 This is Precision Agriculture in the Southeast. I'm Mark Hall, Extension Specialist with the Alabama Cooperative Extension System. And with me today is Dr. John Fulton. We've been talking about precision agriculture and our lesson today is site-specific management. John, tell us about site-specific management. So we've talked a lot about technology up to this and other modules. And yes, this is really gonna focus on just grid versus zone-paced approaches to managing either soil fertility or some of this variability that we measure out in the field. This is probably the most common question that the farmers ask is, should I go grid? Should I do zone-based? You know, there's been a lot of research conducted across the US, continues. And you know, at the end of the day, it's what's gonna best suit your operation and you're gonna have to kind of change over time and grow with it. There's not one thing, one grid versus zone that's the absolute answer. There's no silver bullet. And we encourage them start somewhere because once you get into this, you're probably doing better than you were. Yeah, we're not, don't let perfect be the enemy of good. Absolutely. And so we're just gonna talk a little bit about grid and zone. We're not gonna be able to become experts in any of this, but I'm just gonna give kind of some high level kind of comments to this and take that home and kind of see what best fits your operation. We know that variability exists and you know, and so either have to generate zones or grids when we start to think about the field and the intra-field variability that exists out there. And so just that concept of starting somewhere and ending up with, at the end of the day, Mark, we know that variability to some extent is gonna be best represented by zones, but that might not be the right starting place for you as you start into this, but ultimately we're gonna arrive at zones down the road to characterize the variability. When we talk about that grid or zone, really what we're talking about is trying to treat that area equivalently across. So we've said that that area's gonna potentially be different than the adjacent area, whether it's the zone or grid, and that's what we're gonna manage that area, whether it's, like I said, the grid on the left there or a zone on the right. We're gonna just manage that area as somewhat homogeneous in nature, but recognizing that that might have to change in the future as we get more yield maps, we get some other data in-house that suggests, hey, I might need to split or I can combine some areas. And so anyway, so there is no one right way. Always the question, what's the optimal resolution? And for years, the industry settled on a two and a half acre grid, for example, saying that that's the profitable. Some folks really believe in zones and that's great too. And those could be 10 acres, could be 20 acres. They're gonna vary in size as well. And so there's the optimal resolution, but really it's what's the profitable resolution and at least get started with. All I'm gonna say is there's really three factors to consider and I'll go through a couple of these, but we got the agronomic factors, so we got that yield map, but we might not be able to manage each and every zone if they're really small, because it might be uneconomical. And secondly, that machine, we talked about the size of machines periodically during these lessons, that that 120 foot sprayer or 120 foot planter, whatever, I know that's big, might not be able to manage at the resolution that we can measure things. So there's really three factors to consider. The agronomics, that's the response to fertilizers, seeding, those type of thing. What's profitable or what's the economic optimum that we need to be managing to, but then can we get it done out there with the machine you're giving it for our operation? We have a lot to learn in all these phases. We've got a lot of science in house today that it really has, but we're gonna learn and I think as a farmer or a consultant out there with some of these services, you're gonna learn a lot of things as you go on and kind of grow. So with that, this is just a machine. This is something we talk about a lot. I might have management zones on the top right that are so small, I miss them. I just can't manage. Or if I got them so irregular shaped, I've got a large applicator that can adjust to that shape and also I'm gonna have to compromise. And so these are just some things to think about from a machinery perspective as I build zones or grids, what size should they be and can I manage that? And ultimately too, we talk a lot about rate changes don't occur instantaneously. So as I drive, all field operations are normally performed at different ground speeds, but there has to be a rate change effect in there. Just keep that in mind as you build your, again, if my rate change takes two to three seconds, which can occur in some, and I'm going 15 miles an hour in my zone or grids, really small possibility, I totally missed what I was trying to accomplish from a target rate perspective. So just some things to think about from an engineering perspective. Here's the same field, managed two different ways, went out and we did some work on basically one acre grids on the left. We zoned it out on the right using some different data layers. Again, a little bit different in terms of what we get to look at, ultimately, but it just showcases that, you know, there's different ways to slice the pie. I'm not gonna sit here and tell you there's one best way, but what fits your program the best and what you can learn most from and what seems to be most economical. But if field variability exists, then it's gonna make sense to probably implement a site-specific program at some level. So you got some people saying you need to go grid, you got some people saying the zones, but you really, as a farm owner or manager, consider what makes the most sense up front for you to start out with. So we're gonna talk about zone management first. These are just some generic comments on them. These are areas that we consider to be very similar, okay, and we're gonna manage them as such. They might provide a better representation of that true variability. I think, again, we look back at the maps, the yield maps we were talking about. Most of the times you would say, well, they're more zonal in nature, not nice square grids, but to generate these zones is a little bit more difficult to implement, Mark, because what are you gonna base your zones