“Vertical tillage doesn’t work against no-till, it works with no-till,” says Tom Evans of Great Plains Mfg. Above photo courtesy of Great Plains Mfg.
Dealers who haven’t picked up on the push for “soil health” in the last few years haven’t been paying enough attention. When you see mention of ag-related trends in media like the New York Times, it’s probably not because they were looking to write something about agriculture (“Farmers Put Down the Plow for More Productive Soil,” New York Times, March 9, 2015).
In all likelihood, the collective volume of coverage soil health is getting in local, regional and ag media somehow got their attention.
In many cases, for the general public and mainstream media, when discussing issues such as this, it tends to center on conservation, the environment and “regulation of agricultural pollution.”
For the farmer, the issue is far more pragmatic. A Texas farmer, who switched to no-tillage in 2005 for his 6,000 acres, was quoted in the article, and put the issue into “farm” perspective: “My goal is to improve my soil so I can grow a better crop so I can make more money. If I can help the environment in the process, fine, but that’s not my goal.”
Farm equipment dealers and manufacturers who make tillage tools are dragged into the debate because conventional tillage practices are often cast as the villain when the discussion turns to soil health. To paraphrase Shakespeare’s Hamlet, “To till or not to till, that is the question.” That’s to say, to purchase tillage equipment or not to purchase tillage equipment is becoming the question.
It’s one that is near and dear to the hearts and wallets of many dealers and equipment makers.
Tillage improves our influence over pests, weeds, insects and diseases by exposing them to organisms in the soil, says Jim Boak of Salford.
Photo courtesy of Salford Group.
Do farmers who have consistently produced high crop yields by using conventional tillage have to give it up to attain a high level of soil health? Or is there a middle ground that can produce high yields while improving soil health?
Soil Health: A New Fervor
The amount of recent attention devoted to soil health is clearly beneficial as a precursor to increasing crop yields that will be required to feed the extra mouths that will need to be fed in the next 20-30 years. This year has been designated as the International Year of Soils. According to USDA, this year of awareness aims to increase global understanding of the importance of soil for food security and essential ecosystem functions.
“I think part of the excitement is the catchiness of the new term. Years ago we called it soil quality and now it’s soil health,” says Tony Vyn, professor of agronomy at Purdue University. “Part of it is also the growing concern for hypoxia (oxygen depletion) in the Gulf of Mexico and the phosphorous going into Lake Erie.” These factors, he says, would seem to indicate that there’s significant nutrient loss from the soil taking place, including phosphorous and nitrogen. “This and increased societal scrutiny have advanced the notion that we need to increase our attention to soil health.”
He says that farmers need to placate these concerns by emphasizing the positive things they’re doing through farm practices to hold soil, sediment and phosphorous in place. Vyn cites practices like no-till and strip-till that improve nutrient cycling through crops, as well as the use of cover crops to avoid nutrient losses to air and water.
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“We’re learning more and more about soil microbes that we have never known before. And if we give them a good home they work for us,” says Jodi DeJong-Hughes, an extension educator at the University of Minnesota. “It’s only in the last 5-7 years that we have really talked about soil health. For many farmers, it’s a really new concept. With a new practice, many farmers will watch other farmers try it out first. If they are successful, then they’ll give it a try too.”
For Paul Jasa, an extension engineer at the University of Nebraska-Lincoln, all of the talk about soil health is a wake up call to farmers and the rest of the industry. “Soil health disappeared from the radar screen when large scale farming really took over and farmers could buy technology and we didn’t have to worry about soil health.”
Jasa says prior to 1950, everybody was an organic farmer. All of the pesticides, fertilizers and technology weren’t available. Farmers practiced diversity through crop rotation. They utilized things like green manure cover crops that boosted soil health.
“We became lazy managers with the introduction of commercial fertilizers, pesticide to kill pests and herbicides to kill weeds. We ignored the importance of a healthy soil system and started doing it with technology instead,” he says. Jasa points to the emergence of glyphosate-resistant weeds as a more recent example of how the industry has gotten lazy when it comes to soil health. “Unfortunately, a lot of our technology serves as a band aid. We are treating the symptoms. We’re not treating the problem itself.”
