The University of Arizona

Impacts of rotational grazing on mixed prairie soils and vegetation.

J.F. Dormaar, B.W. Adams, W.D. Willms


In this study the impact of a rotation grazing system on the soil and vegetation of a Stipa-Bouteloua-Agropyron community in the mixed prairie ecoregion was compared with the ungrazed treatment in exclosures. At a low stocking rate, grazing had no effect on the vegetation but did alter soil quality. Grazing pressure was so light in the rotational grazing treatment that recovery of productivity, as measured by standing crop and litter, was not significantly different from the ungrazed treatment. Conversely, the species distribution was unchanged but was indicative of a lower seral state for this mixed prairie. The effect of grazing on this community was indirect, possibly by altering the microenvironment. The relationships observed among forage production, soil chemistry, and species composition raise questions on the importance of any one variable expressing range condition on the mixed prairie.


Elymus lanceolatus;Hesperostipa comata;Alberta;rain;chemical composition;rotational grazing;Bouteloua gracilis;grazing intensity;soil chemistry;biomass;range management;plant litter;botanical composition

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