Hello and welcome back to University of Minnesota Extension's Nutrient Management Podcast. I'm Jack Wilcox in communications with Extension.

Today we'll discuss phosphorus in Minnesota and in the Midwest. What's the current state of the phosphorus guidelines? What are some tips about phosphorus management and the four R's? And then, of course, some recent, as well as ongoing phosphorus research.

We have a big panel of four specialists today. Can you each introduce yourselves?

This is Daniel Kaiser, I'm a Nutrient Management Specialist with the University of Minnesota located out of the Twin Cities campus in Saint Paul.

I'm Jason Clark, I'm at South Dakota State University, I'm stationed at Brookings, South Dakota.

My name is John Jones, I'm an assistant professor of agronomy and fertility specialist at the University of Illinois in Champaign.

Hi, I'm Manbir I'm an assistant professor at The Ohio State University, and I'm based in Brewster.

Dan, you and your colleagues are working with the USDA on several issues related to phosphorus. Can you tell us about that work? I think it'll help contextualize today's conversation.

So the USDA project that I got, we have received funding. It's been a little over a year ago, and that's mainly to there there's, again, about three areas where I look at main main themes of the project. One is essentially is to put together a a joint regional project that we all look at the same thing. The other thing was to look at the removal database, which, there was some work back around, I think, 2015, 2016 when that when the last one was released, across the region, looking at, removal of PK and grain. So we wanted to start looking into that a little bit more, and kind of the thing that, you know, John, you've kinda talked me into is kinda looking at some of that metadata.

So that's I said one of the things we need to discuss, what exactly we need moving forward. And then, you know, really in the end was well, I wanna put together some type of white paper or extension publication or something that just talks about some of the terminology we use in soil testing to be more clear on certain things because there is meaning behind what we recommend. You know, particularly, you look at our soil testing categories, there's some meaning behind that. It's just a question of what that is. So that was a lot of the education I've been giving to a lot of my growers and consultants is a lot of the meaning behind that that wasn't necessarily put in place before, in a lot of our our bulletins that where people can start, knowing a little bit more about what we're talking about and hopefully answer some of these questions.

And, really, what I'm trying to avoid are situations where so this continual build situation where everybody talks about build, build, build, build, build because, you know, data really with fertilizer doesn't show where that's really a good option. So it's okay. What what do we mean by certain things that we talk about in our guidelines and how we think those growers can effectively utilize it? It's really been one of the key goals I want to get completed by the end of this project.

Dan, what are the state phosphorus guidelines like currently, and are they satisfactory?

Well, I mean, you notice we've got a few people from other states on here, and one of the things that we've all been involved in is a project right now to look at some of these differences among states and the guidelines, and that's always the one thing that does come up at times talking to people when I go across Minnesota as just wondering why we have some of the changes we do that occur at the state lines because the soils will cross state lines, but our fertilizer guidelines have historically been different, mainly been because of some of the historical research and the people working at these locations in terms of their thoughts and how phosphorus should be managed. So it's one of the the things that we've been trying to look at with this new project is to look at how consistent things are across the region because in many cases, I mean, really, the philosophy is the only thing that that differs, and there's a lot of similarities between a lot of our data. So that's one of the, I think, the challenges. I mean, the other thing too is with soil testing itself is recommended test methods across the regions do vary, and that's I know another issue, and I hear that more from NRCS than anything else, you know, wondering why we recommend certain things and not others.

So it was a good time, especially with some new faculty coming in. Gerber Singh, who's in University of Missouri, couldn't make this this podcast recording, but he's also been involved in that. So we've got, six states right now looking at, doing a similar project across the region, looking at this. And a lot of us are also involved in the NCERA thirteen, the regional soil testing committee too. So it's kind of a good, I think, good stepping off point to start looking at our guidelines and then just seeing kinda how things differ because I you know, looking at my data, think a lot of the underlying principles are about the same no matter what the soils are.

It's, again, just that the management philosophy that tends to differ.

Our early work in Illinois is kind of agreeing with that. Illinois has a a fairly pure build and maintain philosophy, where it's very soil test target soil test based. And, we've looked through actually some of the original response curves that were were produced by Roger Bray in Illinois. Our early research so far is showing that the levels of where we should or should not expect response to p or k fertilizer are not that far off of what our current systems are at. Some of the regional interpretations need to be updated, but we're also just looking at the philosophy of a short versus long term ROI concept, especially with a high percentage of rented land in the state of Illinois.

