Nate Firle, owner and chief agronomist at AgRevival, has tested a lot of products and practices on his research farm. Since 2014 he’s seen it all—from promising products that fall short to products and practices that have performed so consistently that they should be no-brainers for farmers seeking to improve their farms’ productivity. During our discussion with Nate, we asked him to recall the most unique studies he’s conducted over the past several years. 

Tire Pressure at Planting Study

The first one that comes to mind is the tire pressure study we just finished this past year in partnership with NTS Tire Supply. We started with a question: Does tire pressure really matter when it comes to soil health? Our goal going into this study was simply to answer this question. So we looked at different tire pressures on both the tractor and planter during the spring planting pass ranging from thirty-five psi all the way down to six psi.

In addition to my role at AgRevival, I also provide agronomy services to area farmers. When I was visiting with farmers during the spring before we started the tire pressure study, I made a point to ask them about their tire pressures. It was clear that very few guys either knew what their tire pressures were set at or why. I got used to hearing, “thirty-five psi, because that’s what’s on the side of the tire.” 

The cool thing about our tire pressure study is that we were able to open people’s eyes to the importance of tire pressure, and to the fact that there are a lot of bushels on the table. So, at the end of the day, something like a tire inflation system, which allows you to set your pressures correctly for the weight and speed of your machinery, becomes a fairly low-cost improvement for the right operation.

Our tire pressure study was one of the most consistent we’ve ever done, to the point that it almost became boring by the third year. 

Digging Up Dirt on Tillage

One of our newest studies that we feel is differentiating us from other research companies is our tillage study. There are very few (if any) groups out there comparing a no-till program, stip-till program, and a conventional tillage program side by side. We’re taking the time and space to do that. And we’re looking at everything that tillage can affect, from nutrient stratification to soil aggregation. Which type of tillage keeps the nutrients in the zone where they’re going to provide the best ROI? 

Soil structure is probably the most intriguing aspect of the study because it’s something we can dig down and assess. We’re also able to look at the ROI of each tillage program, right down to fuel consumption per tillage pass. At the end of the study, we want to be able to build a whole picture of the net ROI for this practice versus that practice. 

Tillage Tantrums

It has taken some time to get the research blocks built to do this study, because this is going to run across multiple years. We’re in our third year of the no-till block being a no-till block and the strip-till being part of a rotating strip I’m calling the “minimum till block,” which we till with a vertical till disc in the fall and spring. Likewise, our conventional till block is in its third year. We’ve ripped that ground and cultivated it, using more of the heavy tillage program. So we haven’t published a lot of data on this study yet because it has involved so much ground work, pun intended. 

However, the insights have already been piling up on this study while we’ve been working on getting it established. During the first year, we had a hard time making the test strips for the study because the ground was so loose. There was hardly any structure to the soil. Initially, the strips were of poor quality because of this. As we’ve built soil structure on this ground by not tilling it over and over, we’ve made better strips. 

Farmers can have the same experience; they try strip till one year and think ‘boy, I don’t like this one bit’. Well, we didn’t like it our first year either. But what we’ve learned is that, with time, we’re starting to see more of a benefit to it. Also, it’s a big investment for any farm to make a leap to an entirely different tillage strategy. So we feel as if this is going to be one of the most valuable datasets that we provide to farmers over the next three to five years.

To my knowledge, there’s no other research group out there that has really gotten to know all these tillage tools side by side. And it’s no wonder why—we have to find a partner for each piece of tillage equipment we want to test, but who wants to loan out a ripper for five years?  

No Perfect Tillage Method

Last year a company invited me to speak about tillage to a group of farmers in Iowa. The event hosts were just drilling me and drilling me about the “best” tillage practice, as in a ‘you’re not coming off that stage until you tell us’ sort of thing. Eventually I just told them, “well, you should have a plow, a ripper, an inline ripper for deep soil structure, and a vertical till disc—one that you can change your gang angle on. So, if you can’t get your hands on one of those, you should also have two vertical till discs and a strip till bar and a no-till planter.” So they all looked at me funny: thanks for the impractical advice. 

But according to our data, that’s exactly what you should do. Maybe this is the year to run a plow. It may be most beneficial to roll the soil once every ten years to prevent over-stratification. In some years, it may be most beneficial to subsoil your farm because it was really wet that fall. You have to get your crop out, but you also created a bunch of compaction that you now have to lift and fracture out of the soil. Yes, it’s not practical to own all this equipment, but the best practice is to use the right tool for what you need to accomplish with each tillage pass.

Be Intentional with Every Pass

Speaking on a practical level, whatever tillage equipment you own, we’ve found that the important point is to be intentional with your tillage. Don’t just hook the ripper up and head out there and go to town. Probe your soil first and figure out how deep you need to set your tillage equipment. It seems like eighty percent of the time we just hook on, grease, and go. Like I’ve said, what we’re seeing with this study is that it pays to be intentional with how you set up your equipment. 

For example, a couple years ago I had my field cultivator set at three inches and it was enough to work out the tracks and level everything off in spring. This year we did the same thing and when I probed the soil after my spring pass, I thought, ‘boy, I need to be down deeper, more like four and a half inches’. I needed to roll in more soil, set it a little deeper to create a better seedbed. Last winter we didn’t have any snowpack or moisture. So the bugs weren’t out there working on the residue. This spring we had more residue and so we had modify our tillage strategy to achieve the same end result. 

Someone might point out that the implement is going to be pulling harder and that I’m burning more fuel. That’s true—I’m going to burn another gallon of fuel to the acre. But think again about seedbed quality; that extra four dollars in fuel per acre may yield me an additional five bushels per acre, which puts me ahead in the end. 

Looking Beyond 'Typical' Products

A third category of unique studies we’ve done has to be all our work with humics, carbon, and biologicals. Some of the first studies I ever conducted as a researcher back in 2009 (prior to AgRevival) dealt with mycorrhiza helper bacteria. And we’ve also done extensive testing on sugar products, applying them both foliar and in furrow. Basically, we’ve looked at a lot of the products out there that you won’t find for sale at your typical co-op. 

Research has taught me to give everything a fair chance, whether it’s something “standard” or not. I tell farmers all the time: If you adopt a new product or practice into your operation, and it makes you money, don’t give it up. It works for your farm. The purpose isn’t just to add something new and then something new next year and the year after that. As I’ve said, we need to be intentional about what we do, whether that’s tillage, your tire pressures, or how and when you add biologicals to your fertility program.