Spring nutrient management decisions
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. Today on the podcast we're talking about spring nutrient management decisions. We have six members of Extension's nutrient management team. Can you each give us a quick introduction?
Dan Kaiser:
This is Dan Kaiser, Nutrient management specialist at University of Minnesota Extension located at the St. Paul campus.
Fabian Fernandez:
Hi, I'm Fabian Fernandez. I'm a Nutrient management specialist at the University of Minnesota in the St. Paul campus and I work primarily on nitrogen management for corn cropping systems and environmental quality.
Brad Carlson:
This is Brad Carlson, I'm Extension educator. I work out of our regional office in Mankato. I work statewide on water quality issues with a lot of focus on nitrogen.
Chryseis Modderman:
I'm Chryseis Modderman, I'm an Extension educator out of the Morris office. I focus on manure and nutrient management.
Jeff Vetsch:
This is Jeff Vetsch. I'm a researcher here at the Southern Research and Outreach Center in Waseca.
Lindsay Pease:
And I'm Lindsey Pease. I'm the Nutrient and water management specialist at the Northwest Research and Outreach Center in Crookston.
Paul McDivitt:
Great. So starting off, what are field conditions looking like around the state?
Lindsay Pease:
Well, up here in northwest Minnesota, we had a rapid snow melt here in the past couple of weeks. We had a lot of snow over the winter and I was really surprised how much of that actually infiltrated into the ground. We do have slightly deeper frost depth than normal here. I've heard some reports that it might be about nine inches at this point. We're at the end of March up here, and that gave a lot of space for that snow cover to infiltrate.
Lindsay Pease:
And on top of that, we had quite a bit of rain last October. So coming off the drought, I know a lot of people are probably pretty worried about what the residual soil moisture is like. But from what I've been seeing up here in the northwest, we're going to at least be starting off the growing season with a good amount of moisture in the soil.
Jeff Vetsch:
So this is Jeff and down here at the Southern Research and Outreach Center, we're at currently at about one and a half inches less than normal precip so far for the 2022 calendar year. We don't have any tiles flowing that's primarily because the soil is still frozen from about 10 to 20 inches.
Jeff Vetsch:
Once that frost is gone, a few warm days and dry days will allow for fieldwork to begin. But right now there's really not a lot of those warmer, dry days in the 10-day forecast. And as far as a moisture status in our soils, I would not be surprised when the frost is gone. We will see some light tile flow, but it's definitely not wet.
Chryseis Modderman:
My situation out here in west central Minnesota is very similar to what Lindsay talked about right away. We had at least a foot of snow sitting on the ground and then a really fast melt around March 16th to the 20th, something like that. We got up in the 50s and everything, but it was gone in a week.
Chryseis Modderman:
We still have a couple of snow banks hanging around, but most of the snow is gone. That doesn't mean we're done with snow for the year. We know how Minnesota is with that. But I'm hoping fields will dry out quickly once the soils warm up. We're still sitting at soil temps around freezing 30 to 35 degrees.
Chryseis Modderman:
And I know people are itching to put their manure out. I know that's a thing in everyone's mind, but I'm urging you to pump the brakes just a little bit. You want to be able to incorporate that manure into the soil and you really want to avoid all that runoff. The Runoff Risk Advisory Forecast sends me a text every morning almost saying there's a high risk of runoff in our area. Maybe pump the brakes on nutrient manure applications right now.
Brad Carlson:
I might just add one little tidbit. I got some data out of the Southwest Research and Outreach Center in Lamberton. It's looking at their soil moisture status after nearly record deficits, it actually got drier almost than the drought in the 80s there in the middle of summer. They've had, I guess for the time period above average precip starting about the middle of August and they are currently almost at field capacity and actually above average as far as soil moisture water in the rooting zone right now compared to their long-term average. So the western side of the state I think all the way down is actually relatively wet.
Fabian Fernandez:
Yeah. And I have a study there in Lamberton, southwest, where we are measuring nitrate leaching and it was interesting because we have a new graduate student that started his project and he had no water collection all season long until the very end around in November where we finally started to get a little bit of a trickle, not too much, but we did get a couple of measurements late in the fall which is telling me that the soils finally recharge and with yeah, the snow and the precipitation they had so far, I think that they're setting up in a pretty good place right now.
