Annual fall fertilizer outlook
Nutrient Management Podcast episode: “Annual Fall Fertilizer Outlook”
July 2022
University of Minnesota Extension
Written transcripts are generated using a combination of speech recognition software and human transcribers, and may contain errors. Please check the corresponding audio before referencing content in print.
(Music)
Paul McDivitt: Welcome back to University of Minnesota Extension's Nutrient Management podcast. I'm your host, Paul McDivitt, communications specialist here at U of M Extension. This is our Annual Fall Fertilizer Outlook episode. We have five members of Extension's Nutrient Management team. Can you each give us a quick introduction?
Dan Kaiser: This is Daniel Kaiser, nutrient management specialist with the University of Minnesota. I'm located out at the St. Paul campus.
Jeff Vetch: Hi, this is Jeff Vetch. I'm a nutrient management researcher at the Southern Research and Outreach center in Waseca.
Fabian Fernande...: And I am Fabian Fernandez, also a nutrient management specialist located in the St. Paul campus, focused on nitrogen management for corn cropping systems.
Brad Carlson: Brad Carlson. I'm an extension educator, I work out of the Mankato Regional Office and work statewide.
Lindsay Pease: I'm Lindsay Pease, and I'm a nutrient and water management specialist based out of the Northwest Research and Outreach Center in Crookston.
Paul McDivitt: So starting off, what are growing conditions looking like around the state?
Lindsay Pease: Well, to start out with maybe a more positive looking corner of the state, we've had a lot of good rain this spring, which is the total opposite situation of last year for us in the Northwest. And some of those have come down for some pretty heavy rains, including actually this past weekend we had a storm with 80 mile an hour winds, which to be determined how much crop damage that may have caused. But besides that, we have been getting a lot of moisture. The moisture in the soil is looking really good. We've had some nice... I've seen a lot of nice looking corn fields this year, which compared to last year is really positive. It does depend a little bit on your crop, though. I mean, I think the wheat could use a little bit more rain at this point. The soybeans, they probably got a little bit too much rain early on. I've seen some better stands of soybeans, but still to be determined how things turn out for the rest of the summer.
Brad Carlson: I'd say, as you move south, it's really sporadic as far as what happened for precipitation. There's been a fair amount of talk in the media about drought. If you look at the weather services' drought monitor, drought index, it doesn't really show or look real severe in Minnesota. There's a bullseye from the Twin Cities moving Southwest, and really, if you drive around, the crops don't look just terrible either, but I think everybody knows just from their observation that we just haven't been getting what's normal. I think the thing is, of course, we're in thunderstorm season now, where we don't get these big pockets of rain that just park over top of us like they would in the springtime.
And the thunderstorms do tend to be very spotty. I know, Jeff, you were saying that the recent event you got in Waseca, you had a couple inches and I'm 13 miles from the S Rock and I only got about a quarter of an inch. And that's what we've been seeing all over the place, and so when we come to the point of where we're going to start making some recommendations based on soil conditions for nutrient management, it's going to be quite variable. A lot of farmers are actually going to have very different conditions just on the land that they run.
Jeff Vetch: Yeah. I think that's a great point, Brad. We were part of the haves on Saturday, and there's still a lot of have nots in the area. We got two and a half inches of rain on Saturday, which was desperately needed. We were about three to three-and-a-half inches below growing season normal up until that point, so now we're pretty close to normal again. Our distribution has been weird all year. We were wet early, and had delayed planting, but like Brad said, you only had to go 10 miles south of Waseca, and down by the New Richland area, they planted on time and everything was perfect, but they didn't get the rain that we got in early May. So currently, we're looking actually quite good corn, the VT/R1, even some of the later planted corn here at the S Rock is starting to show some tassels today, I noticed.
GDUs, interestingly, even though we planted a lot later in last year, our GDUs are actually slightly ahead of last year, which was a very warm year. The GDUs we start recording, of course, on May 1st and not all the corn was planted May 1st. But as far as getting this crop to maturity, I don't think that'll be a problem. But Brad's spot on, it's very spotty around southern Minnesota with areas that have had adequate rainfall and areas that haven't. I've been in southeast Minnesota quite a bit here in the last few weeks. And in general, the counties around I-90 and south have had plenty of moisture and the very southeastern most counties have had probably almost excessive moisture. In the Rochester area and north there's a few spots that are drier. But in general, the crops look really good over there.
