“We don’t have this all figured out. We need to utilize a big toolbox for nitrogen in a no-till system.”
— John Fulton, Ag Engineer, Ohio State University Extension
In this episode of the No-Till Farmer Influencers & Innovators podcast, brought to you by Crop Vitality and Thio-Sul, listen back to a popular episode of the No-Till Farmer podcast from our archives featuring Ohio State University Extension ag engineer John Fulton.
There is considerable interest among no-tillers in making fertilizer programs more efficient. One option is splitting nitrogen (N) and phosphorus (P) applications throughout the growing season to spoon-feed today’s high-yielding hybrids and varieties.
Fulton tackles this topic and discusses how new technology can help enhance delivery, timing and placement of N and P. He also unpacks environmental risks, agronomic response and application field capacity, as well as other general tips to consider for success.
If you are interested in more no-till history, you’ll find great stories like these and many more in the newly released 448-page second edition of From Maverick to Mainstream: A History of No-Till Farming that includes 32 more pages than the first edition. Order your copy here.
No-Till Influencers & Innovators podcast series is brought to you by Crop Vitality and Thio-Sul, the original thiosulfate liquid fertilizer.
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Welcome to the No-Till Farmer Influencers & Innovators Podcast, brought to you by Crop Vitality and Thio-Sul, the original thio sulfate liquid fertilizer. I'm McCain Vogel, assistant editor of No-Till Farmer. Today we are revisiting a previous episode of the No-Till Farmer Podcast from our archives, featuring Ohio State University extension ag engineer, John Fulton. Fulton discusses how new technology can help enhance timing and placement of nitrogen and phosphorus. He also unpacks environmental risks, agronomic response, and application field capacity, as well as other general tips to consider for success.John Fulton:
And I'm going to primarily talk about placement and timing. We don't have this all figured out. Nitrogen is a tough thing to... It's a year by year, field by field, week by week in some cases as we found out this year... But I do want to consider that we are in this change of public opinion about how we are better stewards of the land. And we're facing that in the state of Ohio, we know what's going on in Iowa, and we know these discussions are going on in many states around that topic. And so the way I look at it is we do need a big toolbox, and I think as we look forward, especially within the no-till systems, we've got to bring more of that P & N application in season. So that's what I'm going to focus on tonight.
So this is what we have to work with today, just in general.We know broadcast has been used, but from a best management practice today, it's basically where we see nutrient stratification, that kind of puts a little bit of risk on a no-till system, because in some areas a lot of the talk is if you apply it, you've got to work it in. And so we don't want to do that. But I don't see the idea behind broadcast ever leaving us, I think that's something that we're just going to have to have in certain conditions and we'll continue to see out there. But broadcast is one opportunity.
I'm going to talk a little bit about starter fertilizer. I think we're kind of transitioning from thinking about that from an agronomic perspective to a stewardship perspective. In the state of Ohio this year we saw a lot more use of starter fertilizer, but I think that just the opportunity to place nitrogen and phosphorus at the time of planning subsurface is a stewardship means, it's basically where we're seeing some of the stratification.
There's three things about starter fertilizer and I don't have all my data set to show you everything but there's three aspects. You can basically do a popup, which is just as an in-furrow delivery. We can do a two by two, or what is up there, called starter. The new thing that we're exploring and we see some benefit to is what we call a relay. It's a little bit of popup plus two by two. You think agronomically you at least got something there for the seed to take advantage of. I told you our best results this year, we're putting about 10 pounds of nitrogen, a little bit of phosphorus in-furrow on the two by two side. We were throwing anything from a 10 to 25 gallons out, Primary 28. I'll comment on that. But this relay thing, we saw a lot of benefit to it as we just think about that, you got some there in the furrow and then you got some that, as those roots developed, they've got an intersection point and then you can come back and use side-dress and possibly some late season from that perspective.
But relay's showing some real promise. We're getting some data in on that in several states that kind of bring that to the forefront. We got deep band injection, I'm going to call it injection a day, primarily because that's what a lot of the regulators like to talk about. But the idea primarily, in my opinion, that's for your P and K. Again, within no-till conditions, we're going to have to do a little bit of tillage, but I think there is opportunities in some cases to deep band P and K, and I'll talk about that. There's some other ones listed there. I'm going to talk about those today. But surface banded, incorporated, again, that's not something I'm proposing today, and then some dual-band. So the first three there I want to kind of walk through today and focus on.
