Designing a Variable-Rate Manure Spreader w/ Gary Robison
Interview with Gary Robison, Co-Owner of Plains Innovation
Do you have to be a rocket scientist to build a manure spreader? It doesn’t hurt. At least that was the case for farmer Gary Robison. Along with his son Joey and another relative with ties to NASA, Gary developed a hyper-accurate manure spreader, using variable-rate technology and hydraulics. Gary is a co-owner of Plains Innovation.
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INTRO: Welcome to Organics Unpacked, a podcast for the business-minded organic grower — an interview podcast where we hear from the top experts in the commercial organic industry, with a focus on the business elements of organic growing both in and out of the field. You will gain insight and grow your operation. This show is brought to you ad-free by Avé Organics, a Wilbur-Ellis company. To learn more about Avé Organics, visit our program notes. In the meantime, enjoy the show.
TOM: Hello, everyone. Thanks for tuning in today. Welcome to another episode of Organics Unpacked, a podcast where we discuss organic farming from a practical perspective. I’m your host, Tom Buman. Today, I’m joined by Gary Robison. Gary is one of the owners of Plains Innovation. And actually, Gary wears a lot of hats and is involved in a lot of different things, but we can talk about those as we go along. Gary, welcome to the show.
GARY: Glad to be here.
TOM: All right. So, Gary, the reason I had you on the show today — there are probably multiple reasons I could have invited you on — but I’ve heard you have an innovative manure spreader. And of course, anybody that works in organic farming — or at least a lot of us — we are very used to using manure, and we don’t always have really good equipment. So I understand that Plains Innovation is a company that’s developed an innovative manure spreader. I just wanted to talk to you about that today. But before we get started, Gary, maybe talk a little bit about your background and how you got to be one of the owners in Plains Innovation.
GARY: So my background is I’ve farmed my entire career of about 45 years of farming. During that time, we were in the hog business. And in the late 90s, we exited the hog business, along with a lot of our friends and neighbors. And to make up the difference in the farm, to have some outside income, we got into the silage chopping business and manure spreading business. They kind of complement each other. You have trucks. You have people. So, as I worked in the manure business, I became excited about the opportunity to do variable-rate spreading. The equipment wasn’t there to do it. So we tackled the project of doing our own, building our own equipment. At that time, I brought in my uncle to help us with that because of his hydraulic background.
Variable-Rate Manure Application
TOM: Your initial thought of doing things differently was to do variable-rate manure application?
GARY: Yeah, everybody was — prior to this technology being available — they just would pick a rate that they were trying to achieve: 20 ton, 10 ton. I was basically dealing with all cattle manure at that time and trying to shoot for a steady rate. But knowing what I knew about farming and soil sampling, especially in our area — in our farming area, all of our land had been leveled for gravity irrigation. And that leveling process threw a lot of variability into the ground, into the farm. So that’s why I was looking at variable-rate.
Designing a Variable-Rate Manure Spreader
TOM: Well, that’s a unique concept. When I was a kid — and we had the old manure spreader that had the metal web drive in the beater in the back — the only variable rate is it went on three times faster at the beginning of the load than at the end of the load, right? So I understand some of the challenges of using manure in a professional way. Applying it at even a constant rate sometimes is really difficult, but a variable rate is really interesting. So, when you started this thought process, how did it begin, and who did you call for resources?
GARY: To begin with, we looked at the equipment that was already available on the market. And there was limited equipment that would even try to do variable rate and even address a problem that you were just talking about: the beginning of the load and the end of the load. It was pretty iffy, just getting the spread out there even. I tried working with a couple companies that said they could do something like that, but it wasn’t reliable. The technology drive, the floor chain, was just not there.
TOM: Okay, so you looked at a couple technologies, and you decided, ‘Hey, I can do better than this.’ Right?
GARY: I knew the technology well enough to know that if we could put it together in a different configuration, we could do better than anything that was out there. And this was actually almost 12 years ago that we started down this path.
TOM: So who did you reach out to for help once you decided you were going to go your own way?