Fabian Fernande...: Yeah. One thing that I've noticed as well, and this happens every year where we start getting dry is the soil conditions, those soils that have been tilled correctly, that have not been compacted, those are the soils where you have more of a reserve in terms of collecting water and saving it for this time of the year when it tends to get dry, and the crops really need a lot of water. And soils where there have been poor soil management, that's where you start to see the droughty conditions happening quicker. So just as an observation, that seems to happen every year when we get to this time of the season.
Brad Carlson: I was at an event over the weekend, a tractor show, surprise, surprise. I had a chance to interact with a lot of people from all over the place. The one thing I'm hearing consistently is that the light-textured soils, so when you get in that St. Cloud area where there's a lot of sandy soils, any of that stuff that's not irrigated is really in a lot of trouble. Obviously, people set up for irrigation, that's been rolling and that's fine, and I would say that even in my own area, that I live near a lake and there can be some sandy pockets. Those areas look awful. There's probably not much to be expected of those, but the heavier-textured soils are still holding in.
Fabian Fernande...: Yeah. And it's interesting you mentioned that, Brad. I did a study a few years back when we actually had pretty good precipitation during the growing season, and still in those soils with sandy textures, even with what you would say adequate rain through the whole growing season, I think the average was about 70 bushel difference between a site that was irrigated, versus not irrigated at the control with nothing else, no inputs of nitrogen or anything. And then as you, of course, increased nitrogen rate that gap got bigger, with or without the irrigation. So I am not surprised if we see more of these dry conditions where that crop will really get hurt. Last year, in some of the irrigated versus non-irrigated studies, we saw zero yield in the non-irrigated, even at high end rates. Obviously, nitrogen was not the limiting factor, it was water.
Dan Kaiser: Yeah. We took off second crop alfalfa, that was about the week after the fourth. It was interesting, at Rosemont, if you don't know that station, there's a couple of different areas there. One is more or would be similar to some of the irrigated soils around the Hastings area, which is at Waukegan. It's a silt loam, but it's got a sand sub soil underneath of it. So had alfalfa on one of those soils versus one that was on a deeper loess, consistent with the southeast part of the state. And just the difference in tonnage was incredible on that. It boils back to water holding capacity. So I mean, you're going to see a lot of those areas, particularly if you've got lighter areas, this year, and it's pretty easy to see on that.
We'll see that area hadn't gotten a lot of rain. It has. So see what third crop does, if they're more closer, because if I get adequate rain, I can get some pretty decent yield off of that. Some of that lighter soil there. But a definite difference in what you're seeing in terms of the capacity of some of these soils to hold water in some of these areas that have rain. It, I think, leads me to believe we had a fair amount of recharge in the spring, which is helping us, but we're getting now into that R1 stage towards the end of July, we're, I think really at that critical stage where you start running out of moisture now. We're really going to start suffering some pretty significant yield losses, particularly for corn.
Paul McDivitt: What is the current status of fertilizer prices and availability in Minnesota?
Brad Carlson: Well, I was talking with a farmer friend of mine this morning and he had some price quotes from middle of June. And they're still looking at MAP at right in around $1000 a pound, and potash at about 900. He had a price quote for urea at 670, although I think we do want to point out the fact that we've really not been recommending urea applications for this fall. And I think one of the themes that came through last winter when we were talking about a lot of the fertilizer price issues was exactly where availability was going to be.
And of course, one of the things we also talked a little bit about was whether your retailer was going to actually have product available. They have a lot of sensitivity to putting product in inventory, and then having falling prices and potentially having to sell it for a loss. So the fact that there's urea quotes out there tells me that some retailers did stock up on probably more urea than they should have. And there is a chance that price is going to fall out. So watch it, I guess. We can elaborate a little more on that in a little bit, but I know Paul, you found some fertilizer prices too, recently, posted online.
Paul McDivitt: Yeah. So DTN, the progressive farmer, Russ Quinn, his fertilizer report from July 20th has urea down 10% from last month. On a price per pound of nitrogen basis, urea was 94 cents per pound, anhydrous, 88 cents. So anhydrous is going about 14.50 per ton. Yeah. If you're looking at compared to last year, MAP is still 44% more expensive than last year, and anhydrous is 100% higher compared to last year, and everything else is somewhere in between those. So, yeah, it's interesting to see those trends.
