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[00:00:00] Mike Howell: The dirt with me, Mike Howell, an eKonomics podcast where I present the down and dirty agronomic science to help grow crops and bottom lines. Inspired by eKonomics.com farming’s go-to informational resource. I’m here to break down the latest crop nutrition research use, and issues helping farmers make better business decisions.
[00:00:30] Mike Howell: Through actionable insights. Let’s dig in.
[00:00:39] Mike Howell: Well, hello again everyone. Welcome back to the Dirt. Spring is quickly approaching and everybody’s getting itchy to get in the field and get started with our field work. We’ve been talking here for a week or two about things that we need to make sure we have in place before we get in the field. We wanted to look at eKonomics and understand what our crop prices and our input costs we’re going to be.
[00:00:59] Mike Howell: We wanna focus [00:01:00] on the weather, make sure we have an idea of what’s going to happen with the weather. And the final thing that we wanted to mention in that list was our soil samples. To help us go through that and talk about what we need to be looking for for our fertility levels and talk about some different situations is Dr.
[00:01:15] Mike Howell: John Jones. We have John with us today. John’s from the University of Illinois. John, welcome to the Dirt.
[00:01:21] John Jones: Thanks, Mike. I appreciate being here and looking forward to our conversation.
[00:01:24] Mike Howell: We’ve had John on before he joined us last season. He’s relatively new there at the University of Illinois, but wanted to give John a chance to introduce himself to our listeners and let us know what he’s doing there.
[00:01:35] John Jones: Sure. Thanks Mike. So I’m been an assistant professor of agronomy in Department of Crop Sciences and Soil Fertility extension specialist for the state of Illinois. My research generally revolves around soil fertility and nutrient management, a little bit of precision agriculture, and then reducing nutrient losses as well.
[00:01:51] John Jones: Probably what you’d expect in terms of general fertility work and focus. What we’re trying to do is also fill in some knowledge gaps around the state. And [00:02:00] provide information that’s readily usable for farmers.
[00:02:03] Mike Howell: John, sounds like you’ve got plenty to do. Let’s kick it off and get started today. One thing we wanted to talk about is just a basic review of a soil test.
[00:02:11] Mike Howell: Go through a little bit of that. Tell us why it’s so important and. What’s meant by the different categories that growers are gonna get back when they send in a test, when they get that report back, I see different things. I see low, medium, high, optimum, different categories in there, and it’s gonna vary from which lab you use.
[00:02:28] Mike Howell: Tell us a little bit about that and what we need to know about that. Well, when we think about the value
[00:02:33] John Jones: or the number you see for your field, your grid point, your sample that you send into the lab that you receive back, that value really needs to represent in index or availability of nutrients throughout the whole growing season.
[00:02:46] John Jones: It’s not just one snapshot in time, and we’re gonna say, this is gonna be the nutrients available. From planting to B six, that value has to represent the nutrient dynamics of a whole growing season. So that’s something that’s really important and we need the statistics to be [00:03:00] sound and repeatable behind those relationships when you see those ranges, let’s say very low, low, optimum high, very high, some states use excessive states range and change depending on what the terminology is.
[00:03:13] John Jones: And that probably just goes back to personal preference of the original scientists that came up with those. But in general, what those ranges represent. Our levels of responsiveness that we would expect those soils to be to fertilization. So when we think about a low testing soil, or we mention a low testing soil, it’s usually a soil that the nutrient concentration is low enough where it’s inhibiting yield, but also inhibiting our response to fertilization.
[00:03:38] John Jones: On the flip side, when we look at very high testing soil, we don’t expect a lot of fertilizer response or fertilizer to change. Yield, let’s say relative to an unlimited yielding situation. We kind of move back into that middle space, that optimum or medium category. Usually what that’s representing, and again, some states vary, but that represents a soil test range of where you’ve [00:04:00] optimized or sometimes maximized crop yield.
[00:04:02] John Jones: Usually there’s a range in response to Fertilizations, and we can talk about that as well. It depends on the state and the system that’s set up. In general in those ranges, we’re trying to replenish and replace what nutrients were removed in the field of harvest, and we’re trying to kinda live within that one range.
