“…Research was conducted during 1989-1990and 1990-1991 to May, at an eastern Nebraska site (University of Nebraska Agricultural Research and Development Center near Mead, NE) and dUring [1989][1990], December to May, at a western Nebraska site (Panhandle Research and Extension Center near Scottsbluff, NE). Plots were constructed in which the native soil was removed to a depth of 0.46 m and replaced with soils having defined textures.…”