How Does Fall Residue Impact Summer Nutrients?
24 Oct 2326 min 26 sec

What you are doing in the fall — from the combine pass until the calendar flips to the new year — can have a big impact on nutrient availability for your crops come next summer. XA’s Matt Swanson explains how the impact of tillage, residue degradation products, or cover crops affect nutrient distribution and availability for next summer’s crop. A great discussion on a subject you’re probably not thinking enough about in this episode of Cutting The Curve with Damian Mason.

Presented by Advanced Drainage Systems

00:00 How does fall or residue management affect and impact your summer nutrient availability? 00:07 That's the topic in this edition of Extreme Ag Cutting the curve. Welcome to Extreme ags Cutting the Curve podcast, 00:17 where you get a guaranteed return on investment of your time as we cut your learning curve with the information you can apply to your farming operation 00:25 immediately. Extreme ag, we've already made the mistakes so you don't have to. Managing your farm's water resources is a critical component to a successful and 00:36 sustainable farming operation. Advanced drainage systems helps farmers just like you increase their yields up to 30% with their technologically advanced water management products. 00:49 Visit ad s to see how they can keep your business flowing. Now, here's your host, Damien Mason. 00:57 Hey, they were talking about nutrient availability come summer based on how you managed your residue last fall. I'm recording this in the fall, 01:07 and this is probably a good time to talk about how you manage your residue so that you then get proper nutrient availability come next spring and summer. Uh, 01:15 Matt Swanson proposed this topic. He's my guest. Swanson is a, an, uh, an army veteran, a farmer, an Illinois guy, and he takes a lot of classes, 01:25 so he knows a lot of stuff. Um, he's gonna share it with us about this 'cause he says, we can build a program around your climate, your tillage practices, 01:33 and your herbicide usage in the fall that then will help nutri availability. Uh, come summer, we want nutrients in the summer. 01:41 Most people at this time of year, you know, combines are running Matt. Uh, we're we're talking about getting that fall application done, 01:47 maybe putting on some winter spraying, some winter annuals. Uh, some people go crazy on tillage, which you and I think is overdone. Uh, 01:56 but we're not doing it because we're thinking about nutrient availability come summer. Are we? 02:03 Uh, not usually. I mean, a lot of, a lot of the fall work that we, that we do now, especially fertility application is based on, 02:13 on getting it done, right? Yep. Which there is, there's a definite argument to be made for that. Um, but maybe we can tweak it a little bit to help us help ourselves out. 02:22 It's always kind of like go time, you know? Uh, farmers love the idea of going from neutral to road gear and, and the, you know, span of one day, oh, neighbor's planting, 02:33 everybody then runs the field, starts planting, oh, it's time to harvest. Gotta go a hundred miles an hour. Are we doing something wrong in the fall? 02:40 Getting the crop harvested is a priority. Uh, are we doing something wrong? Are we rushing it? Are we doing something wrong with the residue part of it? 02:51 This is stuff we never thought about. Hell on the, you know, 20, 30, 50 years ago, get, when you're done combining, 02:57 done with the corn picker, you bring out the moldboard plow and plow it up. We don't do that anymore necessarily. What are we doing wrong? 03:05 Well, I wouldn't say that I hesitate to tell anybody that they're doing something specifically wrong because I don't understand everybody's climate. 03:14 I don't work in their situation. Right. But there are some things we can think about that kind of are us universally applicable in that it works the same whether we're in Arkansas or 03:25 Minnesota. It is just a matter of a adapting that system, right? Or that function or that biological activity to the climate that we're in, 03:34 right? So, take something like potash, for example. A lot of potash is applied in the fall in Illinois, and the vast majority of it are, are potassium fertilizer. Uh, 03:45 a lot of that potash, especially if we have a wet earth fall, um, releases outta the granule releases into soil solution and then gets locked up. 03:55 And a lot of times we don't see it again for quite a while. Um, so that's, that's just one example. Followed applied nitrogen being another. And, and, 04:03 and there are multiple examples of that. The, the one thing you talked about was tillage you, and I think tillage is overdone. Um, I, I probably am more, uh, 04:13 uh, opposed to tillage than most people in