He likens issues of soil health to human health. “My doctor says my cholesterol is too high and I need to lose some weight. It’s a lot easier for me to take a cholesterol-lowering pill than it is to exercise and watch what I eat.”
Making a Case for Tillage
Jasa, who is an unabashed proponent of no-tillage, believes there’s no reason for a farmer to ever till his ground. But considering that USDA reports that of the estimated 335 million acres of cropland used for crops in the U.S., nearly half (48%) are tilled every year, a lot of farmers aren’t backing off what’s worked for them for decades.
Richard Welker’s operation in Kingsville, Ont., is a case in point. He typically rotates his corn and soybeans on a nearly 50/50 basis, but also works in a small number of acres to wheat. “We plow everything, bean and corn ground 100%. Then we broadcast our fertilizer in the fall and plow it under to mix it in the top plow layer. We follow up in the spring with a Triple K cultivator at about 2-3 inches deep.”
He says he sprays his corn for foxtail and fall panicum, but spring tillage is the only real way to get rid of many of the weeds he’s dealing with, including common ragweed, giant ragweed, pigweed and lambs quarter. It also helps to suppress established deep-rooted thistle that can often be controlled with Basagran afterward. But a new weed, fleabane, appeared about 3 years ago and “it is getting out of control and glyphosate won’t touch it. Tillage seems to be the only way of controlling it,” Welker says.
Welker also produces seed beans, or what he calls food grade beans, for which he’s paid a premium. With his rotation program, if he was to no-till, there would be too many stalks going though the combine and it could spoil the beans. He says, “For food grade beans, that’s a no-no. So we’ve always plowed our cornstalks, plowed everything and ended up getting good yields.” For corn, that’s about 175 bushels on average, which he says, “We’re happy with that.”
Welker acknowledges that plowing isn’t suited for all situations or soils, and he would like to reduce the amount of tillage he does. So far, he hasn’t found a better way to accomplish what he needs to do.
The fact of the matter is Welker did give no-till a try at one point, but says he didn’t have any luck with it. “You have that yield drag and it really reduced our yield. By the time we got through this yield drag, probably 2 or 3 years, it would be costing us a lot of money. And no-till equipment is fairly expensive, and there’s so much controversy out there. Every farmer you talk to says this tool’s no good, this one’s better. So we never even got settled on what we should pull in the field.”
Fall strip-till will give equal yields to conventional till in most soil conditions, says Tony Vyn of Purdue University.
Another advantage that Welker has that he says others may not is his fields are square. “We don’t have all these odd-shaped fields, which is a real drawback when you’re plowing. We have nice square fields. We strike it out and we can usually plow 50 acres in less than 4 hours. And plowing totally eliminates dealing with residue. We like to get that trash mixed in the top plow layer. We think it rots better and you get away from the hair pinning that can happen with no-till and cornstalks.” He also believes that fall plowing helps preserve soil moisture.
He says plowing has also helped with surface drainage in low areas of his fields, but for Welker the decision to till conventionally comes back to weed control. “We’re dealing with a lot of these glyphosate-resistant weeds. I believe plowing is a big part of why I have clean fields and don’t have a big problem with dandelions, wild carrots and thistles. These are some of the things that keep us plowing.”
And farmers should keep plowing if it’s required to improve soils and be profitable, according to Jim Boak of the Salford Group, manufacturers of tillage tools, seeding and fertilizing equipment. It’s a matter of improving producers’ influence over pests, weeds, insects and diseases, he says. “This is simply a matter of exposing those pests to organisms in the soil.
“We grow huge amounts of residue and huge amounts of carbon these days,” says Boak. “The fastest way to digest it is to put it in contact with the soil organisms. The thing we need to understand is the soil can only digest so much at a time.