You know, and I think that is kind of, you know, interesting at some of the things that I've been looking at too, because those are, think, some of the key questions. And, you know, the way I've gone about a lot of our guidelines is been really, my philosophy is providing data to growers. You know? And if they depending on how they wanna manage, they can manage it any way which way they can. But, you know, historically and I don't know, Jason.

I mean, your your guidelines out there, you've been more of the sufficiency style. That's kind of the historical Minnesota recommendations that we've had, and I've gone away from or at least tried to offer some other options for growers. So that's been the big thing going from east to west. It really is the the shift in philosophy has been the thing that's, I guess, been more noticeable.

Yeah. I think the philosophy is probably the biggest difference. Traditionally, in South Dakota, it's the sufficiency approach. Approach. I think there's a little bit of build into it as I've done research with phosphorus inherently and as I've talked to my predecessors some about what they did.

But mostly, it's a sufficiency approach, and we've been looking at evaluating some different aspects of that as well in in recent research over the last few years.

Manbir, do state phosphorus guidelines need to be revised? And if so, in what ways?

Yeah. With respect to how our crop production and cropping systems are changing over time, there's always the need of revising the nutrient management decisions as as as we go forward. So in Ohio, we revised our fertilizer recommendations in 2020, and some of the big changes that we made was, one, switching from BRAY one to MALEC three. Majority of our commercial labs these days offer MALEC three, so that was one of the biggest change that we made in nutrient fertilizer recommendations. Now we propose megalix three rather than BRAY one.

And another one that we made a change, there was little bit confusion with regards to what we do once we are above the maintenance level. There was a drawdown philosophy there that they skipped to avoid the confusions among the farmer community. So right now, we are just now focusing on buildup and maintenance approach. So

And that's one of the questions I've had for you, Manbir, because I know, you know, traditionally, the tri state recommendations, which would be Ohio it's Ohio, Michigan, and Indiana, I believe, those three. They had that drawdown philosophy. And I've kinda looked at the the same thing here for us in Minnesota when I I did our build guidelines, mainly to just to kind of note where growers could be looking at mining some of the soil, which I think is really important right now with prices. I mean, if there's situations where they're too high, mean, there's really no reason to be well above the critical level. But, you know, in your state too, I mean, there has been a shift towards more no till, correct, in there?

And I'm just kinda curious if that's affected some of the the things that you've looked at with some of the the fertilizer guidelines or just, you know, the kind of that shift towards that if that's changed anything in in Ohio versus where it used to be before that was a general practice?

Yes. Nortelage has definitely increased in Ohio, but we haven't made that change so far in our fertilizer recommendations. So far, it's very generic. We are not changing based on what kind of system you are working in. So it's quite generic at the moment.

I think moving forward, that's there is that opportunity to tweak those recommendations based on what kind of tiller systems you are using. There's a lot of push towards cover crops, lot of data coming in that cover crops improve phosphorus availability. I think there those are some of the other questions that as a soil specialist we should be looking into.

Yeah. And depth of sampling always is kinda one of the bigger questions too with reduced tillage. I mean, we haven't really adjusted everything. We're still on, no matter what the tillage is, you know, six inch sampling depth. I think some of you probably may be eight inch depth, but, basically, that's that's the mean, that's really the trick on a lot of this is is looking at some of these these things, you know, going back to kinda what I talked about before across The states is that just those those small tweaks, especially with phosphorus, can really change some of the interpretations.

So, you know, just have to be careful, using guidelines, from especially other states. That's but that's kinda what my end goal was to start having these conversations in in their across the Midwest to see if we could actually at least streamline some of the terminology of of what we're using to at least maybe reduce the confusion of of some of what's out there in terms of soil testing across the region. But I don't know if we'll always get there because, you know, John, I know you coming from you've working Wisconsin and Illinois. I mean, you kinda have your feet dipped in both both areas there that it's it can be a little bit challenging when you've got two different systems when you're trying to come up with recommendations when they when they're necessarily the same across both state lines.

Yeah. I I think there's also just the the reporting differences as well. Illinois still, for the time being, reports in pounds per acre for for p and k. I see you laughing, Dan. But we're we're getting that converted over, but we use seven inch sample depths for the current interpretations.