ag. Um, it does do the, it does do the job of getting the residue incorporated into the soil, 04:22 but also we know that it also then caused it to break down too quickly. And that hurts us for long-term buildup of organic matter. Yeah. 04:30 So tillage, essentially what we've relied on it for a long time is, is one, being able to plant in the spring, 04:37 which is a completely legitimate concern. Um, but also we've, we've used the mechanical breaking of that residue to make the nutrients 04:46 more available or release them out of that. And, and quite frankly, there's a lot of good residue management products that we spray on now that will 04:55 do a lot of the nutrient release portion anyway, and at least some of the plantability on their own without having to do the tillage. And I am not an anti tillage guy, but like you said, I I, 05:07 I think there's a judicious use of it and a lot of times we're over that judicious use of it. 05:12 If it's as easy as spraying a product on and it causes the breakdown of the residue Yeah. And then the residue is gonna be there come summer. 05:19 That seems like it's a pretty easy answer. Is it as easy as that? Yeah. So the, the challenge with releasing all those nutrients in the fall, 05:27 which is essentially what we're doing is that, that those released nutrients, we still want them available in the summer. So by having, you know, 10 years ago when we were, um, 05:40 leaving all that no-till residue on top, you essentially ended up with a slow release form of nutrients coming out of that residue challenge with the residue was that the 05:50 plantability and keeping soils wet in the spring and all of these other challenges, which are completely legitimate. Um, 05:58 so you kind of had a slow release form at least coming out of corn residue into the crop that was growing soybeans generally. Right. Um, 06:07 now we're using, or you know, we're using tillage now or we're using a residue management pro product, and those work really well to release the nutrients. 06:14 The flip side of that is that those nutrients releasing, they either have to be held in the soil and some of those mechanisms, 06:23 like the potassium mechanism for example, don't re-release it very readily. Um, phosphorus is less of a problem, but it becomes very surface centric, 06:33 which actually would be an argument for tillage. Right. In that case You mean because the phosphorus remains on the top and it should be down at the 06:40 root level, five to three to eight inches. That's right. So that would be an argument for tillage in that case is that we're gonna run 06:47 the, the nutrient management product Okay. That we'll call 'em. And there's five, at least five of 'em that I can think of right now that work. 06:54 Mm-hmm. Um, in the phosphorus case, you know, we don't really wanna leave that phosphorus on the surface. The stratification as far as plant uptake is an issue, but not as big an issue, 07:05 I think as some people make it, but as a very real erosion issue. Um, especially if you have any kind of slope to your ground like Kelly does or like 07:13 I do in a lot of places, having that phosphorus on the surface subject to erosion is a problem. Right. Um, and then 07:22 Well for two, first off, it's, it means that you don't get any value out of the phosphorus. No. If it aros you get no value out of it. Yeah. And, 07:28 And it, and it does. It's got an environmental, uh, There's a cost, environmental cost, Environmental negative, environmental negative, 07:35 and as well as an agronomic negative, you lost it got no value out of it, and the guy downstream or the lake downstream just got an overdose of 07:42 phosphorus, which is gonna cause all kinds of issues, algae, et cetera. Right. I mean, it as farmers, it, there's an economic cost to it immediately. Right. 07:49 We lost the phosphorus and there's a governmental or regulation type effect that's more long-term from losing that phosphorus. 07:58 So in that case, that would be an argument for judicious tillage. Right. So we don't want to clean plow at something like that, 08:05 but moving that phosphorus down, now there is a, there were other costs to this, and this is why you, when we talk about building a system, 08:13 you have to build a system that works and it's not probably going to be the same system across your farm unless you happen to fla out. 08:19 Everything you farm happens to be flat and black. Right. Or conversely, everything you farm is highly erodible. Right. So that's a different system. 08:26 But if everything's relatively consistent, then you can use the same system. But for me, you know, 08:32 we really look at three different systems as far as what the next crop is gonna be and what the soil or field conditions are. So 08:39 You base your system, Matt, on, on the soil type. 