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On this edition of the Strip-Till Farmer podcast, Bill Preller, longtime agronomist, Strip-Till Hall of Famer and founder of AGuru Machinery, kicks off a 3-part series exploring why strip-till is the ideal system for most soil types.   

In part 1 of this 3-part series, Preller breaks down the agronomic benefits of strip-till, including the following 6 factors: residue management, soil tilth (air and water balance), plant food availability, seedbed conditions, seed placement accuracy and crop protection. 

“Strip-till is the best agronomic system for growing a crop,” Preller says. “These 6 components all make up the agronomics to get you the best possible harvestable crop.”  

Coming soon — Preller will address the environmental benefits (soil health and water quality) of strip-till in part 2, and the economics in part 3. 

This edition of the Strip-Till Farmer podcast was brought to you by the 2025 National Strip-Tillage Conference, taking place July 31st and August 1st in Iowa City, Iowa. Head to StripTillConference.com to cash in on the super early bird registration rates. 

Full Transcript

Noah Newman:

Hello and welcome to the Strip-Till Farmer podcast. Great to have you with us. I'm technology editor, Noah Newman. So on this edition, Strip-Till Hall of Famer, Bill Preller kicks off a three-part series exploring why strip-till is the ideal system for most soil types. In part one, Preller breaks down the agronomic benefits of strip-till, including the following six factors, residue management, soil tilth, plant food availability, seedbed conditions, seed placement accuracy, and crop protection. Without further ado, here's Bill.

Bill Preller :

Hello everyone. This is Bill Preller with AGuru Machinery. We're focused on strip-till and getting more awareness to strip-till and more understanding of why it's the best agronomic system, the best soil management system, the best crop growing system of anything that's available in most soil types. The title of this podcast is Why Strip-Till, and that's really the setup for this, which is strip-till is still a niche soil management practice in most of the Corn Belt and it's mainstream in the Western Corn Belt. In the Western Corn Belt, Nebraska, parts of Kansas, Colorado. It's very much mainstream and it's heavily due to water conservation, keeping residue on top and yet giving the benefits of tillage and yet somehow that hasn't reached the rest of the Corn Belt. Having said that, from my information strip-till is the growing soil management practice. Other tools, other practices have stabilized or even declining, speed discs for example, are declining now in the industry-wide. Still growing in some areas. Vertical tillage is stable, but strip-till is growing and you see that with a number of new entrants into the market, new manufacturers.

You see that with growing acres in previously heavy tillage areas such as Minnesota strip-till is growing. And you also see it in growth in formerly heavy no-till areas, whether that's Western Kentucky, Tennessee or Ohio or other areas with sensitive watersheds. Strip-till's growing for a number of reasons, all coming together all at the same time. In the watershed areas, NRCS, soil water conservation districts are clearly promoting it as a version of no-till and is approved no-till, simply because they're working very hard to get nutrients below the surface of the ground. We surface apply nutrients in a no-till system. Some of those nutrients wash off and they end up in groundwater or surface water. They end up in groundwater, they end up going into rivers, streams, lakes, et cetera, and doing damage.

In the conventional till areas with the current economic circumstances, people who were very intense tillage disc rippers and field cultivators or vertical tillage, et cetera. They're saying, "Wait a minute, how do I cut costs?" And the efficiencies of a strip-till system are really driving it. It's the economics. So you have environmental drivers in some areas certainly supported by government and non-government organization support. And then you also have just flat-out economics. But the driver is actually agronomics. Everything, anything that doesn't work for a farmer to grow a good crop, in the end doesn't work in spite of other forces. Crop farmers make their living growing a crop and we all know that, but sometimes we skip over it with the agenda of the day or a particular point of view trying to drive a particular approach to crop management. Well, crop farmers grow crops and that's how they make their living.

