The previous crop residue is a resource to conserve and use. In addition to controlling soil erosion, crop residue limits moisture evaporation from the soil surface, maintains desirable humidity levels in undisturbed soils, and provides a food source for beneficial fungi, bacteria, insects and weed seed predators.
This project, funded by the ND Soybean Commission, compares soil conditions, and soybean plant growth, development and yield in previous year’s wheat and corn stubble fields under strip till, conventional till, and no-till. The site is located near Jamestown in central North Dakota.
Vertical tillage generally refers to soil tillage four inches deep or shallower. The term “shallow” indicates the tillage equipment is designed to stir or ridge the soil without inverting the soil. Some soil particles are mixed with surface residue, but the residue is not completely incorporated into the soil. Vertical tillage equipment may use disks, or shanks to disturb the soil. Crop producers use shallow tillage for several reasons, including to: 1) stir the soil surface to encourage drying or warming prior to planting; 2) incorporate surface-applied fertilizers; 3) size crop residue; and 4) facilitate crop residue decomposition.
Air seeders are commonly used to plant most solid-seeded field crops in the Northern Plains of the United States. Air seeders components include a commodity cart, an air blowing seed delivery system, soil openers, and packers.
The two basic opener designs used on conservation tillage seeders are disc and hoe openers. "Hybrids" of these two opener designs incorporate some of the same features of both disc and hoe type openers. Disc openers can be single or double disk, with gauge wheels mounted beside and in contact with the disc opener or with a trailing packer wheel functioning as a gauge wheel.
The trend among northern Plains farmers is toward using less tillage to produce field crops with more residue left on the soil surface. Strip till is a field tillage system that combines no till and full tillage to produce row crops. Narrow strips, 6 to 12 inches wide, are tilled in crop stubble, with the area between the rows left undisturbed. Often, fertilizer is injected into the tilled area during the strip-tilling operation. The tilled strips correspond to planter row widths of the next crop and seeds are planted directly into the tilled strips. Strip tilling normally is done in the fall after harvest, but it also can be done in the spring before planting.
Aerator rollers can be effective in preparing Conservation Reserve Program (CRP) fields for crop production or grazing because they cut plant material into short enough to lengths, allowing no-till planters to function effectively. The aerator roller sufficiently smoothes the soil surface to allow effective tractor and machinery operation.