This is the Illinois Nutrient Loss Reduction Podcast Episode 79. Why you should use the in rate calculator, a presentation from the Annual Farm Assets Conference. I'm University of Illinois Extension's Todd Gleason. During the December Illinois Extension Conference, we were joined by a panel of experts: John Jones, a soil fertility specialist from the University of Illinois, Garish Nikke, an agricultural economist also from the U of I, and Laura Gentry of the Illinois Corn Growers Association. In an era of fluctuating input costs, costs, these three believe corn production is about maximizing profits rather than yields.
Todd Gleason: 00:45Today you'll listen to them break down how the in rate calculator and the Precision Conservation Management Program are helping farmers protect both the local watershed and their bottom line by finding that sweet spot for nitrogen applications. We'll begin with soil scientist John Jones.
John Jones: 01:05I'll show a quick snapshot of the core nitrogen rate calculator website on the left, some data from some or excuse me, not data, but sites for some of the trials that we're running this year. But this is really more of a reference slide of the snapshots from the core nitrogen rate calculator website, And this is really the landing point for the database that feeds into the guidelines that we communicate out of of University of Illinois Extension. You'll see the URL up there. You can select your region in Illinois, your previous crop, and then enter the price considerations for for corn and for fertilizer. You can do it on a per ton or per pound of nitrogen basis.
John Jones: 01:43And then that will kick out a an output that you see in the bottom left. There's also some graphs and figures and summaries. But, essentially, if if you haven't seen that before, this is the the default output that will occur. We've got some exciting projects to look at how we can refine that to a more granular scale, but not not necessarily have the data to to communicate that yet. But one exciting thing is that we really ramped up the data production side of of the amount of response to nitrogen data going into this effort.
John Jones: 02:12They're a little hard to see on the screen. There's supposed to be U of I orange, but you can see the dots across the state. Annually, in the past few years, we've usually ran under, the advisement of doctor Nafsinger and Dan Schafer with IFCA around 30 to 40 trials a year, and we really kind of ramped that up this year. And this summer, I think we ended up having about 91 response trials around the state. And I think that's a a pretty realistic number to continue on.
John Jones: 02:36These are a combination of on farm and small plot trials. About 85% of them are are on farm strip trials. So we're pulling data off of commercial scale investigations on nitrogen rates, some on nitrogen timing. And the idea going forward is we'll have some some pretty comprehensive reports for those individual farmers involved in the trials, but then summarizing some some regional data as well. So if you don't see a a dot around where you're farming, come talk to me and we'd, we'd love to work with you on on some on farm research.
John Jones: 03:08This is, again, a a table that I I think can maybe be referenced more in a discussion, but this is just output from the calculator. And it's in the context of specific anhydrous ammonia prices. We look at the the point five and, up to point, point five two range that might be considerable when we start thinking about spring spring, spring end prices. But this is some a different way that that data is summarized. So looking at moving from regions in the North, Central, and and Southern Illinois, previous crop, and then the pricing scenarios.
John Jones: 03:40One thing that you'll see is there's only one single value here that's communicated. If I'll go back and show the output of the calculator on the Mhmm. Bottom left of the screen here, you'll see a range. And that profitable range is communicated as a $1 per acre, range in maximum return to nitrogen or the economic return to that last pound of of n that was applied. So I'm not showing the ranges here in this table, but generally, they're about 12 plus or minus 12 to 14 pounds of of n on on each side of these values.
John Jones: 04:12If you've used the calculator in the past and you've maybe looked at it recently, one thing that we did so the numbers should change because we update them annually. And this year, we also started dropping data that was over ten years old. That was another change. Previously, it included data back to 2006, and we just saw thought some of the yield levels and some of the more cropping system components, and there were some odd years didn't really represent our our scenarios that we're dealing with now. So the data should look different in the 2023 moving into the 2024, and now we'll be updated eventually with the '25 data.
John Jones: 04:47Something we did drop was the continuous corn consideration for the southern part of the state. If you are growing continuous corn in the southern part of the state from the data that we we, at least have, and we don't have a lot of trial data, and that's why I dropped that that option in the calculator, was because the the data was over nine to ten years old, and I just didn't think it it was rigorous enough to to provide a a recommendation from. So we we recommend, and there's some language up there about following the corn after soybean n rate if you are growing continuous corn. But you can also, you know, advise that or or adjust that depending on previous previous crop production in your given field. This is just another way of showing those ranges.
John Jones: 05:30So if you can go from corn following soybean on the top, corn after corn on the on the bottom, north, central, and south. So again, it's just a different way of communicating those ranges. You'll see those n numbers. That's the number of trials that is represented in the output of the data. And I think that's that's probably one of the the strengths of this this process of of identifying optimal nitrogen rates and communicating them is that it's a very data driven process.
John Jones: 05:55So this is, I'll I'll say probably one of the higher amounts of N rate trials that that the any country any state in the country has ran to create a database that that we can that we can have some trust and and replicability of. These are just some other on farm research trials that we've got in our research group going into 2026. If you're interested, feel free to to reach out on those. I'll I'll say one thing on on p and if that's alright. But when when looking at our so one of the large efforts that we're doing is also working on updating phosphorus and potassium recommendations.
