Trampling may enhance soil seed contact and increase surface roughness, thereby potentially enhancing seedling germination and survival, particularly if litter cover is increased to prolong soil moisture in the upper 2.5cm of the soil profile (Winkel and Roundy, 1991). To test this hypothesis, we broadcasted Green Sprangletop (Leptocloa dubia) and Kleingrass (Panicum coloratum) seed at approximately 4.5 kg Ha-1 PLS each on former cropland that had been unsuccessfully seeded to plains bluestem (Bothriochloa ischaemum). Four 0.1 ha plots were trampled by placing yearling heifers at high stocking densities (90,702 kg live wt ha-1) for 12 hours following a rainfall event of 4.3 cm to enhance soil-seed contact and put standing plant material in contact with the soil, while 4 adjacent control plots of the same size were left untrampled. After trampling, we scattered Sorghum-Sudangrass hay on portions of the untrampled and trampled treatment plots to achieve 100% soil surface cover. We then provided extended grazing deferment to determine if trampling and/or enhanced litter cover would have an effect on seedling establishment and total vegetative cover. Before trampling and after precipitation events, six Daubenmire frames were randomly placed in each treatment plot to determine foliar, basal, litter, and total cover. Trampled treatments had less vegetative cover (P<0.01) and average soil bulk density was higher (P<0.01) than untrampled plots immediately after trampling. Significant recruitment of Green Sprangletop and/or Kleingrass did not occur. Additionally, there were no differences in cover amount, species, or seedling recruitment between trampled and untrampled plots since plains bluestem cover increased in both grazed and ungrazed treatments to a similar degree. However, there were differences in foliar cover and seedling frequency in the supplementally covered versus no covered treatments (P<0.05), indicating that high levels of vegetative litter cover after a high stocking density grazing is important for range improvement.
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