Benefits of rotational grazing not supported by research

Benefits of rotational grazing not supported by research
- 4, 2008

In spite of overwhelming experimental evidence to the contrary, rotational grazing continues to be promoted and implemented as the only viable grazing strategy on rangelands. A new comprehensive study has synthesized the existing data on grazing strategies, and the researchers conclude that long-term research does not support this widely held claim.

The experimental results, dating as far back as 1961, conclusively demonstrate that rotational grazing is not superior to continuous grazing across numerous rangeland ecosystems. These results further corroborate the long-standing position that stocking rate and weather variation account for the majority of the variability associated with plant and animal production on rangelands. The use of rotational grazing is not supported by experimental data because past studies have found that this grazing system has not had as beneficial an effect on plant and animal production as previously thought. Two broad explanations are provided: 1) the presumed benefits of rotational grazing were overextended and 2) similar ecological limitations occur on production in all grazed ecosystems.

This synthesis demonstrates that continued advocacy for rotational grazing as a superior system of grazing is founded on perception and anecdotal interpretations, rather than on the preponderance of experimental evidence. Rotational grazing as a means to increase vegetation and animal production has been subjected to as rigorous a testing regime as any hypothesis in the rangeland profession, and it has been found to provide few, if any, consistent benefits over continuous grazing. It is unlikely that researcher oversight or bias has contributed to this conclusion given the large number of grazing experiments, investigators, and geographic locations involved over a span of six decades.

This synthesis establishes that several potentially effective grazing strategies exist, none of which have unique properties that set one apart from the others in terms of ecological effectiveness. Most likely, this is because the performance of all grazing ecosystems is constrained by similar sets of ecological variables, indicating that differences among them are dependent on the effectiveness of grazing management rather than the occurrence of unique ecological processes.

The researchers conclude that though rotational grazing is a viable grazing strategy on rangelands, the perception that it is superior to continuous grazing is not supported by the vast majority of experimental investigations. They recommend that these evidence-based conclusions be explicitly incorporated into management and policy decisions addressing this predominant land use on rangelands.

For more information on this study contact the Society of Range Managment.