GARY: Well, I have an uncle that’s a physical engineer. His background is heavily in hydraulics. And I ran it past him, and he was intrigued by the idea. He started putting ideas together. And then, at that time, probably the most innovative company out there that was interested in, aside from doing anything on the side, was Trimble. The big companies — Deere and those guys — they were just like, ‘Yeah, no. That’s not something we’re interested in. The market wouldn’t be big enough.’ So Trimble, at that time, locally, was handled through our Case dealership. So I started working with our technology person at the Case dealership and my uncle, and we started putting this together. We first developed the spreader box and made sure it was perfected. Being completely hydraulic-driven, that we knew we had to have in order to accomplish the variable-rate spreading. Then we started incorporating the actual GPS technology.
Two Different Hydraulic Systems
TOM: So, in your new spreader, if you broke it down into components, you said there’s the box. There are the hydraulics. There’s the variable rate. What are all the components of your spreader in a big picture?
GARY: In the big picture, we basically started with a traditional spreader box, but we built it ourselves because we wanted to control the whole thing. So we built the box with all plastic liners — replaceable, plastic liners — side, bottom. One thing we wanted was to reduce friction. We drove both the floor chain and the spreader apparatus with two different hydraulic systems so that one wasn’t dependent upon the other robbing power when we needed to speed up or slow down that floor chain to get that variable rate. Our goal all along was to be able to do this at a good rate of speed because the technology that was on the market already, the limiting factor was it just was slow.
TOM: In hydraulics, then, you have a hydraulic system, you said, for the floor chain and one for the spreader, right? Are these traditional hydraulic systems, or is there something special about them, Gary, that makes your spreader stand out?
GARY: Well, what made it work was — and this was completely on the engineering that the professional brought to the table — I’m not saying it’s unique. It’s not unique equipment. It’s just unique in the way that it was incorporated to do this task. And what it does is it creates the pressure to move the floor chain with a bigger volume of oil, instead of just raising the pressure, which keeps the temperature of the oil down and gives us the ability to finally tune that movement of that floor. That was unique in that way. Initially, we started doing it in bigger volume cattle manure, to variable-rate over a wide range, from 15 to 40 ton. And that was unique to the industry.
TOM: So, when you talk about increasing the amount of oil that you’re using, is that like a twofold increase, a fivefold, from what traditionally might be done?
GARY: About a threefold increase of what was actually being done, which is still unique to the industry.
How a Variable-Rate Spreader Works
TOM: You’ve got your spreader box that you said you started from scratch and you made. Then you put in your hydraulic system, then the variable-rate part. So there are different ways you can do the variable rate, right? You can change the speed of your tractor and spread it thicker or thinner. Or you can increase the amount that’s going through your spreader that you’re putting out, keeping the same rate or a combination. How does yours work?
GARY: That part I understood from the technology that was coming along so that we could put on starter fertilizer evenly over the field or spray evenly over the field as the machine speeds up from the end to slow down, coming to the end. I just needed to get what we call a driver, or a hydraulic computer-driven program, that would do that with manure. Nobody wanted to tackle it for the size of the market that was probably out there. Originally, we took equipment that was designed for dry spreaders — dry fertilizer spreaders — spreading more like a couple hundred pounds up to maybe 500 or 600 pounds an acre. We just made that work in our system. The problem with that all being was the calibration factors didn’t mean anything. They were just calibration factors that you just, over time, messed around with until you got it right. The longer you did it, the more accurate you could do it, and the more it made sense. But it wasn’t something that you could tell somebody, ‘That calibration factor means this.’ It was just a number.
TOM: Right. So, if you wanted to apply two tons or 25 tons, at first, it was a lot of trial and error to get it right until you recalibrated it.
GARY: Yeah, exactly. Exactly. Basically, we’ve had to work our way through the different companies. Some of the original equipment that we were using, Trimble abandoned their commitment to that program. So, then, we switched to Ag Leader and used their equipment, which was basically the same thing, just newer equipment doing it the same way. Finally, we hooked up with a company that was actually trying to accomplish what we were trying to accomplish. It was a smaller company, a foreign company. And we worked with them pretty closely, and they were in the process of writing software to do both liquid and dry manure. Basically, all applications: side-dress, liquid, flow liquid through bigger equipment. I got pretty involved with that company, and we literally fine-tuned that software so that those calibration factors would be something that you could explain. That’s the point that we’re at now, with the calibration factors, and that allows us to really get accurate on the spreading.
TOM: You can write a prescription for a manure and say, ‘I want it variable-rated across the field, just like you do for anything else.’ But you have a prescription in your spreader, and you can go out. Do you, then, hold the speed the same with your operation and, then, just vary the manure application? Or do you speed up and slow down?
