|Briske, David - TEXAS A&M UNIVERSITY|
|Milchunas, Daniel - COLORADO STATE UNIVERSITY|
|Tate, Kenneth - UNIVERSITY OF COLORADO|
Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 3, 2008
Publication Date: March 18, 2009
Citation: Derner, J.D., Briske, D.D., Milchunas, D.G., Tate, K.W. 2009. Experimental Evidence for Grazing System Research: What Does it Tell Us?. Society for Range Management Meeting Abstracts No. 19-3. Technical Abstract: Research on grazing systems has been conducted for the past 60 years and the experimental evidence consistently indicates that rotational grazing is comparable to continuous grazing on rangelands. For example, over 80% of the peer-reviewed studies reported that rotational grazing did not result in higher plant production, animal production per head or animal production per land area compared to continuous grazing. These results are not entirely unexpected given the strong relationship that has been established between plant and animal production and stocking rate. In addition, limited and erratic precipitation characteristic of many rangelands reduces the predictability and magnitude of production. Successive, repeated grazing and rest periods associated with rotational grazing do not appear to override the affect of stocking rate or the inherently unpredictable growth patterns to increase plant production. Reduced animal selectivity due to high grazing pressures and movement of livestock between pastures results in similar or lower animal gains with rotational grazing. We conclude that the production responses of grazing systems have been effectively documented, but limitations of experimental grazing research include: 1) spatial and temporal scales of investigations (i.e., whole ranch enterprises), 2) research protocols may not mimic adaptive management, 3) role of human dimensions (i.e., socioeconomic benefits, including personal goals and values), and 4) conservation goals (i.e., heterogeneity, diversity). These data suggest that grazing management strategies should deemphasize grazing systems and emphasize fundamental adaptive management decisions, especially during critical events and periods.