The "Feed the Soil" Myth: Why Chasing PPMs is Costing You Money

In this solo episode of Rhizometrx, Faith drops a major agronomic hot take that goes against decades of industry advice: It is time to stop blindly "feeding the soil" to build arbitrary PPM levels. With fertilizer prices climbing and margins tightening for 2026, dumping hundreds of pounds of bulk nutrients into the soil is an expensive, outdated strategy that ignores plant stress and nutrient tie-up.

Faith uses a highly relatable "Pantry and Milk" analogy to explain why hoarding Phosphorus in your soil is useless if you don't have the Zinc required for the plant to consume it. She challenges growers to look at all 17 essential plant nutrients—not just the big five—and explains how feeding the plant first encourages root exudation, pumps carbon (WEOC) into the soil, and unlocks the fertility "bank" you've already paid for. If you are tired of the industry's scare tactics telling you to apply more pounds or go backwards, this episode will give you the confidence to rethink your budget.

In this episode, you’ll learn:

The "Feed the Soil" Myth: Why over-applying hundreds of pounds of fertilizer to build a soil test PPM actually degrades your carbon levels and reduces overall system efficiency.

The 17 Essential Nutrients: The industry hyper-focuses on N, P, K, S, and Ca. Faith asks: If you blow your whole budget dumping hundreds of pounds of just those five, how are you paying for the other 12 your crop desperately needs?

The Pantry Analogy: Why Phosphorus is like boxes of cereal and Zinc is like milk. You can stuff your soil "pantry" with cereal, but if you don't buy milk, the plant can't eat it—it just sits there as wasted money.

The "Bad Bank" of Soil: Traditional soil tests are like a bank that is only open 16% of the time and doesn't post its hours. Faith explains why you need an Indicator test to understand when your nutrients will actually be available.

Real-World Audit: After reviewing 300 soil tests across 60 fields in just two days, Faith reveals that she only recommended Phosphorus applications on 10% of them.

Realistic Yield Goals: Why setting your yield goals based on APH (Actual Production History) rather than arbitrary sky-high numbers prevents over-spending and carbon burnout.

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• Audit Your Pantry: Look at your 2026 fertility plan. Are you buying more "cereal" when you really just need a little bit of "milk"?

• Share this episode with a grower who is feeling the financial stress of the current fertilizer market.