GARY: It’s at the level we’re at now with the technology. You just pull in the field. You understand what you’re trying to do. And as you speed up the spreading equipment, it changes the rate. And it’ll change the rate as you speed up and slow down, as well as you’re crossing the variable-rate zones on the prescription.
Cattle Manure in the Midwest
TOM: So, Gary, I know that you live in a special part when it comes to manure, especially cattle manure. You’re in the center of that. Talk to me a little about how where you live, maybe, was a benefit to developing your manure spreader.
GARY: We live in south-central Nebraska. The county that we live in goes back and forth between the county in Nebraska with the largest number of cattle on feed, between us and a county up in northeast Nebraska. And we’re also probably about as big a cattle feeding area as there is anywhere, other than a few giant commercial yards in a little more arid places. So, in our area, there is a large amount of beef manure that needs to get moved and spread every year. I just wanted to bring the technology to the situation, where we were just out there, just blindly throwing 25 to 30 tons on fields that maybe didn’t need that much. And we were putting too big of a load of phos out there. Phos is the product that generally all manure is wanting to be applied for. Some organic people are interested in nitrogen. But, generally, what I got started with was phos. So we drove everything that we learned to do off of the phos levels of the field and the phos levels in the manure. We got to sampling. A massive amount of sampling I’ve done over the last 10 years to understand beef manure, understand moisture levels of the manure and the rates that we needed to spread. So, as we’ve evolved here, especially the more progressive grain producers have understood that we really need to do this. The more we self-regulate, the longer we’re going to be out here doing what we want to do. If we don’t learn to self-regulate, the day’s coming when somebody from the red team or the blue team is going to be telling us what to do.
Determining Manure Amounts
TOM: Now, I understand. So, with your system, when you’re applying, as you said, to those phosphorus levels — and you’re meeting the crop needs with that — are you able to track the amount and record the amount you spread for manure management plans so that you actually have documentation of the tons of manure that you spread and how it was spread across the field?
GARY: Yes. We start out. The process starts where we understand the field. We look at the soil samples, and we really like to look at grid samples, one-to-two-acre grid samples. And we determine the amount of manure that we’re going to need to bring to the field by the sample of the manure at the feed yard. We pile that. We make a pile in the field, a stockpile in the off-season while the crop is growing. We’ll use a small amount of the edge of the field that’s in a good spot, where it’s away from people that live in the area and drainage. Understand the drainage of the farm, so we’re not piling it in a low spot. Then we come back after the crop is removed, and we’ll spread that field. We understood that we added no tons by weight. So we use loaders at the feed yard to load the stuff out, so we know exactly the right tons that we get to the field. We use loaders with scales as we load the spreaders so that we’re checking our work, so to speak, as we spread. And through that process of the last few years, we’ve gotten extremely accurate, so we’re just putting the right amount of phos out there. For maybe a five-year plan or a seven-year plan, we’ll try to put enough phos. If you try to go too far — too much phos — it just gets lost and tied up in the field, and the crop can’t use it anyway. That’s why I was trying to bring the spreading levels down. Spread the manure over more acres. It’s an idea that’s catching on.
Manure Moisture Content
TOM: How many tons can your manure spreader hold? When you load it, I assume it depends a little bit on the moisture content of the manure. But if you had, generally, cattle manure, how many tons can you fit on it?
GARY: Our spreaders run about 20 tons, 25-to-30%-moisture cattle manure. If you get it wetter than that, you can put on more tons. The moisture in manure is the same as moisture in feed. It’s figured on a dry matter basis. We actually use an idea that — and I didn’t come up with this idea, but I worked in a company that did — they push the manure up into piles in the pens. Then we haul it out of the piles in the pens and make another pile, which is basically like composting the manure twice. So we can generally take about 15 to 20 points of moisture out of that manure from the raw state that it was in the pens, getting pushed up, to by the time it’s ready for us to spread it in the fall or the winter. Our goal is to get it down under 30% moisture before we spread it, so it spreads nice, and we’re not just hauling a lot of water around and driving around, spreading out water instead of actual product.
Manure Spreader Speed
TOM: So, typically, then, how long does it take you to empty a load? Just for listeners to know, okay, you’re going to put about 20 tons in the spreader. Then how fast do you unload it?