John Jones: 06:32There's large we've got a large network of of trials going around the state. And what we usually do with this as well is look at the yield response to phosphorus and potassium fertilizers, but also look at the ROI to the to those fertilizers and sometimes categorize that in different different crop price scenarios. And and the thing that that we're looking for is that this break even point, it matches what we're seeing and where we're plateauing yield or we stop seeing a yield increase with phosphorus or potassium fertilizers. I think this gives us a little more confidence in the recommendations and guidelines when we're comparing yield responses to an ROI consideration. So I'll stop there and we'll just have these slides for options before coming up.
Todd Gleason: 07:14And I want to take you back to some of the slides to begin First, if you want to find the in rate calculator search Google at in rate calculator. It will show up, There is you can do corn in ratecalc.org, but search Google for in rate calculator. I do have a couple of questions. Oftentimes, for our part of the world, it'll come up around one eighty five, thereabouts, a 185 pounds of in that need to be applied. What variables can a farmer input?
Todd Gleason: 07:47So can they input the price of in?
John Jones: 07:50Yeah. So there's there's four main variables that go into this. Your region of the state, your previous crop, the price of corn, and then the price of nitrogen fertilizer. So those are those are the input variables that that are Right. So living as the the calculator
Todd Gleason: 08:03is You can say, but I expect to raise 200 bushel corn or two twenty five and I think it'll be worth $4.20 cash and it will
John Jones: 08:12There's no yield number that's an input. So it's just the the price of the price of
Todd Gleason: 08:15the Oh, there's no yield number.
John Jones: 08:17Yeah. Because the we've we found that not a strong relationship between the yield at optimum end rate and the optimum nitrogen rate that's applied Ah, gotcha. Due to the colors of soil you see on the map. Okay. So you just input the price
Todd Gleason: 08:29of price of corn grain. And then it gives you it max it optimizes the nitrogen rate
John Jones: 08:36It shows the nitrogen rate that pays for the last bushel or excuse me. The the it shows the nitrogen rate that produces the last bushel that pays for the nitrogen. So the the last pound of n applied is paid for by the last bushel produced.
Todd Gleason: 08:51So it shows me a 185 pounds of n. Is that what I set the anhydrous rig to?
John Jones: 08:56That is not what you set the anhydrous rig to, but that would be what you you do that's a product base. But these are the pounds of n per acre. Right.
Todd Gleason: 09:04So so you're counting how you're counting n and what nitrogen applied plus what else?
John Jones: 09:11Nitrogen applied. So you you can you can also because you can choose your fertilizer source, it will give you a pound of product output as well. So if you see the pound of nitrogen applied for this scenario, the optimum end rate was $1.83 and the pounds of anhydrous would be $2.23.
Todd Gleason: 09:33Wait. Doesn't it
John Jones: 09:34This include this includes all of the n that's applied. So when when we look at the data set
Todd Gleason: 09:39When you see the $2.23, you have to subtract your map and dap and those things. Right? That that's that's what I was trying to get to. I'm sorry. I was getting there the long way around, I suppose.
Todd Gleason: 09:50But this is not the number you apply. That's the number you This
John Jones: 09:55is the number you apply,
Todd Gleason: 09:56but this is not the end hydration.
John Jones: 09:57There's only an end source indicator
Todd Gleason: 09:59there. Yeah.
John Jones: 10:00So this this kind of brings up another another ongoing effort that we've got right now to build a state specific calculator that has more options. And we're working with some other collaborators at U of I to do that so that we can maybe get a little more granular than just North Central and Southern Illinois, splitting things like prairie and timber soils and different soil associations. One thing about the data that's that's included here and interpret is it does count all nitrogen that's applied in the fall as MAP and DAP and your specific end source. And that the decision to do that is really comes from research results where we've compared the available end in fall and spring applied DAP, and we did not see a difference between those two or spring applied UAN. So the fall end could be counted on in your total end budget.
Todd Gleason: 10:47Okay. I know you'll get this question, so I'm gonna ask it. I'll ask you a question first. Who remembers the nitrogen formula for the state of Illinois? Anybody?
Todd Gleason: 10:57Oh, surely you. Some of you used it.
Todd Gleason: 11:02There it is. Yeah. I won't say it out loud, but that's that's the one I'm talk minus 40 pounds for and we always get asked, does the
Todd Gleason: 11:14The is there an in credit for soybeans here? And it doesn't appear to show up. Why?
John Jones: 11:18The the answer is that the change in available end, soil available end from a previous crop of soybeans and corn is already represented in how the data is interpreted. Because you click pick your previous crop, we have n rate curves or response curves to nitrogen for both scenarios. So when you pick your previous crop, we're already seeing how that corn would have responded following corn or soybeans. So the change in soil and availability after corn and after soybean is already represented in the dataset. We don't really call it this the credit the way that that the 40 or 50 pounds would have been considered before.
John Jones: 11:56Interestingly enough to the 1.2 number, I wish we just stopped talking about that
Todd Gleason: 12:00because most That's why I didn't wanna say it out loud.
John Jones: 12:02Well, most farmers, if you look at your end budget are nowhere close to that. And that's considering the output of this or not. When we look at on farm research, we're bouncing between point eight five and point nine five more more likely than not. And so, I I think we need to stop mentioning that that, that number in decimal and and go go off to some some results of of relevant data.