'cause climatological, you know, one of the things we talked about is climatological differences. You're, 08:48 you're not, your, your stuff's all within a county or two of western Illinois. So it's, it won't, 08:53 it won't have any appreciable weather or climatological differences. It'll just be topographical and, uh, soil type. 09:01 Yeah. When we talk about climate as far as building a system, it's just dependent on where your area is. You know, this, 09:05 the system that works for Matt Miles or the system that maybe should be applied in southeast Arkansas is different from mine, is different from, 09:14 Yeah. Okay. So the system, um, the system is, you're a big fan of products being sprayed post harvest to begin the degradation of the stove. Yes. And you do that just on corn? 09:29 We're not, we don't need to do anything on soybeans. 'cause there's not enough stuff. No. In, in my area in soybeans, the, the soybean residue one is, 09:36 is nitrogenous enough that there's enough nitrogen in it that it'll break down readily, pretty readily. Yeah. Anyway. And by and large, 09:45 unless your combine does a poor job of residue management, it's spread fairly evenly. 09:50 So that's not generally as big of an issue. Is that an issue anywhere? I wouldn't think that even, even if you were in a different part of the world that soybeans, 09:59 soybeans aren't typically a residue issue anywhere, are they? Well, I mean, the further north you go, 10:06 the more tendency to a cold and wet soil if you have a thick mat of soybean residue, 10:09 especially if they're late cut soybeans where the residue doesn't have time to break down more northern, so it warms up slower. It, 10:17 it could be an issue and you'll see guys do some tillage or, or something in those situations. 10:21 But I would argue that the residue management products would have a fit on soybeans in those areas. 10:25 And I wouldn't even say that they don't have a fit here in my geography, especially if they're after like a double crop wheat or they're double crop. 10:32 Okay. Although we don't do that much of that in your part of the world or my part. I'm in a weird geography where it's almost, 10:38 it's too short to do one and too long to do the other. Yeah, exactly. Okay. So, uh, you're a big fan of using the product. So from a management standpoint, come fall Yes. Right after the common, 10:49 do you have, we talked about this in a webinar. Do, and I don't think most people do have on their corn head those devices that shred or chop the stalks. 11:02 I know that Kelly Temple use those kinds of things, but I don't think they're common practice. Am I wrong? The, the stock stomper or, or the yetter devastator, the roller type situation? 11:13 Those are fairly common. Um, as much for tire damage as anything. Um, but there, there is a gain to having that residue in contact with the surface. 11:23 Okay. Because the biology can get on it, it gets going. Okay. Um, the stock chopping corn heads are not as common. Um, 11:32 we use a gearing off head that has, um, the way the knives are set up, it chops fairly small pieces. Mm-hmm. Use the calmer rolls, which chop even finer pieces. Um, 11:45 and you know, we've talked about in the, in the webinar, you know, the other guys like to to cut theirs as close to the ground as they can so they 11:52 get more of that processing. Uh, honestly, I'm kind of the opposite. And then I like to leave the, the stubble portion mm-hmm. You know, 12:00 fairly tall because the tire at that point can push it over. Mm-hmm. But in our area, especially on the, what we call the planes of our area, right. 12:11 The, the prairie type soils, the open areas, the winds and the winter can blow that residue all over and you can end up with piles. Well, when we leave that the stubble high, 12:21 the wind never has a chance to get going fast enough to pick that residue up and pilot. So it kind of stays in between the rows. Um, 12:30 so again, this is a system that not everybody uses, but there's a very definite reason why we use it. Leave the stubble high catches snow, keeps the residue from moving. Yep. 12:41 But, um, you know, we have other options to do the other things, but that's why we run a, a, 12:45 a more aggressive role to have smaller pieces for the rest of it. Mm-hmm. All right. So there's gonna be someone that says, well wait a minute. 12:53 It doesn't sound like you're managing your residue. Hell, you're leaving a stalk out there that's two feet tall that doesn't seem like 13:00 that's beginning to break down or doing anything that's gonna help availability of nutrients come summer. In fact, it'll still be a two foot come summer. 