“There’s actually a formula that was developed in Europe and Australia, but it can be used as a guideline here. It calls for roughly 1 ton of residue per inch of soil. So if you have 6 tons of residue above the ground, you need to incorporate that into 6 inches of soil and leave the rest on top of the ground.” And this requires doing some tillage, says Boak.
But he also thinks part of the problem in the debate pitting tillage against no-tillage is that crop production is not a black and white process. “What’s happened is we’ve forgotten about what makes sense and we get limited by terms like tillage, no-till, conservation, sustainability. We limit ourselves by just using those terms.”
For example, “What we should be thinking about is what’s right and do what’s right to make the most profit. Yield and profit don’t necessarily go together, but if you take the fact that you’ve got to have good, healthy profits to grow high corn yields, then the result of healthy soil is an almost automatic.”
He says that if farmers put their focus on soil health first and achieving high yields, they are going beyond mere sustainability and conservation. “We’re stepping into the regeneration side and building soil. And in some areas, that means doing it with no-till. It means you’ve got the environment where you can produce without tillage. In other areas, such things as moisture, temperature and light limit you, and you need tillage to help you out. We need to start the conversation about regeneration and leave conservation, sustainability and limiting terms applied to tillage for historians to discuss.
“We have a full range of tools and an arsenal of knowledge unprecedented in human history, and we have the wealth to enable change. All we need to do now is tune out the marketing messages that suck profit out of the pockets of producers and apply our resources to regenerating the soil.”
Tillage & Tradition
DeJong-Hughes from the University of Minnesota places herself on the tillage side of the debate, but with a big qualifier — farmers need to reduce it.
“If you reduce your tillage, you will improve your soil health. Whether or not a farmer looks at reducing their tillage depends on their goals and perceptions. Do they believe profit and reduced tillage are separate goals? Do they believe the only way to get the highest yield is to aggressively till? Or do they believe improving soil health will ultimately improve profit and yields?”
She says another aspect of reducing tillage that should get farmers’ attention is it goes hand in hand with reducing costs. “I’ve seen that by reducing tillage we won’t lose yield, however, we decrease our inputs, especially fuel and labor, plus it improves soil health. Once farmers see this and get used to it, they usually keep going in that direction.”
DeJong-Hughes estimates that about 70% of Minnesota farmers utilize a disc ripper, disc chisel and/or a chisel plow, which she considers “conventional tillage” and which leaves less than 30% residue compared to a moldboard plow, which leaves less than 15%. “It wasn’t that long ago that moldboard plowing and leaving the soil black with no ‘trash’ made you a good farmer. We’re trying to show there are new ways to leave more residue.”
She says the biggest battle in getting farmers to look at new techniques is tradition. “Never underestimate tradition. If their dads did it and their dad’s dad did it and it worked for them, then why change?”
When conventional farmers see residue levels created by 3 years of corn-on-corn, they’ll probably pull out their plows, says DeJong-Hughes. “I’m trying to show them that there are other ways to manage residues without a plow. If they have a corn/bean rotation, they have a lot more options.”
Regardless of circumstances, DeJong-Hughes is recommending to the farmers she’s working with that the best approach to tillage is to reduce its depth, number of passes and aggressiveness. “I’m pushing for the least amount of soil disturbance possible. I’ve suggested that some of them take a look at vertical tillage to manage heavy residue build-up.”
What she’s leaning toward is getting her farmers to consider strip-till. “It’s not going to be ideal for everyone, but I think it’s the best marriage of no-till and full-width tillage. You can get the seed bed to warm up while leaving 50-60% residue to protect and build soil health. With strip-till, you incorporate your nutrients so they’re not sitting on top of the soil, and, if needed, you can also till in lime. In between the row, you have full residue where you get all your soil health benefits, including erosion protection, water infiltration and water-storing capacity.