Todd Gleason: 12:26The first time I heard the point nine number was in the mid nineteen nine mid to late nineteen nineties, at some point, but we were well above that using still the old 1.2 formula at that point. Let's turn our attention to a long running research project now called PCM, Precision Conservation Management that the Illinois corn growers started to put together. I'm gonna let Laura give the history on this one with Gary Schnitke at the University of Illinois. But Laura, why don't you start with kind of the history and background about precision conservation management? This on the flip side is about nutrients coming off of your properties and trying to control them in some form and what might be the best opportunities to do that in a whole bunch of different ways.
Todd Gleason: 13:14Laura?
Laura Gentry: 13:15Thanks. Thanks, Todd. So everybody cast your memories back, back to the 2014 and think about what that fall was like. If you remember, and it was already referenced here once today, the Des Moines water works lawsuit. Does everybody remember that?
Laura Gentry: 13:32So that was happening in the 2014. And then there was also, who remembers the huge algal bloom on Lake Erie that fall, that late summer and fall? Does anybody remember that? When nobody could drink the water. Nobody could cook with the water.
Laura Gentry: 13:49You couldn't even give your dogs and cats the water. You couldn't they were warning you about even bathing because it was a harmful algal bloom. That was happening at the same time. The city of Toledo, Ohio at that time was under a do not drink the water ban for for a couple of weeks. There was just a lot going on in the 2014.
Laura Gentry: 14:12And back here in Illinois, we also had the Illinois nutrient loss reduction strategy was about to be released. It actually came out in July 2015. But we had all the stakeholders were engaged in developing that nutrient loss reduction strategy. And here at Illinois Corridors, we knew that that was going to be document that when it came out, everyone was going to be talking about it in the Midwest and maybe around the country. Because it wasn't just Illinois, there were a total of 12 states that had to develop the nutrient loss reduction they called them nutrient reduction strategies.
Laura Gentry: 14:49Strategies. Illinois is the only one that referred to ours as a nutrient loss reduction strategy, emphasizing that it's not that we want to reduce nitrogen, it's that we want to reduce the loss of the nitrogen and the phosphorus. So 12 states were doing this, so it was a big deal all up and down the Mississippi River at that time. And it was just clear that there were going to be long term ramifications from that document. And in response to that, Illinois corn and and a lot of other agricultural groups in in Illinois as well were thinking about how we were going to address water quality issues.
Laura Gentry: 15:30And Illinois, corn started a program in 2015 called Precision Conservation Management, PCM. And, we launched it in 2016 with the help of a regional conservation partnership program grant from NRCS. We got $5,350,000 to start that program. And, that was a ton of money back then. That seemed like a lot.
Laura Gentry: 15:56And and it was a it it it well it still is yeah if it's just yours it's a lot but we are now on the tenth year of PCM and the whole idea behind the effort of the Precision Conservation Management Program is that we work one on one with farmers. So every farmer who enrolls in the program has a a we call them a specialist, a Precision Conservation Specialist that works directly with them. It has a very strong data component. And these guys, I look at them because they both know very well all the different pieces that go into it. And we we sit down with farmers two to three times a year and collect data of and we put it into our secured data platform, our farmer portal.
Laura Gentry: 16:42And it includes information about your management decisions. So every farmer puts in information about every pass that they make across their field and the details of that in terms of what their equipment that they used were, what was the pass for, was it a tillage pass, a spray pass, planting, harvesting? And we assigned the equipment to that and the inputs. Were you applying were you spraying an herbicide, a fungicide? Were you, applying a fertilizer?
Laura Gentry: 17:11How much of the fertilizer? What type of fertilizer? And so it's it's got quite a lot of data points in there, but our specialists are there to ease the pain points of getting that that data into the program. So it's a very data intensive program. And every year in February and March, our specialists come out to the farmers in the program and deliver a custom made report to them.
Laura Gentry: 17:34A RAP report, a resource analysis and assessment plan. And that RAP report spells out all the different the data that we took summarized by field for that year in all previous years. And it shows it to them in terms of their tillage decisions, their nitrogen management decisions for corn, and their cover cropping decisions. And then it allows them to be able to compare their own economic decisions, their own economic outcomes, and agronomic outcomes with those of farmers who are near them, like in the same region. Of course, not by name or by field, but it's, at an aggregated and anonymized level.
Laura Gentry: 18:16The farmers can say, oh, this is my one pass tillage system with vertical till for my soybeans, and I wanna compare it to how farmers were doing who grew corn grew soybeans with no till or with two tillage passes. So it's a benchmarking type system. And what doctor helps us to do is to take an assigned cost for every single one of those passes that they make. We assign cost using data that he gives to us. And so the farmer can actually compare their their own net bottom line with those of farmers who are using other practices.
Laura Gentry: 18:55And so that's the big idea behind the biggest part of the Precision Conservation Management Program, helping farmers to make decisions, financial decisions about conservation.
Todd Gleason: 19:08Gary, how did you get involved?
Laura Gentry: 19:12Don't sound so impressed.
Todd Gleason: 19:16I was. I just wanted to get to Gary. I was just going to skip the rest of way over you.