But I want to back up, because I think we're really at a decision to point. All I'm trying to show here, this is primarily your nitrogen gas gauge over there on the right, showing where critical times or critical uptake is and as it related to corn. What I think what we're trying to do and think about is, "Can we start to move some of that nitrogen application out here in that, essentially a V6, all the way up to an R?" Okay? That's kind of where we're focused at. I know some people have gone beyond R, but I think V 10 or V fourteens they come in the sweet spot in a lot of cases where you see response as I look at research in general. So over here, I still think there's some opportunities for some pre-plant and maybe fall application of P, but we got to be cautious, especially in no-till, where we see stratification. And I'll come back and talk about where these opportunities with starter...
I think there's opportunities for some of you in some areas where you have high soil test values and you need a little shot of P, that the planter might be the opportunity to place that P under subsurfacely to reduce the environmental risk. But we can put that all in one shot with the planter. But the quarrel question I have is we know that split application continuously provides a value, provides profit to all of you, but are you willing to move from two applications, let's say an anhydrous and side-dress, a planter side-dress, whatever that might look in, and starting to throw in three. We were talking out in the hall prior to this, and some people were talking about four or five applications of the N. The question is, are you willing to take that risk? How do you build your nitrogen budget around that to really drive yield, but really profitability? Okay?
And so I think that's a question for a lot of growers. I think normally, most guys are putting at least two shots of nitrogen on. We know that's a benefit. The question is are you willing to wait in some cases and bring three shots in sometime after V8? V10 or V14 specifically in a lot of cases. So that's kind of where I'm at, talking from the starter to that late season. I'm going to start at the planter and we're going to end up at the planter. I thought Steve did a good job of making some comments about biomass residue management, and that's where I'll end up today. But we're going to start with the planter and see what opportunities are out there.
But one thing in common is we're seeing a lot of central field planters out there. Okay? I'm going to talk about what we did this year, some of the experiences we had. But I do, like I said, think that in some cases, growers have the opportunity, especially with high soil P, to put all their P in where you need a shot of P, and corn in particular, all with the planter.
This planter right here, we're set up for two things, and I'll show this in a bit. The front tank here is our starter fertilizer, and in the back, and you can barely see it, is basically our pop-up fertilizer in furrow. Okay? Again, I'm just proposing this as some idea around in those environmentally sensitive watersheds that this is kind of maybe a BMP that you can show against those... The public, essentially. So how do we get that? Okay, and I'm not going to show anything today about what these options are, but again, pop up, we're putting a little bit right in here, hopefully right in the furrow. It'd be great to put underneath, but consistently we haven't found a product that really gives us an opportunity to put that right underneath the seed, kind of put a little soil there and then put the seed down.
We haven't found something that can consistently do that, so it's really just something that's being placed in furrow on some of our setups. Our two by two, and again, I know some of you, or there's a lot of people that may not just do a two by two, it'd be a two by one or two by zero. There's a lot of different opportunities out there for that. But our idea, and you're starting to see this in the last two or three years being kind of promoted, is this relay, where you're actually doing some popup by the two. For our examples this year, again, front tank here is our two by two, you see it out front here, is what we're using to place that with, and then our popup was in the back tank. And basically that was just a two back there on the backside of the firmer, essentially.
On our popup, we were doing anywhere from about three and a half to three and a half gallons an acre, and depending on what we're doing from an all-farm perspective and what the grower preferred, we'd either used a 10-34-O with a little bit of zinc, 6-16-6 with one unit of [inaudible 00:08:22] in it. That was basically what we had to throw out there. On the two by two, anywhere from 15 to 30 gallons an anchor. Again, a lot of that's driven by what the preferred application rate was with the grower. Some of that was straight 28%. You're seeing quite a bit more the two by two going out at 28%, but again, we also saw some mixtures and put out some 10-34-0 mixed with 28.
The only thing I would say basically on this popup idea is to really watch rates. You got some salinity issues to consider there. You get your rates too high and that's going to influence emergence if not have a little death with that seed emergence. So you got to watch that salinity on the popup. In our data... Again, basically that was our delivery. There's some different ideas around this. One thing, I'll come back and show you and some of the imagery that we collected, when you start to put all that load on that toolbar, you get a lot of opportunities, especially in a spring like we had this year, for potential compaction. And we saw anywhere from a 10 to about a 32 bushel issue on those pinch ropes in behind a planter. And so that's something to consider at soil conditions. Even under our no-till conditions, you can still get these pinched rows occurring. You can throw these tanks on there, that's quite a bit more rate to carry besides having two full tanks there of seed out in the field.
