Date of this Version
FIELD CROPS G-6, Cropping Practices Issued March 1981, 15,000
Selecting a tillage system that is best suited to a particular farming situation is an important management decision. In the past, a crop producer's primary concerns were field capacity and the costs of owning and operating equipment. However, with rapidly increasing energy costs, alternative tillage systems are being carefully evaluated and selected by more producers.
Previously, the most common tillage system included a moldboard plow to turn residue under either in the fall or spring. Following plowing, spring tillage normally included one or more shallow diskings to kill weeds, incorporate fertilizer and pesticides, and provide loose soil for seed. Other light tillage operations, including field cultivation and harrowing, were also conducted to provide a finely pulverized, weed free, seedbed. Today, preplant tillage operations are being reduced on many farms. Labor, fuel and equipment costs, better erosion control, moisture conservation, and more timely planting are all reasons for the trend toward reduced tillage operations.
The wide array of tillage and planting systems available today provides an opportunity to match the tillage system to specific soil and cropping conditions. Six different tillage systems are described here to aid in tillage system selection.
Tillage System Descriptions
Moldboard Plowing. Fall or spring moldboard plowing has been an accepted tillage operation primarily because of soil pulverization and nearly complete residue incorporation (Figure 1). When followed by one or two spring diskings, moldboard plowing provides an excellent seedbed and allows fertilizer and pesticide incorporation before planting. Even though the moldboard plow buries weed seeds, postemergent cultivation for weed control is often needed. Fall plowing also speeds up soil drying and warming in the spring, thus avoiding delays in spring tillage and planting on soils that dry slowly.
Fall moldboard plowing has often been used to reduce the number of spring tillage operations. Poor weather conditions in the spring may cause crops to be planted late because of insufficient time to plow and prepare the seedbed. The primary disadvantage of fall plowing, however, is the potential for soil erosion throughout the winter and early spring because no surface residue is available to protect the soil.
Spring plowing not only reduces the potential for wind and water erosion, but also provides winter grazing for livestock. Spring labor and time shortages, however, often offset these advantages. Furthermore, spring plowing may produce clods, which require an extra, unplanned tillage operation to develop a desirable seedbed. Excessive soil moisture loss, especially during dry years, is another disadvantage with spring plowing.