Severe Mechanical and Chemical Range Renovation in Northeastern Wyoming

Abstract

Range renovation using a moldboard plow, disc plow, rotovator, blade, and strip spraying with atrazine was evaluated on a clayey and a sandy range site 35 miles south of Gillette, Wyoming. Herbage yields and vegetative composition were influenced by the individual renovation treatment, range site, and distribution and amount of April, May, and June precipitation. The amount of total perennial grass was significantly increased on the plots treated with the rotovator and strip spraying with atrazine on the clayey site, and on plots treated with atrazine on the sandy site. The 5-year average yield of blue grama from the atrazine treatments averaged 872 and 939 lb/acre on the clayey and sandy range sites, respectively, as compared with 237 and 229 lb/acre, respectively, on the check. The blue grama on plots sprayed with atrazine produced a profusion of seed heads and remained green later in the season than on any of the other treatments. The disc plow and the rotovator appear to have a greater potential than the moldboard plow or blade for range renovation. Annual grasses may become a problem with any range renovation, and should be controlled.