Paul McDivitt:
What have you been hearing about fertilizer prices and supplies in Minnesota?
Brad Carlson:
Well, I've been doing some calling around and this of course, has been a pretty hot topic going back all the way towards the end of the growing season last year. So called a couple of different dealers in the last few days. I'm hearing anhydrous prices right in the vicinity of $1,575 per ton. Urea prices right around $975 per ton. 32% is roughly about $750.
Brad Carlson:
So looking at the anhydrous and the urea price that puts us right in between 95 cents and a $1.5 per pound of actual nitrogen, I guess, as far as other products, DAP is in the vicinity about $975 and potassium actually I've gotten some wide variability on that. One vendor I talked to said $645 and another said $850. I think also been hearing though that because of that product coming out of Canada, the Canadian rail strike has really affected that. And so I think some of that depends on whether they got product in earlier or not.
Brad Carlson:
As far as availability goes, I've really spoken to no one who thinks that's going to be a big problem. I think one of the topics though we've been talking about all winter is the fact that dealers are not going to want to incur a lot of risk related to fertilizer inventory and falling prices and the possibility of losing money on fertilizer that they purchased and then had to sell at a lower price.
Brad Carlson:
And so I'm still hearing that same message that a lot of dealers were fairly conservative with their purchases this winter. And so I'm hearing that the pre-plant applications' not going to be a large problem, still strongly encouraging producers to get the fertilizer priced. It's not really very likely you're going to see the price go down. So you might as well bite the bullet and get that taken care of. But I am hearing that there still could be some issues relative to the sidedress, topdress time because again, a lot of these dealers were fairly tight on their purchases. And so if you did not pre-book that, there still could be some risk relative to that.
Paul McDivitt:
How can growers save on fertilizer cost this spring?
Dan Kaiser:
Well, certainly, looking at our recommendations, nitrogen, we are already building our recommendations around economics. So it just paying attention to that. And I'll talk about before we end here today, a little bit of the changes that we're looking at for some of our recommendations.
Dan Kaiser:
With the other nutrients, the advantage really is if you've got soil test data, it's a good time to start using it. If I look at both the phosphate, whether it's MAP, DAP, or any of the other products that are out there, if you're in a situation where you're above the critical level, so say above 20 part per million Bray phosphorus, we know that the overall probability you're going to get a response to that nutrient is really low. And if you have starter as an option, that's something to think about. It's one of the things on the supply side. I know Brad, I'm assuming they didn't mention anything on starter. So like 10-34-0 at all, whether or not there's any issues in that or not.
Brad Carlson:
I think that's all clicking along. I think most of the dealers are pretty well up on how much product they go through. It's really only when producers start really switching radically from one product to the next that it starts causing a lot of issues. And so no, I didn't really hear... I didn't get a price on that, but likewise, nobody indicated that was going to be an issue this year.
Dan Kaiser:
So that's an option. Starter only if you do have that option, even with as little as about two and a half to three gallons of 10-34-0, generally if we look at phosphorus, you're going to see the likelihood that if you get a response, if you start getting into some of those higher soil test levels, it's likely going to be to the first 10 or 20 units. So that's generally what we look at like a two and a half to five gallon 10-34-0 rates.
Dan Kaiser:
So that option's there, there's always that question and I know that'll come up with growers that are maintaining, what's it going to do to my soil test values? And certainly there is a risk if you don't apply phosphorus. On average, generally we're looking at around a two part per million average decrease over time if you look at yearly decrease over an extended span of time with no phosphorous application. Some of the data if I go back to some of the studies we've had within the last 10 years, we've been able to maintain medium to high soil tests with this little as about 40% of crop removal.
Dan Kaiser:
So I know generally, some is better than none if you're going to get into that situation. The situations when it comes to phosphate, you really need to look at are those medium to low and very low, which the low and very low is where you're going to get a pretty high return on your investment. So those are areas I wouldn't cut if you can variable rate, then look at some of those other areas and just look at a lower rate. If you're looking at a spring application, I would bet though that a lot of the acres have been applied already. There may be a few out there with spring application, especially with phosphate that might be looking at this. But that's one both that and potash. You're probably looking at quite had a bit of that going on.