GARY: On cattle manure, we’re running 10 to 13 – 14 miles an hour with the truck spreaders. So we’re using horizontal beaters. And our idea was it really gives you a nice spread. It’s beating it up, and it’s just spreading it the width of the truck. So you can drive farther with the load. And it made no sense to us, as we developed this, that we spread a wide pattern for a short distance and then drive back and get another load. We actually go all the way through the field on quarter-section fields, which, out where we live, everything is full quarter sections, all irrigated with center pivots. So we’ll go down and back to the pile, so we don’t have a lot of wasted time. We’re spreading about — I’d say our average speed is about 12 mile an hour, probably unloading in less than five minutes, three minutes.
TOM: So you can spread a lot of tons in a day.
GARY: Yeah, the trucks can spread a lot of tons in a day. We use bigger loaders. Generally, one loader can manage three trucks, and we can spread about 40 acres a day per truck, maybe a little more than that some days. But the days get shorter at the time of the year when we’re spreading, and we do not spread at night.
Manure Spreader Equipment Needs
TOM: All right. So, yeah, that seems like it really has speeded up the process and added professionalism to it in order to do that. So your box — your spreader box — does it sit on a truck? Or is it a trailer pulled by a tractor? How does that operation work, Gary?
GARY: We have both. We have trucks, boxes on trucks. We use tri-drive trucks that have three driven axles. We use big metric floater tires. A lot of the ground that we’re working with today is minimum-till ground. They’re going to leave the trash on top of the ground. We spread the manure into the trash. I’m talking trash as the residue of the corn, the residue of the soybeans, and we just leave it there. In the spring, they’ll maybe strip-till the ground, maybe totally no-till the ground. Very seldom anymore is the ground getting worked with discs or plows. We leave the manure there, the worms in no-till ground. There’s a massive worm load out there — earthworms — and they literally grab the manure and pull it down into the root zone. So we’re using tires that are friendly with no-till, and then we have the same thing with tractors. We have the big tires on the tractor spreader. In the tractor spreader, we can go both ways. We have horizontal beaters, the same as the trucks. Or we have designed a unit that fits on the back of the spreader. We still use the horizontal beaters to basically break it up and meter the manure down into a set of big spinner discs that throw the manure a little wider pattern, like a 20-to-24-foot-wide pattern, pretty evenly. Same equipment being driven, but we drive the pumps on the tractors. We still use the same hydraulic system with the unique pumps. We just drive that system with the PTO of the tractor. The advantage of that is having the GPS of the tractor can help us manage that wider pattern, which is not available on the trucks. To set a truck up to be driven on GPS, we basically have to follow the old farming rows as we’re driving the trucks.
TOM: So is there anything special about a tractor that you need? Any tractor work? Or if you’re going to have the box on a trailer, hook it up to the tractor, any special needs there?
GARY: So, this last generation, where we were working with a company, our goal all along was to get this to be ISO-compliant. I don’t really know the name of, basically, the legislation. As farm equipment companies were building GPS-driven equipment, they were all trying to build their own little unique thing so that people had to buy their equipment, their color of equipment. And somebody finally stepped in and said, ‘No, let’s just make this compliant. Everybody be compliant so that you can plug a red tractor onto a green planter or vice versa and all across the board.’ So our equipment is ISO-compliant. So, literally, we can back any tractor up to our spreader trailer and plug in the cord from the driver that’s mounted on the trailer. The spreading program shows up in the tractor, and off you go. If you’re familiar with green running inside the Deere program that does your GPS, maps your fields, measures your acres, it’ll just be a little driver program inside of your big Deere program. It makes it user-friendly for people, that they don’t have to completely learn a whole new operating system, so to speak.
Manufacturing Manure Spreaders
TOM: It’s really important to have compatibility across equipment or whatever. Let’s talk a little bit about: you’ve got the blueprints. You’ve got a few made. How many spreaders have you manufactured now?
