Myths about Farming without Tillage

No-till offers many advantages, including weed control and resistance to pests and disease

Editor’s note: the following is an excerpt from The Complete Guide to Restoring Your Soil by Dale Strickler. Used with permission from Storey Publishing.

With all the very real negatives associated with tillage, you would think that every farmer in the world would be farming no-till by now but, unfortunately, it is practiced on only a distinct minority of cropland. In the US, only about 35 percent of the cropland is farmed no-till at all, and only 10 percent is farmed no-till 100 percent of the time. Worldwide, only 7 percent of cropland is farmed with no-till methods.

Why is no-till not more popular? Obviously, there must be either problems with it or misconceptions surrounding it. Following is a discussion of reasons farmers cite for not converting to a no-till system, the drawbacks of no-till—both perceived and real—and what to do about them.

Myth #1: “There will be more weeds.”

Quite often the biggest fear of farmers considering no-till is a perceived inability to control weeds. Experience has demonstrated, however, that this fear is largely unfounded. If tillage actually controlled weeds over time, we would no longer have weeds after a century or more of the practice. In reality, most of our weeds tend to thrive in tilled conditions and gradually become less problematic without tillage.

For example, many large-seeded weeds, such as common cocklebur, almost disappear when tillage is no longer performed. These large seeds fail to establish without burial by tillage. On the other hand, weeds with very small seeds that can establish well with only slight disturbance will often increase without tillage. Examples of these include dandelion and marestail.

When I still tilled, my major weeds were velvet­leaf and cocklebur. When I switched to no-till, my major weed became marestail, while velvetleaf and cocklebur all but disappeared. In no-till, there really aren’t more weeds, but there are different weeds.

Small seeds contain very limited energy reserves. They must reach sunlight and begin to photosynthesize very quickly after sprouting; otherwise they simply starve and die. A good thick mulch of crop residue or cover crop residue can greatly reduce problems from small-seeded weeds by denying them access to sunlight, as is discussed in Chapter 10.

Weeds are a sign that we are not utilizing all of the sunlight, moisture, and nutrients we are given, and that to control weeds we should increase our intensity of cropping. In my experience, the most effective tools for weed control do not involve some new herbicide but rather the use of cover crops and perennial pasture sods in the crop rotation.

Myth #2: “I will become more reliant on herbicides for controlling weeds.”

One of the main reasons farmers use tillage is to kill weeds. Without tillage, much of the heavy lifting for weed control has fallen on herbicides. But does no-till really use more herbicides than tillage farming? Yes, but not much more, and since switching to no-till I have found that I can actually use fewer herbicides. Most acres of cropland in the US receive both tillage and herbicides; if tillage makes herbicides unnecessary, why do tillage farmers still use them?

The primary difference between no-till and tillage farming is that no-till usually substitutes an herbicide “burndown” application for preplant tillage, to eliminate all competing vegetation prior to planting. In other words, there is a total of one more herbicide application per crop with no-till than there is with tillage.

But what about herbicide-resistant weeds? Oh boy, is this currently a hot-button issue as I write this book. Palmer amaranth has recently been discovered in Missouri to be resistant to not only glyphosate but also dicamba, 2,4-D, ALS inhibitor herbicides (such as Imazethapyr), triazines (Atrazine and metribuzin), and PPO inhibitors (lactofen and fomesafen). That does not leave a lot of herbicide options. Many farmers are so scared of herbicide-tolerant weeds that they are abandoning no-till and breaking out tillage tools in droves. Biotech companies are frantically researching how to make crop plants resistant to different herbicides to expand our arsenal of chemicals that we can throw at weeds. But you cannot solve your problems by using the same methods that created them. New miracle herbicides will only serve to create weeds resistant to those herbicides.

The ultimate solution to herbicide-resistant weeds is to gain an understanding of weed biology, learn the weak points of each problem weed, and exploit those weak points to fight the weed. As noted earlier, I have found that wise use of cover crops can all but eliminate my weed problems because I can select cover crops that capitalize on the weak points of the weeds I am fighting (see Chapter 10 for more information on cover crops).

