Conducting on-farm research: Four Midwest experts weigh in on design tips, planning and more
Hello and welcome back to University of Minnesota Extension's Nutrient Management Podcast. I'm Jack Wilcox in communications here with Extension.
Jack Wilcox:Today we're gonna talk in-depth about on farm research. What's new with on farm research? What practices can be easily managed, and lots more. We have four guests with us here today. Could you each please introduce yourselves?
Brad Carlson:Yeah. Brad Carlson. I'm extension educator. I work with water quality, nitrogen fertilizer management. I work out of our regional office in Mankato and work statewide.
Fabian Fernandez:Hi. I'm Fabian Fernandez, also at the University of Minnesota, nutrient management specialist focused on nitrogen management for corn cropping systems, and I have an Extension research appointment.
Dan Kaiser:This is Dan Kaiser. I'm a nutrient management specialist with the University of Minnesota at the Saint Paul campus. My area is in fertilizer guidelines, and I do a fair amount of on farm research.
Matt Pfarr:And this is Matthew Pfarr. I'm an Extension educator on the crops team based out of the Mankato Regional Office. I'm serving crop producers across the state of Minnesota.
Jack Wilcox:Brad, the practice of on farm research has been here for decades. What's new about on farm research?
Brad Carlson:I think most people are aware that we have research stations all over the state, but they don't encompass all the soils and various climate features and and so forth. And so there's been a lot of, what we would call off station research, you know, for decades, and a lot of farmers have been keen to have projects located in their fields. There's been a lot of conversation over the years about, know, well, my situation is different, or how does that look if it scales up to a field size and so forth. So there's always been a lot of, university research in farmers' fields. You know, I think what's what's changed a lot is the farmers' ability to do their own research.
Brad Carlson:And so that really kinda started, you know, very particularly in the the mid nineteen nineties or so when yield monitors first showed up in combines. You know, there was obviously some other technology that was advancing at the same time, the ability to variable rate apply other GIS systems that allowed you to map other field activities and so forth. And and then it kinda took some time for the computers to kinda catch up for the ability to analyze that stuff. And so I think a lot of farmers then started saying, well, can I start looking at stuff on my own? And, we did start to see some of that stuff, but I think we often, also, tend to frequently see farmers doing on farm evaluations, and they don't really pass muster.
Fabian Fernandez:You know, another thing that I think has changed, is the fact that there are programs out there where, if you are regulated on on certain nutrients, specifically nitrogen right now, you know, there is some ability to go a different route than the specific guidelines from the university if you can prove in your own farm that, for instance, like, you need more nitrogen for a certain specific condition or something like that. And so there is some of that as well where where people can document, the need for perhaps, more nutrients than than the guidelines, call for.
Dan Kaiser:So one of the things that, you know, we see in the market now, you know, if you look at marketing on products, I think that's the main thing. And and it if you look at now, especially with a lot of the ag media being more nationwide versus regional that were in the past, I think there's there are a lot more information that's thrown out there in growers' faces in terms of products, management, and just a number of other things that they're just, I think, more questions now in terms of the overall efficacy of this, you know, especially with you know, one example I'll give is, you know, some of the work that has been done out in in Indiana on sulfur and soybeans. There's been, I think, some really good work out there, and it gets really good traction across the country. But, you know, Brad, I think, hit it a little bit is, you know, growers, you know, with their situations wondering what's gonna benefit them. And I think that's, you know, kind of the big thing that's really spurred a lot of this.
Dan Kaiser:I mean, the the technology certainly, you know, is there to make it easier that you don't need to do like you did in the past, get a weigh wagon, you know, put strips in and and, really with yield monitors and what can be done with with some of that. And as as, you know, people are more in-depth on the precision ag techniques and technologies and analyzing data, it's made it, I think, a lot easier to start looking at some of these things on their their own farm. But, you know, certainly, it to me, you look at now just the amount of marketing. I just to be a farmer right now and try to wade through a lot of this and figure out, you know, what's good, what's bad information, what's gonna help me, it it's there's just a lot of stuff out there. You know, the big thing right now is the technology.
Dan Kaiser:They mean you know, I think one of the bigger challenges right now, though, for growers is the fact, you know, if you are a smaller operation, it's probably a little bit easier at one point in time to put some of the stuff in versus if you're you're farming thousands of acres. It gets to be a little bit harder to do some of this, this testing. But, you know, it's just trying to figure out what to do because, you know, we look at a lot of, what I recommended. I guess I'm a little more simplistic in my views, especially on the fertilizer side with management and really be a little more skeptical on some of these these products that are out there that are being sold to growers that there there I think there's a really good call for doing some of this on farm work. It's just whether or not a lot of these growers have the time to try to sort some of this stuff out.
