Wildlife Habitat Management Institute
CONSERVATION TILLAGE AND TERRESTRIAL WILDLIFE
September1999
Fish and Wildlife Literature Review
Number 1
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As the United States Department of Agriculture Natural Resources Conservation Service
(USDA-NRCS) develops Outcome-Oriented Performance Measures for Conservation
Tillage, it is important to document the impacts that this conservation practice has on
wildlife habitat and populations within the agricultural landscape. A landscape where
wildlife habitat has decreased as cropland monoculture replaced the once small fields that
produced a diversity of crops such as small grain, hay, and pasture (Vance 1976, Taylor
et al. 1978). An additional purpose for this review is to provide technical information to
NRCS personnel and others who provide conservation technical assistance to
landowners.
Most of the papers in the wildlife literature concerning tillage fall into 2 categories, those
that compare conservation tillage with conventional tillage or those that use conventional
tillage, reduced tillage and no-tillage for comparison. Conservation tillage is a system
that leaves crop residue on the soil surface. Conventional tillage turns the soil and crop
residue under with a moldboard plow. This is usually done in the fall, followed by
disking in the spring, which leaves a residue-free surface (Best 1985). Best (1986)
explains the differences between conventional, reduced and no-tillage systems. The
differences noted are the amount of residue left on the soil surface, the timing of residue
disturbance (fall vs. spring), and the number of equipment passes in a cropping cycle.
There has been limited research on the impacts of conservation tillage on terrestrial
wildlife, and much of the work is summarized in several excellent reviews (Rodgers and
Wooley 1983, Best 1985, Wooley et al. 1985, Nicholson and Richmond 1985, Best 1986,
Best 1995). These reviews were relied upon greatl