You can also expand your thought processes to do battle against weeds. I held a meeting in far western Kansas about a year ago, doing my “cover crops and no-till” talk. Two young men approached me after the talk to say they were giving up on no-till and going back to tillage. I asked why. They said they were unable to control herbicide-resistant Palmer amaranth and kochia. I asked them to describe those two weeds. They said the plants came up in solid stands, outcompeted everything, and grew whether it rained or not. I asked them if any of their crops could do the same, and they said no.

I suggested that since kochia and Palmer amaranth were so superior to their crops, perhaps they should make kochia and Palmer amaranth their crops. They were stunned and speechless. I continued to explain that besides all the attributes they listed, those weeds were as high in protein as alfalfa and produced the same amount of protein per pound using one-third as much water as alfalfa. If they were to switch from their current cash grain program to a grazing program, they’d stop spending $80 an acre per year trying (unsuccessfully) to kill those two weeds and instead earn money from them. (I am doubtful that they took my advice.) 

Developing new crop varieties that are resistant to multiple herbicides is not the answer to herbicide-resistant weeds like Palmer amaranth. We will simply get weeds that are resistant to multiple herbicides. It is already happening. The solution is to create conditions in our field that mimic the conditions found in native grassland, conditions in which Palmer amaranth cannot thrive, or even survive. I am not necessarily anti-herbicide: They can be useful tools that can eliminate the need for tillage, which to me is a greater evil. But doesn’t it make much more sense to create conditions in which neither tillage nor herbicides are needed?

Myth #3: “I will need to buy expensive equipment.”

A no-till planter or drill can be quite expensive, much more expensive than the comparable piece of equipment that works in a tilled system. Planting in a soil that has not been tilled requires a stronger, heavier planter with more attention to the nuances of proper seed placement.

On the other hand, a farmer can get rid of several pieces of equipment: the plow, the disk, the field cultivator, and the huge tractors needed to pull them. Plowing takes an enormous amount of horsepower per unit of plow width. A no-till planter requires much less horsepower per unit width because it is not being asked to disturb much soil, so the tractor can be smaller and cheaper and requires less fuel to operate. Whereas a tillage farmer needs lots of pieces of equipment, a no-till farmer needs only a tractor, a planter or drill, a sprayer, and a combine.

Myth #4: “The soil warms up too slowly in spring.”

One perception, especially in the upper midwestern United States where corn is king, is that you must till to warm up the soil in early spring. Tilled soil does in fact warm up faster on a sunny day. But it also cools down more on cold nights, and the concern about cold should be greater. A residue-covered soil has less fluctuation between day and night temperatures, and if temperatures are taken just before sunrise, there is very little difference between the soil temperatures of no-till and tilled soils.

I was speaking at a meeting of US Department of Agriculture Natural Resources Conservation Service (NRCS) employees, when one participant told me that “no-till just doesn’t work around here.” He said that the soil stayed too cold with no-till, and thus delayed planting, and the late-planted corn would end up pollinating during the hot, dry part of summer and yield less.

I said, “Pretend you are a farmer, and you are trying to decide whether or not you should start planting in the spring of the year. Just then the phone rings, and it is God. Yup, Jehovah himself. And God tells you that if you plant a week later, he will give you an extra 3 inches of rain this summer to use whenever you need it. Would you accept that deal?”

I doubt that any farmers would say no. But that is exactly what no-till can do for you. You can begin planting just as early with no-till as with tillage because there is little difference in soil temperatures; but even if there is a delay, the added moisture-supplying ability of a no-till field can erase much of the yield penalty from later planting.

Myth #5: “The soil stays too wet in the spring, and you can’t get in the field as early.”

This goes right along with the “too cold” excuse. When I began no-tilling (along with cover cropping), a friend who had a long history of no-till and cover crops told me that I would eventually develop a soil that will “stay wet longer and dry out quicker.”