So just some ideas to consider as you think about. So that kind of brings me to the next thing. We chose to put all ours on the bar. Okay, that's one option. We got tractor-mounted storage, and we also have towed carts. I sell quite a bit of towed carts. Typically, the carts are going to give you more capacity in terms of more starter that you can carry on board through the field.
I'm not going to go through all these different planter options. You got a couple good companies here providing those options here that are supporting the no-till. But again, I think you got to think about what best your planter is, if it's built for that planner. There's several of these products we've had a lot of success with. This year on ours, we were actually using what you would actually get with the Case planner in terms of delivery system on this planner. So this is something you can basically check and get right on the planter out of the manufacturer.
So with that, here's just an example of what was seen this year. And I'm not going to sit here and tell you that there was a tremendous amount of yield boost when we throw this relay concept in, but what I will say there is that you see definitely we saw a difference in crop development, the crop development stage. If you look at the difference between the one that... Basically where everything was surface applied to that, even in a relay, you actually saw an extra leaf or two in many cases. In most cases, you actually gained a collar or two. Again, both of these are selected on the same day, planted the same day, just different delivery mechanisms for nitrogen phosphorus in the case of starter.
And so that's just something to consider. The relay definitely was more advanced, but I'm not going to sit here and say that we saw a tremendous amount of yield advantage to that, because each of these plots also received side-dress and in some cases they see received both the side-dress in late season. So we're adding some extra nitrogen in there, depending on how the season... And I don't know if what I'm showing you here can fully explain some of the yield differences we saw, but definitely there's a difference in the growth stage of that corn that was consistent amongst the delivery system out there. I can say that for a fact.
From a side-dress perspective, again, I'm just stating what a lot of guys are doing out there, a lot of you're doing today. There's tremendous amount of benefit. Consistently, we know a split application with side-dress is profitable. The idea of putting that nitrogen below the surface, stirring that with a [inaudible 00:12:20], reduces runoff and leeching. That's a positive. Again, I look at that as a B and P that we can go back and show the public that we're doing good stewardship around nutrient management as released in nitrogen.
The most profitable end rate, though, I will say in any study that you can see, and you can see some of that, is it's just going to vary from field to field. And I'll take that out a year to year. And I'll kind of touch on that here in a little bit. But the idea here is that we're getting into split application, side-dress in all of our studies today, whether we're doing late season or not. Showed benefit at least in 2015 in what we were doing.
Talk a little bit about high clearance. That's what I'm going to talk about here for probably the next 15, 20 minutes. I think high clearance, we're seeing a lot more of these spreaders available, especially through the retail sector, cooperative sector. We're seeing this high clearance. It does give us the opportunity to come back and do some side-dress with things like urea later in the season, because we have some clearance there.
I would promote that one thing that we have seen in our research that the dual band delivery, in this case showing phosphorus and potassium in the bins, I can control each one of those better and I can get the machine probably set up a little bit better and be a little bit more uniform on delivery than I would if I blended those products and put them in one. There's some advantages to keeping them separated on a machine like this, but if we're just going to go out and do our urea, we have the opportunity to do there. We can do that later in the season and use it as a side-dress product.
We have seen good yield response. I think that's nothing new. We continue to see good yield response from broadcast P, but timing is important. I think when we look at some of the Ohio and we think about dissolved reactive phosphorus or DRP there, I think we really need to think about, when we're going out and surface applying phosphorus, whether that's fall, spring, and as it relates to some of these heavy storms events that we get. With stratification, we know that that can run off, and if you get into some of the science, and I don't know if I fully understand this, when we get stratification, we get high PPMP levels at the surface. They're locked up in that soil [inaudible 00:14:37]. We're still going to get run off of DRP or phosphorus in this case. And doesn't take very much.
Kevin King, I think, talking tomorrow and it takes a pound or two to have a significant impact on water quality. And so timing is very important to consider when we're doing broadcast P. We can't do urea mid-season. You see some research that shows that as long as we get some rain events, we get that worked in that there is some benefit to using urea. But again, I think you got to consider if we're going to deliver P and N or P at the surface and we got stratification, that's just something we got to consider. We could be adding to the problem, but if we consider some of the rains we've had the last few years, we might be adding to the runoff for sure. Okay, so just some things around that. But the dual band definitely can help in the delivery and the uniform application of P and K, based on our research.