[00:04:19] Mike Howell: John, I’ve looked at a lot of soil reports and help growers make decisions on that, but one of the most often asked questions I get is, which nutrient is most important? A lot of growers can go put out a nitrogen application and they can see it green up almost instantly after that nitrogen application.
[00:04:35] Mike Howell: It’s not hard to see a response to that or vice versa if you miss a spot in the field with that nitrogen. Nitrogen application, you can definitely pick that up. Some of the other nutrients, it may not be quite as easy to see that. Does that mean that nitrogen’s any more important than any of our other nutrients?
[00:04:49] John Jones: In some senses, yes, and some no. We know that nitrogen is the primary macronutrient that we usually focus on in terms of. It really representing a large portion of [00:05:00] the yield that’s produced or the biomass that’s produced. So in some senses, nitrogen takes the top priority In that cases, however, we get to a point where if there are other limiting nutrients that we see those other nutrients playing, kind of a flipping a switch that reduces crop yield or allows it to optimize or maximize as well.
[00:05:19] John Jones: When we think about how nutrients interact in the plant and soil, I think it’s really important to kind of define those relationships between one, two, or three other nutrients. And I think there’s specific types of interactions that take place. A few studies that that I’ve been working on have been looking at interactions between soil test phosphorus, potassium, and nitrogen for corn and soybean production.
[00:05:41] John Jones: Really looking at the nitrogen portion and the corn part of the rotation. When I talk about those results of those studies, I like to say we have really three different types of interactions of nutrients within our production systems. We have true internal physiological interactions where we know that one nutrient is reducing the [00:06:00] effectiveness of some metabolic activity.
[00:06:01] John Jones: The second type is really more statistical, and I would say that’s what we see mostly in field agronomy research, where we have a fertilization level for PA fertilization level. For nitrogen, maybe we have different rate ranges and we try to say there’s an interaction between those. I think that’s really what most of the production agronomy research results, when they talk about interactions represents.
[00:06:24] John Jones: And really I think that’s more meeting different thresholds of requirements of nutrients. Not so much a synergistic effect, but you’re meeting the threshold that’s really restricting that yield level. Sometimes that’s framed in the the Le Big’s law, the minimum I challenge any listeners to read about scientist Carl Springle, who also published a little bit earlier at that time, relating to limited nutrients within systems.
[00:06:46] John Jones: I think that’s really what we see more often. Then there’s also that third interaction, which I can’t leave outta the conversation. As a soil scientist, you have nutrient interactions solely in the soil on cation exchange sites at interfaces. Those are really strong kind of [00:07:00] inorganic chemistry interactions between specific nutrients.
[00:07:03] John Jones: So when I’m talking about nutrient interactions or soil tests, phosphorus and potassium effects on corn, response to nitrogen, I’m really talking about different meeting, different thresholds of nutrient requirements. So to wrap that back up to your question about nitrogen, yes. Generally nitrogen takes the cake in terms of we want to get that right, but we know from our research we can get our optimal nitrogen rate perfect.
[00:07:26] John Jones: But if we had a low enough soil test, P and K, our yield and profitability was reduced. I.
[00:07:31] Mike Howell: John, you mentioned when you talk about this, and I guess I should have led off with this, I was in Des Moines, Iowa and got to hear you make a presentation where you talked a good bit about this stuff, and one of the things in your presentation you mentioned, you said to think about soil test levels in the context of response to fertilization, not an absolute yield level.
[00:07:51] Mike Howell: Can you elaborate on that a little bit? Tell us what you mean by that. Yeah,
[00:07:54] John Jones: certainly Mike, when I talk about interpreting soil test levels in that work, we were really focusing on phosphorus and [00:08:00] potassium, so the nutrients that we rely on, soil test levels to guide fertilization. We’re really looking at three variables.
[00:08:06] John Jones: In that case, I. We’re looking at a soil test level or that value on your soil test report, we’re looking at in the research side, a yield of an unfertilized treatment and then the yield of a fertilized or unlimited treatment. What we’re really looking at, and it kind of harkens back to those interactions I talked about, were that we’re thinking about three variables.
[00:08:26] John Jones: Essentially how, let’s say Z affects how X changes y in essence, how soil tests affect, how yield is changed when we fertilize. There’s no yield change. Then we have a low response to fertilization. If there’s a large yield change, then we probably have a low testing soil, I’m guessing, and we have a high response to fertilization.