And so from Indiana to Illinois to Iowa, it's eight seven six, and that's and we've done enough studies at looking at one inch increment changes in soil sampling depth or seeing dry falls when soil sample depth was compromised, that it does shift interpretations, across the large variants. And so those are things that I've I think I'm excited about this project is that we can clear up some of that unnecessary noise in the interpretation process.

Would a phosphorus rate calculator that incorporates economics kinda like we do now for nitrogen, would that be a useful tool?

That's an interesting question. And in a lot of extension talks, I I discuss ROI by soil test levels and the fact that if your yield response based critical level matches your ROI breakeven point, which matches your certain probabilities of p response, you probably have a fairly good and rigorous system to base fertilization decisions off of. What I would not recommend is chasing soil test levels based on economics. If in in in the nitrogen world, if if nitrogen fertilizer changes from one year to the next, it's pretty sensical to to to adjust your nitrogen rates based off of a profitability standpoint. But trying to chase soil test levels, which do not change always very easily or in a predictable way based off of economics, is not something I would recommend.

I think instead, you adjust your annual rate decisions. And that that, I think, lends credence to maintaining optimum soil test levels where you're not in a situation maybe currently now and for the phosphorus piece where you do really have to apply p, and it's so expensive. And so I I would say soil test levels really shouldn't be targeted based on economics, but annual rate decisions or rotational rate decisions make a lot of sense.

And that's one of the things that I've been wondering. I mean, John, you bring up a a good point because a lot of our our research really isn't designed to look at long term, you know, that question of whether or not, you know, if I invested in Phosphorus and built when it was cheaper, you know, is that better versus letting the soil test get to a point where I get a high return on investment? Then you've got something like the sufficiency approach, which is supposed to really maximize the ROI as much as possible for that decision. It just it it's a tough decision because, you know, what I see with phosphorus, and I don't know if some of you are the same, that when you look at our rate responses, you we get a large yield increase to the first increment we apply, whether it's, you know, twenty, thirty pounds in our studies. And then beyond that, you know, you get very little response.

So it's not like nitrogen where you get that, if you look at that marginal return or that yield increase per every unit of n applied, you don't get as high of value out of it as you do with Phosphorus as you do with nitrogen. And that's where, you know, looking at a rate calculator, like, I've done this before with, like, what I call maximum return to p calculator, and you can do it. It just I don't know how accurate the data is because the issue with the mobile nutrients, there's just so many other factors that impact things. So, I mean, I guess, I mean, John, it's probably the same way I've been doing it. Essentially, just, it's well, I think we both learned from the same person.

I mean, in terms of, being both at Iowa State that, you know, kinda looking at any way you can look at net return based on soil test levels, really the best thing to do. And my general fear, though, you know, still talking to some growers. I mean, there's well, I think a lot of it, there's growers out there essentially on our end that essentially have just turned their checkbook over to their coop, and they just do whatever they write at the check or whatever the co op wants, and there's a lot of emphasis on build, build, build. And it goes back to some of what Manbir was talking about. I mean, the the tristate used to have a drawdown set of guidelines.

I think it's kind of important to start thinking about that because, you know, continually building, what are you building for? I mean, really, and right now, I mean, you know, where the ratio of a price per of a bushel of of corn to the price per pound of p two zero five is so out of whack that it just it worries me somewhat that growers are gonna sacrifice in some other areas just to continually apply some of the higher rates of phosphorus when their soil tests are probably sufficient enough where a starter rate or even a low rate of p might be enough just to get them through the year. So, I mean, I know some of you are seeing the same things, but that's you know, just going talking to a lot of these growers, I think we've done a good job selling phosphorus and the value of it. It's just right now trying to get in their heads that they don't need to be doing essentially the same thing they've been doing for the last twenty years, we can start making some changes now, the soil tests, I mean, aren't necessarily gonna suffer where they're gonna plummet down to have extremely low soil tests within a year or two if they start cutting back their rates.

We've seen that with one of our farmers. I spent a while talking to one the other day. He told me his grandpa just ingrained him, put the phosphorus on every year, and they haven't soil tested. He said that he's never taken a soil test. And I'm like, well, you probably have a pretty decent amount of phosphorus in there.

With the prices in there, it might be worth it to go out there and at least zone sample it to see where you're starting at, to see if you can cut back during some of these really high price years. So I think that's that's another economics part of it, is sometimes they're just blindly going in there and doing it. Whereas if they have a soil test level, they could at least, you know, have an idea of maybe I can slim down these years where we're really high phosphorus prices as well.