Jeff Vetch: Yeah, I think that's a good point, Paul, is that most growers are going to prepay. And last year they would've prepaid in July or August for the 2022 growing season. And they paid prices... Their prepaid prices at that time were, like you said, 40 to 45% less than they're looking at right now. So the reality of these prices is just starting to hit them, and that is really concerning.
Brad Carlson: Well, another element that set up last fall, particularly, we were hearing a lot of this as we were traveling around the state, doing educational meetings, was because the increasing prices really blindsided a lot of people. They were getting faced with, or I should say approached, by their retailers, their dealers, about changing their application practices. And very specifically, a lot of retailers were able to get anhydrous in the fall, and moved a lot of that product. And so there's a lot of producers who may not have planned on doing a fall anhydrous application who did, because they were able to get a price and get it on, and then not worry about what it was going to be in the spring. As far as that being a reasonable management practice, I think the parts of the state where that happened, it was fine, and it worked out fine.
I think the real take home, though, is that the farmers themselves probably had some thoughts in their head, or management plans in their head, what they intended to do, and then they ended up doing something else. And so that's at least another note of caution here, as we're sitting in the middle of summertime. Maybe be starting to have some conversations with those retailers about what this is going to look like. Because I know one of the things that really changed a lot was that we'd been seeing this increasing trend for split application, and some side dress. And there really wasn't nearly the extent of that this year as there has been in the last few years. And I think a lot of that was because producers got worried about whether an was going to be available and they just put it all on early.
Paul McDivitt: So what should growers be thinking about heading into fall?
Jeff Vetch: Yeah, it's about it's about this time of the year where I always get a couple of calls, or talk to some growers, people that work in the area, and people that maybe work here and part-time farm, and they look at their prescription maps as they start looking at picking on, or determining what they're going to apply. And there's a lot of concern about that out there, and it should be. As we mentioned earlier, the prices are way higher than they prepaid last year for. They knew that, they saw that coming up as the price ran up last winter and into the spring.
But they've also seen the last few weeks, corn and commodity prices starting to decline a little bit. And that is really a problem when you start looking at what the cost of production is going to be for this 2023 crop. We don't have Melissa with us today, but we also have to think about manure, and making sure that we utilize that manure at its best capacity. And that is a fall application, especially something like finishing manure that has a high ammonium content. We want to get that on out there as late as possible, make sure that we utilize all that nitrogen and don't put it out too early.
Fabian Fernande...: Yeah. And coming back to what Brad mentioned in terms of best practices, I think it's so important when prices are so volatile, and there is so much uncertainty, to remember the things that we are certain about. There is nothing we can do about the price. We had to deal with it as it comes. But the things that we are certain about is some of the best management practices that we have been talking about for years. And so whether the price is high or low, or the availability is high or low, that doesn't change the fact that fall urea, especially in south central Minnesota and really and truly throughout the state, based on some of the stuff that we have done recently, it's just not a good practice regardless of what the price of nitrogen is.
We've looked at that. We know that we lose nitrogen, and we lose yield. And we've looked at doing all sorts of different things with urea in the fall to see if we could improve the efficiency of that fertilizer. Banding it, applying it with an inhibitor. And of course, waiting until the soil temperatures are low, anything like that. And none of those practices ever yielded more than a spring application of the same amount of nitrogen. And so those are the things that we know for sure. So it gets panicky at times with the uncertainty on prices, but just remember at least those things, the things that we know for sure. And so when we are looking at high prices, of course we need to be looking at what is the most efficient way to apply fertilizers. And so sticking to the best management practices is a key component.
Dan Kaiser: Yeah. And I think that's one of the things to consider on this is, say you put on fall urea, all of our data says you're likely going to lose a portion of it, which isn't necessarily a good practice in general. From a PR standpoint, particularly, since we know that that's likely going to occur, and then you're come back in the spring, probably have to apply higher priced fertilizer again, anyway, to make up for some of that loss. So I mean, it's one of the things just to really look at the data that's out there, and that's pretty strong dataset, I know that Fabian put together, just looking at the potential yield loss from those fall applications, particularly in corn production. And we're looking at it right now in sugar beet production, too.
I know that's more of a standard practice, is fall urea particularly for some of the southern growing regions. Last year wasn't probably the best year to test it. Didn't really necessarily have the rainfall to move some of it out. So that's a work in progress there with some of the other crops, but it's just one of the things, I think, to think about. And then start prioritizing what makes the most sense for our applications and the best data that we have right now is with phosphorus, that we know if you've got a good soil test, and we know what the general risk is, should you not apply phosphorus, for a potential yield reduction.
