Document Type


Publication Date



drought, rangelands, south dakota, stocking rate

Extension Number

ExEx 2046


Agricultural and Biosystems Engineering


The vegetation of rangelands in a large portion of western South Dakota is an overstory of cool-season grasses such as western wheatgrass and green needlegrass and an understory of warm-season grasses such as blue grama and buffalograss (Fig 1). In semi-arid environments, precipitation is the main factor that determines forage production. Many western South Dakota counties receive less than 17 inches of annual rainfall, with 75% occurring between April and October. Pastures are usually managed as large units (more than 160 acres) because fencing and water developments are costly. Regrowth is usually limited to the spring, and 90% of forage is produced by July 1 (Heitschmidt 2004). Most grazing systems are continuous season-long grazing or simple rotational grazing with less than eight pastures.


April 2005.