Minnesota Soil Health Coalition: Adjusting Nitrogen Management with John Kempf

I was asked to speak about nitrogen management in particular and perhaps touch on phosphorus management as well, and how we can think differently about managing nitrogen from a plant health perspective and from a soil biology perspective. And particularly when we look at the, the macroeconomic conditions of what's happening and what's going on in the world, Many years ago on the podcast, I was having a conversation with Gary Zimmer and I asked Gary the question, if you could wave a magic wand and change one thing, and you're with the goal and the objectives of accelerating the adoption of a different form of agriculture, though what at that point in time Gary was referring to as a biological agriculture, if you could wave a magic wand and change one thing, what would it be? And Gary's answer to that question was, "I would make nitrogen really expensive." And what he intended by that, what he meant by that, is that what he had discovered in 30-some years of what he called biological farming is that you can grow your own nitrogen. And he wasn't even talking about COVID crops. Cover crops were part of it, but he was speaking more about the soil biology and the discovery and the realization that soil health and the ability to fix and sequester nitrogen and supply nitrogen to a crop is closely connected to each other. And if you wanted to incentivize the adoption of soil health in a significant way at a large scale, one easy pathway to do that would be to make it cheaper to grow your own nitrogen than to buy it. And Since that— since he made that comment, it's now, I don't know, at least 6 or 7 years ago, probably longer. We've learned a lot more about nitrogen, the impact that it has, and the way that it changes plant physiology and the way that it changes soil microbiology. So for the discussion today, I'm going to provide a quick overview of some of the ways that we think differently about nitrogen today than we did 10 years ago. And how we manage it differently. I want to just dive right straight into the practicalities of it because obviously spring is here, planting season is upon us, and what can we do differently this season that can have a very significant impact. So there's many starting points in this conversation, but one of the things that I want to put out there for us to think about is I think it would be wise for us to— it would be helpful for us if we stopped having a conversation about nitrogen. Because from a biological system perspective, from a soil biology and a plant perspective, nitrogen doesn't exist. Plants and biology do not interact with N. They don't even really interact— well, biology does, but plants don't even really— interact with N2, the nitrogen gas that's in the atmosphere. We would be much better served if we started having a conversation about nitrate and ammonium and urea and amino acids, amino sugars, protein forms of nitrogen, because the plants and the soil biology interact with each of those differently and in some cases in extremely different ways. It weakens our understanding of agronomy, and it weakens our understanding of plant nutrition and nutrition management to talk about nitrogen generically when we really should be talking about nitrate versus urea, because those two have fundamentally different impacts on plant physiology and on the, on the way that plants express themselves. So I'm going to just jump right in. And the, the core objective here, what I want to speak about is I want to speak about just— there's so many— I could literally talk about these various forms of nitrogen and how they interact in biological systems for 4 hours. But that would— I don't, I don't think that would be a boring conversation, but I want to make it really practical and focus on what we are doing, how we are managing nitrogen today the growers that we do consulting work for, what we've learned over the last half a dozen or more years, and how, yeah, we're constantly evolving. So I want to focus on the practical aspects but also describe how we got there. So we know that one of the challenges with nitrogen, particularly in the nitrate form, is that it's water soluble, and that's problematic both when we have too much water and when we don't have enough. And this was one of the pieces that I found quite intriguing when we started working with biological nitrogen. The discovery and the realization that nitrogen and other nutrients that are coming from soil biology, from biological cells, bacterial cells in particular, are still available to the plant in the absence of free soil water. You've probably heard stories of farms that had improved soil health. They started making changes, and in dry conditions, drought stress conditions, they still went on to produce a high-yielding crop that was not only a high-yielding crop but also had high test weight. And this has been something we've— I've observed now a number of times where you have these exceptionally high-yielding crops that with high test weights that are completely out of proportion to what you would expect when you have— given that you might have very dry conditions in August and September. And in every instance when that occurs, when we measure what's happening and what's going on with soil biology, we have this biological nutrient delivery that can continue to deliver the nitrogen and other nutrients in the absence of free soil water. And that is such a powerful— such a— it builds so much resilience for us from a soil health and plant health and yield perspective. So, um, one of the things— one of the most popular webinars that I ever, um, that I ever did was— I forget, it was something— the title, something to the effect of How Nitrogen Creates Yield Drag. And on the surface, I mean, people's kind of first reaction to that is, wait, nitrogen can create a yield drag? Like, everything we've been indoctrinated with and everything we've been told for the last 40 years is the opposite of that. We're constantly putting on more nitrogen and we want to drive more vegetative growth. And it was intriguing to me to observe that over the years, there's