And even with higher prices with MAP or DAP near 1000 per ton, we know generally if you're in that low to very low situation, you're likely going to get a positive return on investment, even with higher prices. It's not going to be as good as you'd normally get, but overall, those are areas that you want to be looking at targeting. And if you're medium and higher, you really can look at cutting back in that area. I mean, you don't really need that full rate if you're not putting that 80 pounds removal on for your 250 bushel corn crop, you likely aren't going to see any effect for the 2023 crop. And I know some people may want to argue with that, but if you start looking at our data more and more, that even a cut rate, one thing about it, you look at 40% of removal or less, you could put that on, would slow down your decline. Although your general decline in your soil test shouldn't be that rapid where you couldn't avoid putting it on for a year or two.
I mean, the other thing is to look at your starter practices, you may or may not need that, or maybe you can get away with just the starter in some of those areas. So I think with phosphorus, there's much more flexibility. Potassium's an unknown, just on my standpoint, because the soil test can change drastically just over time from dry conditions. And we know that as we get into the fall, if we get a dry year, that they tend to be a little bit lower, and likely a lot of that's because we've got a lot of potassium, the residue that hasn't washed out. So that's the one I'd be a little bit careful on.
I mean, if you're around 150 parts per million in most of your fields, I would just be a little less inclined to cut potassium, versus all my fields are 20 parts per million in gray phosphorus or plus, it's a pretty easy one to make that decision. So I think it's just going to be sitting down and looking at where you're at, because if you have built your soil tests up, if you're in a situation where you can do that, they always talk about the soil as a bank, it's a good time to withdraw. And then if we get lower prices, the other question then to conversely, is, should I up my rate? And that's just a question on your overall economics.
But in general, we've got good data at least to tell you what a good target point is, particularly for phosphorus, where you should be good, where you shouldn't really have to put on that high removal rate, if you're looking at a place to cut cost. In nitrogen, we already adjust for that. That's what the recommendations adjust for us. We can play around with that a little bit in terms of the prices, but some of these other ones, I would just start looking at, if you aren't soil sampling, it's what we say every year. It's a good time to start doing it, because the overall price of soil analysis, you see that remain relatively stable. I think it's good information to have going into 2023, if you're looking at making a decision on when and where to apply phosphorus in some of the fields.
Fabian Fernande...: And coming back to the timing of application and some of the things that we've talked about, especially for nitrogen, I think delaying the application until the spring when it's the best time to do the application anyway, adds flexibility to your whole operation. I mean, potentially we are looking at areas in the state where it could be pretty dry. Hopefully things will get good, we'll have good crops, but what if we are in a situation like we were last year, where we ended up with residual nitrogen? Or this spring, where we were late, it was cool and somewhat wet, and we got delayed planting? And if you're already applying nitrogen, you're basically set. There is nothing you can do in terms of adjusting things. You already put that investment out in the field. If you delay that application until the spring or even side rest time, you have a lot more flexibility in how to manage that nitrogen application to the best conditions based on what you already know about that growing season. So that flexibility can be extremely important.
So holding off and waiting, I think, is very, very important. And then as Dan mentioned, in terms of prioritizing things, nitrogen obviously is one that we definitely need to prioritize. I would highly recommend looking at the nitrogen rate calculator, because that already knowing the prices of corn and knowing the price of nitrogen, it will allow you to determine where the economic optimum is. So you'll get the best return on the investment. And then down from nitrogen to phosphorous and potassium as Dan mentioned, I think it's so important to prioritize. Look at your soil test values for those two nutrients, and figure out whether you need both of them, whether you need more of one and not so much of the other. In my experience, typically people tend to go for the priority is nitrogen and then phosphorus, and then last potassium. And based on my experience from before, typically potassium should be more of a priority in some sites where there is plenty of phosphorus to go around.
Lindsay Pease: Yeah. And I think, as we went around the state talking about the different planting conditions we experienced, I think a lot of crops went in late, which is also going to give you less time to put in fertilizer this fall. So in case you need an extra motivation to maybe wait until spring, I think the extra time that it might take to do that application, that's just another reason to maybe sit tight and wait until the spring. Especially, I think a lot of guys in the northwest it's always scary to do that, especially when we have wet springs and a lot of flooding. But this could be a good year to maybe try that, maybe go with, as Dan mentioned, a starter fertilizer, especially for phosphorus, I think you could probably... It's a good year to maybe experiment with that.
