In this first instalment of a five-part series, Todd Botterill takes a look at the new movement to vertical tillage, what it really means and how to make the conversion on your farm
Vertical tillage is all the rage today. You can’t turn around without seeing a new vertical tillage machine or hearing about one. For those of us who have been involved with vertical tillage since the term was first coined, the recent pandemonium can be bittersweet.
It feels good to have the recognition, and know that what we started working on so many years ago isn’t just some flash-in-the-pan idea. It’s also frustrating, though, to see so many touting the virtues of vertical tillage without really understanding what it is. It’s kind of like someone showing up late to your birthday party and yelling, “Happy New Years!”
The concept behind vertical tillage isn’t new. I’ve been told that research into the idea actually first started in the 1950s, but the technology wasn’t ready then to allow the machinery to run reliably. And it was a far cry from the practices used at the time. It wasn’t until the late 1990s and early 2000s that we saw the research brought up again.
Most of the credit for the popularity of vertical tillage can be given to an agronomist in Central Illinois named Ken Ferrie. His ongoing trials with Farm Journal Magazine showed very good results in corn, where seedbed preparation was looked at from a vertical perspective.
So what is vertical tillage? Simply put, it’s a farming system focusing on creating a consistent seedbed vertically through your field. It doesn’t really matter which direction the dirt moves when you work it, it’s about what kind of density layers there are in your soil and how they affect moisture and root migration through the soil profile.
Vertical tillage tools
Not all vertical tillage tools are meant to do the same thing.
Many conventional tillage tools, such as cultivators and tandem or offset disks, create a “smear” layer below where they run as they drag through the soil. The soil above that layer is loose and fluffy. You typically place your seeds in the fluffy dirt where the roots can grow and move easily through the soil profile. As they grow down, they hit the smear layer, which is much denser than the fluffy soil the root is used to. The root will often take the path of least resistance, moving sideways until it finds a break in the smear layer where it can grow downwards. If the smear layer was created by a tool like a cultivator with full-width sweeps, there aren’t too many places for the root to grow down.
This dense layer also prevents moisture from migrating up through the soil by capillary movement, or moving through the cracks in the soil, which really cuts down on the amount of moisture available to the plant later in the year if it becomes dry. For the most part, whatever moisture the crop is going to have for growth is what the soil can retain above the depth that it was worked to.
So if you ran the cultivator three inches deep, you have three inches of moisture retention. If you have consistent rains, you don’t notice much loss. But if it turns dry, you can have deeper moisture that really isn’t available to your crop.
In a vertical tillage system there are no soil density layers to affect root growth and moisture migration. Studies have shown that vertical tillage farming systems actually improve moisture migration through the soil even though in many cases they are doing less overall tillage than other practices. In wet years, water will be better able to migrate through the soil, and in dry conditions migrate back up again.
Transitioning to vertical tillage
To transition into a vertical tillage system you must first remove the tillage (different density) layers in your soil. Then you need to make sure that any subsequent pass does not put a tillage layer back in. There are a large number of tools out; in the next instalment, we’ll classify these tools into different categories. †