Brad Carlson:And you bring up a good point, Dan, with a lot of these new products that are emerging on the market. We'll frequently hear farmers say, well, I'm gonna give that a try on one field, you know, or or sometimes they'll say, you know, I've been comped a certain amount of this product, so we're gonna put it out and see what happens. But oftentimes when I engage producers about those circumstances, what we discover is, well, they just put it on one block or one area, and then they just sort of, you know, see what kind of impressions they get, or they just compare one side to the other or something like that. And I think it's important if you really are concerned that you actually design some sort of on farm research versus just simply putting it out there and getting some overall impression of whether these products work.
Jack Wilcox:Fabian, on the continuum of management practices, what are the ones that maybe are more easy to evaluate, and what is more difficult to evaluate?
Fabian Fernandez:Yeah. So with, on farm trials, the the key thing is keeping it simple. You know, in the research farms, as Brad mentioned, we have those all over the state. We do pretty intricate work in there where sometimes we have as many as, like, 20 or more, different treatments that we are comparing, and we have to be really careful on how we set them up so that at the end of the day, when we have the data, we can actually understand and compare things, from one treatment to another. In a farm situation where you're dealing with, you know, your own farm equipment, much bigger scale, keeping it very simple is the the key thing.
Fabian Fernandez:You can test just about anything. The important thing is you you ask the right question. Typically, what I suggest is doing a yes, no kind of question. Right? Like, Dan mentioned, for instance, some of the products that are out there.
Fabian Fernandez:Well, you can test that product versus your typical application, or you can do higher nitrogen rate versus a lower nitrogen rate. Those kinds of questions where it's kind of a yes, no, or this much versus something else. One thing that you keep in mind always is that at the end of the day, when you have the data, the more variables that you have into the into a treatment, if they are not comparable across, then you are left with the question of, like, well, was this change that I observed here that I calculated, based on BL monitors or whatever you're using? Are they related to the treatment or or the thing that I really was interested in testing or something else? For example, if you are looking at, a new product that you're interested in versus your typical application, well, make sure that if it's nitrogen, for instance, that you're using the same rate of that that treatment that you're interested in compared to your practice.
Fabian Fernandez:If you are applying, you know, a 50 pounds of nitrogen with this product and only a hundred with your typical practice, well, you will not be able to tease apart whether the difference that you observed was because of the difference in nitrogen or the different product that you used. Same thing if you do I don't know. You have different hybrids. You know? Then you don't know if if the treatment was related to, let's say, a nitrogen rate versus having a different hybrid.
Fabian Fernandez:Those kinds of things. So whatever you do, make sure that at the end of the day, you're able to compare apples to apples. That's one way to to do it. The other thing is to kind of do more of a systems approach where you're looking at a whole bunch of variables together. Let's say that you're interested in, I don't know, throwing the kitchen sink at at something, saying, you know, doing all the best possible practices that you can think of versus something else, maybe a traditional practice.
Fabian Fernandez:Well, at the end, when you look at the data, you'll be able to say, well, this practice, let's say let's call it an advanced practice, approach, produce x amount more yield or better outcomes than something else. But you will not really be able to tell which one of all of those variables was really the one that was most impactful. You will just simply be able to say, this practice as a whole, with all the variables that we threw at it, is better than something else. We call those kinds of things in in in statistics lurking variables or confounding variables. And so that's what we we are trying to avoid is asking the right question and having the right kind of treatment to, at the end of the day, being able to to get at the question and be able to answer whether something made a difference or did not make a difference. Bottom line, keep it simple.
Matt Pfarr:The Pfarr farm is in Sibley County, so we're in crop production somewhere between Gaylord and and LeSueur, Minnesota. We have these questions that boil up, and this gets to the point of of marketing that farmers are seeing, and it's a national sort of message now on new products. And maybe you could debate me on this, but I feel that maybe biological products for nitrogen fixation in crops other than legumes, right, where there's this history of partnership with certain bacteria in the crop to get nitrogen. But how about how about that concept translated to corn or wheat or these grain crops that haven't historically had that partnership has evolved over time.
Matt Pfarr:And so we, in around 02/2019, you know, already six years ago, we had a lot of these messages coming out to our friends, neighbors, and us. And we just took a marketing message for one particular product where they were saying you could cut your nitrogen inputs by half on corn and still achieve the same yield. And we said, well, that's a research question right there. That's our hypothesis. So what we did is is, to Fabian's point, focused in, and we did a very small amount of nitrogen preplant or at plant.