Brad Carlson: I think one last thing I'd like to mention in this regard is that last year we focused a lot on the potential for residual carryover of nitrogen, nitrates in the soil. We had a lot of conversation about soil testing for that, and of course, where we're dry this year, we're going to have that potential again, going into next year. But it's worth mentioning that because nitrates are so mobile in the environment, they're prone to leach or to de-nitrify, that unless you're out on the western side of the state, we really don't recommend taking that test in the fall. So it's a point worth thinking about, that we may have some carryover nitrogen. And particularly if you're in the central part of the state, south central part of the state, and you're looking at putting on fall anhydrous, you may think about lowering your rate.
Particularly if you're in a situation that's had a manure history, or if it's corn on corn, and it's been quite dry, you very well could see a nitrogen credit for next year. However, we probably aren't going to want to see most of those producers' soil sample and credit that until the springtime, when we can be more certain that the results are usable for that. And I guess the last little point of that is if you do want to take that test, make sure you got an area that you didn't apply some nitrogen on. So if you put a half rate on, for instance, you're probably not able to soil sample that anymore and get an accurate, usable result for nitrogen credit. So there has to be at least a little sliver there for you to be able to sample that had no fall nitrogen applied, or else we aren't really going to know what's out there.
Dan Kaiser: So I'm going to pose this question actually to a few of you that have been out looking at some of the fields. I mean, how does the deficiency for nitrogen look this year? I mean, to me, looking at some of my fields, I can start to see some of my zero end plots, but it hasn't necessarily been as striking as I've seen the last few years. And you look at some of these wetter areas too, I just drove through one closer to Spring Valley coming up Highway 63 recently, and water's sitting around there, but you still, everything looks pretty green. So just curious, we talk a lot about carryover, but it may be an indicator in some of these fields that there was something there that, seemingly, even if we did lose some right now, which we should be, if it's warm and the soils are saturated, that we're not going to be quite as bad of a situation maybe than we were last year, when it seemed like we had more striking nitrogen deficiencies.
Brad Carlson: That's exactly right, Dan. In fact, I was chatting with somebody about this very thought, because it's so dry... Some of the areas like where I'm at, it's so dry in that top foot, but the crop looks really good as well. If we did have a lot of carryover N from last year, there's a chance that N was deeper. And so if we're using deeper water reserves and there's nitrogen down there, it's still feeding the crop. And that's a good thing because we're using that nitrogen then, and not losing it to the environment. But I think there definitely is the possibility that we've got some deeper nitrogen that's still left over from last year that these deeper water reserves, as the plants are picking that up and staying fairly green. But I know Jeff, you guys have had some experience at Waseca where green crop this time of year doesn't necessarily mean it won't still run out by the end of the year.
Jeff Vetch: Yeah, that's true, Brad, and I would agree though, with what Dan had said earlier, and what you mentioned, Brad, is that I think over the last two weeks, I've probably scouted eight or nine nitrogen studies and looked at every plot. And my general consensus would be that the N response curve or the amount of N that's going to be needed this year is going to be less than we've seen over the last three or four years. And I think that makes sense, because we came out of a relatively dry year last year. There's probably some residual N leftover in many fields, and we've also had minimal N stress. Now here at Waseca, we did have a really high rainfall event in mid-June that probably contributed to some denitrification.
But prior to that, we hadn't seen a lot of nitrogen stress or nitrogen loss conditions being extensive. So what I see right now is nitrogen rates that are less than 100 pounds are starting to start to look yellow and have some lower leaves that are starting to be nitrogen deficient in both corn on corn, corn after beans. But in corn after soybeans, the MRTNs right now look like they could be in the low hundreds, and certainly not above 150. In corn on corn it's just hard to say, because boy, until this rain last week, our corn on corn was really struggling. And when it struggles, it's hard to tell what an optimum nitrogen rate's going to be when it was so stressed for moisture.
Fabian Fernande...: Yeah. And we did measure some of that this spring in terms of residual, and there was quite a bit, and as Jeff mentioned, there was really not a lot of potential for nitrogen loss this spring. And so I highly suspect that there is quite a bit. And as Brad mentioned, as we go into the season and the roots go deeper for water, they will tap into some of that nitrogen. So I think as long as we have moisture to carry the crop through, we will be in a better situation, needing less nitrogen than in previous years.
