop. We often times start with the goals that we're building a cover crop mix for.

1:56 And then how it's going to be terminated because that's really going to differ. Then in the recommendations we give, for instance if somebody was using roller crimping as their cover crop, it would probably be important to keep that mix maybe a little bit simpler if it's roller crimping alone because we really need things to be at a similar stage to get the proper kill at that timing versus if it's something like plowing it under or spraying to terminate, those things we can be a little bit more creative with those mixes.

2:28 Yeah, absolutely. And then also, you know, pre-planning your days—Southeast Kansas we're supposed to be 80 degrees this weekend, which is great, stuff's actively growing during the day. But then we get a day like today where we're only in the mid-50s and we've got to consider that as we're going into our termination. And temperatures play a huge part in how well things will terminate, whether it be roller crimping or.

2:57 Herbicide, absolutely, yeah. We often talk about different chemicals needing a certain temperature range to really be taken in by the plant effectively to get that kill. Sometimes that is a factor when somebody says I sprayed this and it didn't kill it. Oftentimes the coolness of the temperatures is a factor there.

3:17 You mentioned though even on roller crimping that that might have an effect. Have you seen that on your place before? Sure, so it may not have the immediate effect on like while you're roller crimping it, but having a colder or more drawn out spring can push the maturities of those crop species back. So in your planning for roller crimping, if you know your date is May 1st on a normal year, it could push it back seven to 10 days pretty easily just because the spring was kind of drawn out and didn't have as many Growing Degree Days.

3:52 Yeah, that makes a lot of sense. So timing, just to focus on that factor.

3:55 For just a little bit, I think it's important to think about the timing in regards to the season that you're given, so not just the timing on the calendar but what has this season actually brought as far as temperatures and moisture because that's going to differentiate how that cover crop is growing from one season to the next.

4:16 I'm also thinking about timing from the standpoint of how long we let that cover crop grow before terminating might also depend on how familiar you are with cover crops, how long you've been doing it. I like to talk about the journey that people might be on with cover crops and the way you manage cover crops in year 1 is probably going to be different than the way you manage cover crops in year 10. And that year one, it might be a good idea to terminate much earlier than you may end up doing in year 10, just so that you can have a little bit easier control on it.

4:56 Now obviously we want to make sure that it's warm enough, see above with it topic that.

5:00 We just discussed but I think it is a little bit easier to start out with maybe a little bit less residue that you're going through and a little bit less aggressive cover crop. What do you think?

5:10 Oh absolutely. If you're just new to the situation and just learning how to manage a cover crop in general, it's definitely air on the side of caution. The other thing that comes to mind when you talk about terminating a little bit earlier, where I'm at I'm a big advocate of plant green. The reason I'm a fairly large advocate of that is because things just cut so much easier with the planter as they're green.

5:39 There's this middle stage between completely dead and green where that's where we see the majority of our issues happening. That termination time frame is very critical. The other thing to consider in the spring time is with the cool temperatures, even though you can get stuff killed it doesn't die fast, so a lot of times we

6:00 Need a lot longer than we think to get it completely dead and dry to go plant into. And then just planning ahead for that and not just waiting, you know, seven days. If you spray something seven days before you're planning it, this time of the year there's a really good chance that it is not going to be crispy dry yet and it can potentially cause some planting problems.

6:22 Yeah, that's true. Yeah, Nathan and I were actually in the test plots yesterday, so that would have been April 9th, planting into some growing cereal rye which was green and growing but it was pretty small in its growth still. It was enough to hold the ground, we were cutting right through. So it's like you say, we can't necessarily have that middle ground. We need to either have something that's dry and crispy or we need to make sure that we have something that's green and growing. And then we were planning to spray terminate that right after we had planted, before anything was up and growing.

8:00 Wouldn't trust that as a total method with grazing, but I think I certainly would want to utilize that cover crop, and especially where you can utilize it for forage while keeping the benefit in that field where it's been grown. So I think it's a great idea to still graze that and maybe it reduces the next termination method that you use, say for instance following up with some chemical. It might reduce a little bit the overall chemical that you have to use, but I would still have the expectation that there's going to be another termination method having to be used.

8:34 What do you think? Oh yeah, I think I would agree 100%. In some of these situations down here, you know, if you're going from forage to forage, maybe it's not concerning enough to do that, but you have to judge it off of your system and what it looks like. Definitely going into a commodity setting where you're planting corn or soybeans, looking into that next step of termination, definitely.

9:02 Beneficial right so I've got to ask because people often ask us maybe I've grazed it maybe I haven't but I need to go out and spray that cover crop what should I do?

9:16 That's a good question Davis. So it's funny we're getting ready to plant corn the next few days here on our own farm and I've got a few friends and neighbors say hey what are you spraying right now and I tell them what my PCA has recommended for me. And they're asking rates and you know that's such a weird place to be because every herbicide has right on the jug on the label the rate that's recommended for the species to use and you know that's always the best recommendation is to start with your agronomist see what they have to say and then follow the rate that's on the jug. We never want to go off label with that that can cause potential long-term problems for us.

9:56 Absolutely yeah sometimes when people will ask me that I can make some general recommendations.

10:04 If you're planting this next cover crop mix, let's say if we're going to terminate something and go into a cover crop, let's make sure we use a burndown and not have a residual that's going to have an impact when we've got a mix that has grasses and broad leaves. So we can talk generally about a burndown versus a residual, but as far as that exact product that we might use or the rates, like you said, agronomist and the label, those are the two resources that we really have to consult the most.

10:33 Absolutely, just to wrap it up a little bit, we've covered a variety of things. We talked about timing, we talked about comfortability or how long you've been at this and how that may factor into your termination plans. We talked about the method that we're going to use, whether we're going to try to graze that, whether we're going to roll or crimp, whether we're going to spray it, whether we're going to till it in. Are there any other things that we discussed there just to finish?

11:03 Just keeping in mind the diversity of your crops. The cover crop because like you had mentioned, roller crimping can affect the diversity, can affect the roller crimping but it also can affect the herbicide because not all cover crop species are equal. Just take that into consideration and essentially know what your plans are before you get to the field. When you think you have everything, just double check. It's never bad to give that last minute phone call and say, 'Hey, this is a species that I have, this is what I'm using to terminate. Am I going to get the results that I seek?' And just plan ahead for that. So much of cover crops is just management and planning and just being ready for it.

11:50 Right, and you said earlier context is everything. Don't use the termination method and timing that somebody in Kentucky is doing if you're in eastern Colorado. Moisture is a big factor and making sure that we've got the right moisture for the crop that we're going into. So context is everything. But as we get into termination season, we wish a safe and productive growing season for all of our customers out there, and if you need any help, give us a call.