[00:08:48] John Jones: In that context, we’re not looking at soil test P by yield relationships. Now those exist. If we’re low enough in P, we can limit yield. What’s the management decision we wanna make from that soil [00:09:00] test? We wanna fertilize with something if we’re low enough in limiting yield. That’s why we take response to fertilization into account.
[00:09:06] John Jones: Usually if you’ve seen graphs or figures on presentations that are discussing this. There’s a term called relative yield that’s used. Relative yield is simply the relationship and the way that I define it, a control treatment where we don’t fertilize in relation to the statistically highest treatments in that given study.
[00:09:24] John Jones: Sometimes that includes a control if we didn’t see a yield response. That’s why you see relative yield plateau. Usually between 95 and 105 when we get to really high testing soils. Now, one of the questions that arises is how do you get above 100% relative yield? And that’s because we simply see yield variation, maybe a fertilized treatment, reduced yield by one or two bushels.
[00:09:45] John Jones: That’s just the realistic range and noise of this data. But the general trends show that our soil test levels have a strong relationship between relative yield. Or response to fertilization. ’cause at the end of the day, that’s the management practice. We wanna know if we [00:10:00] need to do or not, should we fertilize or not.
[00:10:01] John Jones: That’s why I talk about relationship between response to fertilization, not absolute yield. Now I do get the question, how does yield level. Come into this discussion. And I think one important thing, and that’s something to challenge and ask about recommendations and interpretations are what were the unlimited yield levels within the study?
[00:10:20] John Jones: Are they profitable? Are they competitive? So those are things that are nice to piece out of this work and are kind of in the foundation and baked into a lot of what’s, say, recommendation discussions. I think it’s important in cases where you can break out yield levels and show that, for example, I was working up some data the other day for a very low P testing soil, five to eight parts per million of break.
[00:10:39] John Jones: Our unlimited yield in this study was still 245 bushels of corn, but that required that high rate of phosphorus fertilizer to get to that point. The yield level of the unlimited treatment was relatively high and very profitable. The yield level of the unfertilized treatment around a hundred sixty eight hundred seventy one bushels per acre was low and not [00:11:00] profitable.
[00:11:00] John Jones: So that’s why I look at yield response to fertilization, not absolute yield.
[00:11:04] Mike Howell: I could have talked forever and wouldn’t have known that. Appreciate that, John. Some great points there. Another question that I often get is around eKonomics and you know, fertilizer prices have been relatively high for the last couple of years.
[00:11:17] Mike Howell: Growers are thinking about cutting back on some inputs, trying to save money, and I totally understand that. And we’ve done several podcasts talking about that. One thing you talked about was the agronomic optimum ranges for p and k and that they should not be adjusted based on variable pricing. You said to focus on which soils will and will not provide.
[00:11:36] Mike Howell: ROI to fertilization. Talk a little bit more about that and help growers understand the pros and cons of backing off of these fertilizer rates.
[00:11:44] John Jones: Sure. One of the things that we’re always considering, and I think we take this sometimes from the steps that we build nitrogen recommendations, for example, or assess a nitrogen response.
[00:11:54] John Jones: Generally there’s some price consideration in that when we move to phosphorus and potassium, because we’re managing [00:12:00] soil tests. That’s really the goal, is to look at how our fertilization affects soil tests and gets to a certain range where we can kind of live in an optimized space. When I think about strategies to optimize profitable crop production, we really need to be in a place where that we’ve got some buffer against large swings in prices.
[00:12:20] John Jones: Generally, we see that if we maintain optimum or in some states medium soil test levels, the reason that’s the case is when we get to those ranges, we have a relatively low or moderate response to fertilization in most cases. That’s why we’re usually, in most systems, there’s a recommendation for.
[00:12:39] John Jones: Applying to removal rates or the nutrients that we know would be taken off in the crop. One of the things that’s important to talk about in this case though, what’s going on in those low testing categories? Do we need to take prices into consideration In those cases, and one of the unfortunately cliche answers is it depends on the system you’re using.
[00:12:55] John Jones: I know in the systems that I’ve worked in when I was a student in Iowa. When I was working [00:13:00] in Wisconsin and updated their phosphorus recommendation, potassium recommendations, and now working in Illinois. My philosophy that I’ve kind of learned from mentors and throughout the system is that for fertilization rates in our low and very low categories, we need those to optimize, yield and be a profitable system.
