The interest in “vertical tillage” management has increased throughout the grain production region of the US in the past several years. The perception exists that certain traditional tillage practices create compacted layers and may reduce soil quality relative to crop production. These layers basically restrict root development into the soil; whereas vertical tillage systems “open up” the soil to better root growth down into the soil. Many companies now promote their tillage equipment as vertical tillage implements. However, it is likely that the practice means different things to different people. It has been suggested that vertical tillage could be conducted shallow, at a depth of 3 to 4 inches using tools that are equipped with specialized disks or harrow attachments or deep to depths well beyond 12 inches using subsoiling-like knives that create slots and do not invert the soil.
Perhaps it is easier to describe what is understood to not be vertical tillage (i.e., horizontal tillage). Such practices are those that shear the soil horizontally using a moldboard plow, field cultivator, or similar tools designed to cut and lift the soil often across the full tillage width. A chisel plow equipped with sweeps could be considered a horizontal tillage tool, while the same implement with straight points would provide vertical tillage. The principal effect is that there is a downward force associated with their operation that compresses the soil underneath as it cuts and lifts the soil, thereby creating a tillage pan. According to Dr. Randall Reeder, an agricultural engineer at The Ohio State University, negative factors associated with horizontal tillage practices include surface soil compaction, poorer root growth, increased erosion potential, and greater energy requirement to prepare a seedbed.