slight variation, of course, dependent on genetics and region and so forth. But as a general rule, the highest yielding crops are not— they're practically never crops that have— actually, I shouldn't say practically never. I cannot recall of a single instance where we've been consulting on, uh, with a grower, and the highest yielding crop was the crop that had the highest levels of nitrogen. I've never seen it, not once. When all of the other nutrients are balanced and are being managed well, and nitrogen is, is applied in excessive rates or at higher, higher levels than it should be in a certain field, we always see a yield drag effect. It has a negative effect on yield past a certain threshold. Nitrogen has a negative effect on yield rather than a positive effect. So there's a number of reasons for why this is the case. I'll give you a non-corn example as a, as a starting point in the conversation. The, the highest yielding— we'll look at watermelons as an example. The highest yielding watermelon crops often do not have enough vegetation to cover the watermelons. The watermelons stand out in the field very clearly. You'll have another field right beside it where there is such lush and abundant foliage and vegetation that it completely covers the watermelons, and it'll yield 20 to 30% less. And that is a signal of a plant that had high levels of nitrate. And we could have a long conversation about the effect that has— that nitrate has on plants, but I'll start with, um, this was not Don Huber's PhD research. It was one of his colleagues. It wasn't Bob Kramer. I'm forgetting the name of the individual right now. I've heard this story secondhand, and I'm in the process of tracking down the original PhD paper right now. But the story that was related to me, this was research that was done at Purdue back in the late '70s. I want to say '76, '77 timeframe. And at that point, they determined that the highest yielding crops— this was on corn specifically— the highest yielding corn crops were crops that were getting, of their total nitrogen supply, they were getting 80% as ammonium and 20% as nitrate. We've known this since the '70s. And this was, of course, before we fully appreciated and were fully aware of the impact of soil biology. So they were not yet measuring amino sugars and amino acids and various organic forms of nitrogen. They were just looking at the ammonium to nitrate component and they were saying the highest yielding crops are crops that are 80% ammonium and 20% nitrate. And that was consistent across a wide variety of different soil types and different growing contexts. And the reason for that, we have— we've also found that nitrate nitrate in particular can have a yield drag effect for 2 reasons as we understand it right now. There's a few other— I'll expand it to 3 reasons. There's a few other secondary reasons, but the 3 big ones are: 1, a plant that has high levels of nitrate requires higher levels of water. You make a plant thirsty for additional water requirements when you provide it with lots of nitrate. And this is, this is not rocket science, rocket science, and not anything that's that complicated to figure out. If you go into any plant nutrition handbook or textbook, or you can readily look this up online, and you look at the nitrate conversion pathway that is required to convert nitrate to glutamine in the protein synthesis process, that conversion process requires 3 molecules of water. So for every molecule of nitrate the plant absorbs, it requires 3 molecules of water additional and extra that it would not require if it absorbed that nitrogen in the form of ammonium or in the form of urea. So simply by giving the plant nitrate, you make the plant thirstier, you increase its water requirement. That's part 1. Part 2, to convert nitrate through this nitrate conversion process and eventually into glutamine and into peptides and proteins, requires much higher levels of energy, much higher levels of sugar. There's much greater sugar requirement and energy requirement to convert nitrate than it is to convert ammonium or urea or amino acids and amino sugars. So the nitrate conversion is both— creates both additional thirst and it creates an additional energy drain. Which is— are two of the significant contributing factors why they originally identified that the highest yielding crops were crops that were getting most of their nitrogen in the form of ammonium. But then the third reason is that you could arguably— when we look at plant phytohormones and phytohormone interactions and the impact that they have. We can have these conversations about various forms of gibberellins and cytokinins and abscisic acid and on and on the list goes. But you could arguably look at nitrate as a hormone. Nitrate has a hormonal effect and it drives very rapid vegetative growth and very rapid root expansion, leaf expansion, leaf surface area, and so forth. What is interesting, you know, years ago, there was this concept that I introduced many years ago that we used to call critical points of influence. And we don't talk about critical points of influence quite as much because it was not necessarily complicated to understand, but it was not intuitive for a lot of people. But we learned that, and I think we all know, that plants all have these critical points, these, these critical leverage windows where any type of stress or any type of beneficial impact in this very narrow window can have a disproportionately positive effect. So this goes back all the way to Charles Tsai's research at Iowa State University back in the— I want to say this was the early '70s, like '72, '73, somewhere in there. He identified— and now this has been updated, there's updated research on this— but his original research said that the number of potential ears that a corn plant will have on a flex ear hybrid is— excuse me— that the embryos for those potential ears are determined 9 to 11 days after emergence, and that The number of rows are determined 14 to 21 days after emergence, and the number of kernels per row is determined 42 to 49 days after emergence. And so there's a few things that, that are interesting about this