ABSTRACT
In the United States, the 1970s and 1980s were characterized by growing interest in conservation tillage systems, both from their adoption and adaptation by farmers and their development and evaluation by the agricultural research community. Of particular interest has been the no-tillage (NT) system. Under periodic tillage, the question arises as to the fate of short-term changes in soil properties when a NT soil is periodically plowed. East Lansing is situated in the south-central part of the lower peninsula of Michigan, approximately equidistant from three of the Great Lakes — Michigan, Huron, and Erie. Soil test K levels were in the medium range for Michigan soils. In 1987, soil test K in NT was highly stratified in the surface 200 mm. Plowing a soil in NT management redistributed soil nutrients within the plow layer. The surface stratification of NT was not entirely lost when plowed and was increased over time, relative to conventional tillage.