And so at the core of anything involving crop production needs to be agronomy, needs to be how the agronomics work. And I go back to the 80s when the government was very aggressive about promoting no-till. I happened to graduate from college in 1980 and I happened to start working as a crop consultant in the early 80s. So I guess the introduction to me here is that I must not be very bright. It's the depression in ag of the 80s and I decide I'm going to stay in ag. And not only that, I'm going to be a crop consultant. Of course, for those of you who remember, a pick here in 1983, there weren't very many crop bakers for a newly minted consultant to make a living, but nonetheless stuck it out. Long history, here we are. With that background, in the 80s, no-till reigns supreme. It was the answer to everything.

It was erosion. Before we even knew what the term soil health was, it was all about erosion. But it was that early days of reducing tillage, reducing greenhouse gas, all the things that we now understand or at least hear about as "climate." Well that was no-till in the 80s. There's a catch. The catch is that in my area, in my crop production consulting geography, we have a lot of poorly drained soils. Central Illinois, former swamps, some of it wasn't drained until the 30s. Conservation Corps work gangs literally dredging drainage ditches, putting in tile and turning swampland into farmland. And it's very productive, but it's also very poorly drained. And the number of my customers back in those crop consulting days, farmed average to poorly drained prairie soils and no-till wasn't working. It was just a disaster. And on the one hand, they know they needed to do something different and on the other hand, they were taking yield hits, 10, 20, 30 bushel an acre and you just can't afford to farm if you're going to be behind the curve.

So early on that drainage connections, poorly drained soil types, struggling with no-till was something I learned the hard way with my customers. And early on we started using strip-till as an antidote for that or as an approach to that. That gets us down to, if we go back to agronomy, the most fundamental driver of agronomy, but it ties to environment and it actually then ties to economics, is air and water. Plant food, fertility, all that is secondary to air and water. Plants need air and water to live. It's obvious. It's almost insulting to say that to you as a listener. You know it. And yet so many things that we have done in the past and continue to do, do not optimize soil, plant-available air and water. My dad had a saying, first we plow it, then we un-plow it. And he was talking about moldboard plowing, which destroys all the soil structure.

And then we come in and work it down to a super-fine seedbed, but we've destroyed the structure, we've taken all the air out, we've packed it basically back into something that was probably worse than when we started. And another personal story then is that when I was in high school, actually late junior high, we farmed bottom ground. It's creek bottom ground, it floods back then on a fairly regular basis. And we plowed in the spring because of that. Continuous corn. It's a cattle farm. We grew corn both for silage and for grain corn. And we plowed in the spring, we worked it, we planted it. Well one year, early 70s, it flooded right after we plowed and it took all the soil down to the plow pan. And of course we had conventional planters back then. What did we do? We worked the ground again.

We worked up the plow pan in order to be able to plant. And my dad said, "Never more, never again." And we went to the local John Deere dealer and he asked to buy a no-till planter. And literally very nice man, very successful John Deere dealer laughed like, "What? That's not a thing." And my dad said, "Yes it is." Well, my dad was an inaugural subscriber to No-Till Farmer, the Lessiter Media, No-Till Farmer magazine. The very first ones printed on paper, sent out. He was inaugural. The second year we no-tilled, we grew rye as a cover crop. And I planted no-till corn into hood high on the tractor rye. It was a disaster because it happened to be a dry spring. We didn't know what we were doing. Rye sucked all the water out and we barely got the kernels in the ground and then a lot of it sat there until it rained.

So why do I tell that story? I tell that story because I have a lifetime of wanting to do things better and better is always different. Different isn't always better, but better is always different. You have to learn and unfortunately you have to learn the hard way. So that was a learning story about no-till and cover crops in the early to mid-70s. That's 50 years ago. Okay, so relevance to 10 years later when I'm a crop consultant working with customers on poorly drained soils and we're working on no-till, we didn't have enough air in that soil. It was poorly drained, it was wet and we're no-tilling. And so we go from tillage that puts in too much air, destroys the structure, we fluff it basically. Then we go to no-till that puts in no air. On well-drained fields, no issue. Sandbars, you bet. Poorly drained prairie soils, not so much.