“It’s a long list of benefits for farmers. It’s a wonderful way to reduce tillage but still produce high yields,” says DeJong-Hughes. When it comes to “pure” no-till, she doesn’t promote it because it is at a yield disadvantage unless it’s done on sandier soil. “On really nice growing seasons, no problem. When we have a cold and wet spring, we have research that shows no-till gets hit hard, even in southern Minnesota.”
On the other hand, she acknowledges that in states west of Minnesota, Iowa and Missouri that have very little rainfall, no-till can be an excellent solution. “My state and east have a lot more rainfall — 2-3 times more — and we don’t need to preserve the soil moisture like others have to do. In the spring, we need to get our soil to dry out.”
Though he would prefer that farmers avoid the conventional tillage practices many utilize, Francisco Arriaga, assistant professor & extension soil scientist at the University of Wisconsin-Madison, says there are times when some level of tillage is necessary.
He points to this past year when farmers in different parts of Wisconsin needed to harvest in less than ideal conditions; it was too wet. “They called concerned about compaction and rutting issues to the point where their ground was not level, so they didn’t have a good seedbed. In this scenario, tillage is about the only way you can go about it.
“It’s bad enough that they’re probably going to have to do some discing, and what I recommend then is to check to see if there’s any subsoil compaction. There might be some areas where they have to do some subsoiling. This is a prime example of not being able to avoid tillage. When conditions are not the best and it’s time to harvest, the farmers must get in the field. It’s a business after all and they have to get their crops out,” says Arriaga.
He believes crop rotation is an ideal approach to minimize tillage and discourages farmers from planting corn-on-corn for more than 2 seasons. In instances when they plant corn after corn for 3 or 4 years, some tillage to address residue buildup will improve yields somewhat, Arriaga says.
“This was the original purpose for developing vertical tillage. It was a pretty good way of addressing the residue without disturbing the soil too much,” he explains. “But it was meant to be a one-pass operation. A lot of people are doing multiple passes, sometimes in the fall, sometimes fall and spring, and this can actually be detrimental. It varies a lot, depending on the manufacturer and the setup of the implement. It can create severe disruption of the soil, which, in my view, is not a good thing.”
Without the cost of tillage, in most cases, no-till is more profitable than conventional tillage, says Paul Jasa.
Till/No-Till Middle Ground?
While many soil scientists and extension engineers would prefer that farmers avoid tillage whenever possible, others believe strongly that it’s often necessary and good, and some believe the middle ground is where vertical tillage comes in and sets the stage for a farmer to initiate the use of no-till and strip-till.
“Corn is a good example of a crop that really likes tillage if it can get it, and it will respond accordingly by producing high yields,” says Tom Evans of Great Plains Mfg., a maker of tillage and seeding equipment. “It’s a different matter if you’re on highly erodible land. Then too much tillage can add to the problem.
“So regarding your question to till or not to till, the answer is yes,” he says. But rather than only discussing conventional tillage vs. conservation tillage, Evans says there are really three categories that need to be brought into the conversation: conventional tillage, vertical tillage and no-till.
He goes on to say, conventional tillage, which would typically include a moldboard plow, a disc harrow and a field cultivator, “needs to cease. Conventional tillage restricts the root system in a lot of crops because it causes density changes in the soil profile and it’s prone to erosion. When it comes to pure conventional tillage, I believe it’s a negative for everybody.”
Evans maintains that vertical tillage is the ideal method for creating soil density and healthier soils. “It makes a uniform density as deep as possible and that depends on the farmer’s ground. The idea is to get as much of the soil profile as practical to a uniform density. To do this, the first time you’re probably going to run a subsoiler as deep as practical, 12, 14, 16 inches deep to reset the profile.”
Evans makes a point of stressing the use of a subsoiler, not a v-ripper. “A subsoiler will actually pick the soil up and set it back down and bury no residue if it’s run properly. A v-ripper with a parabolic shank, on the other hand, is designed to roll the soil over, so it will disturb it way more than what an inline subsoiler would do.
