Following 40 years of rest, Wyoming mixed grass prairie grazed at light and heavy intensities for 12 years had significantly greater carbon and nitrogen in the root zone of the soil profile than an ungrazed control. Although above- and belowground production in the control contained more total nitrogen than grazed pastures, total ecosystem (root, shoot and soil) nitrogen to 30 cm was greater under grazing, which increased nitrogen accrual. Peak standing crop declined with heavy grazing, but was similar under light and no grazing. Further, blue grama (Bouteloua gracilis) increased from 17 to 27% of peak standing crop under heavy grazing, while western wheatgrass (Agropyron smithii) and forbs dominated under light grazing (45%) and no grazing (33%), respectively. The observed increase of soil C and N in the surface soil where roots dominate indicates a greater opportunity for nutrient availability and cycling, and hence enhanced grazing quality.
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