Dan Kaiser:
Potash is the other story. And I don't know right now. The last couple years, we've seen pretty strong responses to it because of the dry conditions. That's one. If I had to make the judgment call in a normal year, you'd normally say, well, a lot of our soils are more likely going to be deficient in phosphate, but I think the opposite is true. So those two, you can go by soil test. K is going to be one of those ones that it's just going to be situational depending if we get to a wetter year, we may see some of the availabilities go up of that nutrient where may not see a strong response.
Dan Kaiser:
Looking at them the easiest way is to go by soil test. Nitrogen and sulfur, those are the ones since they're mobile. They're ones that are going to be probably more needed than anything else, but P and K are one of those that I would just go back to the soil test and just see where you're at with that. And zinc's the same way with micros. If you're looking at trying to save somewhere because you want to try and invest somewhere, those are at least ones that we can look at some data and just see a relative risk for them being deficient.
Fabian Fernandez:
Yeah. And of course, we always talk a lot about nitrogen because like Dan mentioned, this is a nutrient that it doesn't really store very well in the soil and we just need to apply it every year. But we need to remember that last growing season was pretty dry in a lot of places. There is a lot of potential for residual nitrogen in the soil.
Fabian Fernandez:
And I know Brad mentioned the issue of, well, we have supplies this year, even though the prices are high there, the supply is not really a problem. The problem is when people radically change what they're doing, but this is one year where potentially waiting to apply nitrogen could be important because, well, first, if you do a soil test, you see how much residual you have. The longer you wait, the better it is because if you take a soil sample, it gets really wet. Then that number could potentially mean very little because you don't know how much nitrogen is available after the potential for loss.
Fabian Fernandez:
But if the spring comes a little bit drier or normal where the potential for nitrogen loss is not very high, you could potentially have quite a bit of nitrogen from the residual of last year still available. And so looking at side dress application timing could be very helpful this year to save on the fertilizer application simply because at that point, when you're doing a side dress, you know what the season brought in terms of precipitation and potential for loss, and then you can adjust those rates based on what you may have seen in a soil test and how the crop is developing, looking at how green the crop is looking, things like that can help you determine whether you need to do a full application or if you can buy with less.
Brad Carlson:
Yeah, we were privileged to have some data shared with us from Minnesota Valley Testing Labs on soil nitrate testing. And so these were soil nitrate tests sent off this last fall. So I'm going to presume mostly on the Western side of the state, we really don't recommend taking that test farther east where it is going to be wet. But of those samples that came back only about, even less than 30% had a zero credit. So more or less 70% of all the samples that came in had some nitrogen credit of at least 35 pounds. And in fact, almost 30%, 28% had a credit of 155 pounds or higher. And so the potential is fairly significant.
Brad Carlson:
Now, I want to remind everybody, this is not a random sampling of fields. These were fields where testing was done because they already suspected there was going to be nitrate. But the bottom line is, if they thought that it was going to be there pretty much it was. And so I think farmers do need to be cognizant of that, especially in the, we talked about the field report and the South Central parts of the state where we still have a significant moisture deficit, there still could be the opportunity to take a fairly significant credit.
Brad Carlson:
The other thing we got for data was Central Consulting did share some data with us that was done as a pre-sugar beet test. Now, that was a little bit farther north. And in from those results, actually there was much less residual nitrate, but I think that was probably more relative to some different cropping systems and so forth.
Brad Carlson:
I guess the one thing, though, I would remind anybody that's looked at taking that soil nitrate test is that the interpretation of those test results, our University of Minnesota calibrated results are in parts per million. And you can find the chart that goes through what those credits are to interpret that online and our fertilizer recommendations. But I want to remind everybody that we start at six parts per million. And so that's an assumed background level of soil nitrate.
Brad Carlson:
And so if you get the results back in pounds per acre, usually they aren't subtracting that off the top. And so that data could be or that interpretation, I should say, could be a little bit on the high side. And so you'll either want to make sure you get the test results back in parts per million, or you're going to need to do some correcting if the results come back in pounds per acre. And so I don't think we need to go a lot farther on that, but that's just a little caution relative to the soil nitrate test.
Dan Kaiser:
Yeah. And that's one of the things I'm concerned about looking at some of the river levels. If we do get a lot of water, what's going to happen with some of the nitrate concentrations because it's setting up probably not as severe as '88 was, but you saw some of the water started to turn back on some higher levels coming through just because there were some credits that could be made and growers are putting full rates on.