Gary Schnitkey: 19:20So that year I did a sabbatical with Illinois corn. And that was one of the things that I worked on was helping develop the procedures for collecting the economic information with with associated with the PCM.
Todd Gleason: 19:39He went on vacation with Illinois corn for
Gary Schnitkey: 19:42a whole year. So that that you can look at it that way. Most people would pick a different place to go. Just just so just so we all know all know that.
Todd Gleason: 19:52Usually it's a sabbatical overseas somewhere.
Gary Schnitkey: 19:56Bloomington is a good place to go. Yeah, I was happy with that.
Todd Gleason: 20:02In the ten years of data, Gary, what are the most striking things you have learned?
Gary Schnitkey: 20:09So, well, we'll start with nitrogen. You know that MRTN, PCM would show that that is correct. That that 170 to 180 pound range is profit maximizing range. We do see higher yields occasionally above that and that's not every year but on average above that but additional bushes do not cover the cost of that. And that's particularly important now because you're gonna have four twenty corn and eight fifty anhydrous ammonia.
Gary Schnitkey: 20:55That's that's that's why I looked at that's the last value from Illinois production cost report. So you're looking at a relatively low cost price, high price input. So if you look at those those charts, John was using four fifty. I that that would be optimistic by my by my ag economist to look at things. The other thing that's really interesting, and by the way there's a lot of farms that apply well above that level and we're talking well above that level.
Gary Schnitkey: 21:36So we're not talking slightly above, well above. If you're higher than MRTN you're doing, this is the prediction that I would look at from that data. If you're above MRTN you're doing more tillage, more passes applying nitrogen. You're applying more fungicides and you're applying more herbicides. So and it the that's most people.
Gary Schnitkey: 22:11When you're above in one profit maximizing level, you're likely above in all of them. So here's what what I would tell you tell you is maximize profits not yields. And I would and you know there's only probably about only one person that comes out to your farm that suggests lowering inputs and that person won't but the person is the FBFM field staff who says cost matter right? The rest of the people we can spend $10 and we'll get an ROI of 150% and that's pretty much the sales and you add up all those sales pitches and we have inputs that are well above the profit maximizing levels. So maximize profits, not yields.
Todd Gleason: 23:13There's a lot of room for improvement. Did the ag economist in you put a number on how that dollar bill amount is per acre?
Gary Schnitkey: 23:23So, you know, when I it's significant and it and and again, we we see this all up and it's not just PCM, it's FBFM as well.
Todd Gleason: 23:40Farm business, farm management.
Gary Schnitkey: 23:40Farm management. You're in a commodity based business, Corn and soybeans primarily. Commodity based business. The way in a commodity based business producer differentiates themselves from the other people is lower cost. It's the only way.
Gary Schnitkey: 24:00So if you want to maximize profits, you have to have lower cost. And you know, if if you begin adding it all up, can get $40.50 dollars per acre pretty pretty quickly.
Todd Gleason: 24:14So it's about efficiency then, PCM is to some extent. About well, and Laura, about avoiding regulation in the future, think, is one of the had must have been one of the reasons that the program began to begin.
Laura Gentry: 24:33It was entirely the the effort around it and knowing what was happening with the Illinois nutrient loss reduction strategy being released. All the other black eyes for agriculture that were happening back in that period of fall twenty fourteen and 2015. It was all around concern of regulation, and and it was more than this idea that many people have about, you know, keep the government out of my business. It was about maintaining the flexibility that we had and, you know, we we had already lost a great deal in terms of other regulatory requirements. But this was about maintaining the freedom that we have to be able to respond to climate issues, to markets, to other economic factors that that we need to have some flexibility around, without the constraints and being hamstrung by onerous record keeping and regulations for around our fertilizer applications.
Todd Gleason: 25:28And and I think, but I'm not sure that this is the right timing. One of the things that came up at the very end of the policy section was the Des Moines Water Works and that was an issue. It was a scary issue at about that time. Am I right?
Laura Gentry: 25:42Oh, it was. Yes. That every everybody in every farmer in the Midwest was aware of the Des Moines Water Works lawsuit and was keeping their eye on it at that time. Every Ag magazine that came out had an article about what was happening with it.
Todd Gleason: 25:56John, I suspect you learned a lot about that over time. And you and your agronomist friends probably talk about the movement of nitrogen and other things through the water systems. How well and how easily does it move, and what happens when you over apply? We've got a
John Jones: 26:16leaky system by nature. When we look at the amount of water, nitrogen is gonna follow water in most cases, both up and down as as we lead to water induced volatile losses of of nitrogen into gaseous forms or if we lose nitrogen through through tile tile lines or if we lose nitrogen leaching through non tiled fields that tracks right along a fragipan. If anyone's in Southern Illinois and has, fragipans or or, or root limiting layers that are about 24 18 to 24 inches deep, water can track horizontally on top of those as well. And this is just an inherent part of the system. It's it's leaky.
John Jones: 26:59And one of the interesting things that, some myself and some colleagues have found when looking at what nitrogen is found in the tiles is it's not necessarily fertilizer nitrogen. The majority of that nitrogen is from organic and in the system that's been mineralized and then lost. We have a lot of organic matter in Illinois soils. We've introduced oxygen in many different ways and it burns up organic matter. That's also how our plants get get nutrients is that organic matter has to burn up.