And therein starts the journey of strip-till literally in the Corn Belt because that's where strip-till started in the Corn Belt in the 80s. And you have Jim Consola and you have other pioneers that drove it. Today we understand the agronomy way better. So I'm coming back to the theme of this. The first reason of why strip-till is, it is the best agronomic system for growing a crop. It is the best agronomic system of soil management for crop growth in most soils. There are some exceptions, but it's in many, many soils, it is better. And I'm about to tell you why. So there's six agronomic factors that I'd like to talk through. Crop residue management, soil tilth, and that doesn't mean tillage. Soil tilth is actually soil, air, and water balance. It's a precursor to soil health, which is about biology. Plant food availability, seedbed conditions, seed placement accuracy and crop protection.

Those components all make up the agronomics to get you the best possible harvestable crop. So let's talk with crop residue management. If we look at no-till, residue all stays on the surface, great, because agronomically, that means it's not in the seed trench. It's not where the seed is. If we look at mulch-till, the definition of mulch-till is we are mulching the residue into the seed zone. Moldboard plowing buried residue, that's fine. It wasn't in the seed zone. Lots of other problems, erosion, but it wasn't in the seed zone. So mulch-till right off the bat takes a hit because we are putting residue into the seed zone. And you have never heard an agronomist like me say, "Seed to residue contact." We all know better. It's seed to soil contact. No-till has the benefit that if we do a decent job with a row cleaner, we're getting the residue out of the way and we're not putting it into the furrow.

But it has the opposite advantage that now that residue mat is there, whether it's corn, soybeans, cover crops, whatever, and no residue mat is perfectly uniform. So we have thick spots and thin spots, we have wet spots and dry spots, we have cold spots and warmer spots. We have an uneven seedbed for temperature and moisture because the residue is not managed until the planter goes through. So what that planter sees is wet-dry, warm-cold, very not uniform. So both no-till and mulch-till take a hit. What does strip-till do? Strip-till whether it's two days ahead of the planter or in the fall ahead of spring planting, you are moving the residue out of the strip and you are creating a uniform air and water environment in that strip. The residue all still stays on the surface of the soil to protect and cover that soil. So you truly get the benefits of, in this case, clean tillage and no-till. That strip-till, agronomic benefits crop residue management.

Let's go to soil tilth. Soil tilth is about air and water and soil balance. Air and water. We're really talking about the density of the soil and the pores in the soil and really a pore size distribution. There's big pores in a soil, for example, earthworm holes and those are drainage pathways. And we've all seen the data and so on about no-till, more earthworms and water infiltration. And that may be true and that water can go deeper in the soil profile. That's all awesome. But if we look in the upper root zone, if there is residual compaction that has never been dealt with, which is quite often true in no-till fields, even long-term no-till fields, especially if they're poorly drained, then we still are not getting air and water into the root zone the way it needs to be.

Air is critical for root growth. Air is critical for soil biology, which is actually how roots function. So both the physical growth of the root and the biology around it both depend on air and specifically oxygen. All the good stuff is aerobic. All the bad stuff is anaerobic, as in without oxygen. The more water you have, the smaller the pores, the denser the soil, the more poorly drained it is. The less mid-sized pores you have in that soil profile, the less available air holes you have, air holding and water holding, they go together and they have to give and take air and water. So anything with a residual layer, anything with a residual compaction, even with earthworms and other soil activity punching holes through it, you don't get the holding of the water, you don't get the infiltration of the air. Strip-till breaks through that, at least if you're running down through that with a knife or a shank, maybe not running shallow coulters, but with a knife or a shank, you're punching through that, you're breaking through that.

And the secrets, one of the pieces of secret sauce of strip-till is that you don't re-compact it. You're doing tillage just in the row. You're preserving the soil structure in between the rows, but you never come back over the top and pack it back down. That's the part of the art of strip-till is you've created this air and water balanced area that then we don't drive on it and we don't till it to mess it up. So that's soil tilth, it is the best system. It is better than no-till that doesn't deal with old compaction, old layers, and it's certainly better than tillage systems that put in layers and compaction.