“Vertical tillage doesn’t work against no-till, it works with no-till,” he explains. “If a farmer is going to convert to no-till, the first thing he should do is take an inline subsoiler and reset the profile of the soil and then no-till on top of it. He may not have to subsoil again for years. But that will reset the profile to a uniform density while you’re no-tilling on top of that.”
Purdue’s Vyn believes the better alternative to achieving high yields and overall soil health when growing corn is strip-till. “From a crop yield point of view, there is every reason to believe that fall strip-tillage will give equal yields with conventional till in almost every soil condition. In other words, when it’s done right in terms of using RTK guidance and when the implement is properly set up in the fall, and whether it’s on soy bean or wheat stubble or following corn, it will produce the same yield as a standard chisel plow or disc operation followed by secondary tillage.”
He adds that strip-till can also produce a bonus opportunity to gain yield by providing a planting date advantage. This is because it creates the opportunity to plant earlier than often possible with no-till, where there are high residue cover and cooler soils. This same advantage can often be seen in strip-till compared to conventional till programs where secondary tillage needs to be completed before planting. “We’re seeing this again in more northern environments and with wetter spring conditions.”
Another aspect that needs to be considered, says Vyn, is the consistency of soil drainage. According to Vyn, there is more flexibility to go 100% no-till or 100% fall strip-till on well drained soils, and on sufficiently-intensive systematically drained land, than would be the case for rented land with sporadic tile drainage.
This also plays into the on-farm economics of owning equipment from a single tillage system vs. multiple tillage systems to have flexibility to contend with different soil types, soil drainage and crop rotation (e.g. acreage in corn-after-corn vs. corn-soybean rotation).
“The major challenge with fall strip-till is that some falls are too wet after crop harvest to create the ideal strip-till berms. Farmers then need a spring strip-till or vertical till option,” he says.
Vyn points out that with the growing emphasis on soil health, nutrient availability is getting much more attention. The advantage of strip-till, he says, is that it facilitates nutrient banding of the less mobile nutrients like phosphorous and potassium into deeper soil layers.
“This leads to a more uniform availability of these nutrients at deeper depths than you would achieve with a no-till program or with broadcast applications followed by discing, chisel plowing or ripping. From a nutrient availability point of view and that aspect of soil health, there are gains to be made with the strip-till system relative to both conventional and no-till,” says Vyn.
He says another aspect of soil health is nutrient availability to plants from the organic nitrogen in the soil. “Our experience is that the advantage of a strip-till program compared to a conventional till program is that strip-till tends to result in an equal amount of mineralization from the organic nitrogen pool and will tend to lower the nitrous oxide emissions from sidedress nitrogen applications compared to conventional till. It’s generally equal to or better than no-till in terms of organic nitrogen.
“The other advantage of both no-till and strip-till is that as long as nitrogen is injected and crop nitrogen uptake is the same, there are lower gaseous losses of nitrous oxide compared to conventional till.”
It’s All About the Soil
Joe Dedman, vice president of agronomy for Monty’s Plant Food Co., is a proponent of no-till and he has another theory on the growing attention to soil health. He says, “We’ve pretty much brought everything that we have in our arsenal to the marketplace, including new chemistries, new genetics and new varieties. And of course, farmers are paying for that stack of genetics they have in that seed to help protect it from insects and diseases. At the same time, we’ve not made the jump in yield that should come along with all this new technology. People are saying, ‘There’s something missing here.’ What we’ve been missing is paying attention to the health of our soils.”
Dedman also serves on the soil research team at Soil Renaissance, a branch of the Noble Foundation. He says they’re working to formulate standards to measure soil health which allow producers to know the condition of their soil, which can affect its production capabilities.
What people are beginning to discover, Dedman explains, is the more they treat their soils like living organisms and maintain and feed them, the more it benefits the soil’s biology and the more its biology will increase. “The more it increases, the more it lends to soil health,” he says. “Then you see better crop yields, better crop quality and better seed test weights. All of these things go together with soil health, and conservation tillage goes hand-in-hand with better crop yields and soil health.”