[00:13:16] John Jones: So the response to fertilization again, and building soil test levels is not something that we want to chase based off of prices. You certainly don’t want to chase soil test levels based off of price considerations. I think that would be very difficult to try to adjust because we know, in essence when we try to build or draw down soil test levels, it’s not always clear how exactly we’re going to change that level that we get back in the lab the next year.
[00:13:43] John Jones: I always like to use the term you have to pay the reaper in some cases because we have clay minerals and organic matter that disrupt exact responses we’d expect within soils from fertilization. You’ve seen that in some research. When we look at the rates of soil test buildup [00:14:00] and soil test drawdown are not necessarily equivalent.
[00:14:03] John Jones: That’s something important that maybe we can go off on a different topic another day that’s defunded to dive into, but the way we expect our soils respond to fertilization isn’t always consistent. So a more even keeled and predictable way that we can have a profitable system is maintaining those optimum categories.
[00:14:21] John Jones: Now, where I think we should adjust strategies based off of price considerations are when we start thinking about our rate decisions, our fertilizer rate decisions. I. If you’re in a high testing soil, we know we have a fairly lower probability of an ROI or response to fertilization. We can probably back down on our rates and let that soil draw down, at least to a point where we know we’re getting towards that ocland range.
[00:14:43] John Jones: If you’re in the optimum range, and maybe historically you’d been putting a little bit extra on to build to a high category, maybe you can cut back just to your removal rates to maintain that ranges. But there’s a caveat in all of this and that we need consistent soil sampling. An interval within the rotation to track that [00:15:00] because we know, for example, in K.
[00:15:02] John Jones: We can draw down very fast. The research that I’ve done in Wisconsin showed that our ability to build up soil test K was more difficult, but we could draw it down pretty fast. Mostly looking at the pools of K where our crops are pulling those nutrients out of. If indeed we get to a point where we’re, let’s say, really stepping back on our fertilization rates, we’re either just going to removal.
[00:15:23] John Jones: Or a lower rate. Make sure to keep those soil tests collected at the correct intervals in the rotation so you have consistent data to show where you’re at. That would be my recommendation. In general.
[00:15:33] Mike Howell: John, one thing I’ve seen over the past few years, a lot of growers are backing off on their fertility to try to save money and.
[00:15:39] Mike Howell: You can get away with it for a year or two and it really doesn’t affect yield. But when you start getting back to the curve on that plateau, you can fall off of that plateau really quickly and it’s not a gradual decline. It’s kinda like falling off a cliff. We wanna caution people to make sure they don’t fall off of that cliff.
[00:15:55] John Jones: One of the challenges, and I think that holds true on the yield levels that you’ll [00:16:00] see with that, but then also. I caution against trying to stay away from letting your soils drop down into the low and very low categories, because when the time comes that you need to build back up to the Optum range, you’re really.
[00:16:14] John Jones: Playing dice or bedding, that prices are gonna be favorable when you do that. It’s much easier and profitable in a system to maintain soil test levels that are going to maximize yield and profitability than let them ebb and flow and flux, because then you’re really at the whim of what the current market’s gonna be.
[00:16:33] John Jones: If you, let’s say, run into a situation where you have very low case soils and you need to build. So that’s a struggle, and I think it’s something that is not solely agronomic. It’s taking eKonomics into consideration. Maybe land tenure rented versus own land as well, and thinking about how you get to the point where you can buffer some of these big fluctuations.
[00:16:52] John Jones: There’s also the point in the rotation to consider where I’m at in Illinois, we have almost ubiquitously. On soybean [00:17:00] rotations, you get to different parts of the country where maybe that rotation is in the point where you know that crop really needs potassium or really needs phosphorous. Maybe that’s the point in the rotation where you’re hitting those fertilization rates to build a little bit if you need to.
[00:17:14] John Jones: We always do quite a bit of research, I think in the north central region on in a corn soybean rotation, is it best to fertilize for both crops before corn? Should we be fertilizing every year? Do we switch nutrients? And I’ve been fortunate enough to work on some of that research. Throughout Wisconsin and now we have studies in Illinois looking at that as well.