So strip till, or what we'll call injection today, that seems to get a lot more interest when we use the term injection. I think there's been some positive research done in the last few years that shows profitable benefit of placing P subsurfacely. Okay? A lot of that is anywhere from three and a half up to a five six inch depth. It is banded. And I know there's a lot of concern, but again, if we're in a situation where we have stratification, this might be the opportunity to at least get some P down underneath the surface, reduce the potential risk of runoff. The only caveat to it in some cases is that before you jump into doing strip till, and you're worried about timing that, just think about field capacity or what we define as field capacity, the acres per hour that this machine can do, okay?
In some cases, it won't affect your fuel capacity when you start comparison, but there is a lot of cases that basically, by going to strip till, there are some benefits. But you're going to spend a little bit more money, because you're out there a little longer, a little bit more fuel usage, but fuel capacity is going to be reduced. So timing, if that's important on your PE management, strip till might be something to just considered. Do the math, do the cost comparison between them. I am an advocate of using RTK with this. I know there's a lot of other opportunities with things like SF2 with John Deere RTX. I think they can be good, but if you're going to strip till and come back and actually want to place that seed at the center of that strip till, RTK is going to be the only thing that does that consistently for you.
We can all argue, and I'm sure I can get examples people have told me about with some of the other differential corrections, but there is a potential drift, and there's been some research that suggests when you get out on the outer edge of that strip till, doesn't matter to the crop, you're going to have a yield reduction. So RTK, in this scenario, to me, you can run it on a strip till tractor and then come back and plant right down consistently down the middle of that row. So that's just my two cents on that, but if you want to consistently go out, RTK is a must.Mackane Vogel:
We'll come back to the episode in a moment, but first I'd like to thank our sponsor Crop Vitality and Thio-Sul for supporting today's podcast. It's as important as ever to ensure you're getting the most out of your fertilizer. Recent studies from Auburn University and Crop Vitality Show, when paired with a UAN solution, thio sulfate fertilizers slow down the process that causes you to lose your nitrogen into the atmosphere and groundwater. Visit crop vitality.com to explore the studies on nitrification inhibition. Check out the ebook, Nitrogen and the Thio Sulfate Factor, and learn more about Crop Vitality's thio sulfate fertilizers. That's cropvitality.com. And now, let's get back to the conversation.John Fulton:
Talking a little bit more, I'm going to spend some time on this, is the mid to late season. And I guess I'm going to advocate today. I've convinced myself, especially this year, through a several for our projects, and then looking at results across the country, especially here in the Midwest, and this idea about late season nitrogen application.
I think there's opportunity, there's profitability to be made, but there's some considerations with this. I think number one, you got to consider about machine clearance. Not all high clearance sprayers are made the same. But a high clearance, if you truly want to get the full benefit of nitrogen application, like I said earlier, a V10, a V14, some people are trying that afterwards, you're really going to need a high clearance machine. That's a 72 inch plus machine that are out there. But you're going to see a lot of machines on the farm lot or available that are only going to be that 52 to 60 inch. That'll work. I'm going to disagree that it will not work. But in our case, well I've had some machines that are 52 inch. I try and go out at a V10 or V11, I get to pulling stalks. Okay? More consistently than I will with a 72-
Inch machine. So hybrid selection and stalk strength really has a big thing to do with that. And so you get those machines that are a little bit not as high clearance, you are potentially going to have some issues with trying to do this consistently late season nitrogen application. It may limit you not able to get in there some of that late season. So anyways, that's just something to consider. In delivery system, I'll talk about this. I think there's three options: drop tubes, wide drop and nitrogen tool bars. So we'll talk about that here in a second. But then field capacity, I'll make a couple of comments on this.
In our case, at least one farm we work with, we were able to take a late season, a high clearance machine and basically equip it to do in nitrogen delivery. Okay? We made the decision to get rid of the side-dress unit and use that high clearance sprayer to do both side-dress, the V4 to V6, plus come in at late season, whenever we were going to come back in. So we're starting a V10, could end up around R, depending on the rain. But we improved our field capacity at that farm. We went from basically one day, earth... We doubled our capacity at that farm by using that high clearance machine for two reasons. We had more load that we could carry, gallons, on that machine, and secondly, we almost doubled the speed in which we could do that side-dress. We were running about a 12 miles an hour during side-dress and coming back and essentially doing a little bit slower than that in a taller corn, about a 10 in our case.
But the idea Darryl wanted me to talk a little bit about is, for that farm, we went almost three times in some cases what we could do. In one case, it took them three days to do a few of the fields, about 800 acres, and in one day, we covered that 800 acres. That's one example. One example. But going to the high clearance machine and adding a little bit more capacity and the speed to that machine greatly adapted it to some of the timing concerns or considerations around timing. So those are the three things.
