Tillage tools have long been a part of the agricultural industry. Although the tillage trends and tools have changed throughout history and around the world, understanding the global perspective of tillage equipment in the marketplace is vital to continuing to develop and supply innovative products to meet producers' needs.
Deep Vertical Tillage Tools
With more focus on reducing input costs over the years, deep vertical tillage is a very important step that is often overlooked. The purpose of deep vertical tillage is to improve soil health and reduce compaction. From a North American perspective, this operation seems to be most concentrated in the Corn Belt, however, it can be found in all regions of the U.S. with arable farmland. Growers have experienced positive effects on corn yields by using deep tillage tools, like rippers and chisels; therefore, these tools continue to be commonly used. In addition to standard chisels and rippers, a variety of combination tools are present in the marketplace today. These are the traditional deep vertical tillage tools, but with added sections of coulters or disc gangs in front of the deep tines. These tools came to market to reduce inputs, as each pass through the field consumes fuel and time for today’s growers. By adding more residue management to the front of the tools, more residue remains in contact with soil, allowing it to break down more rapidly. These tools are popular in the Corn Belt, where high yielding corn stalks are difficult to manage without multiple tillage passes through the field.
From an international perspective, deep tillage is used for similar, yet different reasons. In South Africa, producers use deep tillage techniques in very sandy soils, often up to 36 inches deep. In this application, the growers were using the ripper to reach deep under the sand and break into a layer of clay. This helps to gain some moisture from underneath the clay and move it up to the sandy soil to help producers grow corn with a less-than-ideal soil structure.
In another larger soybean and corn growing region, Brazil, deep tillage has been nearly eliminated. With legislation demanding no-tillage and constant cover on the soil, the deep tillage tools in Brazil have been widely relegated to the sugar cane regions where deep ripping is required to kill the sugar cane roots before planting the next crop.
Vertical Tillage Tools
Shallow vertical tillage is another type of tillage. This is an area of tillage that is less defined due to the high popularity of the vertical tillage message. The message of shallow vertical tillage began with tools to manage BT corn residue and improve soil tilth, without the shearing action of a disc harrow.
For Great Plains, the first tool in the shallow vertical tillage configuration was the Turbo-Till®. The Turbo-Till is a tool with wavy blades, running straight, with zero angle. This tool sizes residue and leaves the residue on the surface similar to no-till. These tools began the vertical tillage revolution because customers needed a tool for loosening the surface of the soil to allow moisture in. This revolution in shallow vertical tillage could not have occurred without the effectiveness of chemical weed control. With early vertical tillage machines, there was a shift to tillage for soil and residue management without the focus on killing weeds.
Then, the evolution of vertical tillage continued. As more tools were sold into diverse regions of North America and as more diverse applications arose, customers began to request greater versatility in the vertical tillage tools themselves. This led to more aggressive tools, where the front gang of blades began to be angled. Typically, 4-8 degrees on the front was enough angle to move more soil, which had two positive effects on the output. The increased soil movement helped to anchor the residue into the soil, which prevented residue from blowing off the field, and secondly, the increased action of the front blades would kill more weeds than a straight angled, wavy blade.
During this same time, disc harrows with variable gang angles were being used, as the original equipment manufacturers (OEMs) realized they could modify a disc to work in similar to the more aggressive vertical tillage tools that were coming to market with variable angles. This is where the vertical tillage systems became more complex. Today, vertical tillage tools can run with up to an 18-degree gang angle front and rear, the same as a disc harrow, but with new blades, they create a vertical lifting action of the soil. Vertical tillage is intended to improve soil tilth without the shearing action of a disc harrow.
In North America, disc harrows represent the highest volume of tillage tools in the market. Over time, disc harrows have not evolved as much compared to other tillage tools. These tools run at a 16-20 degree gang angle, and the primary goal is to completely cut the soil in a horizontal fashion to kill all weeds and regrowth. At the same time, they will bury nearly all the residue if they are run at the maximum depth. These tools can be run shallow to leave some residue on the surface; however, at the shallow depths, they risk not achieving a complete cutout, which would allow some weeds to survive. Historically, disc harrows were often not the first pass of tillage. Plows used to be the first pass to completely bury the residue, then disc harrows were used as the follow-up tool to break down the plowed ground and begin to prepare it as a seedbed. Due to the high weed resistance to chemicals, there has been some resurgence of plows in North America. Despite this resurgence, plows will not likely see a complete comeback due to the cost and time required to cover large acres. However, when looking at disc harrow usage around the world, these are still used heavily today. For example, Brazil, which prides itself on being no-till, still has offset disc harrows on nearly every farm. While they do not use it on every acre and may not use it every year, it is still the staple tillage tool for Brazil and for much of the world. The exceptions where disc harrows are not found are the areas where the plow is still the primary tillage tool; this accounts for most of western Europe and large areas of Asia where plowing is still common. It is still likely that the global ag community will continue to see a high usage of disking to size greater amounts of residue and kill weeds.
Cultivators and Finishers
The standard seedbed tool used right before seeding or planting has traditionally been the field cultivator – a finishing tool. With spacings of six, seven, or nine inches, the sweeps completely shear the soil at a shallow depth. The shearing action is extremely effective at killing weeds and often follows several tillage passes. By the time the cultivator is used, the soil is usually well-prepared, making it easy for the sweeps to pass through.
Over time, manufactures have built cultivators in larger working widths to cover acres more quickly than a disc harrow or vertical tillage tool. In the current ag economy with tight commodity prices, growers are always looking for ways to combine passes of tillage and reduce input costs. This led to combination finishing tools. These tools have different names depending on the brand, but the essence of a seedbed finisher is to add some rotating gangs in front of field cultivator sweeps. This enables the grower to achieve the same field finish that a field cultivator provides, while also handling more residue. The front coulters can be run at a 0-degree angle or a minimum angle to cut the residue and prevent plugging as the residue passes around the cultivator sweeps. Depending on soil and residue conditions, these finishers can be used in a wide variety of conditions and are intended to replace some of the vertical tillage or disc harrow passes through the field.