The other part of course, too, is mineralization, and that is influenced very much by moisture. So if we have adequate moisture conditions, which improve the crop, they will also increase the amount of mineralization. Remember that this spring was cool early on. I mean, there was moisture, but it was cool. And so mineralization was slower early on. And then as the soil is warmed up, then there was plenty of moisture. And I suspect there was quite a bit of mineralization happening as well. And if we continue to have moisture later in the season, that process will continue to kick in nitrogen for the crop.
Dan Kaiser: Yeah. I think the majority of the deficiencies I saw early on were striping due to sulfur. I know Lindsay up your way, I had one of my studies up there. I had one, I had close to 100 pounds of sulfur applied between the fall and the spring applications. It had still striped. And then I saw a fair amount at Rosemont. So that was the big one, it wasn't as much nitrogen early on as it was looking like sulfur deficiency. Now, some of the fields seemingly have started to come out of that funk, but still, it was one of the things I think I saw more often than not this spring, was sulfur versus nitrogen.
Paul McDivitt: What about products that aim to increase fertilizer efficiency? Should more growers consider them?
Fabian Fernande...: Well, that's coming back to what we were talking with prices and things like that. That's always a really tempting thing to look into, is what is out there that can help improve the efficiency? And as I mentioned before, the best management practices, that's really where you need to be grounded. The things that we know for sure that work. And that includes inhibitors, nitrification inhibitors. Now the temptation a lot of times is, you do a poor job in terms of when to apply your nitrogen and then use an inhibitor to save yourself from that bad practice, right? And that doesn't work. Two negatives doesn't mean a positive. And so if you are applying nitrogen in the fall and you say, "Well, I will use a nitrification inhibitor so that it makes it better," well, our research shows consistently that that doesn't work.
The inhibitors, the nitrification inhibitors, they have a life expectancy. If you apply them at the wrong time, let's say too early, when it's warm, they will break down faster and they will not protect your investment. They will just simply wear out before you need that protection. And so while yes, they normally can help you, you have to use them correctly. And the other part, too, is that they do add cost to the total investment. And so I would say the best time where a nitrification inhibitor will pay off is when you do a fall application of anhydrous, for instance. Again, with urea, we've tried it, it doesn't work. So don't try applying a nitrification inhibitor with urea in the fall, because it's not going to help you in any way. It will just add cost to that application.
With anhydrous ammonia in the fall, once the temperatures are below 50 degrees, that's where I would say an inhibitor has the most potential to help you. The second best place would be for anhydrous ammonia in the spring application, if it's done early in the spring. And then if you do applications later in the spring with anhydrous, then the potential of getting a benefit out of a nitrification inhibitor goes down to simply because it's less likely that you will lose, or you will have potential for loss of that nitrogen investment. So the inhibitor at that point doesn't really give you much additional protection. And then, well, this may be a point for next spring, but the other inhibitors that we normally talk about are urease inhibitors, and those are very, very important if you are applying urea on the soil surface, and you know that you will not be able to incorporate it with tillage, or with rain in time, where you can potentially lose quite a bit of nitrogen.
But those would be the things that we know, we have more certainty that they work, as long as we use them at the correct time and form. And then of course there are many other products out there that the research, I don't want to be negative on these things, but the research pretty consistently shows that there is very little potential to have a consistent benefit. There are biologicals, there are many other products out there that promise great efficiency, a reduction of 30 pounds or whatever. And pretty consistently, we don't really see that benefit out there. And so my suggestion would be to stick to what you know that works, and that has worked in the past, and go with that.
Dan Kaiser: I think a lot of the fallacy that people think is that fertilizer prices really dictate how well these things will work, particularly the inhibitors, and it's not the case. I mean, there's a certain set of conditions where they tend to work. If you look a lot of the data on the fall nitrification inhibitors, that here will be a spot there where there will be some advantages, but there will probably be more times where there won't be. So that's the thing when we start talking about costs with fertilizer, that it just adds to the overall cost, as do any of these products. And that's a thing that concerns me about it is, you likely could go in and add a little bit, or take the cost you'd be willing to spend on some of these products, and put it into few more pounds of fertilizer probably is going to have more of an effect with it. So we've been looking at a lot of these biologicals, and while I think there's some promise there, the consistency isn't there.
