Speed Till

The AGCO Sunflower high-speed tillage/finisher, 6830 series.

JACKSON, Minn. – Fall 2018 left much to be desired. Too much rain and winter starting too soon made getting everything done a challenge. As a result, some farmers we unable to complete fall tillage, leaving just a small window of opportunity to complete it in this spring.

“Speed tillage will be an option. There are two different tools that fall into that category,” said Larry Kuster, product specialist with AGCO, during a recent phone interview. “There is the compact or speed disk that a lot of companies are selling today and then there are vertical tillage tools.”

Generally, any tillage faster than eight miles an hour is considered speed tillage. The idea is to develop tillage tools that are effective at faster speeds in order to better prepare the soil for high speed planting and stay ahead of a high-speed planter.

However, there are two draw backs to high speed planting. The larger tractor required must have enough power to manage the planter and the high-speed planting process is more sensitive to field conditions.

“With a high-speed planter, it is imperative the planter is operating in a smooth environment,” said Kuster. “If the planter is running on a seedbed floor that is not smooth, row unit bounce can happen, which can misplace the seed or shake seeds off of the seed disk causing skips and erratic seed spacing.” Choosing the right high-speed tillage tool and operating it correctly are important for success with tillage, and in turn, high-speed planting.

High-speed tillage moves soil more aggressively than tillage at conventional speeds. The tools are designed to contain the soil within the tool to prevent it from being thrown out of the unit.

“You have soil flowing and then being stopped by a sheet of steel placed to prevent the soil from moving out of the confines of the implement. Wet or tacky soil can stick to this barrier and build up on the steel,” he said.

As the soil builds it can eventually plug the unit, so soil moisture is an important factor to watch as speed disc because of their design are more susceptible to plugging as soil conditions deteriorate.

There are many differences between the compact disk tool and the vertical tillage tools. Many would argue the compact disk is not a vertical tillage device even though some companies promote them as such.

“A compact disk is a tandem disk harrow, moving the soil more aggressively left and right,” he said. “Vertical tillage, as the name implies, lifts the soil rather than moving it left and right.”

In order to make the disk tool compact, individual rubber-mounted disc blades are used as opposed to gang assemblies. The rubber torsion-style suspension system permits the blades to be angled on a straight bar rather than an angled gang, creating a shorter implement “short-disc”. The rubber suspension provides the necessary rock protection, but with continued movement, this cushioning material warms, becoming softer and less resistant to movement of the blade. Because of this, disk blades running in compacted soil, such as tractor tire tracks, may not be operating at the same depth. “This is probably the primary contributor to the compact disk’s difficulty maintaining a smooth till floor.”

Vertical tillage tools use low concavity blades to lift the soil.

In the case of AGCO’ Sunflower tillage equipment, they offer two tools capable of high-speed tillage, the 6631 series vertical tillage tool and the 6830 series, also known as the rotary finisher.

“For all practical purposes, the design of the 6830 high-speed finisher makes it unlimited in speed,” said Kuster. “It's a combination of the low concavity blades with a reel mounted right behind the disc blades, which actually stops the lateral movement of the soil. These are then followed by wavy blades.”

The wavy blades cut and fracture the soil to the side. Behind those blades are two sets of rotary spider tines, which lift the soil, separating the solids from the fines and sculpting a smooth floor to the seed bed. The rotary tines also break up any remain soil chunks or clods.

The goal of any tillage is to mix the soil, incorporate crop residue and create a good environment for the planter. The better prepared the soil is, the better the planter will perform and put the seed in exactly the right place.

“Whatever tool a farmer is using for high speed tillage, to really see what kind of a job it is doing. They need to stop the tractor, get out, move some soil and investigate to see what kind of environment they are leaving for the planter,” said Kuster.