Matt Pfarr:And then we did a sort of medium amount side duress on top of the preplant, and then we came back with that full 20 pounds at side duress on top of the preplant. So we had three levels of nitrogen inputs. So we knew we were gonna get a response, right, in in corn yield due to this. And then we had the biological with and without in those each of those nitrogen levels. So we got the right amount of replication.
Matt Pfarr:Our question was very focused, and we got a wide range of corn yields that were very tight around each nitrogen level. And so as a producer, for me, I was able to turn that data over to doctor Carl Rosen at the University of Minnesota, and that gave me two benefits. He did the statistical analysis, and it kind of was right into the system in terms of that raw data now being presented out as something that was done on farm. And the results were eventually picked up by doctor doctor Franzen at NDSU when he did a 60 trial composite white paper talking about all these nitrogen fixing products. And it was great to be a part of that and to contribute to our knowledge, which is showing that in the only very rare occasion where we're these products deliver the sort of benefits that they were claiming to.
Matt Pfarr:So marketing aside, right, because it got our attention. It certainly got us to try the product. You really have to be skeptical when there's huge claims involved, and a lot of times, they give you your research question right in those claims. So I know that everyone on the call is familiar with some of these products I'm describing, but we certainly were were our attention was had. We did a really good one year trial on corn.
Matt Pfarr:And for us on a farm, it it made us decide, hey. We don't wanna take this across every acre. More data would need to be proven out here to show that these products are are gonna give us return on investment.
Fabian Fernandez:You mentioned replication, and that is extremely important. If you're going to do a study, you do need to look at the statistically whether there were differences. And the only way that you'll be able to do that is by having replication. And the more replication you can have, the better it is. You know?
Fabian Fernandez:Three will be the minimum. I would suggest going to, you know, as many as five or six replications. So, basically, whatever number of treatments you have, you have to basically replicate them or multiply them that many times, you know, three to five times, six six times. And so that's why keeping it simple is important because if now you end up with basically a study that uses up a whole farm. The other thing that, when you were talking about nitrogen rates, for that particular example you gave, this is also an important thing is that if you're comparing something, make sure that you will be able to see differences due to that treatment.
Fabian Fernandez:If you are applying an excessive amount of nitrogen, let's say that you're interested in comparing two nitrogen products, and you're applying more nitrogen than will be needed by the crop. Well, at that point, even if you lost some nitrogen from one of the treatments and not the other, you will not be able to see the differences because it was a nonlimiting, amount. And so you you want to be targeting these things at a level that you'll be able to see those differences. You know, for instance, when we when we look at products that we are interested in testing products side by side, what we do normally is we apply the product at a suboptimal rate so that if we lose any amount of that product to whatever, you know, environmental losses or whatever it may be, we'll be able to pick up that inefficiency a lot better than if you are applying a rate that is at the optimum or above that optimum.
Brad Carlson:If we look at our just simply our nitrogen rate studies, we'll find that, what we would consider our our normal application rate of nitrogen, quite often the crop didn't even need that much, and so if you're going to do a study on a nitrogen product, for instance, you might not find a difference where there was a difference because maybe that crop only needed 80 pounds of nitrogen and you put on 120, and therefore you won't ever tease that out. And similarly, Dan's been very instrumental in helping to frame how we look at P and K response versus soil test level. If you're in a medium testing soil and you only expect a response 20% of the time, then don't expect to be able to see much with your product. So from a university research standpoint, I mean, we frequently have to target low testing soils if we're looking at P and K projects to make sure that there actually is a response and we're able to tease out differences. Similarly, if you're doing nitrogen related studies, you're probably going to have to apply lower rates of nitrogen than you would have otherwise been inclined to, or you're probably not going to be able to see whether the product actually did something or not.
Fabian Fernandez:And with nitrogen too, the the one thing that I would say is, looking for fields that, for instance, have not received recent applications of manure or or that have a lot of residual nitrogen because that's kind of like what you were saying, Brad, in terms of, like, p and k work. If if your soils are testing high, you will not be able to really see differences. The same thing will be true for for nitrogen studies if you have a lot of residual nitrogen. So, obviously, it's it's not as much of an issue to find nitrogen responsive sites as it is for p and k work, for instance, but you do have to be aware of, you know, those kinds of situations where you might have quite a bit of nitrogen.
Jack Wilcox:Matt, what are the design criteria that farmers need to have in place so that they can make a reliable determination of how effective a treatment might be?
Matt Pfarr:I look at it as being as fair as possible to our different treatments. Again, we're we've been talking all morning here about teasing out appropriate treatment variables. Things that you could do ultimately or pick a research question you're excited about, first of all. Because what I'm hearing here and what happened in our trial too at the ultra low nitrogen rates, we certainly lost some yield in those strips, but it was worth it because, you know, we learned a lot. And if there was kind of this new product that was gonna give us really huge benefits in the long run, that would have also paid off too.