Right. And I think there's especially in the times that we are, there's really very tight profit margins. I mean, you look at the price of the map, it's, like, $876 per ton. That's, like, a lot of dollars going into the inputs. I think when we talk about buildup and maintenance approach, especially for years like this when fertilizer prices are just very high, farmers have the opportunity to really cash out what they have built up, especially if they are somewhere even in the maintenance range, which we call as from 20 to 40 PPM.

If they are on the upper limit, say, five PPM, our data does show that if you are somewhere in that range, the probability of getting a yield boost is very low. It's, like, somewhere between 12 to 14%. Even if you get that yield boost, the relative yields has been so minimal. So it doesn't really make any sense to be putting that fertilizer when it's so costly, and it's not gonna give you the return on investment. So I think this is the year.

If you have invested in building those soils up to, like, 40 PPM, you can be fine skipping it one one for for a year or two.

And I wanna clarify. I mean, Manbir, that's the Mealyk three ICP, 20 to 40. Correct?

That is correct. Yes.

That's So that's one of challenges when we talk about these numbers is the fact that you have to weight it against and that's one of the the larger things of this project is you've gotta weight it against what methodology we're using because, you know, for us I mean, I'd say the same thing. If you look at if you're looking at maintenance, really, the most optimal level essentially is when we get into around roughly your high classification, which if you look at Iowa, that would be their optimal level, which is optimal for removal. And I think it's kind of the same thing for all of us. It's it just you get and exceed that point or the the critical level, or we define it where you hit maximum yield or 95 maximum yield, whatever you wanna claim. I mean, it it's kinda the same thing looking at that.

So, again, that's one of the things we're doing right now, hopefully, with this project by the end, is have some clarity in what we mean. Because we'd all talk about these things. You throw these numbers out there, and it's all really contingent on essentially what method we're using and and some other factors we're using for the soil test. So it's it's one of the things that just you have to be careful for when you you listen to us talk across state lines.

What are you telling growers this season as far as the 4 R's in phosphorus management? Do you have any tips for farmers?

In terms of application strategy, one of the things that sometimes gets lost in the the detailed specific studies of timing and placement, even P source, is that farmers really have a a fairly large range of of opportunities to to put pea out there, and they're not fixed to one specific timing or placement option. Work that I was involved with in Iowa, and then we have, you know, now in Wisconsin that that's com or excuse me, Illinois that's that's comparing, timing and placements relative to soil test interpretations. We really don't see any change relative to application strategy. That's specifically with band and spring p applications versus spring or fall broadcast p applications. You certainly do see times or specific years where one one application timing has has benefits, but consistently, we just haven't seen an ability to interpret soil tests different depending on your application strategy.

We have some large projects looking at that and long term strip till systems where we do kind of have this two dimensional stratification of nutrients, and we've done some, archaeological digs, we'll call them, to, quantify that two dimensional stratification. And and it's it's interesting when you move from a 90 PPM soil right where the band is to a four PPM soil between the rows, that's quite a large gradient. And so if we're thinking about that as a long term solution, I still wanna be careful and manage the bulk soil phosphorus. Dan, I know you've got specific application strategy guidelines that that you you've adopted.

Yeah. That's one of the things, John, we're looking at right now because with phosphorus, I mean, numbers of the the more recent data, we haven't really seen the efficiency that some of what our recommendations would claim. Although, I could point back to, you know, probably thirty years or more ago when some of that initial data was developed that went into giving us those it's roughly a 50% credit. And I don't know if, Jason, if you have those built into years to the band credits for South Dakota or not, but, you know, it's been kind of a question right now if if those hold true.

Yeah. We've had some of the band credits, and this has worked for my predecessor, that they'll they'll tell you if you're banding it, you can drop the rate by half or so. And we started a little bit of banding, just Coulter banding. I have a colleague who's worked on some strip till stuff as well. We haven't really seen a lot of effect on placements.

As long as we're getting the Nutrient down there at a good rate, we seem to see about the same response.

And, I mean, that's one of the main thing, you know, that we talk about placement or source. I mean, really, it just I mean, I look at yield. It's it's one of the things. It's always the starter effect. People will claim, you know, you get that nice starter effect from band applications either with the planner or early on that how good things look that that'll translate into yield, and we never really necessarily see that.