John Jones: 27:29I think there's there's three things maybe related to to what we've talked about so far that I wouldn't wanna hit on. One is that interestingly enough in the if we're talking about yield levels at at different rates of nitrogen that are applied, the difference between the end rate that maximizes yield in a lot of our trials and they're they're very relatively high yielding trials when most when the the mean average is two sixty eight to two seventy two across a wide range of of soils in the state. It's about one one to two bushels is the difference between maximizing yield and then maximizing profit. And that's not always the case. Some sites the the bushels or the yield drops a little bit more when you get down to the economic optimum nitrogen rate but it doesn't vary that much.
John Jones: 28:18And in fact, that's one way that we check our dataset to see was this maybe an odd site year or odd trial as we look at the difference between the end rate or the yield that or the yield when it's maximized versus the yield that led to an, economic men rate. Two more things is that interestingly, we look at nitrogen losses and what nitrogen rates exacerbate that, we really don't see a big difference between, I'll say, 30 pounds of n applied. So if you only put starter n on versus the optimum n rate around one seventy five to one eighty. It's after that and the 30 pounds after that rate that we start to see an exponential increase in nitrogen loss. Interestingly, we see that the same way in phosphorus.
John Jones: 29:02The soil test level that optimizes yield with p, that between zero p applied is generally no no difference in p loss and surface runoff or through tile lines. And that was part of the work that I did in graduate school in Iowa. Speaking of the nutrient loss reduction strategy there, a lot of the research that fertility specialists around the Midwest have done is present in a lot of the nutrient loss reduction strategy targets and application or practice efficiencies. But with phosphorus it's the same thing. Not until you increase soil test phosphorus 20 to 30 parts per million past the agronomic optimum, that's when you start to see exponential losses of PE both subsurface and with runoff.
John Jones: 29:44So I think those are something to to think about and maybe it's not always talked about a lot is that agronomic efficiencies also usually parallel with environmental efficiencies and reducing losses.
Todd Gleason: 29:54Thank you. That is a really insightful thought. I I had not come across that one. In PCM, you talked about efficiency some, the number, Gary, of passes, tillage passes. First, I don't know whether and Laura, you may have an idea.
Todd Gleason: 30:16I don't know whether this is related to keeping nutrients on the property, probably is, but it certainly is related to efficiency and maximizing efficiency. Gary, can you talk about number passes and tillage passes that is?
Gary Schnitkey: 30:33So PCM regularly summarizes data and and we do it in no till, one pass, two pass, and two plus pass systems. You'll see that if you go to the business case for conservation you'll see that on the website. The one pass systems versus the no till systems will often have roughly the same profitability sometimes a little bit higher sometimes a little bit lower. There does appear to be a yield a bit of a yield advantage for one one pass sort of system when you go to two two and two plus pass systems we don't see an increase in yields and all you're doing is if you're not getting an increase in yields and we don't see a reduction in in herbicide or pesticide cost. In fact pesticides don't vary much depending on the the the tillage system.
Gary Schnitkey: 31:38You know if you're not getting a yield advantage all you're doing is adding cost. Mean and we're putting in every tillage pass will be roughly $15 an acre so you see sort of that reduction in, in cost or excuse me, in in returns.
Todd Gleason: 32:00And from the water quality side, how much difference does it make ore from we've had issues with wind borne dust storms as well in recent years.
Laura Gentry: 32:13Well, from the water quality side, and I I was gonna add this on based on on John's comment about it's that it's the extra you know twenty five thirty pounds that farmers are putting on of nitrogen that that insurance nitrogen that they're putting on be sure they're not leaving any any yield on the table it's that amount that they're losing that's coming out of tile lines and that is going to, if we don't curtail this loss of nitrogen leaving through our tile lines, is very likely to to result in in lawsuits or additional regulations, down the line. And and I don't say this to scare anyone. I don't say it because it's what anyone wants to see happen. I just it is the most likely scenario for the next line of regulation in the Midwest, is going to be around water quality issues. And this is what I think is so interesting.
Laura Gentry: 33:07Lowell Gentry, my husband, I should I guess say, but his work Central Illinois finds that the average nitrate nitrogen losses from tile lines is 27 pounds of nitrogen per acre. And you just heard John say that it's it's usually, and and I'm comparing myself, the MRTN values with what the average PCM farmer is applying, it's anywhere from well, there was a low number in 2021 farmers, the average nitrogen above the MRTN. It was only eight pounds. The average farmer only applied eight pounds above the MRTN that year. But in all other years, that value is ranging from 25 to up to 48, and that's the average, pounds above the MRTN.
Laura Gentry: 33:52And the MRTN works. It literally is it's a it's an economic model, and it does exactly what it's supposed to do. It it does predict the most profitable nitrate nitrogen rate. And in the PCM program, the only years where we have seen that it didn't work were in those years when the soil when the soil conditions were just perfect or the weather conditions were just great and the soil released more nitrate than it than it was predicted to. And in those years, the MRTN overestimated the amount of nitrogen needed.
