• Cattle Behavior on a South Florida Range

      Tanner, G. W.; Sandoval, L. D.; Martin, F. G. (Society for Range Management, 1984-05-01)
      Grazing, resting, defecating, and urinating behaviors of cattle (Zebu-European cross breeds) were monitored seasonally on a south Florida range from November 1980 through August 1981. Individual animals were continuously during daylight hours in a pasture containing 4 plant communities. Distributions of time spent grazing and resting and counted occurrences of excretion were significantly different among the 4 seasons. Grazing time in the 4 plant communities was not in proportion to their size. Cattle grazed more in those communities that had the best quality of forage available. Cattle grazed more in the freshwater marsh during fall but spent more time in the ecotone during spring and summer. Shade was not a requisite for resting sites, even during the warmest days. Excretion activities were more closely associated with grazing than resting.
    • Change in Bacterial Populations Downstream in a Wyoming Mountain Drainage Basin

      Skinner, Q. D.; Adams, J. C.; Beetle, A. A.; Roehrkasse, G. P. (Society for Range Management, 1984-05-01)
      Ten bacteriological tests were utilized to monitor different bacterial populations found in water samples taken from streams draining high mountain rangeland. Livestock grazing and recreation constituted the major uses of the study area. Vegetation types were typical of those found in other sub-alpine and alpine zones in the central Rocky Mountains. Results show differences in counts of bacteria between sampling sites along individual streams sampled with the exception of those organisms capable of reducing nitrate were not significant. A seasonal variation in the numbers of bacteria were found between streams. This variation is not fully explained by drainage basin areas or related to runoff. In contrast, within each stream counts varied with season and could be related to runoff. Bacterial populations which indicate fecal pollution were low and probably derived from animals not man. Wet meadows and bog areas under snow may be possible sources for sulfate reducing bacteria and those organisms capable of reducing nitrate.
    • Threshing Damage to Radicle Apex Affects Geotropic Response of Winterfat

      Booth, D. T. (Society for Range Management, 1984-05-01)
      The acute end of a winterfat [Eurotia lanata (Pursh) Moq.; Ceratoides 1. (Pursh) J.T. Howell] seed is formed by the apex of the radicle and of the cotyledons. It is postulated that this shape makes the embryo root cap especially susceptible to damage during threshing and that such damage is the cause of a high percentage of threshed germinated seed (germinant) lacking positive geotropism. This study consisted of examining germination behavior and post germination anatomy of the root apex of germinants with and without positive geotropism. The radicle apex was found to be damaged in 25% of the threshed seed. Eighty-five percent of the germinants from undamaged seed had positive geotropism as compared to 53% from the damaged seed. The latter had a range of anatomical aberrations in which the root cap was missing or seriously abnormal. It is concluded that the standard method of hammer mill threshing of winterfat fruits results in 25% of the seed sustaining damage to the radicle apex. This damage causes a loss of root cap functions, particularly the sensing of gravity. It is recommended that plantings be made by broadcasting whole fruits, rather than by drilling threshed seed.
    • Effects of Livestock Grazing on Infiltration Rates, Edwards Plateau of Texas

      McCalla, G. R.; Blackburn, W. H.; Merrill, L. B. (Society for Range Management, 1984-05-01)
      The influence of short duration grazing (SDG), moderate continuous grazing (MCG), heavy continuous grazing (HCG), and grazing exclusion on infiltration rates of midgrass and shortgrass-dominated communities was evaluated over a 20-month period on the Texas Agricultural Research Station, located near Sonora in the Edwards Plateau, Texas. A combination of cattle, sheep, and goats were used in each grazing treatment. Infiltration rates were consistently less in the midgrass (bunchgrass) than in the shortgrass (sodgrass) community. The HCG pasture was severely overgrazed and infiltration rates were reduced to about one-half those in the MCG pasture. The midgrasses in this pasture were destroyed after 26 months of overgrazing. Infiltration rates in the SDG pasture, stocked at double the recommended rate, decreased during the study period. Infiltration rates in the SDG pasture shortgrass community, near the end of the study, approached those in the HCG pasture. The greatest infiltration rates for both communities were maintained in the MCG pasture. Infiltration rates for the midgrass community remained relatively stable during the study when the general trend in the SDG and HCG pastures was toward reduced infiltration rates. The nongrazed pasture subsequent to the 1980 drought had a general increase in infiltration rates.
    • Ecophysiological Studies of Eleusine indica (L.) Gaertn. and Sporobolus pyramidalis P. Beauv. at Ibadan, Nigeria

      Sharma, B. M. (Society for Range Management, 1984-05-01)
      Eleusine indica and Sporobolus pyramidalis are common grasses in the tropics, including Ibadan, Nigeria. The former is considered a good fodder when young, but the latter has low grazing quality. The objective of this study was to describe some of the morphological characteristics of these 2 prominent species. S. pyramidalis is a taller grass having more roots per culm and a longer inflorescence. Seeds of the 2 grasses germinated between 20 degrees C and 35 degrees C and emergence declined with increasing depth until it was zero at and 4 cm for E. indica and S. pyramidalis, respectively. S. pyramidalis had a higher rate of germination. The 2 species have stomata on both leaf surfaces, but the number is greater on the adaxial surface. Experiments indicate that E. indica is more tolerant and adaptable to biotic disturbances. The biomass contribution by E. indica and S. pyramidalis is estimated at 1,100 kg/ha 300 kg/ha, respectively.
    • Effects of Planting Depth and Soil Texture on the Emergence of Four Lovegrasses

      Cox, J. R.; Martin, M. H. (Society for Range Management, 1984-05-01)
      We studied the emergence of 4 lovegrass accessions planted at 0.0, 0.5, 1.0, 1.5, and 2.0 cm depths in Pima silty clay loam, Sonoita silty clay loam, and Comoro sandy loam soils in a greenhouse. Catalina boer lovegrass (Eragrostis curvula var. conferta Nees) emergence was superior to A-84 boer lovegrass, A-68 Lehmann lovegrass (Eragrostis lehmanniana Nees) and Cochise lovegrass (Eragrostis lehmanniana Nees X E. trichophera Coss & Dur.) in all soils and at all depths. Approximately 75% of the radicles of germinating Lehmann and A-84 boer lovegrass seeds failed to penetrate the surface of the 3 soils when surface sown. Lehmann lovegrass seed planted below the surface failed to emerge in the 3 soils.