Once you’ve removed the density layers in your fields, you’re ready to start using vertical tillage implements that fall into the surface tillage category
Surface tillage tools. This is by far where the most interest in vertical tillage tools exists today. These tools are really designed not to put density layers back into the soil after it has been worked. They aren’t designed to remove the layers, just keep from doing the damage again.
These tools started with farmers taking old tandem disks, straightening the gangs, replacing the disks with coulters and using them typically in no-till conditions for residue management. They did a great job of sizing residue and fluffing it so that the soil would warm and dry quicker. Soon manufacturers began building machines and the vertical tillage arms race began!
There are three categories of surface tillage tools: coulter, disk and rotary machines.
Coulter machines were among the original surface tillage tools. Wavy coulters are used to fracture soil and throw it up on top of residue to speed decomposition. The coulters can also cut the residue into smaller pieces to make it pass through seeding equipment easier. That also speeds up decomposition. They typically have a harrow, harrow rolling basket, or stalk chopper system on the back for residue management and levelling.
Coulter machines are ideal for high residue farming, where a farmer wants to maintain as much surface residue as possible in order to prevent erosion and conserve moisture. They are ideal for farmers focusing more on spring use as well, as they work through extremely wet conditions without plugging and without over-drying the soil. They typically leave the seedbed smooth and firm, allowing for easy planting afterwards.
Many farmers are amazed at how much residue these machines can run through without plugging (imagine cat tails in a slough). The differences between these machines usually involve coulter spacing, whether gang or individually mounted, and harrow systems. There are also many choices of coulters that can be used on these machines. The smaller the diameter of the blade and the narrower the wave the more penetrating power and cutting force you have. The wider the wave and the larger the diameter, the more soil movement you will have. A larger diameter blade will also give you a longer working life.
One of the most important things to remember about coulter machines, especially in the fall, is that they aren’t always an immediate-gratification machine. They really rely on Mother Nature to finish the work they started, especially with residue management. I sometimes call them a religious experience, as you have to have faith that they are working, but those who are patient are often surprised to see the difference the next spring after running the machine.
Editor’s note: This is the third in a series of five articles on vertical tillage by Todd Botterill. Look for the next instalment in the February 11 issue of “Grainews.” †