So then we get to plant food availability and plant food availability, that's a name that we pick very specifically because it's not about fertilizer. Think about fertilizer in concrete. It can be in there. No roots going to get to it. It's not available. So for it to be a nutrient to the plant, it has to first be available plant food. So we use the term plant food availability. And plant food availability is all about having nutrients in the root zone where there is air and water because all plants are hydroponic. They don't take in nutrients, they take in water that has nutrients dissolved in it. And the way they do that is they also have enough air to grow and function. So in a strip-till system, you have an air-water balanced zone in the root zone. And if you're also putting the nutrients in that root zone, you've put them physically where the roots are and you've given them the air and water for the roots to function properly and take those nutrients up compared to a no-till system with all the nutrients on top.

The minute it turns dry, they're not available. There's no water at the surface. You've applied your fertilizer and it's in the top inch of the soil. Lots of talk these days about stratification. Well, yeah, it's a big thing. And the minute you have a dry August, which is typical and the roots can't take up the nutrients, you don't get the air fill, you don't get the pod fill, you take yield hit. Mulch-till on the other hand, even if you're running a ripper, it's still mulching its top down. You still end up with stratification. The nutrients are broadcast, they're in the top few inches of soil, not truly in the root zone in the row. Again, strip-till is the better system.

The next agronomy piece is seedbed conditions. Well, seedbed conditions is partly about no residue. We covered that in crop residue management, but we set it up in the residue management section with it's about uniform moisture, uniform temperature, and in our benefit, warmer and drier than is typical in the spring. And that's exactly what that strip does. By clearing the residue off the strip, you have cleaned that. It's more open to the sunlight. It tends to dry out quicker, it tends to warm up faster. And because you have worked the soil, you've put air into it. And if you have a uniform strip, and that's an if because that's part of the art of creating a good strip that will cover in a different broadcast, you end up with better seed to soil contact and you end up with more uniform emergence. More uniform emergence is all about more uniform plants. More uniform plants lead to more uniform ears. More uniform ears means bigger average ears.

When we talk about net effective plant stand, and we'll cover that in a different one as well. We're really talking about how many full-size ears we get and the more uniform the plant stand is, they will have more uniform, full-size ears. It's amazing how many people are losing how much yield because of late emerging plants that have a smaller ear. They're at a competitive disadvantage, they're smaller than their neighbors. They get less sunlight, they get less root growth. They have a smaller ear. When you're listening to this, go look at your corn stand or when you're in the combine, look at the stalk size coming in and look at the ear size coming in. Ear size is directly related to stalk size. When you see variable ears coming in your head, you're going to see variable stalks. Those variable stalk sizes, diameters actually goes all the way back to emergence timing. Seedbed conditions, no-till we have variable temperature and moisture, variable stands. In mulch-till we have residue in the seedbed, which also delays emergence because we didn't have optimum seed to soil contact. So again, strip-till [inaudible 00:22:49], strip-till is the better system.

So now let's talk about seed placement accuracy. Well, a beautiful conventional seedbed worked really fine, great planter ride, but here's the dirty little secret. What's perfect on top is not actually what the planter sees. What that planter opener sees is actually two inches deep. If you're planting corn two inches deep, that's what's actually setting the pressure and those that use downforce systems, what you're doing is you're measuring the pressure relative to the gauge wheels to the opener. Well, what happens in a conventional till system? In most cases people do their seedbed tillage at a slight angle to how they plant. That's typical practice, which means those openers are going in and out of wheel tracks. And even if that wheel track was covered up with beautiful loose soil from the seedbed tillage, there's still hardness underneath, there's still compaction from that wheel track.