[00:17:32] John Jones: In generally, as long as we’re getting those optimum rates out there, we don’t see a big difference in terms of point in the rotation where you’re applying that fertilizer, which is a good win, I think, for growers and agronomists because it means you have some flexibility. Prices are really favorable, and you’re going into a soybean crop.
[00:17:48] John Jones: That actually means that you could put your fertilizer out there before your soybeans, even though it wouldn’t necessarily be when you’d expect to do that, and you’d be safe for your following corn crop. There is some flexibility because we don’t see a [00:18:00] large difference, and I think that hearkens back to the fact that when we talk about, again, these medium or optimum categories, that’s the sweet spot to be in.
[00:18:08] John Jones: That’s where we know that we can buffer changes, we can stay away from large yield losses. But I think there’s also another point, and that kind of relates to. Some stewardship and sustainability context is that if we’re dealing with high testing soils, you can let those draw down to a certain extent, monitor them with soil testing, but you can let them draw down to where you’re reaching that optimum range as well.
[00:18:30] John Jones: I think that gives us a lot of flexibility when we talk about previously manured systems where maybe you just had inherent high soil test P, for example. You’re able to essentially feed off of those residual P numbers for a little while.
[00:18:42] Mike Howell: John, another thing I remember from your presentation was that you stated that there was a clear incidence of P and K limiting corn response to nitrogen and affecting the economic return to NP and K.
[00:18:53] Mike Howell: Tell us a little bit more about that.
[00:18:55] John Jones: For these studies, what we did was we really looked at, again, that interaction of soil test [00:19:00] level and response to nitrogen wasn’t a fertilizer rate interaction. What essentially we did was build different levels of soil test P and K, and then ran nitrogen rate studies across those and corn soybean rotation only the nitrogen being applied to the corn right off the bat, and I showed this in the presentation in Des Moines, when you look at aerial imagery or we took crop sensor images.
[00:19:21] John Jones: You can see clear deficiencies in potassium. In our low testing soils, we didn’t see deficiencies to phosphorus as often, even though we did have low P soils every once in a while or where we were dealing with some very early planting dates. In cool springs, you can visually see the blocks in the treatments where we were low in potassium.
[00:19:39] John Jones: It was for a soil fertility scientist. Really exciting because you get to see these textbook deficiency symptoms. Now if I’m a grower, I’m concerned about that. Where we saw a really clear indication that P and K were limiting corn end response is when we looked at all of the data and started aggregating it across many sites around the state.
[00:19:56] John Jones: For example, in low testing soils for [00:20:00] our, we’ll say, SILT loan regions of the state. When I grouped those types of sites together. We saw about a 25% reduction in corn yield and a 9% higher economic optimum end rate. So we actually saw more nitrogen was needed in that case, and we already reduced yield.
[00:20:16] John Jones: Really, it was just a system that wasn’t very efficient at using our applied inputs of nitrogen. In this case, there was no p and k applied. Certainly it affected yields statistically, and it affected the bottom line. If you look at profitability. Now on the other side of that study, if we had optimum ranges of P and k, usually those were between about 130 and 170 parts per million of soil test K and 16 to 23 parts per million of Bray one soil test peak.
[00:20:44] John Jones: When we got to high categories as well, which we managed usually above those doum ranges, we didn’t see a large response or a change within yield levels or response to nitrogen. What that told us was the optimum sweet spot of where we could be. Living in [00:21:00] and maintaining our soil test levels was not just the best scenario for phosphorous potassium, but also for nitrogen as well.
[00:21:06] John Jones: We looked at the price of fertilizer it would’ve needed to maintain high testing soils, and that’s where we looked at the economic response to NP and K. Essentially, what I ended up doing was looking at the dollars of fertilizer it would’ve cost in the rotations. To maintain high P and K levels and reach the rate.
[00:21:26] John Jones: And what we saw was when we were in optimum p and K testing categories, we had already maximized yield and we had optimized our yield response to nitrogen. That’s why we looked at those three nutrients in. Consideration as a whole, because in general we said, well, what’s the fertilizer bill of the rotation?
[00:21:43] John Jones: That’s where we saw that again, that sweet spot. I think it was a different way, and generally in these types of studies, we look at maybe just response to nitrogen and different price scenarios. We looked at response to NPNK at different price scenarios.