Laura Gentry: 34:27It has never once, Todd, never once in the work that I've looked at, under predicted the maximum nitrogen rate. So farmers can feel like it's a good conservative estimate and very few farmers seem to believe that. And Emerson says it all the time, it's a conservative estimate. John, you, I mean do you feel comfortable with what I said there?
Gary Schnitkey: 34:48When you say conservative, you mean we're gonna get most of the yield.
Laura Gentry: 34:53Yes, I mean it's under, it's it's predicting a nitrogen rate that you will not be under applying nitrogen at the MRTN. That's what I'm trying to say. And if if you wanna correct or add to that.
John Jones: 35:05No. I agree with that. And one of the ways that we we show that in some of the data sets is you'll you'll see a percent yield achieved and it's usually at 99% when we think about these studies. And one of the the, you know, I'll say criticisms maybe of this approach is that yield isn't considered. We we talked about that earlier.
John Jones: 35:23But there's the the lack of relationship between yield and optimum nitrogen rate made up really caused by the amount of of nitrogen from our soils is the difference there. Now there's certain cases in the southern part of the state where you have relatively lower nitrogen mineralization rates or conversion to plant available. There's a little more of a trend between yield level and optimum nitrogen rate. One of the things that that I think is important though to to to break apart there though is that and what I just mentioned is that the yield level isn't necessarily kicking off any any need for more nitrogen. The question of does the plant does that corn plant need more nitrogen nitrogen when it produces more kernels is yes.
John Jones: 36:07But what we're finding is that the soil keeps up in many cases with that additional requirement of nitrogen. A corn now interestingly enough as well, what we're finding is reductions in nitrogen concentration in the grain as we've increased yields over time. So there's there's some evidence that our hybrids have become more efficient at using available nitrogen that's present as well. And so all of this is happening at the same time. One thing that's really interesting in the dataset is we look at the yields at zero nitrogen or zero to 30 pounds of n, which may have been the lowest nitrogen treatment.
John Jones: 36:44Those are increasing steadily over time. What's the difference? Breeding, really. I mean, lot of good things happen when you breed for higher yields. Things like nitrogen use efficiency, leaf angle orientation, everything like that.
John Jones: 36:58When you breed for higher yields, other components of that plant usually are optimizing themselves to to create those more kernels per per plant.
Todd Gleason: 37:08I've got a question. The one trip comparison, I fall strip till nitrogen. Is that one trip?
Gary Schnitkey: 37:15The question is till would be one one trip across the field, but and we would separate out. But, yes, it's one strip unless you're freshening it, and then you get two passes, but one one trip.
Todd Gleason: 37:28Other questions?
Gary Schnitkey: 37:29Yeah.
attendee: 37:31Okay. It's it's all well and good to do this, but are there any things coming down the pike to help us out? Like, we've been tissue testing. We're looking for something to to measure mineralization during the season, we can we been told spoon feed nitrogen through the season. Is there anything out there that we can say in April, May, June and see how the mineralization is coming?
attendee: 37:58Because this year, we raised 280 to 290 bushel corn on that same thing. And for no reason, it was dry at the wrong times and all that kind
Todd Gleason: 38:09of stuff.
attendee: 38:10So is there a way to figure this out?
John Jones: 38:15Yeah. So one of the things that we implemented this year so I feel production agronomy research are either coming from the top up or the bottom down. I'm a soil scientist by training soil chemist and soil. I also call soil fertility soil chemistry with dollar amounts. And and I think what what we've implemented this year in a lot of those trials, and we haven't got the data all analyzed yet from the yields, is that we're measuring soil nitrogen at different times to create a database to predict that.
John Jones: 38:40So the the, you know, the the soil testing for nitrogen kind of boomed and busted. There were certain states that ran pre plant nitrate tests, pre side dress nitrate tests. There was a presence of kind of an organic mineralization proxy of the Illinois soil nitrate test that exist for a while, but they've all boomed and busted. And and the the challenge has been if you're just measuring nitrate, that it's a very quick snapshot of what's available there. And it's more of a site characterization than you can say, you need to apply a 150 pounds from a 18 part per million PSNT pre nitrate sample.
John Jones: 39:20So there's work on that. I would say we don't have the tools yet to say this is the end mineralized. There's some efforts in modeling, and and that's really where we have to combine a lot of the work our group does, and we try to measure everything. We we're in the lab and in the field quite a bit collecting a lot of data. We're working with modeling teams like doctor Kaiukwon's group at at University of Illinois to say, can now can we start to predict that?
John Jones: 39:45My hope is that you take and this is, again, kind of pie in the sky moment, but I I don't think it's worth I don't I don't think it's bad to shoot for these things. Is that you start out with the the optimal nitrogen rate that's maximized profit in the last ten year dataset. And as you move to incur different environmental changes in a given year, that adjusts to consider what you're talking about. Did we have were we coming out of a dry fall where there happened to be residual nitrate? Usually, nitrate in, let's say, of 2032 got flushed out pretty quickly in 2013.
John Jones: 40:22That was why there was a big, I think it was the end watch program that that doctor Brown, worked on and, and Dan Schaefer and and Emerson did as well, looking at what was hanging out there. And my hope is that then as those processes are occurring that's leading to more or less soil nitrate availability, we can adjust that optimum rate. Are we there yet? No. Just the simple answer.