scenario. First, if you consider if you have a flexier hybrid The greatest impact on yield happens earliest in the plant's life. So if you increase the number of ears per plant, or if you increase the number of rows per ear, you will have a much greater impact on yield potential than if you will, if you simply increase the number of kernels per row. So that's one interesting aspect. The other interesting aspect is how early in the plant's life this happens, and also how narrow the window is. Like, number of ear embryos and ear embryo initiation is determined 9 to 11 days after germination. That's pretty early. That's 2 weeks. And it's also, it's a 3-day long window. So this is the concept of these critical points of influence. You have a 3-day window, and if you have severe weather stress or nutritional stress in that window, then that's going to have an impact lasts for the rest of that plant's life. So what I'm coming to realize is that— I'll just cut straight to the bottom line. There's a lot of additional dots that I could connect in the chain here, but the bottom line is that nitrate behaves as a phytohormone and it drives vegetative growth. And It is beneficial to have generous levels of nitrate earlier on in the plant's life. So in a corn plant, particularly when you have— when you're at the seedling stage, all the way starting from germination up until about V5 to V6, you have positive yield influences from having higher levels of nitrate. And from that point forward for the rest of the season, you actually get greater benefits, greater yield responses from having less nitrate 20% or less of the plant's total nitrogen supply and more ammonium or urea or other forms of nitrogen. You want to minimize nitrate after V5, V6, and you want to get the majority of nitrogen in other forms. So I think I'm spending too much time here. Yeah, I see him. I got ahead of the slides here a little bit, but we see here Takes 3 times more energy, takes 15 moles of ATP versus 5 for nitrate with versus 5 moles of ATP for ammonium. 3 molecules of water for each water molecule of nitrate. And the bottom line of what we've come to realize, and this is— this has been difficult to quantify exactly. This is just based on lots of experience and observation. But, um, we would suggest— I would suggest that plants that are getting lots of nitrogen in the form of nitrate can require 20 to 30% more water to produce the same bushels as those that are using biological nitrogen or getting nitrogen from ammonium and urea. That's a pretty big difference. You want to talk about drought resilience? 30% less water is kind of a big deal. So I would suspect many of you are familiar with the rise of AG cycle at this point. If you're not, I don't have the time here to really do it justice. There's lots of information available about this cycle online, but the short version of what we are learning is that plants have the ability to absorb the great majority of their nutrition, including nitrogen, in the form of living bacterial cells and living fungal cells and microalgae and so forth. But that they— let me move this Zoom slide around here a little bit. So this research is credited to Dr. James White from Rutgers University. He's popularized it, published it with a group of colleagues over the last decade plus. And he's describing that plants are absorbing living microbes And these microbes are colonizing the entire plant and providing it with nutrition. And what we're discovering, this is how undomesticated ecosystems work. So if you have wild plants that are out in the forest or out in the meadows and the prairies, these, in these wild ecosystems that are not being fertilized, the great majority, upwards of 90% of all of their nutritional requirements are being provided by this this mechanism— I'm hesitant to call it a mechanism, but this, this pathway, if you will, of plants absorbing entire microbes. And what we're now coming to realize is that we can— this same pathway can also deliver upwards of 90% of a plant's nutritional requirements in an agriculture environment if we stop preventing it from being effective. And there are many things that we do to prevent it from being effective. The short version, let me see if I have it here on the slides. But in short, we have one of the best ways— the way that I've started describing this to just to produce the greatest accuracy, I'm using some language that isn't commonly used in in agronomy, but is still very appropriate. And I'm talking about biology— biological nutrition versus electrolyte nutrition. A lot of the fertilizers that we use are inherently electrolytes. Anytime you have soluble potassium or soluble chloride or soluble nitrogen in the form of nitrates or ammonium, particularly nitrates, and even urea, you have a material that has a relatively high salt index. It has a high electrical conductivity. And what happens when you have materials that have a high electrical conductivity, you know, there's some debate around the truth of this story or this myth, I suppose you could call it. But there's some discussion around how the Romans salted the land of the Greeks when they did not want those states to reemerge and to become strong again. And when you add salt to land, essentially what you're doing is you're adding a very high dose of an electrolyte that will shut down biological activity. And this used to be a standard practice years ago in asparagus production as well. They would actually add sodium chloride salt to the land in high concentrations as a weed control because the asparagus could tolerate that where other plants could not. I've gotten to see some of those soils and see the loss of structure and the destruction that has occurred from that practice. Um, but the reality is we are doing it— we're doing exactly the same thing with our fertilizer applications, but just in smaller doses and perhaps more spread out over time, where the, the fertilizers that we're adding generally have a high electrical conductivity. They have a high EC. And so when you— let's say you have a wound, a cut, or a finger, you get fertilizer into that, you know what that's going to feel like. It's