There's differences here. I want them to just be clear on that. We see a lot of this talked about in the press, and I want to just make the comment today, there is a difference between rescue in and late season in. I want to talk about late season in, but rescue in is something we've done. That's not an intentional application. That's not something we've budgeted for. That's something we came in and basically added onto our nitrogen budget. Whereas late season in is something that we're going into the season... Okay? It's part of our budgeting, our application and we're going to do it. We basically potentially could be intentionally holding back some nitrogen to that late season application.
The question I have is, if you want to do late season, what's your risk level of trying to save some of that nitrogen later in the season? Okay? Are you willing to save back 10%? Are you willing to save back 20% and take the risk to apply it late season or in some cases 30% to 35%? I don't have an answer to that. I think the growing season dictates that too much of what we have. I don't know if I'm risky enough to go 25% to 30% at this time, but I will say that I'm willing to do something between 10% to 20% in most of the cases. Now we're going to continue to research this. We got a lot of other people in the country researching this. There are no answers today, but from a grower perspective, if you're going to do low late season nitrogen application, what is your risk tolerance level to save back some of that nitrogen and bring it back into those later stages?
I do think on the late season, and we proved that at least to myself this year, that there are opportunities to do variable rate nitrogen. The question is, how are you not only going to do all the zones in that late season? How are you going to define rates that you're going to deliver within those zones? There's our optic sensors out there, active crop sensors, Green Seeker is one we've used quite a bit on this. There are value to those, but again, there's quite a bit of management to make something like the Green Seeker. What we've been doing is basically a few shots of remote sense imagery at coming up, or during the growing season, tracking those fields that we want to do variable rate late season, track them, try and get an image prior to that or close to the time we're going to be out there in the field doing that.
We base our zones on that. We do some ground trucing to establish rates, and that's seems like a pretty good way of at least getting ourselves into doing some variable rate. For us, we've been doing anything from possibly a 10 to 40 to 50 unit application in the late season as an example. But again, that's just as some examples.
Late season in this year, again, I'll speak from Ohio perspective. I think late season this year, from a profitable perspective, was just a, "Yes, I'm going to apply. No, I'm not going to apply," in some areas. Had a lot of water, had a lot of rain, basically in May and June. There's just some areas that corn is just not going to respond, but there's other areas of field that had a little bit better drainage that were going to respond. And maybe I just want to throw out another 30, 40 units, and we did see some response from that and basically save their nitrogen in those areas that we definitely would not see any type of response.
So delivery options. There could be some other others out there, but this is what I say. I have not used the wide drop too much. There's a lot of interest around the wide drop, but we've done drip tubes. Drip tubes. If you have not tried a late season, you have a high clearance sprayer. It's a cheap and simple way to get into this, to evaluate it on your farm. And that's how we started probably six years ago when we started to play around with this. But the thing about that is, though it's cheap and simple, I personally think that you're going to move to something like a wide drop or a nitrogen toolbar.
There's a couple things to that. Number one, you're putting your nitrogen out there between the row, in this case 30-inch rows, and if it lays there too long, if you got a 4-, 5-, 6-, 7-day period, and it's just laying there, you may not get any rain, soil moisture's just not getting it worked in, there's just too much risk to volatiles on that. But I do think it's a great way to start. It's a cheap way to evaluate this. All I'm saying is that it can lay, and we've seen some issues in some of our studies that basically we lost that nitrogen, just cause it laid too long on the top out in the middle of that row. It just never got utilized effectively.
Wide drops, and I'll show a picture of that on the next slide, we're basically placing that on the surface, but it's getting right next to the row. A lot of interest. From a cost perspective, and again, these are just kind of retail costs, I can put equip a 60-foot sprayer with about $16,500. That's without insulation cost. And so that's about what it's going to cost you to get in on a 60-foot sprayer to do wide drops. Again, we're putting that closer to the corn. There's a lot more opportunity for that to be utilized, but again, it's going on the surface.
Nitrogen toolbar, basically there's two of them that are out there. Miller, who's been purchased by CNH, or the New Holland brand is basically providing that. That's very similar to, if you have not have been around, it basically has a [inaudible 00:27:30] or has an injection system on it, just like any side-dress unit or most side-dress units out there. The idea is, though, it's got a high clearance bar that gets you out there. What we saw, especially in our research, this really reduced the risk, risk of leeching and, in particular, emissions. Has a great reduction of emissions, especially late season, because it's a little bit hotter normally during that time we're putting it out there, and that was just us. To get into that, first of all, you're going to have to have the right sprayer. Not only a Miller or Haggy, the two companies carrying that, but you're going to have to make sure that model number can hook up to that specific bar as well.