Matt Pfarr:Right? Like, we were gonna have a a good time here, and we were so excited about that question. We did everything possible to keep possible sources of air from ruining our experience. In fact, to toot my horn here, doctor Rosen called it the cleanest response to nitrogen in corn he had ever seen from a field trial on on a farmer's scale. So I one thing that we we were blessed with is, like, our equipment with for corn planting and corn harvesting is exactly half.
Matt Pfarr:So at the time, we had a 12 row corn planter, a six row corn head. We have a perfect trial there because we're bordering our planter passes where we applied the products with three rows on each side, and we're taking the middle six at harvest. So you're not getting bleed over of treatments or contaminants from one to the other. I I could also think of this being really important when doing, like, hybrid trials in corn because of natural height differences. So you're not harvesting a difference in just shading.
Matt Pfarr:You need to have a little bit of a border area. The the research trials done by the university in Saint Paul or at the research centers that Brad mentioned, they are naturally designed to already have borders built in with their four row plots and harvest the middle two. So you can always think like a researcher, and and anyone listening can ask one of us on the call today. We'd be happy to kinda walk you through and be your sounding board for some of these on farm trials as well, especially us on the extension education side. For me as well, I think of cross contamination as when the equipment so if we're gonna put a trial out there, say I was putting a biological organism, a living organism down with my starter fertilizer, I applied that organism second.
Matt Pfarr:Right? I applied my fertilizer without it first because I did not want the equipment in my planter to be somewhat contaminated, quote, unquote, by the product and then go to a clean, you know, area. Right? I wanted to start and so you kinda work clean to dirty in that way, if that makes sense. Right?
Matt Pfarr:So there's the bordering effect. Make sure you have some buffer area. Then there's also just proper sanitary procedures. Make sure you're not applying something when you shouldn't be in your your untreated area, for example, with a biological organism. I also talk about keeping great notes.
Matt Pfarr:You really wanna know your trial maps need to be there. If you can get a drone up to fly, it's really cool. If you do nitrogen trial, you can see the crop response at really low nitrogen rates. That really helps tell your story so people can visually see what you're describing there. And, also, I I think combine yield monitors are great as we've gotten into more, like, gen seven, gen six combines.
Matt Pfarr:They have a scale that is actually truthing that mass flow sensor, but it's not always an exact replicate like a weigh wagon would be. So I know we can do trials these days without weigh wagons, but I do encourage people to design the trial where it's small enough that a weigh wagon isn't prohibitive because that's the gold standard in research. You get a weight, you get a moisture, and you normalize your weight of yield to a moisture. And with length of area, you have your your yield. And then we really, for sure, know there's no air there coming from, you know, a combine yield monitor, which can be a whole another kinda can of worms once we get into that.
Matt Pfarr:Those are the few of the things I wrote down on really planning, but it's about thinking ahead and kinda heading off any questions that are gonna arise after you did all the work of doing your trial. You can probably plan out some of those ahead of time and really make sure you have a a good trial on farm.
Dan Kaiser:And, Matt, you said something before too. I think that's important, and that's, you know, looking at what question are you trying to address. Because I think that's where some growers can kinda get lost and, you know, they may have an initial question, but then they add on a little piece that let's add this or let's add this or let's add this, and it just becomes really messy in terms of trying to figure out what's happening. And, you know, we kinda you know, we take a lot of grief for a lot of our small plot trials, but, you know, Fabian mentioned it before. The the advantage of the small plot trials that we have essentially is that we can test more variables at once.
Dan Kaiser:And, the way I've always kind of thought of this from a grower standpoint is, you know, I'm gonna be doing all these things whether it makes any sense or not. I mean, that's another thing. Every once in while, get a colleague that'll criticize you because you put a treatment in that no grower's gonna do. Well, you know, it's generally done in a way that we can test our hypothesis a lot easier. And, you know, in the end, then maybe a grower can take something out of it to design or, you know, formulate a question they wanna formulate into a non farm trial.
Dan Kaiser:But I think that's the main thing is just sitting down initially and just what question do we want to address to start thinking about then how do you set things in place that you have what we call proper controls. And controls are really the key, essentially, whether it's just a standard practice. A lot of times, our controls are a nonfertilized area that we're looking at, you know, nonfertilized versus fertilized. There's something called a positive control, which you could put in, which is an overfertilized area. You know?
