As the term vertical tillage becomes more mainstream, clarifying what makes a practice fit this system is key
For more than two decades, Farm Journal Field Agronomist Ken Ferrie has worked to understand how uniform soil density and adopting a vertical system sets the stage for higher yields. Today, vertical tillage is a concept that is well known across farm country, although it’s not always well understood.
"Every tool has a specific range of things it’s designed to do," Ferrie explains. "But vertical tillage is not a single tool—it’s a system."
A comprehensive five-year Farm Journal Test Plot that concluded in 2000 showed that creating and maintaining uniform soil density leads to yield increases of up to 27 bu. per acre. This effort is ongoing as Ferrie continues his soil density studies with new machinery and changing practices.
A vertical tillage system involves understanding the soil profile, tackling compaction issues, ensuring that each pass achieves the goal of the system, respecting residue cover and providing a well-prepared seedbed for the planter pass. Simply put, a vertical system means managing the entire soil profile for uniformity.
"With a well-managed uniform soil profile, farmers achieve better water infiltration and drainage, quicker soil warm-up for spring planting, efficient use of nutrients, more drought tolerance, and uniform growth and pollination," Ferrie explains.
Although the benefits sound like a good fit, Ferrie reminds farmers that adopting a vertical system is not a one-step process.
From the ground up. The first step is to understand your soils and the current density profile. This means digging in your fields once during the growing season and again behind tillage tools.
"The roots will tell the story on the field, so wait until later in the growing season and you’ll have plenty of roots to evaluate," Ferrie says.
Dig plants to evaluate the root structure. Also, dig a soil pit to look at the entire soil profile and evaluate soil moisture and structure and root growth. Sudden changes in those characteristics indicate a soil density change.
You can also use a tile probe to find density changes. With even pressure, push the probe in and feel for resistance as the probe goes down. Be sure to pay close attention as the probe enters the ground, as many density changes created by horizontal tillage occur in the top 4" of soil. If the probe suddenly becomes harder to push, you have found a density shift. Compaction layers must be fixed for a successful transition to a vertical system.
"When farmers change tillage systems, any compaction layer can come back to haunt them," Ferrie says.
Vertical tillage tools for primary tillage, which include in-line rippers, chisel plows, disk chisels and disk rippers, have deep-digging shanks that fracture compacted layers of soil.
"The key is full-width shatter across the primary tillage tool," Ferrie says. "Many farmers are surprised to learn that they are not achieving the consistency that they assumed."
For a tillage pass to provide full-width shatter, more digging is required.
- November 2011