John Jones: 40:46But we're trying to come up with proxies and circuits to look at that.
Gary Schnitkey: 40:49Just just so we know, every time a spoon feeding nitrogen means more passes across the field. Everyone what's that?
Laura Gentry: 40:59Unless you're
Gary Schnitkey: 41:00Unless you're irrigating, which maybe. Every time you go past the field, there's a cost. Just just just remember that.
Todd Gleason: 41:11So I wanted to ask both John and well, you can jump in, Laura, on this too, but I think it'll be data that that Gary has worked with. Is there very much of a difference in when the nitrogen is applied? So whether your fall applies, spring applies, side dress, how how many times you make it pass. I I think I wanna I want John I've heard Gary's several times. So I John, what what what do you know about this and what does your training tell you?
John Jones: 41:41Sure. We've got a few papers in review on this and and we talked about this this summer at use efficiency conference. So one of the things that's interesting when we compare optimum nitrogen timings to when we'll say that corn plant is taking up seven pounds of N per acre per day is that the fertilizer timing research doesn't necessarily align saying you have to have your n you put your n on exactly when the the corn plant is taking that up. And that's because of what happens to fertilizer when we immediately apply it. It get a a little bit may get taken up by the crop immediately, but a lot gets mixed into the cycling of microbial biomasses or dead microbes in the in the soil.
John Jones: 42:22Your fertilizer gets immobilized pretty quickly. So the timing research is a lot more muddy. Now where there's some more clear trends, so a paperwork we've got in review right now is a comparison of all spring or all spring versus all fall anhydrous ammonia. What's the difference between optimum nitrogen rates and yield? We don't see any difference in yield between our optimum nitrogen rate being applied all in the fall with anhydrous and all the spring.
John Jones: 42:47Now there's some big big, risks to take with doing that, and I I don't think many people are putting all their all their n on in the fall anyway. But the the comparison is kind of a stark contrast. And there's about an 18 to 24 pound and optimum end difference or lower optimum end with the spring end. When we start to compare timings after planting, things get a little more muddy. In the southern part of the state where you can lose a lot of n by volatilization, let's say if you just surface apply UAN in dry conditions like this year, then it pays for getting it knifed in at side dress versus later Y drop where you're just setting it on the surface.
John Jones: 43:25Everything is always gonna be environmentally dependent on what that corn crop sees in a given year, but that's probably the the biggest challenge. And I think one of the things that's shown up in a lot of nitrogen timing research, and we've got a new project this year looking at that, that'll be on, long term across the state, is that getting at least half year end upfront usually pays off when we have those low nitrogen availability years. Now the challenge I think and what I'd like to see is our our ability to adapt as between planting and v six environmental conditions come about, then you can adjust maybe what your side dress rate is gonna be. Because in in in earnest, what what the major decision is is what your side dress end rate adjustment is gonna be. Whatever your base rate end is is is what it is for your for your whole farm maybe, unless you can start to vary that.
John Jones: 44:14So that's something we're looking a little more into is how do we really dial into not just total end rate recommendation but specifically that side dress end rate recommendation.
Gary Schnitkey: 44:23So in PCM we divide it up by fall, mostly fall, mostly pre plant spring, mostly post plant and then there's three way applications. Fall does not turn out to be the most profitable does not and the primary one of the primary reasons is the nitrogen inhibitor that goes on with it. And that's typically a 14 to $15 cost. So even though you're putting anhydrous ammonia on, you're adding that $14 to $15 cost. You go pre and post plant, we don't see much difference in our data, whether most is pre plant, most is post plant.
Gary Schnitkey: 45:14I would note that if you want to put nitrogen the least expensive way, put it on as anhydrous ammonia. And that has its own sort of issues. The three way did not, also did not have the highest profits. And one of the things that's going on there is you got three three three passes through the field. And the other thing, for whatever reason, the three passes through the field followed the same thing that they do a lot of other things.
Gary Schnitkey: 45:45So they also had higher nitrogen rates. So the the two so if we could find some three pass systems with MRTN rates, we might see something different than than we than we've seen. Those do have differences as far as losses, which Laura might want to say something about, but they're the obvious ones. The one thing I would say is don't forget that every time you go across the field, you're adding cost. So, you know, spoon feeding, three three passes, you know, every pass is a cost.
Todd Gleason: 46:28Any other questions out here?
attendee: 46:30Yeah. I attended your webinar about a year ago and some pulling data from that and I remember seeing Strips Hill wasn't as profitable as I thought it could be. And I was was wondering, like, if you're banding your p and k and your nitrogen and you're eliminating a floater truck pass and you're banding everything and maybe possibly lowering rates. Why are you seeing that as profitable as other?
Gary Schnitkey: 47:00Yeah. So I would say we need to do a better with our strip till. We always say this every year when this comes up, we do so when you're looking at strip till, there's a number of things that get thrown in there. Strip till and then the minute you add a freshening pass, those two things get in there. If you just do a strip till pass without the freshening pass, you're you're going to be comparable to a one tillage system versus a two tillage system.
