One trend that continues to gain momentum across the U.S. and in the Canadian provinces is vertical tillage. Almost every major tillage equipment manufacturer has one or more product offerings that fit into this category in an attempt to offer producers the ability to manage residue, level fields, loosen compaction and reduce overall tillage costs.
There are a number of reasons for the rapid increase in sales of vertical tillage equipment. The major ones that have sold hundreds of disc variants of vertical tillage tools are the high work rates that result from pulling wider tillage across fields at 6-8 mph.
While 30 foot or wider vertical tillage tools require high horsepower to pull them at such high speeds, most growers already have larger tractors available and are happy to be able to achieve work-rates of 200 acres per day or more. Growers have also found the fuel use per acre is very low compared to other deeper tillage tools.
It’s important to note that, depending on specific location, vertical tillage can be defined in a number of ways. The most common are described below.
Many growers are using vertical tillage tools such as the Great Plains Turbo-Till to size residue and level fields. Notice the use of a tracked tractor to reduce compaction.
A set of wavy discs and/or rotating spikes on a frame, which enter the soil vertically to a shallow depth. Such passes are usually made to help level the soil surface, enhance planter/drill opener performance and improve seed placement. Some producers also use them to incorporate manure or fertilizers. They work well in such applications because they don’t work deep, therefore wide working widths can be pulled across the field quickly to achieve high work rates. In far northern locations, vertical tillage tools are also used to help dry out wet soils ahead of planting. But remember wet soils are very prone to compaction, not necessarily from the tillage tool itself, but from the tractor used to pull it. Anyone considering such passes should be encouraged to wait a few days to allow the soil to dry or use a tracked tractor to help reduce soil compaction.
A significant number of vertical tillage tools are sold to farmers trying to manage residue from a corn-after-corn rotation. The majority of these sales are made within the Northeastern states, especially to livestock farms that grow continuous corn for grain on most of their acres. Vertical tillage tools such as the Great Plains Turbo-Till and Salford RTS use wavy discs to slice soil and residue.
These tools help cut, break open and throw some soil over the corn stalks to accelerate breakdown over the winter and early spring period. These actions accelerate nutrient returns to the soil, plus they help the planter tackle residue better in the spring to achieve better stands.
No significant differences in the corn stands across the different tillage systems was found in 2004 research conducted by Van Dee of Iowa State Univ., but an increase in yield of almost 5 bushels per acre was observed using vertical tillage.
A set of subsoiler shanks mounted on a toolbar, designed to engage the soil and loosen compacted soil layers caused by heavy equipment or previous plow-pans. As farm equipment gets bigger (including heavy combines and grain carts) soil compaction will continue to be a growing concern. Farmers need to check for soil compaction and be ready to pull a suitably equipped subsoiler through the field if compaction exists. Subsoiler shanks are either mounted in a line across the toolbar or in a “V” formation, which has been found to reduce draft loads. Such equipment is frequently designed to operate at depths of 12-18 inches and the shanks are ideally positioned around 1.5-2 times the working depth. Tillage research has found that adding wings to the bottom of the shank helps increase the volume of soil loosened, relative to the draft loads taken to pull the shanks through the soil.
Dealers should arm themselves with research to help their customers justify vertical tillage equipment. Two specific examples are provided below.
In 2004, Kevin Van Dee, superintendant of Iowa State Univ.’s Southeast Research and Demonstration Farm, conducted replicated field research to study the effects of vertical tillage in comparison to no-till and conventional tillage. The conventional tillage treatments (upper right) were represented by a pass with a disc and a pass with a field cultivator, followed by a John Deere planter. The no-till treatments were planted directly into residue with a John Deere planter and the vertical tillage treatments were cultivated with a Phoenix harrow, followed by the same John Deere planter.
In 2010 research conducted in Kentucky comparing wheat yield utilizing no-till, conventional and vertical tillage, conventional tillage produced 5 bushels and vertical tillage 1.5 bushels per acre more than no-till.
Van Dee found no significant differences in the corn stands across the different tillage systems, but an increase in yield of almost 5 bushels per acre was observed using vertical tillage, compared to the conventional treatments. With current corn prices, that can add up to a $20 per acre increase in net profit.
In the fall of 2009, I conducted a replicated tillage trial in Hopkinsville, Ky., to determine the yield benefits of deeper vertical tillage in comparison to no-till and conventional tillage. The conventional tillage treatments (following corn) included a pass with a disc ripper, then a pass with a disc. The vertical tillage treatments were ripped 16-inches deep with a Case 2500 ripper, set up with winged shanks and the no-till treatments were drilled directly into standing corn stalks. All the treatments were drilled with a Great Plains no-till drill at the same seed population and managed the same throughout the season. In this specific trial, the conventional treatments produced 5 bushel per acre more wheat than the no-till, but the vertical tillage treatments made 1.5 bushel per acre more wheat than the no-till.
What’s interesting is that this is a well-drained site and the levels of soil compaction were low. There are many fields (or higher traffic areas of fields) that have significantly higher levels of soil compaction, which would likely have increased yields further with the vertical tillage.
Other articles from the Oct./Nov. 2010 issue: