Changes in Grazing Use and Herbage Moisture Content of Three Exotic Lovegrasses and Some Native Grasses
KeywordsHerbage Moisture Content
Santa Rita Experimental Range
MetadataShow full item record
CitationCable, D. R., & Bohning, J. W. (1959). Changes in grazing use and herbage moisture content of three exotic lovegrasses and some native grasses. Journal of Range Management, 12(4), 200-203.
PublisherSociety for Range Management
JournalJournal of Range Management
Showing items related by title, author, creator and subject.
Ingestive behavior of cattle grazing in lightly- and heavily-grazed patches of Lehmann lovegrass (Eragrostis lehmanniana Nees).Ruyle, George B.; Abu-Zanat, Mahfouz Mohammed Waheed.; Roundy, Bruce A.; Ogden, Phil R.; Rice, Richard W.; Swingle, Roy S. (The University of Arizona., 1989)Cattle grazing patterns on Lehmann lovegrass rangelands often create heavily-grazed (HG) areas surrounded by lightly-grazed (LG) or ungrazed patches. The purpose of this study was to characterize the forage resource and ingestive behavior of cattle grazing Lehmann lovegrass plants in both LG and HG patches on the Santa Rita Experimental Range. The general hypothesis was that residual bunchgrass vegetation resulted in sward characteristics which physically inhibited the efficiency of cattle grazing by increasing the manipulative activity per harvested bite. The overall heights of residual stems and green tillers averaged 70 and 49 cm for LG, 8 and 9 cm for HG patches. Biomass of total standing crop (SC), residual vegetation (RV) and green herbage (GH) averaged 4159, 3395 and 764 kg/ha for LG, 345, 185 and 160 kg/ha for HG patches, respectively. Bulk density of SC, RV and GH of LG and HG patches averaged 58, 48, and 19 [(gm/cm³) X 10⁻⁵] for LG, 38, 23 and 20 [(gm/cm³) X 10⁻⁵] for HG patches, respectively. The ratio of green herbage to residual vegetation averaged 0.22 for LG and 0.86 for HG patches. The different sward structure of LG and HG patches affected the ingestive behavior of the grazing cows. Overall handling time for each grazing bite averaged 1.5 and 1.2 sec/bite in LG and HG patches, respectively. Cows employed different foraging tactics in response to the dynamic changes of the sward conditions. Cows employed top biting extensively to harvest the seed-head and other green herbage at the top of the sward surface. As the height of residual stems increased and dominated the upper strata of the sward, side and low biting were mainly used by the cows as grazing methods to bite the plants to reduce the manipulative activity. Avoidance of LG patches or preference for HG patches was related to the sward structure and largely shaped by the build-up of residual vegetation. Removal of residual vegetation through fire, mowing or heavy utilization for short periods late in the growing season to allow for more accessible green herbage could improve both animal and pasture utilization of the range resource.
Emergence and cool-season growth of Lehmann lovegrass and Arizona cottontop on different soilsSmith, Steven E.; Rogstad, Kristin Alix, 1972- (The University of Arizona., 1998)Lehmann lovegrass (Eragrostis lehmanniana Nees.), a perennial bunchgrass, has established itself well since its introduction from South Africa. Arizona cottontop (Digitaria californica (Benth.) Henr.) is a native perennial bunchgrass that sometimes appears on the same sites and soils as Lehmann lovegrass. In a greenhouse, emergence was evaluated using line-source irrigation which simulated natural summer precipitation on two soil types collected from the Santa Rita Experimental Range (SRER). Density and cool-season growth of each species were monitored along transects located at the SRER on three different soils. I found that although Lehmann lovegrass and Arizona cottontop emerge similarly on two soils, Arizona cottontop un-emerged caryopses had a better percent survival rate. Also, Lehmann lovegrass plants had more green above-ground biomass from November to May than Arizona cottontop, and Lehmann lovegrass was able to greenup more rapidly following rain. This study showed these species have similar emergence characteristics, but that their cool-season greening differs.