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Transcript

SPEAKER_00 0:02

Soil fertility is no longer about applying more, it's about understanding more. Welcome to the Rhizometrics Podcast for Dirt Meet's data. I'm your host, Faith, a farmer's daughter, farm wife, entrepreneur, and economist seeking a deeper understanding of what drives results for farms today. Each week, we dig deep beneath the soil surface to uncover the chemical, physical, and biological metrics that impact crop performance. We know farm profitability doesn't start at a spreadsheet, it starts at the root. So if you're ready to turn rootstone insights into actionable economy, challenge outdated assumptions, and explore how the risosphere holds the key to farming for today, while building soil resilience for tomorrow, you're in the right place. This is Rhizometrics, where we turn roots into revenue. Let's dig in. Welcome back to the Rhizometrics podcast. I want to say good morning because it is morning here. We're gonna have kind of a little coffee chat today. Um I'm doing my best to try to work some guests into the schedule, but with planting potentially right around the corner, that's obviously becoming a challenge. Um, so thank you obviously for your patience. We kind of touched on a couple weeks ago that, you know, I might be on and off of here every every other week. I'm gonna still try to get something out um to provoke some thought every week. But nonetheless, we are back. Today I want to touch on a couple things. I like doing these little recaps of what I've been up to. Really, since I was last recorded an episode, I've been to a few different meetings. I held a meeting myself, I went to a couple meetings, and I've just been working through wrapping up guys' fertility plans with them in the last few weeks here. Visiting their farms, going over their results, implementing and tweaking their plans. I would like to say finalizing their plans, but the whole goal of what I do is really for your plan to be, as a grower for your farmer, for your plan to be solidified going into the season, but also knowing we can pivot at any time. So the idea of finality is fleeting at some points. But nonetheless, we've been going over results from last year, not only soil tests, but what changes some guys made on their farms and what impact that also made. Still really good results rolling in from customers that are very happy um surpassing yield goals at, you know, I would say mid to no mid to lower 200 bushel type yield environments. We we well surpassed most of those goals last year. And the guys that have some really high yielding, high protect productivity crops, um they seem to pan out at expectations or you know, five to ten bushel above that. So a lot of really good feedback. Again, always tweaking. Um, the fertilizer market has not been friendly in the last few weeks here. And so we're kind of working out some ideas around that. I touched on a few different specific tweaks that some guys may be making last time we were on here. But today, what I really want to talk about, and I'm hoping again to do it in fairly short order, is a rather hot topic or a hot take, I would say at the moment, that's circling the industry, and I've heard it at other meetings. I made mention of it at my own meeting, but here it is. For decades, you've been told to feed the soil, to build a soil test PBM model. But what if higher yields and profitability come from feeding the plant first? Maybe for some of you, although you listen to this, maybe this strikes a nerve, maybe this does not. It seems in the industry as a whole right now that for some schools of thought, this is not striking a nerve. And for others, it's striking a major nerve. Here's the long and the short of it, if you really think about it. We've fed or we've applied nutrients to the soil at a fairly high rate for decades. PPM values have gone up, yields arguably have also gone up, but in a lot of places we're seemingly hitting a yield plateau, and more fertilizer is not the answer. We've fed the soil and applied at removal rates, we've applied at build rates, we've applied at crazy, crazy, crazy amounts of pounds to the soil, and I'll tell you what, it's not working anymore. Spoiler alert. The reason it's not working is because irregardless of how many pounds you apply to your soil, if your plant is under stress, it can't take it up, right? That was a whole episode in and of itself, stress mitigation, the name of the game in 2026. It's really the name of the game anytime, but specifically with ultra-high fertility prices, the name of the game. So the name of the game outside of stress mitigation then is efficiency. And how can you build efficiency into a system that we've been taught we have to apply hundreds of pounds of something, but the plant is potentially only taking up tens of pounds of what we actually applied. I've been saying this often lately that no one no one outside of your farm really cares what your soil test looks like. Not from my perspective. I care what your what your indicators look like. But outside of your farm and on a piece of paper, it doesn't matter what your soil test says, it matters if you can pay your bills. Which again, I also say this too a lot. I'm not telling you anything that you don't already know. And this might be a more of a truth hurts episode, I suppose. The reason that we've been taught to apply pounds is that the pounds, the hundreds of pounds that we've been applying, we hope are enough of it remains or becomes available to supply the plant. Again, we overapply to compensate for availability. And historically, up until I would say the last