going to burn. And that burning is cellular oxidation. It is that electrolyte damaging and degrading cell membranes. The same thing happens to microbial cells in the soil when we add fertilizers to the soil. Whenever we add a high electrolyte content nutrient or fertilizer to the soil, that has a detrimental effect on soil biology. So The pathway forward, if we want to enhance this, if we want to enhance the ability to grow our own nitrogen, fix our own nitrogen from biology, and feed it to provide that to plants, the kind of the science of navigating this transition is providing an on-ramp for biology and biological nutrition while we create an off-ramp from electrolyte nutrition. So the— if you can just imagine that you have, you have an on-ramp on an XY axis, you have up to the upper right of the corner, you have an on-ramp for biological nutrition, and then you have an off-ramp for chemistry nutrition or for electrolyte nutrition. The question is, how do you, how do you navigate those and how do you balance those without compromising on yield? Because I'm of the persuasion that there should not be a need for a yield loss. If you have a yield loss during a transition, that's a reflection of bad agronomy, not a reflection of the challenges with— the challenges with rebuilding soil biology. So I'm going to— I'm just going to dive right into The way that we manage the transition on farms that we work with is we try to reduce the concentration and the quantity of electrolytes that we are applying at any one point in time. So we do multiple applications, we split applications out over the course of the season, and we try to apply as much to the plant as possible and as little to the soil as possible while still getting good, good performance and good yield results. So I'm going to— we're doing on time here. I'm going to just provide a very rapid, high-level overview of our thinking and our approach to nitrogen management. And We'll go through some specific applications and the thought process behind them, and then I'm just going to open it up for Q&A. We can, we can chat about any questions that you might have. There's a few pieces of information that are important for all of this to make sense. The first is something that I learned, an old rule of thumb that was developed by a team of Brookside agronomists 50-some years ago, when they were looking at corn nutrition, they identified that sulfur— at that point, sulfur was much more common in the atmosphere than it is today— and they identified that sulfur, the first 25 pounds of sulfur, can deliver the same yield response as a pound of nitrogen, that there was this threshold effect that the first 25 pounds of sulfur had the same yield, crop yield effect, as 25 pounds of nitrogen. And after that 25-pound threshold, that effect would diminish and taper off. It no longer held true at a 1-to-1 ratio. So they described that in any nitrogen program or nitrogen recommendation, they would replace the first 25 pounds of N with 25 pounds of sulfur and get the same yield response. So that was one— that's one interesting aspect, one important consideration. The other is, and this is— this research was originally done at University of California Davis by— ah, I'm blanking out— Patrick Brown, if I recall the name correctly. He described that a foliar application of urea, there was some variation from crop to crop, but that in many crops, the crops that he studied, it would have Producing equivalent crop response, 1 pound of nitrogen as urea foliar produced the same crop response as 7 pounds of nitrogen in the form of urea applied to the soil. And there have now been a group of growers that we've worked with. Beau Clausen has worked with this extensively. Patrick Fabian has worked with it extensively. And they're reporting on corn specifically and on small grains reporting a minimum of a 4:1 ratio. And just a couple of weeks ago, I heard one conversation where they were using some specific forms of urea, and they were reporting when applied at particular crop growth stages on corn, they were reporting as much as a 12:1 ratio, that a pound of nitrogen to the soil— excuse me, to the plant— produced the same results, yield results, as a pound of N applied to the soil. Well, my goodness, if you could cut your nitrogen application rates down to 25%, cut it 4 times with foliar applications, wouldn't that be worth it? I mean, yes, there are application costs and logistics, and there's lots of things to figure out, but that's a pretty substantial variation. So When we combine those, those various pieces, we say, all right, how can we optimize foliar applications? How can we, particularly at times of greatest plant need, how can we minimize the concentration of electrolytes at any one point in time? How can we spread that out over time? How can we make sure that the plant has a good dose of nitrate for the first 5 to 6 weeks of plant life? And then it's mostly ammonium and urea for, for later on. How can we incorporate the rule of thumb of the first 25 pounds of sulfur? What does that look like? So what that looks like is— and this is, this is kind of a broad, very broad brushstroke starting point for making recommendations. If, if the frame of reference here or the context here is if, if a grower asked me to make recommendations and I knew nothing, about the soil, about the crop history, about what was going on. All that I knew is that he has historically been applying 200 pounds of nitrogen and, and producing a certain yield outcome on his soil that he is satisfied with. I would— and I would be asked to make a set of recommendations just off the cuff without any further information. Of course, the obvious thing is you then start looking for further information so you can dial things in. So this is— I'm putting this out there— this is a starting point from which to customize. You then customize what fits your soil, your context, your operation. But if I'm starting with a soil and a context that has historically been using 200 pounds of nitrogen over the course of a growing season to grow a corn crop, here's what my math would look like. I would say, all right, in my general