The more attention soil biology and soil health get, the more conventional tillage will be scrutinized. He explains that the soil ecosystem builds networks. Earthworms dig channels through the soil and deposit all kinds of nutrients and break nutrients down. Conventional tillage destroys these networks every year when farmers prepare a seedbed. So the biology must to be rebuilt every season, according to Dedman.
“The more emphasis that is put on soil health and the more data that begins to get released, I believe it will show the tremendous advantage of not tilling the soil as much as we have been. By growing the soil ecosystem to its maximum potential, we will take yields a lot higher than we’ve ever been able to do. That’s because it’s all about the soil,” he says.
“Even though tilled soil warms up sooner, it also exposes the biology that’s in the soil on the surface to too much heat and too much light,” says Dedman. “You could say it kills them. I want the numbers to go up when we’re talking soil health. Soil health is related to undisturbed soil or where there’s very little soil disturbance to allow the ecosystem to continue to grow and to build and multiply. We need them to multiply to do all the work for us when we throw the fertilizers down or apply chemicals. We need those chemicals to break down for next year’s crop.”
Regardless of the new technology to maximize yields, “It still goes back to soil health; feeding the ecosystem that’s in the field so it works for me,” he says. “There’s a whole new horizon that people are writing about and digging into and teaching. There are all kinds of things yet to be discovered about soil health.”
Advocating for No-Till
To say dedicated no-tillers are passionate about what they do would be an understatement. Boak of Salford says it’s “a bit like a religion. You get guys who start down the road to no-till and they work really hard to make it work for them. All of a sudden, they’re opposed to anybody who does tillage.”
Jasa of the University of Nebraska. makes no apologies about his stance on no-tilling vs. conventional tillage. “If you think about it, Mother Nature never tilled her soil. She’s been growing things for a long time. She has the best soil structures anywhere because it’s never been tilled. That’s what we want to get producers to do in their fields as well.”
He says when it comes to soil health, tillage is one of the things a lot of people are looking at because it really hasn’t been considered much before. “Tillage has always broken down soil health and destroyed some soil structure. No-till is the practice that’s going to build the soil health the best,” Jasa says.
And so when it comes to no-till itself, “Once a farmer builds a good soil structure and no longer destroys it with tillage, soil health builds. More importantly, the structure allows water infiltration, air and gas exchange, and better root penetration. Once your soil gets healthy, the need for tillage sort of drops away. In the past, tillage begot tillage. If a soil was tilled and you didn’t have that air exchange, you had to till again to fluff it up to get some air exchange to get the plant up and growing. So if tillage was so good, why do you have to do it again next year? It’s a temporary fix,” says Jasa.
But soil doesn’t get fixed by only parking the tillage implement. It often takes a couple of years before producers see the change and, according to Jasa, a lot of producers don’t have the patience, especially those who want to raise a single crop and be done with it.
“If they’re willing to do cover crops, crop rotation and apply livestock manure, they can help jumpstart soil biology. Then no-till becomes a lot easier and a lot faster,” he says.
What tillage does is “erase some management mistakes,” Jasa adds. “It made us lazy managers.”
For example, if the farmer didn’t do a good job of weed control in the early season, he goes out and tills again. If he had a crust on his field, he went out and tilled it again, which left little or no soil structure, so the soil formed a crust again.”
And while they can be valuable tools, Jasa says, Roundup Ready crops made lazy managers out of a lot of no-tillers. “In some cases, people switched to no-till or Roundup Ready technology because it took less management than tillage did. Unfortunately, those are the same producers who are having problems with glyphosate-resistant weeds. Roundup Ready technology is only a tool to be used, but it has been misused.”
When it comes to corn yield, Jasa explains that he’s had a set of tillage plots since 1981 that he uses to compare no-till to fall plow, fall chisel and spring disc. “The first couple of years until I got the soil biology working with me, the yields were statistically the same. After about 5 years, no-till has always been the most profitable statistically. Whether it’s been the highest yield or not isn’t that important. It’s more profitable because I don’t have the cost of tillage.”