Read that last statement again. What he told me was physically impossible! A soil cannot stay wet longer and dry out quicker; those situations are mutually exclusive. But after a couple of years I discovered exactly what he meant. The first year or two of no-till, my field was definitely wet longer than the tilled fields were, and I did indeed need to wait a bit longer to plant. As my soil began to change, however, with higher levels of surface organic matter, I discovered that I could plant at much higher moisture levels than my neighbors could because my soil had changed over time.

This same friend posed this idea: “What is the problem with planting in the mud? Mud is a perfect seedbed. The only problem is that our combination of equipment and low-organic-matter soils means planting in the mud will result in soil compaction and sidewall smearing of the seed trench. But what if your soils were not susceptible to those issues, because you now have high-organic-matter soils?”

Sure enough, as my soil changed and began to resemble peat moss—instead of pudding when wet and concrete when dry—I could plant when the soil was quite wet and get perfect stands without yield penalty, because there was no soil compaction and no sidewall smearing. My soil did indeed stay wet longer, but it didn’t actually dry out quicker. What it did do was allow me to plant in high-moisture conditions and get just as good or better results than waiting for the soil to become “dry enough” to plant.

Myth #6: “There will be nutrient stratification.”

As there is no burial of residue in no-till conditions, the residue (which contains much of the fertility once taken up by the previous crops) remains on the soil surface. Therefore, the surface of the soil tends to become enriched in fertility at the expense of the lower soil layers. It was once thought that this would lead to yield reductions when the surface soil would become dry during drought periods, and there was no water movement into the roots from that layer of soil. These concerns have mostly been found to be a lot of worry over nothing.

In no-till fields, roots tend to proliferate in the top few inches of soil and thoroughly explore that zone for fertility. In dry periods, this layer of soil will retain more moisture than the same layer in a tilled field, and quite often more moisture than the layer below in a tilled field. Nutrient stratification has been proven in research to cause zero yield loss. If nutrient stratification causes you to lose sleep at night, simply use a thin-bladed fertilizer applicator to place nutrients 6 inches deep below the crop row. Alternatively, develop a system in which the soil creates much of its own fertility (see Chapter 6) and the nutrients, instead of being stratified, are everywhere.

Myth #7: “There will be more disease problems.”

This perception is based on the belief that diseases are worse in higher-moisture conditions and that any diseases carried on crop residue will persist longer if the residue is not buried. It is very true that disease issues can certainly be worse in no-till, if the crop rotation is too short in duration, especially in the early years after conversion to no-till. In a simple corn–soybean rotation, it is almost a given that gray leaf spot (carried on corn residue) and brown stem rot (carried on soybean residue) will increase in severity because undecayed corn and soybean residue is present on the soil surface, as will many soilborne fungal diseases that proliferate under higher-moisture-presence conditions.

The solution to this one is quite simple: move to a longer, more complex rotation that includes cover crops. This stimulates soil biology that will decay residue and compete with or consume soil pathogens. A good crop rotation should be three or more years in length, with no crop repeated in that period.

Myth #8: “There will be more insect problems.”

This concern, like the increased disease pressure, is based on reality. The extra cover provided by surface residue quite often results in more problems from slugs, cutworms, and other pests. But this problem is quite often temporary in nature. Where there is prey, soon there will be predators. I have found that after the first year or so (if you can refrain from broadcast-spraying insecticides) the population of insect predators (such as wolf spiders, crab spiders, ground beetles, ladybugs, lacewings, meadowlarks, etc.) builds up and provides a mostly complete, but never 100 percent, control of insect pests.

Coupling no-till with cover crops can certainly speed the buildup of predator populations, as can additional crop diversity within the rotation. As described in Chapter 10, adding to the mixture flowering cover crops or companion crops, such as buckwheat or Phacelia, can attract many predatory insect species, such as lady beetles and lacewings, that can feed on the pollen and nectar in the absence of prey.

Dale Strickler is a leader in the soil health movement and an agronomist for Green Cover Seed. He farms and ranches cattle in Kansas.