recommendation, as a starting point, I want to start with 40 units of nitrogen applied at planting in the form of ammonium and nitrate, not urea. I want ammonium and nitrate at planting. And that can be, that can be in a 2x2. A 2x2 is as close to the seed as I want to come. I would actually prefer that it be a little bit farther away. A little bit deeper. It can be put in earlier with a strip till. Obviously, there's lots of variation to different farming operations here that are very context dependent, but that, that would be the place where I would start. And then, actually, let's— I'm going to go on to the side dress, and then I'm going to come back and talk about how I would fine-tune this. Then I would follow that up with an additional 40 pounds of nitrogen side dressed. At about V5 to V6, probably right in the neighborhood of V5. So that gives us a total of 80 units at this point. And by the way, that 40 units at side dress, ideally I would prefer to be in the form of urea, not ammonium and nitrate. Again, this is just giving you what is the ideal, what's the ideal from a yield perspective, from a biology perspective, how does this crop produce the most and have the smallest water requirement? One of the things that we talked about. So in split up between that planter application and the side dress application, I also want a minimum of 25 units of sulfur, 125 pounds of sulfur per acre split between those two. And, um, at the very minimum, in either application, I want nitrogen and sulfur to be in a 10:1 ratio. And then you can also dig into and look at what we've been doing with our nitrogen efficiency program. You will get the highest performance, the best results when you also mix some carbon with this, some humic substances. We use Humicarb a lot, and I have a very strong recommendation for also mixing molybdenum with this application. Takes about a pint per acre of a 3-4% molybdenum product. Molybdenum is the critical enzyme for the nitrate reductase enzyme that is used by both biology and by plants. And every time we add molybdenum and carbon and this combination into this mix, we see the nitrogen leaching goes to practically zero. And even in high moisture conditions. And the reason for that is because if you have adequate molybdenum levels, even when the soil biology nitrifies back— excuse me, nitrifies nitrogen from the various forms, urea and ammonium, into nitrate and builds up nitrate levels. Adequate levels of molybdenum allow other soil biology to convert that nitrate back into organic nitrogen. And so you actually moderate and modulate the nitrate levels in the soil to not become excessive simply by having adequate levels of molybdenum. That means a lot for leachability. It reduces your leachability. But also it increases your plant's energy response because it's now absorbing less nitrogen. It has some, but it's not absorbing 80% nitrate instead of 20%. Um, all right, I already spoke about 25 pounds of sulfur, uh, already spoke about the side dress, and now we go to foliar applications. So, um, Somebody put a significant typo into this slide, but the— our target is 2 foliar applications is the ideal. One at tasseling and one around R1. Both applications targeting 10 units of nitrogen per acre in the form of urea, low biuret urea that has been liquefied and melted as liquid urea. And again, you combine this with a touch of carbon, you add some molybdenum to it, and now you remember these, these 10, we're putting on 10 pounds of nitrogen per acre per application for a total of 20 pounds. But we have a lot of field experience and a lot of growers who are telling us that this application produces a crop response equivalent of 4 pounds of nitrogen applied to the soil. So, with— follow my math here. I'm just sketching this out. We started with 80 units of nitrogen soil applied. 40 at planting, 40 side dress. A total of 80 pounds. To that 80 pounds, we added 25 pounds of sulfur that we expect to deliver the equivalent yield response of 25 pounds of nitrogen. So, 80 pounds plus 25 pounds of sulfur, now we're at 105 pounds equivalent. And we add those 20 pounds of nitrogen as foliares that produce an equivalent yield response of 80 units soil applied. So we're at 105 plus 80, and now we're at 185 units of nitrogen in terms of plant energy equivalent. So we've replaced 200 units with 185. For a fraction of the cost because we put on less, spread it out over time. We've got greater logistical costs in getting it applied. And so we've— but we've got a fraction of the cost of actual product. And what's more important from a long-term perspective, we have a fraction of the cost to our soil biology because we've reduced the electrolyte load Instead of having 100 units of nitrogen applied twice, once at planting and once at side dress, or whatever the equation might be, we have much smaller concentrations of electrolytes being applied to the soil, and they're being spread out over time. So your negative effect on soil biology goes down dramatically, and all of a sudden, particularly later in the growing season, when that soil nitrogen levels become— soil electrolyte levels become less concentrated, soil biology starts fixing a lot more nitrogen and making it available and providing it to the crop. So this is a very large brushstroke, very high-level overview of how I think about nitrogen management on a corn crop at this point, where we are We're spreading out the electrolytes, we're putting some on as foliar, we're replacing some of the nitrogen with sulfur. You can do all those things. It's common for us. You can, you can do the penciling out of the math on your own, what makes sense in your own context. But what is interesting is that this commonly translates to anywhere from a 30 to a 50% reduction in actual input costs, sometimes more than that. And that includes the application costs as well. But there are— there's additional logistics and additional difficulty in making those multiple passes per season, particularly with the foliars. Drones are starting to be quite widely used for the foliar applications of urea very effectively. So that's kind of the big picture overview. And I