Encroachment of Big Sagebrush on Seeded Range in Northeastern Nevada

Abstract

Possibilities for increasing forage production on depleted range lands overgrown with big sagebrush (Artemisia tridentata) have been successfully demonstrated in many places. The proved formula includes brush removal and seeding adapted grasses. The introduced, dought-tolerant wheatgrasses (crested wheatgrass, Agropyron desertorum, formerly known commonly as the Standard variety and now sometimes called desert wheatgrass, and crested wheatgrass, A. cristatum, formerly known commonly as Fairway strain) have been used more than native grasses for this purpose. They are generally better seed producers, easier to establish, and will tolerate as much or more grazing than native bunchgrasses found in the sagebrush zone. The native bunchgrasses have disappeared, wholly or in part, over extensive acres as a result of past heavy grazing, thereby allowing increase of brush. The question arises as to how long crested wheatgrass will persist under grazing, and to what extent it can prevent sagebrush and other undesirable species from reinvading. This paper provides information on these important points from an 825-acre planting in typical sagebrush land in Ruby Valley, Nevada. Prior to treatment of the experimental plots in 1944, big sagebrush averaged 20 plants, 18 to 48 inches in height, plus 60 seedlings, per 100 square feet of Other vegetation in order of abundance included Sandberg bluegrass (Poa secunda), Douglas rabbitbrush (Chrysothamnus viscidiflorus), squirreltail (Sit anion hystrix), tailcup lupine (Lupinus caudatus), hoary phlox (Phlox hoodii canescens), little larkspur (Delphinium andersoni), Indian ricegrass (Oryzopsis hymenoides), arrowleaf balsamroot (Balsamorhiza sagittata), Great Basin wildrye (Elymus cinereus), and trace amounts of a few other species. Grasses occupied only 1 of every 220 square feet of area, or less than one-half of 1 percent of the ground surface. Considering big sagebrush to be 10 percent palatable, the annual grazing capacity was judged to be 40 to 50 animal months for the 82;5 acres, but experienced range man voiced his opinion that one cow would starve on the entire area. One stockman would not risk grazing the area because of larkspur. The area was made available for experimental seeding and demonstrations in 1944 by cooperative agreements between the Intermountain Forest and Range Experiment Station, private ranchers, Bureau of Land Management, and Humboldt National Forest. A major point of interest was to demonstrate on a large scale the feasibility of removing sagebrush and seeding rangeland to provide suitable spring forage for cattle, and thereby relieve early grazing use on certain nearby allotments of the Humboldt Forest. An average annual precipitation of approximately 12 inches and a sandy clay loam soil of average fertility, at an elevation of 5,800 feet, favored success. Treatments and Early Responses