13:07 It's just that it'll be knocked over. Yeah. So one of the things, so we, this is why it's a system, right? So we're using the residue management products and that's gonna help with 13:18 moving the biology up the stock essentially and hollowing it out. So it's basically just the cellulose on the outside. Mm-hmm. 13:26 Like kinda like park on a tree. And then the other part of that is without applying the excess nitrogen and things like that, 13:36 we're creating a system where we're trying to do good release but extend that release longer. Right. So the two foot stocks is a function of, 13:45 and they're not two foot, that's probably an exaggeration, but, um, it solves a purpose as to catch snow, catch moisture, 13:52 and to keep our residue in place so it doesn't blow into the ditch or everywhere else. Yeah. Right. 13:58 But we're using the residue management products to break those what's left or what's on the ground down quicker. 14:03 And then we use something like c a or fulvic acid to capture those nutrients so they don't get in our soils, 14:10 get tied up in the soil itself and become unavailable for the next year. Are we worried about preserving them? You know, 14:17 like we talked about the phospho remains on the surface that can get washed away if you're in a, uh, highly erodible or a a hilly environment, 14:25 obviously between, between the combines and the planters, there's generally some weather events. Yep. Uh, you know, 14:32 melt off of snow frozen ground. You and I both know from our part of the world, the worst thing in the world that happens is it's hard freeze down 14:42 a foot or two or three and then you get an inch and a half of you get a warmup and an inch and a half of rain, 14:48 it takes everything 'cause it's like hitting concrete and it takes it. That could be terrible, but that's not what you're talking about. 14:56 Of the stuff that's down three and four and six inches, what would keep it from being available come summer? Um, just leaching, normal leaching, 15:07 It's one of two things. Either it's become readily available through the use of a residue management product or tillage, one or the other. 15:14 And we didn't use something to tie it up without getting it tied into the soil itself. So like, let's take potassium for example. This is the easiest example. 15:22 So potassium leeches out stocks, whether we use a residue management product or a, or tillage or any combination above. Okay. 15:31 But what happens in in my soils a lot is that that potassium, because of the chemistry involved, which I'm not gonna get into it, it, it gets tied up into the soil colloids or the soil particles itself. 15:47 And a lot of times we never see it again unless it rains a lot. Right. So that's, that hurts our potassium availability late in the season. 15:54 So what we're trying to do with our, with the addition of the C C A, for example, is to keep it in a form that's readily accessible to the plants, 16:03 but is not prone to leaching and, and things like that. Okay. So that's why this is, that's why this is really a system. 16:11 Like none of these things on their own work. Well, like you just, you have to do a combination of them to get the best, the best outcome. Right. 16:20 In a situation, Matt Miles where he's in southeast Arkansas and his biology never stops with respect to the cropping system, you know, there's some challenges, 16:30 but he would be better off to, to let his residue survive as long as it can. Mm-hmm. Because the soils are very prone to leaching. Yeah. 16:38 Because they're very sandy and that residue or the biology is never gonna stop functioning. So he's gonna be releasing nutrients all the time. 16:46 If he could find a way to preserve that residue and still build beds and stuff like he does need to do for cotton, 16:52 which is a completely little legit reason to do that, you know, he would be better off. 16:56 So his system is gonna be different than mine and mine's gonna be different than Kelly's. 17:00 Yep. So you talked about herbicide usage, uh, as one of the things. So in terms of the, the system. Yep. 17:08 Is that just because if you're not tilling, obviously, and we again, you know, think that's gonna, 17:14 I think it's gonna be less and less tillage moving forward that we're just gonna have an winter annuals or something. Is this why? Yeah. So and why does that, 17:23 how does that impact nutrients in the spring summer? Yeah, so winter annuals, obviously the winter annuals, depending on how thick they are, are gonna take nutrients up. Now if they, 17:31 when you kill 'em in the spring, you're gonna re-release them again. Right. So this is just a constant overlapping cycle of all these processes. 