think, yeah, you can dig into. I think we have a nitrogen efficiency calculator on our website, at least we used to. I don't think we've changed it all that much. Um, but this earlier in the slide deck, I pointed out there's this rule of thumb for the nitrogen requirement that's required to grow a bushel of grain. I've seen growers go down to as little as 0.5 pounds of nitrogen that they can account for coming from organic matter contribution and compost and cover crops. And some— there's sometimes some fuzziness in those numbers. Um, 0.75 is readily achievable first year out the gate, no sweat, no problems. It's easy to achieve 0.75 pounds of nitrogen per bushel of grain. And the growers who are taking this approach of putting on foliar applications of urea and so forth are commonly hitting 0.65, 0.65 to 0.7. Is not a challenge at all. It's, it's very, it's a very readily achievable goal. So that's the overview. And yeah, I think I will switch it to Q&A if any of you have any questions. And you can also, if you have any questions for us as a team and you want to dig deeper into what this might look like on your specific soil and context, you can connect with Abby here. You can see her contact information here on the slide deck. But yeah, we'd love to hear from you. And with that, I'm going to switch to Q&A and happy to answer any questions that you might have. See, there's some here in the chat. Yeah, you're welcome to put any questions into the chat, or also I think you can unmute yourself and we can just have a conversation. There's a first question here from Paul. Is there a need to measure the carbon to nitrogen ratio in a soil test? Wondering because of fluctuations of results when utilizing compost extracts in the furrow at planting. Um, all— it's a good question. The I'm struggling a bit to answer your question because both nitrogen and carbon get measured in so many different ways on so many different tests. The answer is yes, I think it would be beneficial, but you're going to have to learn what the results actually mean. So for example, if you use the Haney analysis I was quite a fan of the Haney analysis for a number of years. We used it quite widely, and I still think in many ways it's the correct way to express this. It's the least bad soil sampling methodology that we have for measuring and managing nitrogen, nitrogen to carbon ratios and so forth. But, you know, as is so often true in life, our greatest strengths— this is for us as people and for operations and so forth— so often our greatest strengths have hidden downsides that are also our greatest weaknesses. And that's also true of the Haney analysis. The challenge with the Haney analysis is that it can vary quite significantly based on soil moisture levels. So if you have soils that are dry for 2 weeks and you have limited microbial activity because of a lack of soil moisture, and then you get an inch of rain and you pull a sample immediately before and immediately after, they will look like completely different soils on that type of analysis because the soil that was dry had limited microbial activity and it had kind of accumulated this readily available carbon, you take it into the lab, you add moisture to it, and you get this tremendous CO2 burst. You get this tremendous burst of microbial activity because of all this pent-up energy that was just waiting for moisture. And you don't see that when you've had a good rain. So the short answer is To your question is that yes, I do think it is valuable to measure carbon and nitrogen ratios, but there's at this point either one of two things is true. Either I don't understand them well enough or there's a lot of interpretation that's required to read them well. So that's the caveat that I would offer. Question from Doug, where does manure fit into this? So, Doug, manure. When manure is applied, the majority of nitrogen that it contains will be in the form of organic nitrogen, and that's just the umbrella catch-all term that is used to describe nitrogen in the form of proteins, in the form of enzymes, amino acids, amino sugars, and so forth. The nitrate content and the ammonium content of manure ideally will be quite low. So the And that is what would be most common. And so that biological— the form of nitrogen in manure is essentially biological nitrogen delivery. It's what I've been describing that can happen in healthy soils in the absence of excessive electrolytes. Now, what's interesting when we think about the challenges of electrolytes, you have inside the plant you have a handful of major electrolytes. You have potassium, chloride, nitrate, sodium, and then it's not as significant a contributor, but it's also an electrolyte. You have, to some degree, you have magnesium. And in the soil, you also have the first 4. You have nitrate, potassium, chloride, and sodium as being the significant electrolytes. And we've had a number of observations, a number of instances where dairy manure can be problematic, particularly when applied at high doses because of the salt that's fed to dairy cows. I mean, there are many people who can testify to applying liquid dairy manure and having dead earthworms behind the application, having the soil covered in dead earthworms, and that those dead earthworms are an expression of excessive levels of electrolytes and perhaps other toxins as well, but high levels of salts being applied with the liquid dairy manure. So salts aren't just exclusively coming from fertilizers, they can also come from, from high manure applications, particularly in the case of dairy manure. Question from Mark: Is sulfur being added with the foliar applications during tasselin R1? Ideally, yes. I'd like to add— doesn't take much, but I also want to hit that 10:1 nitrogen to sulfur ratio, pound for pound. That can be in the form of ammonium thiosulfate, which is most common. A few folks are also dissolving ammonium sulfate, which you can also do quite readily. Either one works quite well. Um, question from David: can you expand on drone application rates of late season foliar reapplication to prevent leaf burn? This is, this is actually an area that I need to catch up with Patrick