[00:21:57] Mike Howell: John, another thing that you mentioned that goes [00:22:00] along these same lines is you caution growers not to risk poor nitrogen, use efficiency from inadequate P or K.
[00:22:07] Mike Howell: Talk a little bit more about this relationship and why that’s so important.
[00:22:10] John Jones: From the same research, we really came to that pretty quick conclusion, and I think we were able to expand that across different soils and growing conditions, or that we know annual nitrogen. Investments for form production are one of the highest parts of your input budget that you’re looking at throughout your crop projects for a given year.
[00:22:28] John Jones: And we saw the results of this research indicating that to really make sure that you’re getting the most out of that annual nitrogen investment, making sure that you’re monitoring your soil test p and K levels so that you’re at least getting in the optimum category is a way to do that. One of the things, again that I mentioned before, what we saw is if you could predict the exact optimal amount or exact amount of N that was needed by that corn crop and apply it even in low P and k soils, yield and profitability were reduced.
[00:22:58] John Jones: Now, if you were at least at the [00:23:00] optimum range and higher, we saw no difference in that. If you could predict that optimal end rate Exactly. You were spot on for profitability, but even if you got your nitrogen plan exactly right. Which I don’t know if anyone can claim to do because it’s tough managing the exact time and rate and placement of nitrogen.
[00:23:17] John Jones: But even if you could theoretically get that perfect, we were still limiting yield from low testing P and K soils. Back to your previous question on priority of S to think about getting that annual nitrogen investment is correct, but when we think about P and K, it’s a long term game. We’re looking at changes over time, soil test, interpretations and values, hopefully within every two to three years of the rotation.
[00:23:40] John Jones: We think about that. It’s really important to build that base of soil test P and K when we’re thinking our response to nitrogen. I think one of the things that I always ask in presentations when I share results from this study is who was surprised that when we had low enough P and K, we limited yield and profitability?
[00:23:56] John Jones: I. I hope no one raises their hand because we reckon back to our [00:24:00] old Soul fertility textbooks, our John Lin’s textbooks that show those priorities or maybe the barrel of LE’s Law, the minimals. One of the parts that I think is important and shows that there’s value in a lot of the soul test calibration work is that when we hit that optimum range, that was that sweet spot.
[00:24:17] John Jones: Because really managing high testing p and k soils is another challenge, and it’s a challenge. I think that needs more research focus in general. How do we still either draw those down or have a profitable system? Certainly when we think about safeguarding our annual nitrogen investment, thinking about.
[00:24:34] John Jones: Kind of the balanced whole system for crop nutrients has a lot of value.
[00:24:38] Mike Howell: John, you’ve given our listeners a lot to think about some really great information here today. We appreciate you taking a few minutes to share this with us. Is there anything else you need to talk about before we wrap up here, or any closing comments?
[00:24:49] Mike Howell: I.
[00:24:50] John Jones: Mike, we’re in a challenging spot right now when we think sometimes about fertilizer eKonomics and if prices are a little more unfavorable in certain scenarios. I think one of the points that, and [00:25:00] again, it’s probably not surprising from a soil fertility scientist, is that this is where we can really see monitoring soil nutrients in a very tight interval within our rotation really pays off.
[00:25:10] John Jones: Whether you’re doing a variable rate system where you have a zone system or grid sampling, or you’re looking at whole field averages, having those numbers, those ROI to soil testing is relatively high right now. I think that’s something that’s really important to consider, and then just look at all of the data that you can collect.
[00:25:26] John Jones: Whether you’re layering yield and soil test level data on top of each other and take each year into consideration of the context. We’ve got some long-term data that shows when we’re in dry scenarios. We really see an inefficient use of potassium, most likely because we have some type of restriction or restriction to available K, and we see different optimum rates and dry years as well.
[00:25:47] John Jones: Every time we can pull a soil test, look at yield data and take it in the context of that year, I think it’s really important. One of the challenges we’ve faced over the last few years is we’ve had fairly dry conditions when we should be soil [00:26:00] sampling. If you have two to three soil tests points, and maybe that represents four to six years of the rotation, and you’re always sampling in in dry conditions, that’s something to think about and maybe it’s worth considering.