Dan Kaiser:
So I think on the research side, that's one of the discussions that we're going to have to have at some point is how to account for some of this and look at it because I think it's better done up in say the Red River Valley and around Lindsay's area because growers are used to that, but we get into South Central, maybe Southeastern Minnesota, we don't really look at that crediting going on. So it's going to be I think an issue of starting to look at how do we handle these years and maybe have some flexibility with fall applications. Can we take a sample and then put a partial rate on and then make some corrections in season? Or what can we do to look at some of this?
Dan Kaiser:
Because with some of this, Brad, looking at some of that data, it's incredible seeing that roughly a third of them that, we're suggesting roughly 150 pound credit, which is pretty substantial to what you would need for a going into corn on corn. And the other thing that can impact is soybean this year with IDC and some of those areas that are prone, we may see that flare up too because of some of the residual nitrates in the soil post-harvest.
Dan Kaiser:
So that's going to be one of the things that is going to be see what's going to happen this year, but looking at for the future research side, just seeing whether or not there's some things we need to look at in terms of how to handle some of these years better than we are right now and crediting some of this is going to be I think the key to that and just seeing how accurate those numbers are.
Chryseis Modderman:
To tack onto this reducing fertilizer costs this spring conversation, something you might want to think about maybe is using manure, whether this spring, or if fertilizer costs stay high maybe next fall, maybe something you set up over the summer, that thing.
Chryseis Modderman:
So the number one question that I'm getting right now is about buying and selling manure. And it's both sides that are asking me this. It's both crop farmers and livestock producers. And you don't necessarily need to have manure be a stock producer do this. There's been a lot of new connections between the crop side and the livestock side lately just because of the high fertilizer prices. And it can be a win-win for both sides of it. The crop farmers getting those nutrients from manure. And then not to mention all the soil health benefits of manure while hopefully paying less than what they would for like a commercial fertilizer.
Chryseis Modderman:
And then on the livestock producer's side, they get money for manure that is probably going to need to be applied anyway, and it increases a total land base. They can get more manure out on the land, free up some storage space, that sort of thing.
Chryseis Modderman:
So when I'm talking to people about this, there's a couple things I like to remind them of. So especially if you're coming from the crop side of this and you're not really familiar with manure and how all of that works, first of all, you're going to need to know the rules and regulations because when manure is applied to land that's owned by someone else, not the lifestyle or manure producer, it's called transferred manure. So that's usually has its own set of rules. And if you're using a commercial applicator, there might be other rules or records that you need to keep and all this can vary based on location.
Chryseis Modderman:
So you just got to know what you're dealing with your rules and regulations. And then just the inherent things in manure that can sometimes be complicated and confusing. I had a guy call me the other day and say, "Oh, they're planning on putting on way too much manure. The rate's going to be way too high." But what he didn't understand coming from a crop primer perspective was that not all of the total nitrogen and manure is plant available that first year. So he thought, "Whoa, we're just going to apply a huge amount." But you need to remember that some of that nitrogen is in the organic form. It's not immediately available. It needs some time to mineralize and become available.
Chryseis Modderman:
But by far the biggest question I'm getting is what should it cost? Everyone's wondering about pricing, how much should either they be charging for their manure? How much should I expect to pay? And that's a tough thing because it's not a standardized arrangement. It's not set up by any outside entity. So there's some loose guidelines that I like to spout at people. And whether they follow them or not is up to you. [inaudible 00:22:02] skills is all part of this too. But the biggest guideline is both sides need to feel like they're benefiting. And they need to feel like they're getting something out of this, value out of the arrangement.
Chryseis Modderman:
Here at the Human Extension, we have a manure value calculator that you can go in and it compares your manure nutrients with fertilizer prices, helps you figure out your nutrient value of your manure. Otherwise, I've heard people multiplying the average price of the Urea and [inaudible 00:22:37] by the first year available nitrogen in the manure or some use crop nutrient removal rates to estimate price. But just remember that when we talk about the word "value," it should be based on the amount by which commercial fertilizer purchases can be reduced.
Chryseis Modderman:
So if you have a field that already has high soil test P and phosphorus, yeah, adding more phosphorus to that field maybe isn't needed or valuable, then there's really no value to that manure then. So it all depends on what your field needs, what you have to apply to that. And then I always recommend a written agreement versus a handshake agreement, although lots of people have handshake agreements. My folks have a handshake agreement for using manure. And hopefully these relationships can continue in the future because I see them as really benefit.