GARY: We’ve made five so far, and we’re ready to make a new — I’ve been slow at this process because one thing that has aggravated me over my career is, in the race to be part of a new concept, everybody will make something and throw it out there. Then, as a consumer, I buy that equipment. Then it’s like, ‘Well, we’re working the bugs out. That’s something that we’re going to do when the new operating system comes out.’ And I’m just like, ‘That’s fine, but who pays for that?’ They just always pass that on to us as the consumer. I’ve been reluctant to throw out new ideas. Basically, I wanted to get to this completely ISO system before we really leaned on marketing, and we just got there. This last season, we tested the equipment across both the cattle manure spreading field, and we’ve recently, in the last year-and-a-half, been exposed to some chicken manure and some dry chicken manure, some different levels there. And I definitely wanted to make sure that works before I started hanging my hat out there. So, as we feel like we’ve gotten all that behind us, we have another new prototype that we’re in the middle of making right now that will have a few final changes that we wanted to make. We made some changes to how the manure is delivered to the spinners, went from two beaters to one beater that’s direct-driven. So we have no chains at all on the system now. It’s all just hydraulics and hoses. When this prototype comes out, we’ll test it this fall. Then we’re going to start building and marketing.
TOM: So somebody who is listening to this podcast, they’re interested in knowing more about your spreader and whether they can get one. How would they get a hold of you, Gary?
GARY: At this point in time, they’re just going to have to call my personal cell phone. That’s the level that we’re at right now. We have some arrangements behind the scenes going on — and I don’t want to talk about those right yet — where there are some people that are anxiously awaiting me to give them the green light to start working on this project, to build it. We pretty much know where the cost is going to lay out, so we’ll be competitively priced with other spreaders. We want to test. There’s one more thing that we’re trying to test, and that is we’re probably going to look at building two different — basically, a spreader that would be specific for just chicken litter and then a spreader that can work across the whole gamut, from cattle manure to mulch to chicken, especially raw chicken litter. So we’re going to be looking at two different projects there, but we’re excited about the dry chicken litter that we’ve just gotten into, that we’re able to take those rates down too. We’ve tested 500 pounds per acre on some sizable fields. That’s the same spreader that can go out and spread 40 tons. We just feel that we can build a bigger spreader that would hold more volume of the dried or the raw chicken litter and even extend your ability to cover more acres. And that chicken litter, we’ve been running that. We’ve run that as high as almost 20 mile an hour, with a 22-ton box. So that’s a whole different deal than putting it in a spinner box on traditional spreading equipment. It’s going to give us the same accuracy or even higher accuracy than what those boxes are doing.
TOM: So, Gary, if people are interested, are you ready to start taking phone calls from them?
GARY: Yeah, I take phone calls.
TOM: Why don’t you just go ahead and give your cell phone number, if that’s what you want to do? And if somebody has any questions, they can give you a call.
GARY: I live in south-central Nebraska, and my cell phone number is (308) 991‑3039. And I would be glad to talk to people about what we’ve got coming down in the future here.
Future of Manure Application
TOM: So, Gary, in the few minutes left, you’re sitting in a room with either a livestock producer or crop producer, right? And they’re either getting their manure applied, or they’re getting somebody else’s manure applied on their land. In two minutes, what do you want them to know about your manure spreader that sets it apart from everybody else’s?
GARY: The first thing that we’re able to do that’s coming in the future — and actually, on the west coast, it’s already there — we can real-time document exactly what went on the field, what day it went on the field, what the GPS location of the field is. So, as the future comes and more and more documentation is required, we’re already there. The second thing would be the fact that you can literally tailor-use that manure to the exact amount of needs that you have in your field. And we’re going to quit over-applying or under-applying, just because it’s what we’ve done. That’s what I saw coming in the future. There’s not going to be less regulation, and nor should there be. The rivers need our help, keeping the stuff out of there. So let’s just be responsible people and spread the manure out there, use it. The consumer of the product that we’re bringing to the grocery store, I don’t think they’re as price-sensitive as we would like to think. But I think it’s getting pretty evident that they’re going to be sensitive as to how careful we are out here of using our resources and managing our resources. So those would be the two attributes that I think we have.
TOM: Well, Gary, I really appreciate you taking the time to talk to us today. It sounds like you have a really unique piece of equipment to spread manure. And it sounds like you have a unique journey to thinking about the idea and why you needed it to get to where you are today, as far as implementing it. A lot of work from specialists, a lot of work from equipment dealers and just struggling through it, like all startups do. So, again, I appreciate your time today. And if anybody has any questions, you gave your cell phone just a few minutes ago. They can give you a call and ask additional questions. So, with that, I want to wrap up another episode of Organics Unpacked. I appreciate the listening audience coming here and listening to another episode. Stay tuned next week, when we present another facet of Organics Unpacked and help organic farmers unravel one more issue that they might have in their operations. So, thanks to everybody, and thanks again, Gary.
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