Range Fertilization in the Northern Great Plains

Abstract

Highlight: Nutrient deficiency, primarily nitrogen (N), is a major plant growth-limiting factor on northern Great Plains rangelands. Applications of 30 to 50 lb N/acre/year have commonly doubled forage production with an N-use efficiency of about 20 lb dry matter/lb N applied, or in grazing situations about 1 lb beef/lb N applied. Range fertilization can also increase water-use 'efficiency and improve forage quality and palatability. With applications of 50 lb N/acre/year or less, changes in species composition are gradual and can largely be controlled by timing of fertilizer applications and by season and intensity of grazing. Drastic changes in species composition are usually limited to applications greater than 15 0 lb N/acre/year. The northern Great Plains as described by Lodge (1970) covers approximately 400,000 square miles. Its general boundaries are the Rocky Mountains from the Wyoming-Colorado border north to Edmonton, Alberta, Canada, thence southeast to the intersection of the 98th meridian and the U.S.-Canadian border, thence south along the 98th meridian to the 41st parallel, and thence west to the Rocky Mountains. Native range accounts for approximately 70% of the land area and is primarily of the mixed prairie types with some tall grass prairie on the eastern extreme and some short grass prairie on the southwestern extreme. The Chestnut, Brown, and Dark Brown soils comprise the major soil groups within the area. The northern Great Plains has a climate which is generally considered harsh and extreme. Precipitation is irregular and often in short supply. In the east, annual precipitation averages more than 20 inches and in the north and west, as little as 10 inches per year. Among-year variation is even greater, particularly the seasonal precipitation, which often varies 100% or more. However, precipitation patterns within the northern Great Plains affect the vegetation more than does the total amount. About three-fourths of the annual precipitation occurs during the 6-month growing season (April through September) and about half during May, June, and July. Average growing season of the northern Great Plains decreases from 160 to 116 days going from south to north. Livestock production is a major segment of the economy in the northern Great Plains. Lodge (1970) estimated that this area supports some 12 million animal units of beef cattle and sheep. However, increasing demands for wheat and other cultivated crop products have resulted in the conversion of large acreages of range to crop land. Thus, to meet the The author is range scientist,

Productivity of Cenchrus Ciliaris in Relation to Rain-Fall and Fertilization

“…and Russian wildrye (Elymus junceus Fishc.) produced 1.0, 1.7 and 2.2 kg beef kg-' N, respectively(Wight 1976). Information such as this can be used to help make economic evaluations.…”

Shifts in Botanical Composition of Flatwoods Range following Fertilization

“…Fertilization has increased the quantity and nutritive value of range forage in the western U.S. (Goetz 1969, Wight 1976). In south Florida, Lewis (1970) reported an increase in above-ground biomass and nutritive value of desirable grasses growing on wiregrass (Aristida stricta Michx.)…”

Effect of nitrogen fertilizer on beef production and forage quality of Russian wildrye

“…1986) or by application of a large amount of N fertilizer broadcast periodically (Lutwick and Smith 1979;Read and Winkleman 1982 (Rogler and Lorenz 1970). In central Saskatchewan, Cohen et al (1986) Forage quality can also be influenced by fertilization (Wight 1976 (Lawrence et al 1982).…”