Submitted to: Journal of Range Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 17, 1996
Publication Date: N/A
Interpretive Summary: Does cattle grazing at moderate intensity reduce soil fertility in Southern Plains rangelands? In a comparison of areas grazed or ungrazed over 50 years we found no differences in carbon or nitrogen concentrations in the surface soils. The study indicates that moderate grazing of native rangeland is a sustainable system.
Technical Abstract: The effect of livestock grazing on organic C and N in rangeland soils is not well defined. In this study on sandy rangeland in western Oklahoma, we sampled 8 pastures moderately grazed by cattle and 8 adjacent exclosures ungrazed by livestock for 50 years. The C and N concentrations in the surface 5 cm of soil, total aboveground herbage production, and total N uptake by vegetation were similar (P>0.05) in grazed and ungrazed areas. Litter and total N in litter were greater (P<0.01) on ungrazed areas. Little bluestem (Schizachyrium scoparium (Michx.) Nash) and sand bluestem (Andropogon hallii Hack.) produced more herbage and had greater frequency on ungrazed areas, whereas blue grama [Bouteloua gracilis (H.B.K.)Lag. ex Griffiths], sand dropseed [Sporobolus cryptandrus (Torr.)Gray], and western ragweed (Ambrosia psilostachya DC.) increased in importance on grazed areas. Thus, 50 years of moderate grazing by cattle had no measurable effect on C and N concentrations in the surface 5 cm of the sandy soil or on total N uptake by plants as compared with ungrazed areas, however, significant differences occurred in species composition.