I mean, really, I'm you know, when I look at things, I'm I'm kinda simple when it comes down to yield that really yield is dictated by the total amount of nutrients available, whether it's from fertilizer peer or whether it's from phosphorus in the soil. It doesn't really matter as long as there's enough there. So, you know, that's kind of the thing, you know, regardless of source. I mean, it's one of the issues right now is, you know, talked about fertilizer prices. I mean, you look at MAP or DAP.

I think, like, I did this back in December. I was playing around with I was looking at, you know, the the cost per unit p $2.00 5 whether I credited the nitrogen or not, and I think it was, like, 80 some cents. If I credited the end at the rate current rate of urea versus a buck a pound, if I didn't, that you know, it's pretty substantial for the the number. Now we've got other products, and no coming to play. Triple, we haven't really had a few retailers carrying that.

It had been a little bit cheaper, but that kinda cut off this fall, and they're really couldn't get any of it. And so I don't know of anybody that's been carrying it here in Minnesota. The other one that's out there is Struvite. And I don't know if anybody I think the only one in our region that's had, some work that's on this project is Andrew Marginal. But, I mean, I don't know John, Manbir, Jason, if you had any, you know, experience with that.

Because I met with, with the company, that manufactures those products back in December. I mean, they've got a new plant coming online where they're it's so you know, the the curiosity I'll have is price, but then also look at source availability of some of these things just to see what's available moving forward, you know, if prices still remain high because I don't have a crystal ball to see what's gonna happen.

Yeah. We we had a long term struvite study in Iowa that probably need to publish, and but it was comparing comparing TSP and struvite yield response and then soil test level changes. I I can't remember when that study started. I helped close it in 2018, but really saw no difference in in p response. A pound of p two zero five was a pound of p two zero five regardless of just the comparison of triple in Struvite.

Struvite also increased soil test levels effectively just as well as as TSP did.

And I could kinda give you an idea on that one. I think it started about the time I left because I was working on some of that initially when we we first saw. You know, Manbir, do you have any experience with it?

No. So in Ohio, we we have a very similar story. I mean, Strr has been here. There are other products coming into existence. Majority of them are more towards controlling the water quality issue rather than improving crop yields.

So the claim has been the yield's gonna be the same, but it's gonna have positive effect on water quality.

So and I guess the way I look at this with all these products, I mean, it's really about the cost per unit nutrient. I mean, it's whether I look at starter, whether I look at, you know, Struvite, MAP, DAP, triple, those types of things to look at overall value. And that's one of the issues with, some of these specialty products, which I would kinda lump Struvite into since it the their new manufacturing process, the things they can take about any phosphorus source to make this new product that they have. It's, you know, similar to Struvite. Remember, it's around 33% p two zero five.

But the issue usually is the cost per unit p two zero five is higher. So, you know, you look at a lot of efficiency claims that are generally there for any of these types of products that are generally put in place just from the fact that they're gonna cost a little bit more per unit nutrient. So, hopefully, you can get an efficiency out of them to make them cover the additional cost so they come back similar to some of these other fertilizer sources themselves. I mean, really, I think the thing I struggle with, is a lot of the stuff that's out there, specifically a lot of these fertilizer amendments. I mean, it's really I've kind of the last few months more questions on some of these products that are just supposed to unlock some of the organic phosphorus in the soil, being sold to try to counteract some of this high fertilizer prices, but I'm just not so sure right now if, you know, getting into some of that stuff is really the best option for growers or is still better option to stick your money into just your base fertility program because you know what you're gonna get in terms of total nutrients.

And the other thing that's floating out there, I don't know if some of you've heard too, is, people talking about the first year availability of phosphorus, and then that we only get a very limited amount of the fertilizer we apply that's available and taken up by the plant, which I I think is a misleading stat because I mean, we know, essentially, fertilizer, not all that's gonna be taken up on a year anyway, and a lot of that isn't essentially can be recycled around the future years. So, you know, in effect, that first year availability doesn't really matter as long as the total sum that the plant has available is about the same. So I don't know if that's some of the things you've been hearing as well, but, that's one of the things that I know just recently in some of our crop one of our consulting groups, they had a question on that because, evidently, there's been some claims floating around in that first year availability.

The topic of different phosphorus sources addressing nitrate water quality issues has come up. Is it worth switching from MAP or DAP to a TSP or another fertilizer source?