on? Okay, and so a lot of times it's very dependent on previous management, taking fence rows out, or maybe applied manure over the years in certain parts of the field and not others. And so all of a sudden you have, but how are you gonna measure that and generate those zones? And that's always the question, do I got yield maps? So electrical conductivity, we'll talk a little bit about that, but how do you generate these zones? Because I'll tell you that soil maps provide a great entry place to kind of maybe start dissecting your field, but normally aren't the best representation of the yield variability out there. So that alone, it's not just soil, you're gonna have to have some other data layers to generate these zones. And are you gonna do that yourself, Mark? No, I'm not. Probably not. So you're gonna have to get someone to help you generate those zones out there. And so who's that gonna be? Who's gonna be your trusted consultant to help you build these zones? And what layers, data layers, are they gonna require you to provide them to help you sort this out? So technologies make it easy to implement zones, but there is this idea that you gotta have some data layers in place to develop management zones. Creating management, there is no set rules. There's some programs and we're building some analytics out there to help establish what those zones might be. Most guys starting out with, I would encourage them to consider keeping on the smaller side, two to three zones maybe, four zones, not eight or 10, because you wanna try a major response and have those yield maps to come back. But there is no set rules in this as we know it today. There is no silver bullet. Another interesting thing that we've learned from our research is the zones, how I create zones on one field, and I go over to the adjacent field, it might not be equivalent. And so again, it's a field by field basis about how you generate zones, okay? So there's a lot of things to, farmer knowledge, there's physical properties, what's the potential return on implementing that value proposition, but I will tell you zones are better than probably just doing things in a uniform style out there. You'll learn a lot from this process of generating zones, applying it accordingly and seeing what you learn through the yield maps. Here's all the things just that you could use, you gotta have your boundaries, yield maps are of course a great data tool, soil survey data, some of this data you can get free offline and most of the farm management information systems or AG GIS can pull it all in automatically for you, Mark. And it's unbelievable how much information is out there. And so all of a sudden, you know, on a field, if I have a field boundary, if I just have a field boundary, I can get my soil maps, sometimes I can get DEM maps, I can get some other very quick, free maps off the internet and a lot of these software packages would just automatically pull that in for you. And you start adding your yield maps, your as-planted maps, your variety maps. I mean, there's a lot of things, but then they were talking about zones, we're talking about soil characteristics and how to figure out how yield's responding to some of this. And so there's a lot, so electrical conductivities, so we see a lot of people just bear images. There's aerial images like we see in the bottom line. So there's a lot of ways to do it. Keep it simple is what we always try and tell people that it's just getting into this and start somewhere, but recognizing you're gonna have to kind of change or grow with it over time. The plan, you gotta generate a field boundary, you gotta, we prefer to at least get some kind of bear soil imagery out there. And again, a lot of times this has already existed out there with all the different free locations out there on the internet to get some of this imagery. You can get a bear soil, just that building boundary bear soil could be a really good starting place and I don't have to have yield map data. But again, that might not be the ending place for me, it's just a starting place. So all that, you just add in your knowledge and the data sets as you go and you're gonna change zones over time. But what areas make the most sense? What areas are different from one another? Get those identified, get them marked out and start there. So those are management zones. There's a lot of other information that we're gonna provide here, but we outline them. We try and establish some kind of yield goals. Again, we'd have to have some yield maps for that, but again, what's our yield goals? Those are the kinds of things I wanna see our farmers really thinking through is trying to think about what that zone and what the profitability of that zone might be. Then we're gonna have to fine tune it as more information comes out. Just an example, there's this management zone analyst software out there. Go out and read it, you got the URL, it's free. It does require yield, soil electrical conductivity and other things and a little bit educational how to use it, but the point in the matter is it could give a starting place free if you just wanna start in a field or two and then willing to sit down and learn it. More likely, as you mentioned earlier, someone else is gonna help you with this. But if you're just trying to figure it out, if it's gonna be something I really, really wanna focus on in the years to come at my farm, maybe take advantage of some of these free tools and see what you can learn. So when you go to someone, you have some questions to ask, you might have some data layers already in hand and say these seem like where I wanna start, can you help me get me into the future? So again, go out there and check this out. It does a good job, basically you can tell how many zones it'll tell you what the optimal zone number based on the variability might be three, might be four and can generate and you can go out and see what kind of response you get just on a couple fields out on your farm. So changing gears, that's zones, okay? And that's probably a more natural occurrence of yield variability and things out there. But what happens if you don't have any data and you're leasing land or you're just jumping into this grid approach might be something that gives you the initial estimate of what the soil variability or some of the variability and fertility is out there. Again, we're normally speaking when we talk about grids squares, okay? Two and a half acre is traditionally in the U.S. called the profitable size. We get