Fabian and Beau Claus and a couple of people who've been pushing the envelope here, because I'm— I will admit that I am perplexed by some of the things that they're reporting. So they are— the conversations I've had with them, if I'm understanding correctly, they're putting on 10 units of nitrogen per application with a drone as melted urea. They're adding humicarb to that. And they're putting on a solution that is 50% melted urea and 50% water. So that means the liquid that they are applying is essentially 10% nitrogen. And they're reporting no burning effects on, on that, which I find puzzling. So I want to go back and just double-check and double-verify those numbers, make sure I'm not misunderstanding or didn't misunderstand anything, because that seems to be quite high. Um, but it is also true that because of the leaf structure, the small grains and the corn, sorghum, so forth, these grasses do have a much higher ability to handle those electrolytes as a foliar than a broadleaf crop would. I'm quite confident if you did that on soybeans or other tomatoes or other broadleaf crops, you would absolutely have leaf burn on that. Question from Adam: Does the source or form of sulfur make a difference for the 25 pounds applied during the growing season? I don't believe so. Now, that can be as thiosulfate or as sulfate, whether it's coming from ammonium sulfate, ammonium thiosulfate, potassium sulfate, gypsum. You can even apply this— it doesn't even have to be in the same tank mix. We've had growers that put on, because of their soil conditions, they needed some gypsum applications. And so they're banding gypsum in— perhaps I've had gypsum being banded on with a— my brain stopped working— not side dress, strip till, with a strip till application, and depending on that as a form of solver. And that is equally effective and appropriate. Question from Myron. Hi, Myron. Is there any concern about pollen shed when applying foliar N at just prior to VT and at R1? Would boron potentially be added as well? That's a good question, Myron. I don't know the answer. Um, and yes, you could add boron to the mix. You could add copper to the mix as well. This is a bit of a sidebar, something that we've learned about boron— excuse me, about pollen viability. And pollen tube viability. The— you can keep pollen tubes— what's the word that I'm looking for— not fresh, but they can maintain their strength and not collapse for much longer periods of time when they have adequate levels of copper and boron. Those two in particular, we found, will dramatically increase pollination on a wide variety of crops. If we make sure we have generous levels of copper and boron prior to— obviously it needs to be in the pollen tubes and it needs to be in the pollen weeks in advance of the actual event itself. Question from Kurt: if nitrate nitrogen applications are absent, how much N on average can you attribute to free nitrogen-fixing bacteria from species in BioCoat Gold? Can this seed treatment be accounted for in this new concept of nitrogen management? Kurt, you asked the million-dollar question. So I would rephrase it. If I'm understanding what you're asking correctly, I'll rephrase it just a little bit. I think what you meant to ask is, is not if nitrate N applications are absent, but more if electrolyte nitrogen applications are absent. And maybe that could be interpreted in a couple of different ways there. But the bottom line is that I missed talking about BioCoat Gold a little bit. Yes, BioCoat Gold can deliver substantial amounts of nitrogen and it can vary quite a bit. It will vary based on the amount of nitrogen applied, how close proximity phosphorus fertilizer starter solutions— was there a starter right on the seed? So the variability we have observed, maybe the most accurate way to say this is that we have observed BioCoat Gold delivering— let me, let me back up. I want to be sure I state this accurately. We've observed high-yielding corn crops where the crop contained upwards of 60 pounds of nitrogen that we were unable to account for from applications of any type— manure, compost, cover crops, etc.— that seemed to be coming from the BioCoat Gold. That's the high number that we've observed. Um, 35 to 40 is very common. Um, and actually I do have a few outlier instances that are well above the 60 number, but 60 is a number that's pretty consistently reliable and achievable, I think. But that all depends. It depends on soils having adequate carbon, adequate organic matter for that BioCoat Gold to really become active. It depends on there being not lots of electrolytes right on the seed or very close to the seed. It needs a couple of weeks to really activate. So those are all important variables and important pieces that it's It's— I'm hesitant to quantify and say that you can put BioCoat Gold on and you can depend on it for 30 to 40 units of nitrogen. Now, that will be true for 80% of the operations, but for 20%, it won't be because of other extenuating circumstances. Um, something that is important that I realize I missed mentioning is, uh, there is a critical 2-week window. BioCoat Gold colonization of the rhizosphere, um, or not just biochar coal, but the colonization of the plant root system and that emerging radical right at germination. There is a 2-week window right after germination that is critical for disease resistance later on the plant's life, and that is critical for the highest yield and the best nutrition delivery through the season. That first 2-week window is so important, and The easiest way to shut down colonization in that 2-week window is to put on a starter that has high concentrations of electrolytes. So if you put on a soluble phosphorus starter or a starter that contains a good dose of nitrogen right in close proximity to the seed, that's a good way of shutting down biofilm. It's much better to have it off to the side on a 2x2 or something like that. You know, many years ago, William Albrecht made this quote. It was from a soil professor at the University of Missouri, and he said something to the effect of, the science of fertilizer placement is all about the art of placing soluble electrolytes