five, six, seven, eight years, that's probably worked. It's probably worked, but a lot of also what we've been doing comes at the cost of degradation of carbon. And we all know that that's my favorite word. When we reduce carbon, specifically we ock, in our soils, everything else becomes more of a struggle. I have a lot of guys asking me, how do I build it? How do I maintain it? Meaning we occur. I would say one of the first big steps is to back away from over-fertilizing. A lot of your soils have the ability to supply what your crop needs, the next step in the right direction. And the next step to efficiency looks at what nutrients do I apply when? How do I apply them? Again, the when being timing, like specific timing. And when you do that, and it gets into the plant, or majority of it gets into the plant because it doesn't sit out there months before the plant would actually need it, makes your plant happy essentially. And when your plant's happy, it's it's excreting a lot of carbon. One one corn plant, if it's photosynthetically efficient and let's call if the plant is happy, can excrete up to 10 pounds of carbon per plant per day. 10 pounds. That's a lot of sugar. It's a lot of sugar. That's a lot of carbon. And what that does is that feeds the microbes that go about their business, they excrete enzymes, enzymes break apart, bonds that are tying up the expensive fertilizer that you've applied to your soil, and they're making them available to the plant. The place that we're in is definitely challenging staring down 26. But I think we need to start to become comfortable with being uncomfortable, and we have to continue to push for answers and for discoveries of things that we don't know about. Guys, there's so much that we don't know really about farming at all. We know, gosh, less than 0.0001% about soil, about plants, about biology. And I've also been telling people lately it feels like every day I look at this and every day I go about it, because you're continually learning and seeing trends, it's like the more you know, the less you know. This subject fires me up, although I seem rather calm. This subject fires me up because there are people out there that are telling you that you have to put on these pounds, or your soil test levels are gonna go down, or you're gonna mine your soil, or um, you're gonna go backwards. Newslash. I have guys that have been in this program now for going on five years. We're not going backwards. We are going forwards, and we are going forwards at a really, really good pace. The guys that have been implementing this, this is not a brag. They are in a good financial state, even with everyone breathing down our neck, telling us how miserable we should be. I have guys that are excited to farm in 26. I have guys that are excited to get out there and get going, excited to learn, excited to move forward. The other argument, at least from my perspective, in this, you have to apply pound scenario if we say there's different schools of thought, how many nutrients plants actually need? Hypothetically, the old, you know, I don't want to say the old, hypothetically, a textbook would tell you 17 essential nutrients for plant nutrition. I think there's way more than that. But when I was in college, they'd tell you 17. If there's 17, how come we only really focus on four, maybe five, the four being NPK sulfur, five being calcium, and the only way most guys look at calcium is if they need lime and their soil pH is low. If there's 17 nutrients and we've only focused on five, and we have to apply hundreds of pounds of something, where is there room to apply the other 12? What budget is that coming out of? Who's paying for that? So my challenge to you is this if you feel you are a farmer that needs to apply hundreds of pounds, I would challenge you to ask yourself which hundreds of pounds do I need to apply? Is it those five I just talked about? Is it Bora? Is it molybdenum? Is it zinc? How do you know? How do we know if we haven't been told? There's a lot of I would call them scare tactics going on in the industry right now, telling you that you have to continue to apply more, you're gonna go backwards. I have enough evidence, as do some of my mentors and guys that I work with, that that is not the case. I think that there's a lot of opportunity coming up for farmers that have pivoted, are willing to adapt, and have figured out how their soils are acting and what they can do to manipulate them and their crop to respond better to the growing season. Kind of off of this topic, also, as I write Rex, and I had a conversation with Sean Mettleton yesterday. He's been on the podcast a couple times. Sean and I were discussing yield goals and how, in one respect, um, obviously when you shatter them, they're kind of an arbitrary number. They're just a number on a piece of paper that you told yourself that you wanted to hit. If you're looking at them in terms of APH, um, I would say that they're definitely far more realistic goals for a field. And then all of us have sky-high expectations for our favorite field or um our favorite farm or a handful of fields in our farm that we know that that we can get more out of. But I think it's ironic that we have people out here telling us to apply pounds of something and they're not asking you what your goal is. Again, I'll repeat that. We have people out there telling us we have to apply X amount of usually to the tune of hundreds of pounds of something, and they never even ask you what your yield goal is. They never ask you if profitability is the goal for your farm. They just ask you about yield. And we've talked about this time and time again until I'm