So that's the thing, I guess, that I just caution people on some of these things. It's still a situation where I'd try and see on some of this before I would just completely treat all my acres, because it all carries a cost. And a lot of times, that cost can be fairly substantial, and you're maybe somewhere else that you could divert some of that money that makes sense. So I just, we do a lot of testing on these things. I haven't found a silver bullet. Lindsay, I think you've been doing some testing. You're in the early stages of that. Your area, a lot of times, phosphorus is the big one, that you're looking for ways to unlock the phosphorus that's there, and it's just not easy to do with some of these products. So just be careful with that in terms of cost, because it might be a way you can at least make a few more bucks per acre by limiting some of these out of your overall fertility plan if they're going to give you a low return on investment.
Fabian Fernande...: That's right. Yeah. Yep. And then one other thing that I would mention is polymer coated urea. That's another one that it has an added price compared to urea, and folks looked at that as well. Can I do that for fall applications? And again, we've looked at that, and it just doesn't work. You are way better off applying polymer coated urea as a spring application and being smart about it, where to apply it, too. That's the other important thing. If you do a spring application with a polymer coated urea, targeting parts of the field where you know that potential for nitrogen loss is greater.
So low laying areas in the field, for instance, where you tend to have more moisture and more potential for denitrification, or leaching areas in the field, those will be the areas where maybe you can target an application of these more expensive products that do give you the protection that you need. But again, with fall application, we have looked at polymer coated urea, and the polymer, again, holds urea, protects it for a while, but by the time you really need the protection, which is in the spring, that polymer is already breaking down and the protection is simply not there anymore.
Lindsay Pease: Yeah. And I think as far as the biologicals go, this is the second year of a trial that I've been working on with Paulo Pagliari at the Southwest Research and Outreach Center in Lamberton. And we both got a dual trial going on where we're looking at inoculating some wheat plants with a bacteria, and doing a rate study along with that. Last year, unfortunately with the drought that we saw, we didn't get much of any results to speak of off that. So I think this summer, we should get some better results off that, and this winter will have some things to report.
I also have a trial that we are spraying some SOURCE out there, if that's a product that people have heard of. So we are testing a few things, as we always are, and hopefully this winter, we can have a little bit of data to share with you guys on those. But I absolutely agree with everybody else, go with what you know. It's really important when there's so many uncertainties, but we do actually feel pretty confident as a group on some of these things that we've been telling you for years. So that's, I guess, what I would encourage everybody, to just go with what you know for this fall.
Paul McDivitt: All right. Any last words from the group?
Jeff Vetch: Yeah. Paul, Dan mentioned this earlier and I think it's still worth touching on it. I know there's a lot of growers that stopped soil testing in recent years, and they just don't do it anymore. Part of it may be because they're just putting on crop removal P and K and they just don't think it's necessary, or they don't want to take the time, or spend the money on the analysis. But boy, when MAP and DAP are $1000 a ton, and Dan is right. Phosphorus is the nutrient that in many fields, especially in acid soils in south central, southeastern Minnesota, that they're most likely to be able to save fertilizer dollars on. There's still time to take a soil sample after early harvest this fall, and adjust those phosphorous rates and save themselves some significant dollars. You're not locked into putting crop removal on every year, especially when your soil test are in the high, very high categories.
Dan Kaiser: And I need to get a news release out, just talking about removal because it's not important really to manage down to the pound. And that's where some growers get really focused, they think on, or the retailers, on the factors that we recommend, particularly for removal, or we suggest to use for removal, that there's a window there. And so looking at these high rates, whether I put 40 units on and you put 80 units on, you've got a 250 bushel crop, I doubt you're going to see any difference the next year with it. I mean, it's not a perfect system, and that's one of the things you've got to realize is that while there is some suggested factors to use, that there's some slop there. And so overall, managing down to the pound isn't overly important. I mean, you get to the low and very low, maybe, where we see a higher return, and where the phosphorus is needed. But once you get to a certain point, you have a lot of flexibility. So I think that's really the thing to remember, is that there is more flexibility than you think there is.
Paul McDivitt: All right. That about does it for this episode of the Nutrient Management podcast. We'd like to thank the Agricultural Fertilizer Research and Education Council, AFREC, for supporting the podcast. Thanks for listening.
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