17:39 So the herbicide is, is, there's probably a couple things to touch here. If you're gonna use a fall applied herbicide, 17:45 which we do because we have resistant weeds that are easier to manage in the fall than, than they are in the spring. Yep. Especially with the weather, 17:51 the rain and all the things, the issues we have in the spring. Um, then we want to choose, you know, if we're gonna use a cover crop, 17:58 obviously we need to choose a herbicide that's not detrimental to that cover crop. And that can start as, as early as the spring before. Right. 18:05 So we have to, if we're gonna use a cover crop, you know, there's certain herbicides that we don't wanna use depending on the cover crop 18:11 in the growing season. So, but those cover crops, for example, and I believe there's a fit for cover crops and I also understand that there's 18:19 some detriments to it. Right. But in the cover crop case, which is kind of directly related to the herbicide situation, 18:26 is those cover crops take up all those nutrients, they use them. Right. And then when that cover crop breaks again down in the summertime, 18:34 you get a re-release of all those nutrients in the top three, four inches, you know, kind of surface down. 18:40 So there's a way that we're using that cover crop as kind of an applied nutrient source because it's a kind of a slow release source. Again, 18:48 there's gonna be guys like, oh, cover crops don't work. They do, but there is another level of management to that as well. Right. 18:56 So the herbicide situation kind of revolves around two things you have to do. Your weeded management we've talked to on podcast before about resistant weeds. 19:05 Fall applied herbicide is a, is a key portion of that in my area. Yeah. And if you do cover crops, 19:11 you probably don't need to do fall applied herbicide 'cause the cover crop's gonna smother out, uh, and suppress the other weeds. 19:16 And then can you make the case that cover crops obviously are gonna help summer availability because then you let those go through the winter, 19:24 you terminate them using chemistry with a spring pass, presumably maybe right before the planter, maybe a month before the planter, maybe a day after the planter, depending on how you management system is, 19:37 can you make the case that cover crops retained until spring help with summer availability of nutrients more than, 19:47 I think more than people are willing to give them credit for. Um, and that's because of some, 19:51 a lot of the challenges that people have had with cover crops. Right. They maybe it's too wet. Yeah. Which in our case, 19:57 a lot of times the wetness under a cover crop is not such a big deal, but I understand that people's hesitance around that. Um, 20:03 and then there's the residue portion. A lot of the most widely used cover crops are things like rye and triticale that are very high carbon to nitrogen and they don't break down readily. 20:13 So it's no different than planting into wheat stubble, for example. Like in a double crop situation, they don't break 20:19 Down readily easily. Meaning even if you terminate them, there's still like a straw. Is that what you're 20:24 Saying? There's still an active resid, especially the longer you let it before you terminate it, especially with something like rye. 20:30 Yeah. It's tall Stub can be there all year long. Um, so there's nutrients in that rye stubble again, um, the residue management product in that situation, that's a, 20:42 that could be a spring application or a, when I terminate type application To you can put, 20:48 you can put in one of these multiple products like Loveland has extract or whatever, you can put that in with your herbicide tank mix and it, 20:54 you get two for one, it kills, it kills off the cover crop and it also begins the breakdown and therefore release of the nutrients. Right. 21:01 Depending on the herbicide. Something like Gramoxone, you wouldn't wanna put those management because the Gramoxone would kill the biology. Oh, right, right, right. But a lot of things yes. 21:12 Can be tanked next in the spring and you can, any of these residue management products that we talk about for fall use, they can be used in the spring as well and they'll function. They, 21:20 they function just as well. The issue with that is if you, if you're wanting to see plantability because the residue is more fryable or or 21:29 more brittle, you're not gonna see that obviously if you apply it in the spring versus the fall. 21:33 Right. Well, right, right. All right, get me out of this episode. What do I need to know then, uh, on the way out the door? 21:39 I think you've been really good about, uh, all of this and, and I appreciate when you said, I'm not into the chemistry here. 21:45 I think you looked at me like only because Damien, you won't comprehend it. But anyway, aside from that, what, what, what, um, what, uh, 21:53 what else do I need to know on this? So fall ma fall