Dan Kaiser:So there's there's a number of ways you can do that, but, you know, it all starts with what question you're trying to address. And, really, the biggest thing I can give to most growers, if you're looking at putting in some on farm work is to try to keep your questions simple. You know, you know, Fabian hit on a little bit of this, you know, before when it comes down to the treatments is you're really gonna be limited by the number of space. And, you know, Matt, I think you also hit it just, you know, thinking a little bit about what you have for your harvesting equipment and your planting equipment just so you can make sure that you're you're at least if you're harvesting at the end you know, I always kinda think about it backwards when I'm working with growers and, you know, what's your harvest with? Then I'll just go, okay.
Dan Kaiser:What's the planner with? And then if it's a fertilizer trial, what's my fertilizer applicator with? Just to try to start thinking about how to properly plan this because, you know, people think it's easy. They think it's simple, but it's not. You need to have a little thought into this.
Dan Kaiser:Otherwise, it's, you know, that old adage garbage in, garbage out. You know, if you just don't take the time to do it and you do a bad job setting it up initially, you end up with bad data, then it's it's just a waste of your time to try to even think about this. So, you know, it just, you know, just a lot of thoughtful consideration in first how I'm gonna do this, and it's, I think, something that really you wanna do, you know, starting maybe in the winter just to think about this a little bit more so you have a little bit more time to plan than you know, people get during planning when you're trying to squeeze everything within about a week's time period to get everything in the ground.
Brad Carlson:One of the on farm projects I participated in a number of years ago, we had something kind of messed up because we were looking at, tillage practices and multiple tillage practices, and our farmer cooperator said to me, Oh, I'm really intrigued to look at that third rep, and I kind of perked up and I said, Why? And he said, Well, I skipped one of the tillage treatments on that one because I wanted to see if it really made a difference. And like, well, yikes, well, now we've got one less replication, and no, you can't really tell the difference when you didn't replicate that treatment. That gets into the controlling the variables, and you have to stick to your research protocol or you're not going to be able to answer your question. And, you know, something that I referred to earlier in the podcast was farmers potentially splitting a field in half, you know, and doing one thing on one side and one on the other, and I think everybody realizes you can split the field in half and do nothing, and you can find a different yield on one half and the other half.
Brad Carlson:And so you've gotta be very careful about, the temptation to be too easy, you know, oh, that's just so easy to do it that way. It is, but you're probably not going to answer the question, you know. And then in addition to that, I think it's also important to remember that some of our fields are just too highly variable, and you're gonna end up with, you know, if you got wet spots, if you got, you know, hilly areas and eroded hillsides and so forth, you're gonna have parts of that field that just naturally don't yield as well as others. It can be very difficult to make sure that those are equally represented across the treatments, so you have to be careful about selecting the field and potentially even locating the research within the field to avoid some of those things, you know, and then the other aspect of that is if you do use a field like that, sometimes your results can be so highly variable it's hard to find statistical significance anymore, and so, you know, that's just a problem that can be avoided by better site selection.
Jack Wilcox:What kinds of problems have each of you encountered while conducting on farm research? And then with the benefit of hindsight, how might those problems have been avoided?
Brad Carlson:You know, really the problems that we've encountered, and I've seen a lot of things, and some of them are humorous, and some of them are potentially embarrassing for individuals, and we ought to be careful about not embarrassing anybody. But, you know, it's it's as in a lot of things in life, a lot of things in your personal relationships, your families, your marriages, and so forth. It comes down to communication and everybody being on the same page and not just assuming that everybody understands this is how we do things. I mean, we've had things happen, for instance, where we have marked plot corners with flags and then had somebody show up and with the applicator and use the flags to center on. In their world, that's how they used flags, and it was just never communicated.
Brad Carlson:You know? And then the treatments ended up split between two plots because it was it was centered on the flag instead of between the flags. You know, we've had things happen. You know, Fabian mentioned changing corn hybrids. We had a farmer one time used four different corn hybrids in a in a field, and it it was very difficult to get usable data out of that because now we had a hybrid trial going on when we also had a a nutrient management trial going on.
Brad Carlson:You know, things like that can be avoided if you just simply talk about it. I mean, we had some one time, we didn't realize that the farmer we were cooperating with didn't own a combine, and he had custom harvest going on. And there was never any discussion with the guy doing the combining that he was gonna have to stop for every strip and weigh the the strips in a weigh wagon. He wasn't real happy about that. I mean, his time was money, and and that was not part of what he thought he was getting hired to do.
Brad Carlson:You know? So so, you know, I guess probably the biggest tip that we've we've kind of I can give to any farmer is anything that that's happening in that area where you're doing a research project, make sure you're either doing it yourself or you're there when it happens because you know how it's supposed to be done, and then you can you know, regardless of whether it got you thought it got communicated well or not, you've seen it with your own eyes, and you can avoid those problems. You know, things like setting on the the fertilizer applicator, whether it was set to go to 60 feet or 80 feet or whatever, you know, whether the the the rate got flipped over from the last field to the new field. You know, there's all kinds of little things that can happen that, you know, in the grand scheme of things, if it was just an ordinary farm field, it might not make a huge bit of difference, but in your research project, it could really mess it up.