purple in the face on this podcast, that we have to get away from chasing the last five bushel or the last 10 bushel of a yield goal. I'll tell you when you don't chase them and you set realistic expectations for a field, a lot of the time you surpass it because we don't over-fertilize, we don't degrade carbon as much as we do when we over-fertilize, trying to hit a goal. And in the process, we overspend and we become less efficient, and our profitability goes down. The wildest part about this to me is that this is it's this should be common knowledge. This should be this shouldn't rough this shouldn't ruffle people's feathers. But it does. I think at the end of the day, what we all want is as as farmers, as business owners, as consultants, you want less stress and you want more success. You want more of what you're aiming for. You want freedom to be able to provide for your family, to pay off debts, to buy farms. Whatever your goal is as a farmer or business owner, they're all valid. Whatever your goals are are all valid. It's just we have to figure out how to get there. And this season of planning for me with guys has really, I guess, opened my eyes to the fact that a lot of the time we're definitely going out and we're we're swinging for the fence. But I think when we swing for the fence is usually when we hit, you know, a ground ball, so to speak. All of the best-lade situations and the greatest level of results for my customers have come from a really well-implemented, well-executed plan that was designed to feed the plant at the right time with the nutrients that our soil is not cycling at the critical time that the plant needs it. Again, sounds crazy that that's what I'm saying because it seems like it should be common knowledge. But it it hasn't been because for decades we've been told to feed the soil. As I was making my coffee this morning, which is now probably cold because I've been recording this, I thought about I'm gonna make a terrible analogy because I'm good at that. The terrible analogy is going to be if you think about your soil as a pantry, which many of us do, call a pantry, a bank account, whatever. Think about your soil in that respect and the fact that we've been told to fill the pantry. We've been told to fill the pantry. And let's say last week, meaning last year, right? We shop for groceries every week, usually, or potentially multiple times a week. When you go to the grocery store, do you fill your pantry with things that are already in your pantry? Or, meaning, let's say I have five five boxes of cereal, if I haven't eaten the five boxes of cereal, do I go buy another five boxes of cereal? Or do I check the fridge and make sure I have milk to eat the cereal? That, although it seems like a really terrible analogy, is the analogy for a lot of nutrients in your soil. Your plant, meaning you, can't consume the nutrients in your pantry, i.e. the soil, if it also doesn't have sometimes what it needs to go with it. So the cereal milk analogy can be phosphorus and zinc. You can have as much cereal in your pantry, phosphorus, as you want. You can have built your soil test level to 200 parts per million. I I literally don't care what the number is. But if you do not have enough zinc, or in this case, milk, to eat the cereal or the phosphorus, it doesn't matter. You can keep shoving boxes and boxes and boxes of cereal into your pantry. The only difference in this case is it's not gonna go bad in your soil, so to speak. It's gonna get tied up. And in the case of food, we have loss where we throw it away. In the case of fertility, we have loss where we create an efficiency. And the inefficiency is wasted dollars, just like it is in your pantry. So as you think about supplying your plant's diet in 2026. Think about what you have in the pantry. Get a good get a good. Actually, get a great. Get a great soil test that tells you what you have in your pantry and what you need to purchase to help you consume what's in your pantry. And although I thought starting out this was a stupid analogy, I'm gonna stay on this train for a second. We always want food in the pantry. We never want to run the pantry down to zero, right? Like we'll be hungry. But again, we don't continue to stuff it with the same things, especially if they're not being consumed. The point of applying fertilizer to a soil is to get it in a plant. Again, I am not telling anyone anything that they do not know, right? These are common knowledges and should be common knowledge in agriculture. But for whatever reason, we have strayed away from that and think that the number in terms of people, right? The number in my bank account or my profitability should be equal to the amount that's in my pantry. And that's also not true. When you try to stuff a pantry, there's a lot of waste. There's things that get pushed to the back, they never get utilized, and you ended up throwing them away. And they cost you money. Same thing happens in your soil. Same thing happens in your soil. Although they don't get thrown away, they get tied up and they go to a really, really, really bad bank. And by bad bank, we mean obviously we have seven days a week. They're open a very minuscule amount of the time. One divided by six, if we don't count Sundays, because banks are never open on Sundays, is 16%. So that'd be like putting everything in the bank and you can go there one day of the week or less. Maybe hours, half of a day. And the kind of bad analogy there is the bank doesn't tell you when they're open. You kind of have to guess. And that's also really hard. That's really hard. So banks like traditional soil tests and the fact that they might put on