Paul McDivitt:
What are some key research insights you learned from this past winters meetings or your own projects?
Fabian Fernandez:
Well, I guess to start off and going off of what Chryseis was talking about in the both Nutrient Management Conference and the Nitrogen Conference, I think there were a lot of questions about what Chryseis was saying. What is the value of manure for the nutrient content?
Fabian Fernandez:
And continuing with economics, we had Gary Schnitkey from University of Illinois talking at the, I think it was the Nutrient Management Conference in Mankato. And he talked about the fact that while there are some things that are similar in this high price era to what happened back in 2008, he's forecasting that these prices may continue high for longer than what we saw that previous cycle of high prices. But then he also talked about the fact that the corn prices, the soybean prices are also going up. And so overall the income the farmers are seeing should not be affected very much.
Fabian Fernandez:
Again, I'm not an economist. I'm just repeating what I got out of some of these messages. Bu certainly one thing that we need to remember is that, and some of these things happened before, fuel prices went up and things like that and all the issues that are happening right now with Ukraine. And we need to remember that fertilizers are a commodity and these prices are affected by what happens not only in the US, but worldwide.
Fabian Fernandez:
I'm actually talking right now from Argentina. I'm here for the Precision Conference and the crop is getting ready to be harvested corn and soybeans. I also noticed there was quite a bit of sorghum in the Palmas region which called my attention. But anyway, I think we need to keep that in mind, but that was certainly a lot of what was in people's minds is the price of fertilizers and how to adjust things or make the best use of that fertilizer.
Fabian Fernandez:
In terms of some projects and the things that I've seen this year, well, first of all, last year in a lot of my nitrogen trials, nitrogen was not the limiting factor. It was precipitation. There was plenty of nitrogen. And in many studies, we actually maximized the yield with not that much nitrogen, again, because the yields were very low. And what was limiting the crop was not nitrogen. It was water.
Fabian Fernandez:
But interestingly, some others, I still saw quite a bit of nitrogen needed to optimize the yield, even though the yields were nothing to call home about. They were pretty low yields. We still looking at the maximum return to nitrogen. Those values were still high and I'm still scratching my head a little bit about it because I thought, well there is plenty of nitrogen to go around. I just don't know why that may be.
Fabian Fernandez:
The one thing also in terms of, we're talking earlier about crediting nitrogen from the previous growing season. One thing that I've noticed too in some of these studies where we are looking at based on nitrate tests is that those values were pretty high. And in drought years, those values are pretty difficult to use because they tend to be really high. And one of the potential benefits of that is that nitrogen is in an immobilized form, is in an organic form right now. And so it will be protected from leaching if we start getting we conditions. So that could be a good thing for the early part of the spring if it gets wet.
Fabian Fernandez:
But yeah, substantial nitrogen in the crop because in much of Minnesota, we were dry during the grain field period. And then we started getting rain. And so the crop greened up and took up a lot of nitrogen, but the sink or the grain where that nitrogen would be was already passed. So there was no sink for the plant to store that other than in the plant itself in the green material, in the stocks. And so we have quite a bit of that nitrogen that potentially, again, could serve as really mineralisable nitrogen source, these growing seeds.
Fabian Fernandez:
And I mentioned earlier too that in Southwest Minnesota, we didn't really see much leaching until about November. And even at that point, there was very little leaching that happened into our rain studies before this whole froze. And then the other thing that I've noticed, that we had a pretty large study that we started last year, looking at ESN polymer-coated urea as a nitrogen source, we are comparing that to urea and in different blends and things like that.
Fabian Fernandez:
And last year, there was such little potential for nitrogen loss that nitrogen source really had no much of an effect. Just whatever nitrogen source you use was there, it didn't get lost. So no much problem there. We did see in some sites where we were trying ESN as a split application, which I started this study and I minimized the number of treatments where we apply ESN as a split application because we know that it is a pretty risky thing. And it certainly was this year because with the dry conditions when you apply a product like ESN that needs moisture, it takes a while to just start releasing nitrogen. And so we saw no benefit from doing that. We will repeat the study this year, and hopefully we'll have more of a normal condition to evaluate it a little bit better.