Dan Kaiser:You know, with the technology that's out there and all the settings that have to be gone through, I mean, I think, Brad, you've had some instances where an applicator may have a minimum rate set in for something that just defaults and when you've got lower rates, then you you get too high of a rate on or I mean, it's it's just kinda like that old game telephone too. I mean, communication is problem, and just communicating, you know, who ends up actually having to do the application. It becomes more and more instances where you can get errors, you know, if things happen. You know, my big thing too is on, you know, we're we've been doing some on farm nitrogen trials with the Minnesota Department Ag through their NMI, their nutrient management initiative, what we call these level two plots, which are rate trials, which, you know, we can go in in the winter and make up maps, variable rate maps for growers and fields, the variable rate nitrogen for rate trials. But the the big thing I can say that we you really need to do is if you can get as applied maps on these things just to confirm things were done correctly is really what you need to do.
Dan Kaiser:It can be a challenge, particularly with floater going across field at a high rate of speed, the changeover. I mean, it just you you gotta think of these things, in terms of the size of the plots and those types of things just to make sure that you're getting the data that you need. You know, going back, you know, older probably god. It's been close to twenty five years when I was doing work in Iowa, you know, just to having, you know, growers following up on their calibration with their yield monitors, and it it just a lot of things that can go wrong that you don't always think about. You just take for granted.
Dan Kaiser:I think a lot of growers I mean, you know, some of the things you're talking about, Brad, I think they've got good intentions. They've got questions in there. But you get a plan, you wanna stick with the plan to make sure you get the date out because it goes back to those having those checks where I can compare apples to apples or I can make some sort of comparison that I've changed product practice x, it actually has an effect is really what you need to do. I've run into issues, you know, even when things are properly planned out. I had a boron trial, just around the Cannon Falls area where if you look at the data at the end of the season, it looked like we had a 20 bushel yield response to corn to boron.
Dan Kaiser:But, you know, you look at the data and I look at why we looked like we had that yield response, it was because of how the strips were laid out. The areas where we had boron just ended to being higher yielding soils in that field that I can't separate out just some of that variability within the site. And, you know, it goes back to you know, we talk a lot about probabilities, and I think the thing people get really confused when we start talking about probability values when I'm if I'm up there talking from an audience and what that exactly means. And really what that probability means is it's the chance that we get a false positive. So if I'm talking about a probability of point o five, it means that, you know, one out of 20 times, there's a chance that we're gonna get a false positive.
Dan Kaiser:When you're changing those probabilities, a lot of growers said, well, maybe I want it fifty fifty, you know, in terms of a chance of response, and that's now how we look at those things. I mean, the probability is really set there really to give us an indication of how we think that this whether this practice is good or not. That, is is what we call a type is it type one error or type two error? Fabian can can can correct me on that. But that's really what that probability has put in place and why we use statistics to try to be able to sort through some of the weeds just to make sure that we're making a recommendation that the data can actually support.
Brad Carlson:And, Dan, you you bring up another good point with with your referencing that boron study. The projects need to pass the smell test. You know? If you can look and see something that's problematic, then go with that, you know, that if you see that you've got a high yield in the treatment, but then you got a high yield beyond it where the treatment doesn't exist, you know, maybe then it wasn't caused by the treatment. And similarly, I had a project I worked on one year, this gets back into the design criteria situation, was only replicated three times.
Brad Carlson:But when we looked at the yield data, we saw that every strip we harvested as we moved from south to north, the yield got higher. And so there ended up being statistical significance between these two treatments because that difference was high enough in the one treatment where one was on the north versus the other treatment and, you know, it kind of outweighed the the one treatment where it was they were flip flopped, but by only replicating three times, you know, we ended up having statistical significance there when we looked at the data and says, well, that's that's really not the treatment. The yield's just getting better as we move from one side of the field to the other. It didn't pass the smell test. You know?
Brad Carlson:And so that's that's also we we had a project one time that a tornado went through, you know, and and we we got yield data out of that, but I wasn't gonna use that. I've I've never presented it publicly because, I mean, who who really can say for sure what what you measured out there? You know? And and the the corn was flat. The farmer did the best job he could to get the get what he could out of there, but you couldn't really say that the treatment differences showed anything because who knows what happened?