New, a bar will cost you anywhere from about $38,000 or $45,000. That depends on width, what you want. You can get them used. There's some of the nitrogen toolbars, you can look around and get those used. There's somewhere between $20,000 and $25,000. It'll put you into having a nitrogen toolbar. There's the Miller, as an example, in the background. Between them and Haggy, anywhere from 26 to 60 foot. Okay? I have not run a 60-foot, I've run a 40-foot. It is a little bit different. They fold a little bit different, especially on a Haggy, you got it to come out front. But in the field, you greatly have the opportunity to run quite a bit faster. You're injecting that nitrogen as long as it's set up property, and you're getting a subsurface, again, lowering the risk of volatilization.
The wide drop on the left, we'll be running quite a bit of that this year. I think, again, that's an opportunity, if you got a high clearance, to get into this and consider it. So we'll see how that works out. And there seems to be a lot of promise, just looking at some of the data that's been being presented here this winter at different meetings. The question is... This is just based on our data. Our most profitable means of delivering nitrogen in 2015 in Central Ohio, based on our research, was laying some planter. Basically the relay I suggested earlier by a side-dress and doing a late season shot, about 40 pounds in this case. And so we were putting anywhere from around 40 pounds, 40 units, out with the planter. In some cases 10 units side-dress, really depending on the location, but the majority of that was going out at side-dress.
We did see some advantages to anhydrous, spring-applied anhydrous, plus side-dress and some late season. There was some profitability to be gained in that, at least in our research. My consideration for you all today is, as we think about some of the environmental issues that we're working with, I think a good starter package, followed by a solid side-dress application of nitrogen, followed by a late season shot of nitrogen... And in some years you might not be putting that late season out. It really will be dependent on the year. But I think that's the package that at least from a corn grower, based on some of our early data, is going to be the most profitable for you over time.
If we're going to go from this to variable rate, not only do you need to have the right technology and data in place, I think there's some things around consultants that need to be in plugged into this. I think you have to have experience with data management to make variable rate, basically this nitrogen thing, work out for you. That seems to be the consistent way that we've seen in our research. When we got a lot of people on the team making it happen, got a lot of ideas to bounce off each other, we can take some of this type of technology and make variable rate.
The one thing I would say, there might be some considerations about how do I achieve some of those rates when I do variable rate. If I use a fixed orifice, which is basically there in the orange, that's just an 0-3 nozzle. There are some opportunities to get me a little bit larger range out there. And so these are the kinds of things you got to think about. I was talking about some rates, per se, but what are you trying to accomplish with your variable rate program? Are you trying to go from 10 gallons all the way to 45 gallons, which in some cases I've seen people try that? You can't do that with a fixed orifice very effectively and meet the challenges of those rates out there.
So in general, and I just wanted to comment on this today, just because I'm getting a lot of questions. From a yield map perspective, I think that's a solid way to evaluate your precision ag program. Three things I'll leave you on today that I think that you need to think about. They're great for identifying management zones, especially if you have multi-year yield data and you begin to see some consistency. So they can really define some of your placement opportunities from a zone. Yield maps are great for P and K, and again, I'm pulling this from our literature beyond just our experiences, but P and K can provide, based on removal, is something I think that people should consider to improve their P and K management on a spatial aspect.
So this, in conjunction with sound soil sampling, whether that's grid or zone, with yield maps really I think is kind of becoming a best management practice. But one thing I would say, if you're going to use yield maps to define rates, I encourage all of you to cautiously use that. I think, again, going back from year to year, it's almost in some cases week to week, some of the decisions we might make around nitrogen. And when we're trying to apply, it's basically on a variable rate. Yield maps may be good to kind of begin to explore zones, but to define nitrogen rates, I just would be cautious, cautiously use yield maps.Mackane Vogel:
That's it for this episode of the No-Till Farmer Influencers and Innovators podcast. Thanks to John Fulton and our sponsor, Crop Vitality and Thio-Sul. A transcript of this episode and our archive of previous podcast episodes are both available at no-tillfarmer.com. For our entire staff here at No-Till Farmer, I'm McCain Vogel. Thanks for listening. Keep on no-tilling and have a great day.