Yeah. So I I think there's two ways to looking at replacement of ammoniated phosphates in your fertilization system with with something like triple, or Struvite. And that's so one is is quantifying the the the nitrogen losses or potential nitrogen losses, and doctor Harganaut's work in here in Illinois is is working to that point. I think the the water is pretty muddy, though, in terms of that small amount of nitrogen applied in the fall, parsing that out from background mineralized and that's lost as well. I can say we have a a paper that's supposed to be getting submitted soon that's looking at just the yield response to fall applied DAP, spring applied DAP, and then spring applied UAN as those are the main nitrogen sources applied to a corn crown.

And we don't see differences in yield response to that applied nitrogen. And so that you know, using that as maybe a surrogate of where did the nitrogen go that was applied with the pea products, we didn't see any differences in crop response. I know there's been some other research done in Illinois and and in Minnesota, doctor Fabian Fernandez. And and, certainly, when the environmental conditions are right, you can get some some considerable nitrogen loss. I will say for our nitrogen rate guidelines for corn in the state, we do consider any any n applied with your p source as well in the calculations.

And and many times, that is a considerable amount, and and it it may represent very well, some large shifts within optimal nitrogen rates.

And that's one of the things I'm wondering, John, too. I mean, long term. I mean, I don't know how many growers actually credit what you're talk like, you're talking credit and what they actually credit in terms of availability for fall applied map and dApp. And, you know, the question I've always had in my head is if they don't credit it, why is it even there? I mean, a lot of them would probably throw a fit if you took if you just went switch to triple because they're getting less value because they're getting less nutrients per ton.

But if you don't credit it, I mean, you look at our water quality issues. I mean, what would happen if we would switch essentially to all fall triple across the Midwest and cut out some of this stuff if it's not being credited? I mean, it's likely just additional in that's leaving the field in one way, shape, or form. Could we, you know, effectively make that change? I mean, the issue that would take a big shift in our fertilizer industry right now to shift away from ammoniated phosphates, which I just don't see this is the case.

But, you know, it's it's one of the things I've just been kinda wondering with some of these things whether or not, you know, that's a good option because that's in our Southeastern part of the state, that's what they're looking at doing is trying to go to that, because we've got a lot of issues with nitrogen there, to try to limit that for the fall and giving them a source where I mean, phosphorus is phosphorus. And, you know, in the end, I don't think it's really gonna matter. I don't think the growers are really gonna care as long as they're gonna get what what phosphorus they're trying to get with the fertilizer they're applying.

What ongoing or maybe new phosphorus related research projects are you watching?

We have a couple that we're one we're finishing up, and it was looking a lot about some of the phosphorus questions. We have a lot of different soil health stuff that's been going on in the state. Our Soil Health Coalition has become pretty influential with a lot of growers and people asking, well, for changing our management, are we changing our phosphorus recommendations, and looking at things like that. So we we worked with some USC researchers, University of Missouri for a few years. It's been three or four years back now, looking at can we utilize some of these soil health tests, looking at phosphorus mineralization or phosphorus enzymes with other traditional soil health metrics, and can they be used to help improve our phosphorus recommendations, accuracy as far as response or no response.

A lot of what we saw in both Missouri results and the South Dakota results is that soil health metrics are really good at telling you about soil health, but they're not very good at telling you about nutrient management. But the results that we saw there, they didn't really help improve stuff. And kind of our conclusion there is they're not measuring a lot of the nutrient movement or the nutrients, such as the phosphorus tests, are measuring enough of what's help changing the soil health of the soil that it didn't that it caught it there, and it wasn't needed in the soil health test as well. But that was kind of an interesting thing. We're we're wondering if we could tie some of that better because you just look at cover cropping and other things like that are supposed to help it, but the tests themselves didn't seem to do very much as well.

The other project we've been kinda working on is some of these questions a lot of growers have been asking about sufficiency bills and maintain, so we started a couple of our research stations, kind of an extension project looking at we went just by straights. So our sufficiency approach where we build and maintain over four, six, eight years, or we're looking at crop removal rates. How does that affect our soil? How does that affect our economics? And how does that affect some of our growth and yield responses as well?

So we got a couple of those projects that are just in their first year that we're interested to see kind of long term what some of those economics and results look like.

I I think the the statewide calibration work is really exciting. We've got a lot of sites that were amassing a large amount of data now. And and, really, these processes, I think, regardless of Nutrient, are very data hungry to refine up and update recommendations. And until you really get that kind of mass of information, both direct responses, but also, as Jason was talking, maybe some metadata of subsoil properties, or we we have some kinda antiquated subsoil pea supply and power regions in the state that I think, doctor Morganat's work is is showing that isn't really the case. But, interestingly, when we look at the calibration data, our response to pea, it does differ quite a bit in those regions likely due to, simple topsoil thickness.