Dan Kaiser:Well, that's one of the things to think about here is that no yield response doesn't mean you're gonna get the same exact yield for treatment a versus b. I could go, you know, in one of Matt's fields and we could just essentially do nothing. And if it's got the same hybrid across that field, I could put a dummy set of treatments in there for product x. And, you know, if we did this 20 times, you know, one out of the 20 times, I'd probably find where it would say it's significant, and that's just kinda how it is because of the random variability that's in your fields. That's where the statistics come into play.
Dan Kaiser:Why we use them is essentially what doing is it's it's what we call experimental error, which is, you know, just essentially that yield variation that's due to things that we're not controlling. Essentially, it's it's giving us some estimate of that and just based on that, then our ability to detect differences between treatments. Because you wouldn't expect if you did something different versus your neighbor and your yields were the were different within those those two fields, you know, does that mean that your practice is better than the other? You really don't know. And that's why, you know, we we bring statistics into some of this.
Dan Kaiser:I know people hate it, but it's just a way for us to have some confidence essentially that the recommendation we're giving is actually accurate.
Fabian Fernandez:So, you know, as as you guys been talking about these things, I've I've have had a lot of flashbacks of, different on farm trials and things that didn't go right, and you live and you learn. And I would say probably the biggest enemy of, good on farm trials is a compressed planting season. You know? We have all these great plants during the winter, and then planting season hits, and then it gets wet or something. And we have fewer days, and we are all in a hurry to try to get things done and all the plans go out the window at that point.
Fabian Fernandez:That's that's the biggest the biggest challenge. In relationship to that, I think one of the main difficulties is when you try to make changes on the fly. And in my experience, that typically doesn't work very well. You have to plan these things correctly. It takes some stop process.
Fabian Fernandez:And when you are in the midst of it trying to use to make changes, more often than not, there will be mistakes made. That sometimes cannot be correct. Today, I had an experience one time with a no till farmer. We were going to to to do no till versus conventional till treatments, and we had it all planned out and everything. And then I was not at the field at the moment, and so this goes back to some of the things that I think Dan mentioned about communication and and Brad also mentioned about communication.
Fabian Fernandez:The farmer calls me on the phone and says, you know, I've been doing this thing, and I was wondering if we could do this little change here to make it easier. And I kind of thought through it. It's like, yeah. That should be fine. And then, well, lo and behold, when I looked at the final product, I realized, shoot.
Fabian Fernandez:Now we have no replication here because the the way that it was set up was just statistically, we would not be able to to analyze that data. And so making changes on the fly, it's typically a problem. So try to avoid that. Stick to the plan. The other thing is and this is maybe easier said than done.
Fabian Fernandez:But if you're a farmer interested in doing, research trials, you have to be thinking as a researcher. What I mean by that is don't have to necessarily get all the training to be a researcher, but ask questions. There are no dumb questions. Oftentimes, make assumptions that, oh, yeah. I can do this change or do that, and it'd be okay.
Fabian Fernandez:And in reality, the best thing you can do is just touch the person that is helping you the with the design of the the experiment, and there are no dumb questions. You just ask the questions and go from there. And that also means slowing down sometimes. And that's, again, a challenge, especially with when you have limited time. You have to really be intentional in wanting to do this research because there are always some constraints in time.
Fabian Fernandez:You know? It's like, okay. I have to get this done now, and and it's easy to just go right through and no ask questions. Don't stop to think about it, and that's where the mistakes are made typically.
Matt Pfarr:I would just add one more farmer or crop producer anecdote in here. Let us not overlook compaction and different passes on the field as a possible source of error. I mean, if we think about what goes on in small plot trials, everything is designed so that each plot receives the same pass, the same compaction, the same foot traffic. Now and what you've heard on this call already has been we're harvesting on 20 feet with an eight row head. Maybe we're planting on 24 rows or 60 feet.
Matt Pfarr:Maybe that spreader is 80 to 90 feet, that floated fertilizer. Maybe the sprayer that did the post emerge is a self propelled with a 20 foot boom. How do you match it up so every harvest pass, which is if you're going after yield data, had the exact same foot traffic or same footprint. Right? Like, if we go back to that 24 inch or 24 row, excuse me, planter, you know, we're harvesting on eight rows.
Matt Pfarr:Do we know tsshat where those four dual tractor tires go across the middle eight you know, if you divide a 24 row planter into three sections of eight, those middle eight rows are gonna yield three to six bushels less than the outer eight row contingent that have less wheel traffic just from the planting pass. You know? So if we're looking for small differences here, that way, we, you know, we we may be not measuring what our treatments were. We may be just measuring compaction. So just keep that in mind.
Matt Pfarr:Back to my earliest example about the nitrogen trial, you better believe that even though we had no side dress for our lowest nitrogen treatment, I still dug or drug the anhydrous bar through those those rows. Right? Because the other treatments were getting that sort of soil disruption. You can lose some water. You have compaction from that pass.