Fabian Fernandez:
But those are the things, from my perspective, that I've seen this last growing season and during the winter meetings. And just as a final thing, one thing that we are doing right now is, we are starting a new study where we are evaluating the PSNT, the Pre-Side-dress nitrate test and the pre-plant nitrate test as a tool to determine how useful this tool may be. We have had a number of years where many of us here at the university and others have collected these information. And so we are trying to do an analysis of all those studies to see what we can learn and see if what we have right now in terms of those recommendations still holds if we need to make adjustments.
Lindsay Pease:
Yeah, a couple things that we saw up in Northwest Minnesota that echo what Fabian saw, we really didn't see a lot of nitrogen moving last year. We've been monitoring in the air, in the water, and in the soil on the drainage plots I have up here. And on that study, we're still going through that data, but it looks like similar to what Fabian said, we didn't lose a lot through leaching last year, and we didn't lose a lot through microbial activity either because it was even too dry for the probes.
Lindsay Pease:
So I'm really curious to see what we end up seeing this spring. And as we've mentioned earlier, it all depends on what happens these next couple of months, whether that nitrogen is going to stay put, or if it's going to leave either in the tile drainage or in the air. So I'm really going to be watching that pretty closely this spring.
Lindsay Pease:
The other project that we've had going on that's pretty fun and exciting. This project is with Paulo Pagliari at the Southwest Research and Outreach Center. And we're looking at whether you can inoculate wheats with bacteria to see if that will fix any nitrogen that will be beneficial to the plant.
Lindsay Pease:
So we don't really have good data yet because we didn't have enough rain. As Fabian pointed out, we didn't really get enough rain to maximize our yields last year. So we don't really know how well that's working, but we had some promising looking results. So stay tuned for more information on that. But those are couple tidbits for everybody to keep an eye on.
Paul McDivitt:
Will there be any changes made to the fertilizer guidelines in 2022?
Dan Kaiser:
So right now, looking at reevaluating, we've been looking at the N rate guidelines and I've got an update ready to go. At the time of this recording, I'm not sure if the online corn N rate calculator has been updated or not, but we're looking at that. Seeing an increase generally in the amount of nitrogen recommended, the change hasn't been that much and where we're at out with fertilizer prices.
Dan Kaiser:
If you did a fall application somewhere around the 0.1 price ratio, if you're within that window, you'd probably be pretty close to where we're at right now because I think right now when I calculate things out, we're looking at anywhere from about a 0.15 to a 0.18 price ratio. And we know that the recommended rates do significantly drop all off when we... I shouldn't say significantly, but there is a difference with that 0.15 versus where we're at with the 0.10.
Dan Kaiser:
So that'll be the main thing. We're working on updating the actual print publication as well. Realize if you look at the print publication versus the calculator, the numbers are going to be slightly different because I do round to the nearest five. With a lot of those, I do that because a couple pounds here and there doesn't make a big difference and it's generally within the profitability window with that.
Dan Kaiser:
I am making a small change in terms of how we're reporting the data in the print publication. I'm dropping the 0.05 and the 0.2 because we don't hit those points and add it in a 0.075 and 0.2 to give more recommendations in the range of where we're going to generally be. With that, although, again, this spring, we're looking at closer to the 0.18.
Dan Kaiser:
So that'll be the main change coming forward. We are working on some of the corn data right now with potassium. I don't think we'll have any updates to our guidelines in the spring. The main thing I will say, just interesting looking at some of what we're seeing with some of this mineralogy work, we're doing that. We upped the recommendations a few years back with a critical level closer to 200 part per million.
Dan Kaiser:
But if you're in the far Southeast on some of the silt loam soils, seeing those we're probably closer to 160 with the old recommendations were. And that's what I'm looking at right now is partitioning out the guidelines into the three main classes, which would be of course textured soils. Some of the silt loams, I would have more medium, what I'd call a cation exchange capacity. And then the high clay soils, that would be more relevant to what we have out there with our guidelines now.
Dan Kaiser:
So that probably will be looking at more towards fall. I'm hoping to wrap that work up here in the summer. So those would be the main thing. We're doing a lot of overhaul right now in publications, but a lot of them are mostly cosmetic. I've been making some minor changes here and there stuff that didn't get addressed with some of the last updates to the grass pasture recommendations and a few of the other minor recommendations around.