[00:26:12] John Jones: Taking a few spring samples and seeing how those relate to your fall numbers as well. So take everything in context of how we’re trying to manage it. I think as a discipline in soil fertility, we’re trying to do that. We’re trying to take maybe state or regional numbers that generally, if we’ve kind of used averages across larger regions and take them down to a granular scale or we can say in this type of soil, in this general environment, this is what we would expect.
[00:26:37] John Jones: I think that would be the important thing. Take things into context of what happened last year. And then we’ll try to do better next year. I think that’s what we’re all trying to do.
[00:26:45] Mike Howell: John, that’s exactly what we’re trying to do here. Help people do better this year than they did last year. We really appreciate you taking your time outta your day to visit with us and share this information with our listeners.
[00:26:55] Mike Howell: Listeners, if you will, hang around for just a moment and we’ll be right back with segment [00:27:00] two. Farming isn’t farming without questions, and now there’s a place to go for answers. At eKonomics, an entire team of agronomists is waiting and ready to help for free. No question is too big or too small. Visit Nutrien eKonomics with a k.com at submit your question with the ask an agronomist feature.
[00:27:24] Mike Howell: Listeners, welcome back for segment two. We’re glad you’re sticking around for our ask the agronomist segments. Today we’ve got Dr. Alan Blaylock back with us again. Last week we asked Alan a question about Denitrification and he took us through the process of denitrification and how we can lose nitrogen through this process.
[00:27:40] Mike Howell: Alan, today our question is kind of along those same lines. What can a grower do to manage denitrification losses?
[00:27:47] Alan Blaylock: Keeping in mind that denitrification results from the presence of nitrate in an oxygen deficient soil. We can do some things to manage the drainage and the water status [00:28:00] of the soil. So oftentimes we install tile drainage in those soils that tend to stay wet longer, so removing that water faster can reduce the denitrification.
[00:28:09] Alan Blaylock: Sometimes heavy clay soils, they’re hard to drain and we can’t do a whole lot about. The water status, but drainage can generally help us there. The other thing we can look at that’s very effective against denitrification is some of our different product choices that we have. We have something called nitrification inhibitors that slow the conversion of ammonium to nitrate, so thereby reducing the nitrate concentration for a period of time.
[00:28:34] Alan Blaylock: Typically, they’re effective for anywhere from four to eight weeks, maybe a little longer depending on the product and the environmental conditions. So we reduce the concentration of nitrate for a period of time that reduces the potential for loss. Slow and control release fertilizers are extremely effective at reducing denitrification losses for much the same reason is they’re releasing the nitrogen over a period of time, so they’re reducing the amount of nitrogen, especially the nitrate [00:29:00] form at any point in time in the soil.
[00:29:02] Alan Blaylock: If a wedding event occurs that causes denitrification, there’s less nitrogen exposed at that time to that loss that’s occurring. ’cause these tend to be. Episodic in nature, we get a rainfall event. The soil’s wet for a few days, have denitrification, and then as it drains and dries out, uh, then the process becomes aerobic again.
[00:29:20] Mike Howell: And Alan, what about the controlled or slow release products? Do they have any benefit on denitrification?
[00:29:26] Alan Blaylock: We’ve had great results with the slow and control release products in the research we’ve been doing. We’ve had some sites that have been very poorly drained soils, clay pan kinds of soils where water ponds almost all the time.
[00:29:37] Alan Blaylock: And this has been one of the places where. Our control release product, our ESN product has been extremely effective. We’ve had really very good results in those environments with that product.
[00:29:47] Mike Howell: Well, Alan, once again, we sure appreciate you taking a few minutes each week to visit with us and answer some of our questions.
[00:29:53] Mike Howell: Listeners, thank you for tuning in again this week. And as always, if you have any questions about anything we’ve talked about, you can [00:30:00] visit our website. That’s Nutrien eKonomics with a k.com. Until next time, this has been Mike Howell with the dirt. Hey guys. If you like what you heard today, do us a favor and share this podcast with someone else.
[00:30:15] Mike Howell: It could be your neighbor, your friend, your crop advisor, or whoever you think would enjoy it. Your support helps ensure future episodes, so please like, subscribe, share, and rate the show wherever you’re listening from.