Matt Pfarr:Just wasn't applying any anhydrous ammonia in those lowest nitrogen treatments. Right? So everything was treated exactly the same in terms of compaction passes across the field. I think it really paid off in terms of tight response at the end. So just keep those things in mind.
Matt Pfarr:Every every pass should be monitored. And when it comes to designing where you're gonna get your yield from, make sure that that strip has been treated the same across your whole trial, and you'll have a a really good result in that instance.
Jack Wilcox:Dan, how can farmers participate in University of Minnesota on farm research projects, and how might it benefit them?
Dan Kaiser:After we've talked about this, I don't know why anybody would, just the sort of thing we've been saying. So it's difficult. And the main thing is, I mean, if you are interested, I know there's some groups out there. I don't know if that that Southern, that corn economics group is still active or not. There had been, you know, a few groups that were interested in precision ag that had been working together and coming up with some research questions to try to pool some of the efforts together because I think that's really important.
Dan Kaiser:If you're a grower by yourself, there's there's a there's more power if you can essentially come up with a question, get more people interested, and have everybody do that where you can analyze that data over a larger area to get some sort of answer on what's what's happening. If we're you're just interested in anything, you're at one of the meetings some one of us are at, you know, come up and just, you know, say some things you're interested in and just see kind of what we have going on. But, but we're always looking for sites. I mean, the I know the main challenge, though, for growers, it it's, you know, kinda was brought up before is when push comes to shove, when that growing season gets compressed and stuff's gotta get in the ground, you know, things happen, decisions are made, and it becomes really difficult, I know, for growers, especially to try to work around some of the things that we're asking them to do, and that's where I try to keep things as simple as possible typically for growers. And so, hopefully, then they don't have to do a whole lot, and it doesn't really interfere with any of what they're doing because that's really kinda key that I found, you know, moving here from Iowa's, you know, Minnesota.
Dan Kaiser:It's amazing how quickly we can get stuff in the field in the spring up here because we have to. You just because it becomes a challenge with the the growing season we have. Know, Minnesota Crop News is a good source if you wanna know what's going on. You have any interest in it. Normally, we try to highlight some of the work that's going on.
Dan Kaiser:And, you know, the main thing too is if you got a group of, you know, friends, you know, a bunch of farmers that wanna get together and and look at something. And if you're really interested and need help with that, just contact one of us and, you know, see if we're at least get you some resource or willing to help set some things up because there are some opportunities out there. But, you know, the main challenge is it's for us on the fertility side is finding the right sites. Then also, you know, for me, it's, being able to implement the proper controls we need to because that's why I don't do a lot of on farm phosphorus studies because, you know, growers have access to MAP and DAP, and you've got nitrogen and phosphorus there, so it's hard to work with the controls. So, you know, we know we're comparing apples to apples.
Dan Kaiser:Contact us. And if you're interested or if you've got a group or interested in looking at something, we'll kinda help, you know, get something in place for what you wanna do. There are some options, you know, particularly for those that have infurrow options with stuff that, you can put down in the seed furrow, you know, something like a Dosatron. If you've got that on your plan, there's a lot of things you can do, but it's it's just knowing what you have available to you, what the question you have, and, you know, it's really the main thing then is if you need help, then just figure out who can help you get things in place.
Brad Carlson:I think the biggest challenge over the years with trying to identify farmers when we've got projects is field work that already got done in the fall that starts to eliminate fields from consideration. I mean, obviously, when when the work starts in the fall, you know, most farmers aren't pausing to say, no. Wait. Do you guys wanna do something out here? Because then in the end, we start looking for fields.
Brad Carlson:It's like, well, that already got tilled, and that already got nitrogen, and we already spread our P and K, and there's all this, you know, we put manure on that field and so forth. It's really amazing, you know, when we're trying to research a question and then avoid confounding factors, you know, we gotta be very careful about fieldwork that's already gotten done that does not match the research protocol, you know, so that's probably really the kicker is you can't start looking around in the November and say, oh, hey, how about if we do something out here? Because in a lot of cases, there's a lot of things that already happened in that field post harvest.
Jack Wilcox:Brad Carlson, Dan Kaiser, Fabian Fernandez, and a newcomer to the podcast, Matt Pfarr. Thanks a lot for being here.
(all):Thanks. Thank you. Thank you very much.
Jack Wilcox:As our panel has said, if you would like to find out more information about On Farm Research or maybe have questions about participating, just send an email to our regular email address which is nutmgmt@umn.edu.
Jack Wilcox:We'd like to thank the Agricultural Fertilizer Research and Education Council, or AFREC, for supporting the podcast.
