Summary of Report
Crop Residue Management and Tillage System Trends
SB-930, August 1996
Conservation tillage was used on more than 99 million acres in 1994, about 35 percent
of U.S. planted crop area. Five years earlier, the total conservation-tilled acreage was 72
million. Besides conserving soil, crop residue management practices also cut production costs
on many farms, according to this report.
Conservation tillage is defined as any tillage and planting system that maintains at least 30
percent of the soil surface covered by residue after planting, to reduce soil erosion.
Advantages of crop residue management systems over conventional systems include fuel and labor
savings, lower machinery investments, and long-term benefits to soil structure and fertility.
New or retrofitted machinery may be needed for crop residue management, but fewer trips over a
field and reduced fuel and labor requirements can mean immediate cost savings. Farmers apply
conservation tillage mostly at their own expense. Just 600,000 acres were cost-shared in 1993
under the Agricultural Conservation Program, USDA's major cost-sharing program.
Crop residue management systems include no-till, ridge-till, mulch-till, reduced-till, and
other conservation practices that provide sufficient residue cover to help protect the soil
surface from wind and water erosion.
The Corn Belt and Northern Plains regions had the most planted cropland in 1994 and accounted
for nearly 61 percent of total conservation-tilled acres. Conservation tillage was used mainly
on corn, soybeans, and small grains in 1994. More than 45 percent of corn and soybean acreage
was conservation-tilled. The share of corn and soybean acreage planted with no-till has more
than tripled since 1989.
Where fields were double-cropped in 1994, conservation tillage was used on more than 66
percent of soybean acreage, 53 percent of corn acreage, and 50 percent of sorghum acreage. The
benefits of no-till with double-cropping include timeliness in getting the second crop planted
and limiting potential moisture losses from the seedbed germination zone.
USDA's annual Cropping Practices Surveys, since 1988, show a decline in use of moldboard plows
for all surveyed crops, a decline in all conventional tillage systems for corn and soybeans,
and an increase in use of conservation tillage. Less than 10 percent of the surveyed area in
major producing States used a moldboard plow in 1994, down from 20 percent in 1988.
CONSERVATION TILLAGE systems as defined in both the Crop Residue Management Survey and the Cropping Practices Survey:
No-till. The soil is left undisturbed from harvest to planting except for nutrient injection. Planting or drilling is in a narrow seedbed or slot created by coulters, row cleaners, disk openers, in-row chisels, or roto-tillers.
Ridge-till. The soil is left undisturbed from harvest to planting except for nutrient injection. Planting is in a seedbed prepared on ridges with sweeps, disk openers, coulters, or row cleaners. Residue is left on the surface between the ridges.
Mulch-till. The soil is disturbed before planting. Tillage tools, such as chisels, field cultivators, disks, sweeps, or blades, are used. The Cropping Practices Survey assumes that any system with 30 percent or more residue after planting that is not no-till or ridge-till is mulch-till.
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Updated: September 3, 1996
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