Dan Kaiser:
So those would be the main things going forward. Looking at the data, it's interesting with going through that N rate calculator, I've been tracking yearly economic optimum nitrogen rate trends. And last couple years, seeing the numbers come down for continuous corn, we were seeing a steady uptick in the recommended amount needed yearly, starting at about 2000. But if you look at around 2014, there was a slight down tick. And then the last couple years.
Dan Kaiser:
So these dry years likely having some impact on the situations. And looking at some of Fabian's data, interesting seeing some of those sites that were really low yielding that were struggling to put on you yield being situations, we're seeing a response out to some of the maximum N rates applied with that. So getting back to that yield versus optimal N rate that tie in really isn't there with that. So really stressing a lot of... And that'll be the main thing I think will be the core N rate guidelines expect some changes here. I'm hoping here in April before spring, field work really starts picking up to get some of that stuff out there.
Paul McDivitt:
Any last words from the group?
Fabian Fernandez:
I would just say that every growing season brings its own challenges. And this one will be one where I think paying attention to the weather, again, speaking more from a nitrogen standpoint will be really important. I think there could be a lot of potential there to save on fertilizer if the conditions are right. And so we normally are trying to get everything done as soon as we can, but this is a year I think where little patient could pay big dividends if we see that we don't get a huge amount of rain that leaches the nitrogen. And then if we do have a lot of rain, the biggest concern I have is in terms of the nitrates that we may see in the river floating down to the Mississippi, there could be quite a bit of nitrogen flowing that way if it gets wet. So we'll see what happens.
Dan Kaiser:
The other thing that's throw in there too, these types of years, we always get a lot questions on some of these lower costs, these little products to add in to try to increase nutrient availability. And looking at the cost of them being relatively low, the benefit generally of these isn't really high, if at all any benefit from some of these products.
Dan Kaiser:
So that's one of the things you have to watch out for is you're trying to cut back costs on some of your base fertility programs, and then looking at expending money on some of these things where you could have invested that in fertilizer, which likely would've been the more prudent way to spend some of the dollars.
Dan Kaiser:
So that's just one of the things to consider. Interesting Lindsay, you're looking at biologicals, some of the stuff we're looking at too biologicals, that's been the hot button topic with some of these and you've just got to watch and see how much you're spending on some of these things. Because really where I look at a lot of these things is consistency you to see if they work over a large number of environments, because obviously they're being sold to everybody out there in Minnesota.
Dan Kaiser:
And I haven't seen anything that is generally working that consistently like we see with fertilizer. We can pretty much predict, particularly P and K, we're going to see some benefits. Some of these other things, it's these biologicals, it's really unpredictable on some of these things.
Dan Kaiser:
So I just would be careful on that. And you got to ask yourself if I'm not willing to invest a little bit more in fertilizer, which may make me more money, why invest in some of these things that aren't necessarily tested and proven on all acreages?
Dan Kaiser:
So that's the big thing. We'll see what happens with some of that, but you'll get a lot of these extenders that tend to come in and say a couple bucks here and you can replace a lot of your fertilizer. And really a lot of times you could probably just cut back on fertilizers and you may be a bigger an economic benefit instead of submitting more money on a product that may not necessarily do anything.
Brad Carlson:
I think I'd add to that, Dan, we've gotten a few questions related to nitrification inhibitors and whether because of commodity and fertilizer prices, we should be looking at that. I guess just a reminder on what those products do, they just simply slow down the conversion of ammonium to nitrate. They really don't have an impact on the nitrogen itself. As far as its overall availability, they'll make it more available to the crop or anything of that sort. And they do wear off particularly relative to soil temperature.
Brad Carlson:
So the farther we get into the growing season, the shorter the window is that they're going to actually function. And therefore, the odds of losing nitrogen in that period of time are actually quite small. And so from that standpoint, under most circumstances, we don't look at recommending use of nitrification inhibitors for spring use. Occasionally we'll get people will suggest that maybe they should use them in course textured soils.
Brad Carlson:
But I guess we would also remind everybody that those are also the circumstances where we recommend doing split applications, multiple split applications in a lot of circumstances that the nitrification inhibitors may help a little bit, but they're not nearly as good as just simply not having the nitrogen out there in the first place if you got Sandy soils. And so remember that that's really the preferred method of management in those situations.
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.
