We may have to burn a few of these to assist the planter in placing seed correctly.” The first comment on the photo resulted in the post you are reading right now. That comment read“What’s a no till field? Why would you not till a field?” A great question. There are many kinds of tillage including not tilling at all.
What is No-Till?
What we call trash wheels are mounted on the front of our planter (folded for transport in this picture). These units are designed to move residue away from the seed furrow before seed is placed. Crop residue can impede germination. All we want these units to do is sweep residue out of a narrow path. We don’t want them adjusted too low where they will make a trench in the soil.
No-till is just what is sounds like. A true no-till system avoids disturbing the soil with tools like chisel plows, field cultivators, disks, and plows. Not all of our acres are no-till, but we have been doing less tillage as of late including putting more acres into no-till. I’m 32 years old and I’ve never actually ran a moldboard plow over a field aside from the single acre we took turns playing on a few years ago in our 1956 John Deere 70 Diesel and three-bottom plow. I might lose some farmer points here, but I don’t even know how to plow a field properly. Lack of experience I guess. A plow could be considered the polar opposite of no-till. A plow flips over the top layer of soil incorporating nearly all residue into the soil. No-till relies on natural processes to break down residue from the previous crop.
Advantages
Reducing fuel, labor, and equipment costs are the most quantifiable benefits of not doing any tillage. Our current tillage system normally includes a fall chisel plow pass to manage residue followed by a pass, or two, with a field cultivator to prepare a seed bed for planting. This system would be called minimum or conservation tillage by some, but right off the bat a no-till plan cuts at least two trips across our ground out of our budget. If we quit doing tillage over our whole farm we’re looking at removing a couple of gallons per acre of fuel from our expenses. Take the price of diesel today times our just over 2,000 acres of farmland and you’ll get a fairly substantial number. That’s also fewer hours on a tractor meaning more value at trade-in time, and less wear and tear on tillage tools. In fact I believe if we went 100% dedicated no-till we could sell off all our tillage tools and downsize one tractor from our lineup. We’ve recently purchased a John Deere 2623VT vertical tillage tool, but let’s keep things simple for now.
Improved soil structure is another big benefit. Tillage disrupts the natural structure of soil and releases some of the carbon soil organisms thrive on. Soil biology plays an important role in providing crops with the water and nutrients they need.
Potential for erosion can be reduced by leaving more residue on the surface in the months when there are no crops growing. Residue allows for rainwater and snow melt to infiltrate the soil rather than causing surface run off that will carry away topsoil and nutrients. Of course if enough rains falls on already saturated soils you’ll have some runoff no matter what. We are experiencing those conditions right now.
Reducing soil compaction is a great benefit. Soil gets compacted any time equipment drives over the surface. The weight of farm equipment compacts the air and water pockets present in soil that allow for the movement of water, crop roots, and soil organisms. Combines and grain carts are the worst offenders because they are very heavy. Since no-till reduces the amount of equipment a field sees the threat of compaction is reduced. Compaction cannot be avoided completely, but it can be managed by limiting field traffic to certain areas. Subsoilers and cover crops can also correct compaction issues.
The effect of compaction from our combine can clearly been seen in our oat and radish cover crop that has winter-killed. The cover crop was aerial applied before harvest and actually grew best where the combine tires pushed the seeds into the soil. Cover crop radishes are bred to break up compacted soil.
Disadvantages
With no-till a farmer has lost the ability to mechanically control weeds through tillage. Biotechnology has been given some credit for increasing no-till acres because technologies like Roundup Ready have made weed control by herbicide very effective both in performance and cost. Herbicides with residual action can help stem weed growth post-plant. Row crop cultivators are nearly a tool of the past for conventional farmers. We used to go back into our fields during the growing season and pull a cultivator between the rows in order to slow down weeds enough to give the crop a chance to canopy over the open space to shade out weeds. Row crop cultivating takes resources such as time, labor, fuel, and causes wear on equipment. We now employ cover crops on some of our no-till acres, and some covers are good at suppressing weeds. Cereal rye is one of those covers. I’ve seen organic no-till accomplished by growing a cereal rye cover crop which is later terminated with a roller-crimper ahead of planting. The thick mat of rye keeps weeds at bay.
There is a risk of carrying over plant diseases when crop residue is not incorporated into the soil after harvest. The residue serves as a host for disease and can infect the following crop. However farmers can mitigate this situation by rotating crops that are not susceptible to the same diseases.
It takes time to see the benefits of no-till. One can’t take a farm that has been tilled for 50 years or more and hope to see big gains in yield after one season. Patience is important. Soil needs time to regain structure, and that doesn’t happen overnight. Right now we have a some fields that will be going into no-till and using cover crops between cash crops. I plan to keep this system in place for a few years, and then we’ll see what kind of results we are getting from soil nutrient tests, water infiltration, compaction, and yield.
This field was soybeans last fall that will be no-till corn in 2013. Soybean stubble along with corn stalks washed in from the field pictured above have made a thick mat here.
This field belongs to a neighbor that hosts a plow day in the fall for antique equipment. Notice how there is no residue on the surface. Heavy rains have pounded the surface, making it hard for water to soak it. More rainfall will wash away valuable topsoil. The top layer of soil here will probably be almost a fine powder when the seed bed is prepared.