so that plant roots can avoid them. And he was, of course, looking at this from the perspective of What are— what does biology have the capacity to deliver if we don't shut it down? Um, a follow-up question here from Carl. Speaking of manure, would you say that a major problem with modern livestock production, i.e., CAFOs, is the concentrated part? Way too many animals in one place, difficult, expensive nutrient overapplication, etc.? Um, I would say that that model has lots of inherent challenges with it. And lots of externalized costs that it would be much wiser to go to a different model. That's a conversation for another day. Question from David: Do you have any data around using compost extracts as a carrier for foliar urea applications? Very limited, David. We do have a few people that have, have done that and continue to do that, and they believe they're getting benefits from that. But when you are putting on a foliar urea application, That is a high electrolyte solution. I mean, urea has a salt index of 106, which basically means that it is saltier than sodium chloride by 6%. Sodium chloride is the, is the benchmark index of the index at 100. So urea at 106 means it's saltier than sodium chloride. And so when you have a foliar spray solution of urea with that high salt content, Practical expectation would be that very tiny amounts of those microbes would still be alive when they touch the leaf surface. You would still— I can expect that you would still get benefits from their metabolites, from microbial metabolites, but not from living microbes themselves. Last question here is from Mark. If 32% and sulfur source are applied at planting, would there be a significant difference in the application method currently using broadcast versus indexing to the row? So if you are using broadcast, then your application rate is going— probably going to need to go up. To get the equivalent crop response. So the recommendations that I've been making have been with the expectation of having it banded, and if you broadcast it, then yes, probably your application rates will need to go up to produce an equivalent response. A question from Tom: Do you think there's ever a possibility for melted urea to ever be useful, usable in certified organic use? Tom, the problem with that question is that it's a political question, not a question based on science. And so it's impossible to answer because it's a question based on politics and not on science. As you know, there are many synthetic materials such as magnesium sulfate, for example, that can be used with a documented deficiency. And a number of trace minerals as well, trace mineral sulfates, et cetera, et cetera. So I would argue that there are a number of things that organic certifiers and the organic— I think if the organic certification space had gone down a different pathway of being more pragmatic and less idealistic, we would not be having a conversation today about regenerative agriculture. I think if it had gone down a pathway of actually looking at quality of outcomes and measuring both the presence of quality as well as the absence of toxicity and how we got there and taking a less idealistic approach, we would be in a very different place as an industry overall. But that's a whole separate— that's a whole other conversation. So I don't— my instinct is I don't expect there would ever be the possibility of using melt-and-urea in organic operations. I just don't expect to see that happening. But the good news is this— there's something that I missed mentioning. This process that I described of transitioning from 200 units of nitrogen to— what was the number that we came up with— 100 units of— from 200 units of N to 100 units of N plus 25 pounds of sulfur. That's the net-net difference. I want to be very clear that I'm suggesting that— and we have a lot of field experience with this— but this approach is a transition approach. This is— this would be year 1 of transition. And I don't have an exact count or exact numbers, but the number of growers who started there and then transitioned on further down to even less, where they're applying 30 to 50 units of nitrogen for a season, um, and, and delivering 100% of the remainder with biological nitrogen, is— there's a very large number of those growers. It's measured in the hundreds. Actually, it's probably even measured in the thousands at this point. So this, this is year 1 of a transition period, and that transition can extend in some contexts for a couple of years. But over time, the objective is to get the applied nitrogen down and replace it with biological nitrogen that is fixed from the atmosphere. Cover crops can contribute, manure can contribute, compost can contribute. But what I'm really talking about, I want to be very clear about this, We have a number of farms, a large number of farms. The majority of the farms that we work with are in challenged environments that don't have the ability to use— they cannot rely on cover crops because of water and moisture constraints in many cases, and or timing and seasonal constraints. And they cannot— they don't have access to manure and compost. So those are valuable, useful tools I'm completely in favor of them, but what I'm really talking about is transitioning to a state of soil health where the biology can deliver nitrogen even in the absence of those things, even in the absence of regular cover crops, even the absence of manure and compost applications. Soil biology can still get to the point where it can deliver substantial nitrogen if we just stop killing it and shutting it down. So I think I'm going to call it a wrap there. I've used up an hour of everyone's time. I want to say thank you all for being here. I hope you found the information useful. And if there's any further questions that you have, any further questions that we can answer, please reach out to our team at AEA. I'm happy to jump on a call and have any further conversations about how we might be able to work with you and, and figure it all out. So thank you all for being here. Here's to a great growing season. May you always have timely rains and May your yields be awesome. Thank you all.