So I I think that's that's an interesting part to to see where we can really refine in a more granular level, soil test interpretations. We do have an enhanced efficiency p project starting, that's looking at surface runoff, with some of the the coatings on on dry granular fertilizers either applied on the surface or or subsurface. So that will be really interesting specifically for, producing data for our nutrient loss reduction strategy in the state. We don't necessarily have a lot of direct, pea placement data as some other states like Iowa do and or have. And so, we're needing that information to fill the gaps for our nutrient loss reduction strategy.

I would say those those two, projects are are taking up a lot of the lion's share of our our our time and resources right now related to PN in Illinois.

Yeah. Arlington, Ohio, we we are looking back into really the basic basic chemistry all the way to making big decisions. So when I talk about basic soil chemistry, we we are looking into some of the long term phosphorus trials where we have approaches to build the phosphorus, and we are also tracking how the drawdown is occurring over the years. So those trials have been occurring since for over twenty years now in total. So we are currently analyzing data to provide the information regarding what's the rate of buildup and what's the drawdown rate, essentially.

So that's one of the project. And not only just looking at that specific factor, the rate of buildup and drawdown, but also when you build up, where does that phosphorus really go? Does it go to the labile pool? Does it go to the unavailable pool? The aluminum forms, calcium forms, or the reductive forms.

So that is something additional happening. And then we are teaming up into doing some big data analysis also. The aim is to refine or or kind of fine tune the fertilizer recommendations. Right now, it's like generic one equation, one recommendations across Ohio. But our aim would be to make it more site specific by doing that big data analysis.

And I think one of the the things kind of the themes across this really is think I think John said it the best was I mean, you you start talking about the data. I mean, it we it's data hungry. I mean, we need a lot of information. And I guess John and I, you know, coming out of Iowa State working under doctor Malarino there, we had, I think, a bad example of having a million needing a million data points for anything for this, but it is true. And that's part of this this USDA project that we're all working on right now is really trying to get what information we do have in some forums that we can utilize it through what we call the fertilizer response support tool, which it's a online program that growers can go in and just access data right now just to generate critical soil test levels.

They're looking at the point at which yield should be at maximum, but being able to utilize data across state lines in order to do so. So that's the main goal of this. We've got a joint project in place where we're looking at some of what Jason was talking about, that, build versus sufficiency. I'm actually looking at some rate components with that. We did that a number of years ago in at in Minnesota, but I wanted to do that across the region. And then the other part of this is, really looking at the removal values.

So looking at the amount of p two zero five removed in grain, and it's one of the discussions we need to have is that we there's been some databases developed in the past, but, you know, as Manbir was talking about, if we wanna get into any other analysis, we need more metadata or just information behind the data really to dig into that to see if we can, you know, look at why there are some differences may exist across the region. So, you know, it's kind of big projects, and, I mean, we're kind of aiming towards a lot of this big data, you know, type approach on some of this, but it's contingent on collecting data. And some people might say, well, why do you need more rate trials out there? And it's it's really just because we don't I mean, you never can have enough data, and I guess that's been my attitude.

It gets me into trouble where I've got too many sites where I gotta manage on a yearly basis, but, you you really I mean, it's true. You just never really can have enough when it comes to a lot of this stuff, and there's always kind of the question you never think about where somebody will ask you, and that's that's really the problem with, us having a lot of us having extension roles is, trying to keep up with, some of these growers, especially with technology because they can move a lot faster with technology versus us when we look at our data to develop how to effectively utilize that technology. So so I just wanna put a plug in there. So kind of, hopefully have some podcasts here in the future talk a little bit more about some of the results rolling for some of these these joint projects, but it was just a good time to start teaming up and looking at what we can do to try to provide more information to our growers in our states and across the region.

Our panelists today were John Jones in Illinois, Dan Kaiser here in Minnesota, Manbir Rakkar in Ohio, and Jason Clark in South Dakota. Thank you everybody for being with us today.

Thank you.

Thanks, Jack.

Do you have a question about something on your farm? Just send an email here at nutmgmt@umn.edu. Thanks a lot for listening, and we look forward to seeing you next time.

We'd like to thank the Agricultural Fertilizer Research and Education Council, or AFREC, for supporting the podcast.