management of residue is a couple things. One, consider, you know, some alternate ways, you know, 22:01 guys like for a while we want to chop it all off at the ground, or we wanna do really shallow tillage, vertical tillage type situation. Well, 22:08 what we found in a lot of cases, or a lot of guys have found is that res then the residue blows all over that residue leaving your field is nutrients you've just lost. Okay. It's, it's gone. 22:17 That's money you've spent and you're not gonna get it. Well, Well, but to that point, Swanson, there was this idea that in the old days, 22:24 well, I don't care. It, it makes my field more plantable. And now I think the cost of fertilizer made us more, 22:30 you like to use the word judicious. I, when I started hearing people talk about vertical tillage, uh, I said, oh, it's a disc. No, it's not this a okay, 22:42 it's a disc where the gangs are straight instead of curved or, uh, on an angle, but it's a damn disc, which creates compaction, et cetera. 22:50 But the reason that you people liked it was because plantability, what you're saying is it made, it 22:56 Comes back to plantability and it It helped with the rotting down of stuff. Yeah. The vertical tillage umbrella got really big and it's, 23:04 they've kind of pulled that back a little bit, but a lot of the early vertical tillage tools were basically a damn disc. Yeah. Yeah. 23:11 Right. So appreciate that. So Yeah, uh, vertical tillage as a definite fit and of the tillage systems is probably one of my favorites, um, for a multitude of reasons, which don't have to get into. 23:23 But basically what I'm saying is we need to be really intelligent and deliberate about how we choose our fall residue management because it a hundred percent effects, 23:34 effects nutrient availability in the spring and summer. And it does it both in a good ways and in bad ways. So there's ways that if we're gonna use a resid management project that's good 23:44 for plantability, it's good for nutrient release, but we need to use something with it. Or depending on the soil type to make sure that those nutrients remain available 23:54 and don't just have the residue and go right down the river, for example. Yeah. So the tillage can be a problem because then the, the, 24:00 the nutrients go away, uh, the, uh, the the other. Otherwise it seems like pretty much everything else is just a matter of keeping everything where you want it. And 24:11 Yeah, I mean it's, you know, if we're gonna do aggressive shallow tillage where we detach all those roots or detach all that plant matter and it blows away, 24:17 then you've lost it there and that nutrients not available 'cause it's in the next field or wherever, you know, so there's a, there's a, and there's just, 24:24 it is just a selection of products. A lot of times it's always good to farm next to those kind of people. 'cause then you get their nutrients for free. Right. 24:31 Well, unless it's in a gigantic pile. Yeah, right. Then you've gotta manage, you gotta manage a bunch of pile of stuff. All right. I think that's it. 24:41 His name is Matt Swanson. He is an extreme ag affiliate western Illinois. Uh, he's, he's always got good stuff. In fact, 24:48 he's the one that proposed this topic. If you like this topic, you're gonna like a lot of the other topics we have covered, 24:53 not just with Matt Swanson, but with all the extreme ag contributors. Literally a couple hundred episodes that I have produced just like this, 25:03 hundreds of videos that these guys produce in the field or with me at events like the field days and what have you. It's all free. It's at Extreme Ag Farm, 25:11 extreme Ag Farm, go to Extreme Ag Farm. The stuff is there. It's, it's, it's amazing. 25:20 It's like a library that'll make you smarter about your farming operation and product trials, et cetera. Also, 25:26 we put on a webinar the first Thursday of every month. It's open to the public. You can come to this. If you're a member, you can watch the replace. 25:34 We make these interactive and informative and we cover a different topic. The first Thursday of every month at the Extreme Ag Webinar. 25:40 Be sure to be there. We'll remind you again on the way out the door. Loveland products has great products like for instance, uh, 25:47 accomplished Max that Kelly Garrett uses for stress mitigation and furrow. So next time he's Matt Swanson. I'm Damien Mason. 25:54 This extreme ag cutting the curve. That's a wrap for this episode of Cutting the Curve, but there's plenty more. Check out Extreme Ag Farm where you can find past episodes, 26:04 instructional videos and articles to help you squeeze more profit outta your farm. Cutting the curve is brought to you by Advanced Drainage Systems, 26:14 the leader in agriculture, water management solutions.