And when that planter opener hits it, that's different. And there's no way your planter downforce system can react in the space of three inches from no wheel track to wheel track and then back again. It just doesn't happen that fast. They can do multiple per second, not in three inches. That's the resolution. So that's the challenge. Well guess what? In no-till we've driven on it, we don't have soft soil on top, but we still have wheel track compaction and we probably still have some residual layers and residual compaction back from when the field was tilled, even if that was 40 years ago. And that's what that planter opener is seeing. In strip-till we have loosened the soil, smoothed that strip if we've done a good job of strip-till and that planter ride is phenomenal. With our customers, it's amazing how many people the first-time strip-tillers, or even if they're coming from another strip-till rig, they say, "Wow, that's the best planter ride I've ever gotten. That's the best planter job I've ever done." And it's reflected in uniform stands, more uniform stands and better yields.

So the last piece agronomically is crop protection. And you say, what in the world would strip-till have to do with crop protection? Well, now I'm going to do a little bit of a curve, which is that has to do with cover crops and we'll cover cover crops and strip-till in a different setting. But why strip-till with a cover crop? Well, you are adding residue, you're adding biomass. So soil tilth-wise, you're actually adding organic matter. That's a good thing. Plant food availability, you could do it so it recycles nutrients. Got to make sure you understand what that looks like. If you do indexed cover crops, so you broadcast your cover crops and then strip-till, or you just put the cover crop seed down while you're strip-tilling in between the rows, you have no cover crop in the row itself.

And yet depending on what cover crop you use, the mix, et cetera, you will get weed suppression. So crop protection in terms of weed control is usually better with cover crops. Rye in particular because of the aggressiveness of its root system and the allelopathy. If you keep it out of the strip and in between the rows it will suppress weeds and that's a good thing. You've got less weed pressure. The downside on crop production or crop protection in a no-till and strip-till system is, and we heard a lot about it this last spring, is slugs, the insects that thrive on having a wet mat. And yet a number of people that strip-till and no-till reported dramatic improvements in the viability of their crop and a dramatic reduction in the losses from slugs in a strip-till system. Why? Because the strip was clean. There was no residue there. There was very few slugs there. That's the difference.

So we're looking at the agronomy of crop production. We start with crop residue management. We want it on the surface to protect the soil, not in the seed zone, but also not in the row, that's strip-till. We look at soil tilth, we want to preserve soil structure, but we want to loosen soil where we need it so we get better air and water infiltration, that's strip-till. We look at plant food availability. The nutrients are in the strip, underneath the soil surface, in the root zone, that's strip-till. We look at seedbed conditions. Strip-till is the combination of no residue in the strip and warmer, drier, more uniform for better seedbed conditions, which then feeds directly into seed placement and better plantar ride. And if you have cover crops in the system and manage them well, you actually then contribute to a better crop protection system as well compared to either no-till or mulch or conventional till.

So there is the story of agronomy in strip-till. Why strip-till? And that's part one of this Why Strip-Till series. The other two components are environmental, including both soil health and water quality and economics. And we'll cover those in separate podcasts so that we can provide the focus. In total, strip-till is the only system that optimizes the agronomy and has economic benefits and environmental benefits including soil health and water quality. It's that combination of environment, agronomy and economics that are driving the growth of strip-till in the Corn Belt and beyond, in fact, throughout North America and now actually starting to catch on in other parts of the world. Thank you very much. This has been Bill Preller, senior agronomist and owner of AGuru Machinery. We focus on strip-till. Strip-till is better. Thank you very much.

Noah Newman:

That'll do it for this edition of the Strip-Till Farmer Podcast. Coming soon in part two of this series, Preller will address the environmental benefits including soil health and water quality. And then later in part three, he'll address the economic benefits of strip-till.

Quick note, this edition of the Strip-Till Farmer Podcast was brought to you by the 2025 National Strip-Tillage Conference, which will take place July 31st and August 1st in Iowa City, Iowa. Head to striptillconference.com to cash in on those super early bird registration rates. Thanks for tuning in, until next time. Head to striptillfarmer.com for all things strip-till. I'm Noah Newman. Have a great day.