the door open one day a week or open a half of a day a week, but it doesn't tell you when that is. Get a soil test that tells you what time the bank is open. Get a soil test that helps you decipher what what operating hours they are open. And if you can do that, you'll be able to access the bank. But if you don't, we're gonna be throwing things at the wall hoping they stick. This part of my I want to say air quotes job, because I don't consider it a job. This is more of a mission that I have that I feel like I've been put here to do is to help bring profitability back to the farm gate. And it's happening for my customers. We are headed in the right direction. I think the industry is headed in the right direction, although right now we have this divergence of all the things I've talked about. We have people out there saying you still gotta feed pounds, but we also have a really big part of the industry that's telling you to feed the plant. And do not um do not mistake this by me telling you to feed the plant as to go to a 100% liquid fertility system. Not what I'm saying. Not not not what I'm saying. Nope. We take it a step further by saying you can use dry, you can use liquid, you can use a combination, a lot of guys do. But we also take into consideration timing, timing and availability of when you apply versus when the plant needs it. So essentially we're telling you, you know, when to go to the store and what to buy, because we know how much time it takes to either become available or to prepare, i.e., in your kitchen. This age-old myth about applying pounds has served us to a certain point, but it's not serving us anymore. And it's time to to challenge this way of thinking, I think, on a bolder level, and it's time that we kind of toss it to the side because at the end of the day, healthy plants drive nutrient uptake. It almost has zero to do with what you apply. I've been looking at a lot of soil tests, especially this week. And I haven't come across maybe, for example, in the last two days, so as I'm recording this, it's Wednesday. In the last two days, I've looked at 60 soil tests. 60, excuse me, 60 fields, likely five zones on a field, so 300 soil tests. There's maybe 10% where I know that that phosphorus, like applied phosphorus, would be a good buy. 10%. And I'm still very hesitant. It's gonna come down to a conversation with the customer to say, do you want to spend this money? Is it in your budget? Do we feel like we're gonna get a yield response out of that? Maybe we're gonna look at application timing, application rate, all of those things. Zinc. Biology. We're gonna look at all that to make a decision, but I'm not going to base it off of the Bray PP1 value that's on the test. Excuse me, the Bray 1 PPM value that's on the test. Zero of what I'm doing is gonna come off of that number. I don't even I don't even look at it anymore. I maybe glance at it just to see out of curiosity what my old brain would tell me to do. But yeah, after looking at 300 plus soil tests in the last two and a half days, there's maybe 30 zones where I would be tempted to apply some phosphorus because I feel like that soil needs a help and jumpstart with availability to help feed the plant because the soil is currently not supplying enough. But once we get that cycle jumpstarted, in theory, we should have to use less and less and less. And what I will leave you with is that if we've applied hundreds of pounds of fertility to a soil and it's been getting fed to the plant, we should be to a point where we don't have to be applying hundreds of pounds to the soil because we've built a healthy system that's functioning very well. But the truth of the matter is that we haven't done that. In a lot of cases, we've overapplied and we've actually our systems are underperforming. And so we, as managers, as farmers, as consultants, it's our job to bridge the gap of that functionality and to figure out where the disconnect is and how to fill it so that we can get the system back functioning so you can stop applying hundreds of pounds. With that, I hope you all have a great rest of your week. If you have questions, um concerns, comments, if you um want to come on the podcast and chat or be a guest, have a debate. I'm I'm up for all of it. Um again, my hope is I'm actually hoping to have a new guest on. I'm hoping to potentially actually turn around to record that today if I have some time or some white space. If I don't, I hope we can get that done this weekend. Because I'm sure you guys are here tired of hearing just me talk. And I want to bring on some people that have been utilizing this system for a while, and I want you to hear their take of what it's done for their farm. Not as a sales pitch, but from a peer-to-peer level. As a farmer, what can this do for me? And or what can even this way of thinking do for me? And I think really that's gonna be a key to 26 is to get uncomfortable. Get uncomfortable. Don't don't try to stay status quo. Um, the markets aren't lending themselves to that in terms of fertilizer. Like we can weather the storm. We just gotta have, we gotta have the right mindset. We gotta have the right mentality. We have to be willing to adjust on the fly. We have to be willing to deviate from our best-laid plan if the weather takes a turn one way or the other. But again, thanks for joining me. Hope you guys have a great week, and I'll talk to you soon. Thanks for digging in with us today. Remember, better data built better farms. Please like, share, and subscribe to receive notifications about new episodes launching every Thursday. To connect with me on social media, visit Twitter or at face voice. Number one.