guys one acre, you know? And I think we can all, it depends on what you're willing to spend. And in some states in the South, counties will pay for soil samples. Do one acre grids, takes a little more time but think about how much you're gonna learn. How much data you getting? And so, you know, there is no set size but it depends on what you're really after and what you're willing to pay. Can be the real starting point in the absence of no data. I don't need any data to do the grid approach. All I need is to go out and run a boundary. I tell it the size of grid. Most of the handheld soil farmer will show here in a little bit. Makes that grid for you. Puts the point on the map. You go either to the center or within that grid. You pull multiple samples. You consolidate that into a single sample and send it off and you're off. I don't need any yield map data. I don't need to figure out how am I gonna generate these zones. So a lot of times this is a lot quicker, a lot easier way to get into this but gives you a quick snapshot of the variability are out there. John, a couple of years ago we did this for nematode research. We were trying to determine the nematodes in the field. So you just do a grid and you go pull samples and it tells you right where your problem is. And that wouldn't fit in a normal zone thing because it's a new problem. Yeah, but as time goes on, Mark, you know you can combine grids or you could take a grid and say, man, I've got something out there based on the yield map data. I got what I call a hot or cold spot. I better go out and focus on that. So I can start with grid but move towards that zone management as the years go on. So one thing I'll talk about, just make mention, there's a lot of ways to pull samples within that grid and we're not going to cover those today. But one thing I say is just don't pick a point in the center and just go to that point. Spread yourself out. We've got fertilizer applicators that are throwing fertilizer 70 to 90 to 100 feet. A lot of times that's not uniform so you want a representation. I know there's time involved so just don't go to a point and pick just a few five or six samples. Get your radius out there but try and do it the same way and all the same way each and every time within each other grid. So that's how I just put that at the bottom. You don't have to go to all sections but just don't go and stand around this table and pull samples because of the nature of how we apply fertilizer and stuff. Just take that into consideration. So finally winding down here, all we're saying is most of the guys have been really successful in implementing site-specific management. A lot of times that's on the fertility front, talking pH, we saw that in the yield map module and what that could mean but as we go over time, zones and grids must be analyzed and ultimately it'll change. I don't think you'll go to some of our progressive farmers here in Alabama and they say what we did 10 years ago or five years ago is the same as we're doing today. We learn, we break it up and sometimes it takes us five or six years to really arrive at zones that we feel comfortable with as high yielding, maybe low yielding but comfortable with really described the variability out in our fields. And so there's this growth thing. Once they get there, typically it'll be about the same. They might go out and do some checks occasionally and make sure they're maintaining management of their fertility levels or if they're doing verborate seeding, do some checks just to make sure that still describes the variability. But I just want to emphasize, it's not a static, at least on the front end. It might be six or seven years before you finally arrive at what that zone should look like for you. So anyways, some possibilities at the bottom but then the day most of the guys that start with grids might stick with it for a couple years just took a couple sampling rotations just to see if they're getting things changed but you'll see all sudden it's that movement towards the zones and better defining zones as they get more data layers together to help them define what those zones should look like. So in summary, management zones are different from grids, Mark. The idea from a starting perspective, pick something to start. You'll probably learn more just from that than you do the subsequent years but don't think like that's going to be the way for the future. It's going to be dynamic. These things are going to have to change as you learn and finally there is, there can be more than one optimal sensing and measurement of resolution. All I'm saying there, there's one thing that we can measure variability can we manage variability? That resolution of where I need to be is based on a couple things. Where, how am I measuring things and then at what scale can I manage or employ my treatments? Whether that's target rates or changing target rates as I move the field. That resolution, you know, we're moving towards that in an industry. My last comment would be as we know and we've got science to start to showcase this, where we really need to be managing is infeasible or incapable but we're starting to see machinery, even large machinery. It's not just a large machine today. That machine's broken down and can manage a much smaller area, a sub-unit of the machine and we can really drive down and start to make it profitable to manage the true variability out in the fields. The grids and zones get started, learn, both ways are acceptable and you'll see yourself developing the site-specific management program for your farm and it's gonna look different down the road. John, I think in closing out this lesson, don't be intimidated. Our farmers, I mean, for me, this is intimidating. This is a lot of material. This is stuff I don't deal with all the time but I look at all the farmers I've worked with over the years and who's doing this, you can do it. I mean, you can do this. Our farmers can do this. This is very doable. It's a big dose. You don't have to swallow it. Don't take too big a bite but you just start. Start with the yield monitor, start with the grid or start with whatever you need to but you'll get there and you'll get up like riding a bicycle. That's gonna get pretty natural to you. Pick two or three fields that you know that, hey, I got a lot of variability. You know, be strategic on picking them and just try it. Ask your neighbor. He's probably doing it. Talk about it. Absolutely. This is very doable. Absolutely. Thank you, John. Thank you.