A tillage tool is defined in this textbook as an individual soil-engaging element, such as a plow bottom or a disk blade. A tillage implement consists of a single tool or a group of tools, together with the associated frame, wheels, hitch, control and protection devices, and any power transmission components. For tillage implements, the process system consists of the tillage tools, while the other components form the support systems.
Throughout the world farmers choose from a variety of implements for soil tillage. The set of implements that an individual farmer chooses depends on local customs, crop type, soil moisture level, soil type, and the amount of plant residue from the previous crop. Tillage implement selection is also affected by the availability of implements, power units, labor, and capital.
The three hitching configurations available for these implements are integral (mounted), semi-integral (semi-mounted), and drawn (pull-type). Integral and semiintegral implements are attached to the three-point hitch of a tractor, but a drawn implement is attached to the drawbar. An integral plow, in the transport position, is fully supported by the tractor. The rear furrow wheel of an integral implement provides vertical and lateral support along with the hitch when the implement is in its operating position. Plowing depth for an integral plow is usually controlled by changing the vertical position of the tractor’s hitch. A semi-integral plow is supported at the front by the tractor’s hitch and at the rear by the plow’s furrow transport wheel in both the transport and operating positions. The front of the plow is raised and lowered by the tractor’s hitch while the rear of the plow is raised and lowered by a remote hydraulic cylinder. A drawn plow/implement is fully supported by its own transport wheels and is raised and lowered by a remote hydraulic cylinder.
Tillage operations for seedbed preparation are often classified as primary or secondary, although the distinction is not always clear-cut. A primary tillage operation constitutes the initial, major soil-working operation after harvest of the previous crop; it is normally designed to reduce soil strength, cover plant materials, and rearrange aggregates. Secondary tillage operations are intended to create refined soil conditions following primary tillage. The final tillage operation prior to planting a crop is usually secondary tillage, but farmers may use more than one secondary tillage operation. In some situations, a tillage operation may fit the definition of both secondary and primary tillage. For example, a farmer may prepare a field for planting winter wheat with a single disking operation after harvesting soybeans. This single disking operation is both the initial tillage operation after harvest and the final tillage operation before planting.
Erosion of soil by wind or moving water is a problem that plagues agriculture in many parts of the world. The erosion process removes nutrients and other chemicals from land as well as soil. Some farmers in North America use conservation tillage, a practice which leaves plant residue on the soil surface to reduce erosion. Practicing conservation tillage can reduce the time and energy required for tillage, although this practice frequently requires better management than conventional tillage.