Gary Schnitkey: 47:30For whatever reason, our strip tillers also tend to put on higher nitrogen rates. If we bring those back to MRTN, strip till looks looks looks better. So it's not the strip till is my estimation. It's what some people do in addition to the strip till, like having higher MRTNs, doing a freshening pass, or any of these other things. If you just did a strip till, come in and plant and stay with MRTNs, strip till will be comparable to the other systems.
Gary Schnitkey: 48:15We just need to make that more explicit in the data presentation. So that's your answer.
John Jones: 48:25I was just writing something down as Gary was talking about that. Last fall we did start a long term study at least three sites around the state at Urbana Monmouth and Ore Center. We'll expand that to two more sites this year comparing optimum end rates by tillage system. Strip strip till with fall chisel and a spring freshener compared to full width chisel and field cultivator and then, a no till system. The data from one year now we we need time to to see the tillage effects of some of these some of these systems, but the data from one year shows that the difference between full width tillage and strip till system there there was no change in the optimum nitrogen rate.
John Jones: 49:01No till was a little bit shifted off but some of the especially to the locations we had a little bit tough year with the dry conditions in the if anyone's recently converted any field to no till that's not usually the easiest first year and this wasn't in Champaign County doing that. But the the comparison between full width tillage and strip till, we didn't see any difference at those three sites following corn or soybean. They were they were similar. The previous crop changed the optimum end rate much more than full width tillage and strip till.
Laura Gentry: 49:31Let me get one more thing in there about strip till. Would we believe in strip till. And it's got a lot of great advantages from a water quality perspective. We know that that is is true when you especially when you when you band your phosphorus with it. So one comment that we're seeing, and I think this is important, is that not every year is created equal.
Laura Gentry: 49:54And what we've seen in the last two years with the financial environment being what it is with relatively lower crop prices, relatively higher input costs, especially nitrogen fertilizer. We've seen the farmers pulling back on their nitrogen rates with strip tillage. And in these years, these past two years, '23 and '24 data have shown that strip till has been some of the more strip till and no till both have been the more profitable systems even relative to like the one pass light. And I think a lot of this has to do with the just the popularity of these vertical till systems that happened around 2017, 1819. You just saw all these farmers.
Laura Gentry: 50:37We had a really high yields and farmers wanted to their residue, and they saw vertical till is a great way to do that. And they did well with it, but they were also they weren't going crazy with their input rates and some of the strip tillers were over applying some of their other inputs. What we have seen in '23 and '24 is that no especially on lower SPR fields, we've seen that strip till was I believe the most profitable system in '23 and '24 for corn production just in those two years. And then for high SPR and lower SPR, it did it did really well. No till and strip till did really well in those two years that were like this this client.
Laura Gentry: 51:16This I'm trying to be a fake economist now. But sort of the economic environment we find ourselves in now.
Gary Schnitkey: 51:23Just one more thing, we haven't mentioned this yet, but if you want to reduce nitrate flows from field, put cover crops from corn to soybeans and all the organic end that may be going into the soil, or excuse me, into the water, will be tied up by the cover crop. And that is quite certain from Lowell's work and everything else. And we can, with some CRP and other sorts of money make that a break even proposition. And maybe maybe longer term profitable with the right rate, but that that's one thing that to keep in mind. Corn to soybeans, cover crops, cereal rye on there, will sequester nitrogen and reduce nitrates in water.
Todd Gleason: 52:24Laura, I'm gonna have you wrap up. Two things I want from you. How many acres are actually in PCM and how do they get involved if they want to be?
Laura Gentry: 52:32Great. Thanks. So right now there's 660,000 acres in the PCM program. Right now we have a little over 600 farmers. We have between four hundred and four fifty in the state of Illinois.
Laura Gentry: 52:44And we are enrolling more farmers right now. So there is room in most regions for that we are in. By the way, PCM is not in every single county in Illinois. We're in about 52 counties in Illinois, so half. But if you want to see if you're in a region that we serve and you're interested in enrolling, we would we would love to have you or or farmers that you know.
Laura Gentry: 53:08And you can find the website @precisionconservation.org or you can reach out to anyone at Illinois corn growers and we will put you in touch with the right folks.
Todd Gleason: 53:17John, any final word from you?
John Jones: 53:19The the biggest thing right now, we haven't really talked about things like soil testing, to this point in the nitrogen discussion because usually soil testing isn't discussed, but this is a time when, we just talked about this at over at the soybean associations head headquarters yesterday that this is a time when you can identify parts of fields that really aren't gonna respond to applied nutrients or that really are going to need applied nutrients to to recover potentially lost yield and so it's really a good time that the ROI for identifying what your soils got in it pays off. Give me my final comment. Now Gary.
Todd Gleason: 53:56Gary, you have one I know.
Gary Schnitkey: 53:59Maximize profits, not yields.
Todd Gleason: 54:01Gary Schnitke is an agricultural economist from the University of Illinois and was joined on stage by John Jones, soil scientist at the U of I and Laura Gentry, water quality specialist from the Illinois Corn Growers Association during the annual Farm Assets Conference. Our presentation today from the Illinois Nutrient Loss Reduction podcast was produced in conjunction with Rachel Curry, Nicole Haverback, and Luke Swilling on University of Illinois Extensions, Todd Gleeson.