• Moisture Interception as a Factor in the Competitive Ability of Bluebunch Wheatgrass

      Ndawula-Senyimba, M. S.; Brink, V. C.; McLean, A. (Society for Range Management, 1971-05-01)
      Aerial parts of the caespitose type of bluebunch wheatgrass (Agropyron spicatum) have been shown to direct rainwater and to concentrate it in the soil immediately beneath individual plants. The degree to which water collects beneath the bunches appeared to be related to the size of the canopy. It is possible that the rapid decline of bluebunch wheatgrass under heavy grazing is related to soil moisture redistribution caused by the removal of its aerial parts.
    • Mineral Composition of Native and Introduced Clovers

      Hamilton, J. W.; Gilbert, C. S. (Society for Range Management, 1971-07-01)
      Samples of seven native and four introduced clovers were collected from widely scattered areas in Wyoming and southern Montana. Most of the samples were collected at bloom stage during two successive growing seasons. The levels of calcium, phosphorus, magnesium, sodium, potassium, sulfur, colbalt, copper, iron, manganese, molybdenum and zinc in these plants were measured. Levels of calcium were fairly high and extremely variable, ranging from 1.12 to 5.74%. Magnesium contents were quite variable with a range of 0.22 to 0.97%. Considerable variation in the levels of cobalt, range 0.09 to 1.75 ppm, exists and there were indications of species differences in accumulating ability under identical conditions. Copper accumulating capacity apparently varies from species to species and appears to be in direct contrast to cobalt accumulating ability. The range of copper was 7.0 to 49.5 ppm. Iron varied over a wide range with some unexpected high values. The levels of iron varied from 222 to 3329 ppm. Contents of manganese ranged from 39 to 250 ppm with higher levels being found in samples of alsike and white clover from the mud volcano areas of Yellowstone National Park. Amounts of mineral elements present in the clover samples were high enough to provide an adequate plane of nutrition for consuming livestock and wild game.
    • Mesquite Twig Girdler: A Possible Means of Mesquite Control

      Ueckert, D. N.; Polk, K. L.; Ward, C. R. (Society for Range Management, 1971-03-01)
      The mesquite twig girdler (Oncideres rhodosticta Bates) was found to inflict considerable damage to mesquite in Texas and may prove to be a valuable biological control agent for this noxious species. Preliminary observations in infested areas indicated that about 90 percent of the mesquite trees had been attacked by the girdler and that about 40 percent of all branches from 0.5 to 2.0 cm in diameter had been girdled.
    • Measuring Vegetation Changes on Fixed Quadrats by Vertical Ground Stereophotography

      Wells, K. F. (Society for Range Management, 1971-05-01)
      A photographic technique for recording changes in vegetation on small fixed quadrats has been modified and improved. Two 35 mm cameras fired simultaneously are used instead of one to take stereophotographs. Transparencies are viewed directly by transmitted light under a zoom stereoscope and plant cover measured by point counts made on the photographs with the aid of a counter connected to an electrically operated stage. Assessment of species composition and herbage weight is also possible from the photographs which themselves form a permanent record of vegetation on the quadrats.
    • Measurement of Seasonal Air Temperatures Near the Soil Surfaces

      Fowler, W. B. (Society for Range Management, 1971-03-01)
      A study of the maximum air temperature near the soil surface at 11 grassland locations was made during the summer of 1968 using a simple maximum temperature indicator. Maximum temperatures within the first centimeter above the soil were found to exceed 144 F on a number of these locations. Although the range of indicators was not large enough to include the extremes at all locations, a seasonal pattern was identifiable. Large local differences in near-surface temperatures were frequently observed.
    • Longevity of Buffel Grass Seed Sown in an Arid Australian Range

      Winkworth, R. E. (Society for Range Management, 1971-03-01)
      Three sets of buffel grass seed with germination percentages of 0.8, 35 and 94 were sown in a spinifex grassland near Alice Springs, N.T., at a depth of 2.5 cm. Replicated batches were recoverd from each set at increasing intervals and their germinability compared to seed kept in laboratory storage. All seed lost dormancy progressively, more rapidly in soil than storage. In the soil natural death of non-dormant seeds was probably concurrent with loss of dormancy, the balance leading eventually to small germination percentages. Values of about 10% were obtained 2-4 years after sowing, the seed with highest germinability at sowing having the shortest span. In storage germination percentages remained above 60. Range seeding of adapted varieties of buffel grass in arid regions with infrequent establishment periods can be attempted with confidence in seed longevity.
    • Long-Term Grazing Effects on Fescue Grassland Soils

      Johnston, A.; Dormaar, J. F.; Smoliak, S. (Society for Range Management, 1971-05-01)
      Very heavy grazing of fescue grassland range at Stavely, Alberta, compared to light grazing, changed the color of the Ah horizon from black to dark brown and the pH from 5.7 to 6.2, reduced the percent organic matter, reduced percent total P but increased NaHCO3-soluble P, and increased soil temperature but decreased percent soil moisture. Trends indicated that soil of the very heavily grazed field was being transformed to a soil characteristic of a drier microclimate.
    • Limits on Western Range Forage Production—Water or Man

      Keller, W. (Society for Range Management, 1971-07-01)
      Water is generally regarded as the limiting factor in forage production on arid rangeland. If 800 lb. is taken as the water requirement for a pound of range forage, 12 inches as the average precipitation, and 400 lb. as the average forage production/acre, only 12.5% of the precipitation, or 1.5 inches, is used in producing the forage crop. If we estimate that in addition, 1/2 inch is lost to deep percolation, 1 inch to over-the-surface runoff, and 1 inch to undesirable vegetation, we account for 4 inches. Thus, the remainder, two-thirds of the total precipitation, is lost by evaporation, without benefit to man. The importance of the resource lost by evaporation is discussed in relation to the potential productivity of arid lands.
    • Light Delays Germination of Alkali Sacaton

      Knipe, O. D. (Society for Range Management, 1971-03-01)
      Exposure of alkali sacaton seeds to light for a few seconds after imbibition delayed germination 24 hr, exposure for 9 to 13 hr delayed germination 28 hr, exposure for more than 13 hr delayed germination 72 hr, and continuous exposure reduced germination 40%.
    • Lehmann Lovegrass on the Santa Rita Experimental Range, 1937-1968

      Cable, D. R. (Society for Range Management, 1971-01-01)
      Thirty years' experience shows that Lehmann lovegrass readily establishes itself from seed under adverse conditions, reseeds itself quickly after fire or other disturbance, can withstand heavy continuous yearlong grazing, and can invade established stands of velvet mesquite. However, it is less palatable than native perennial grasses during the summer growing season, and has almost completely replaced the native perennial grasses on and adjacent to seeded areas within its preferred range./Los estudios se llevaron a cabo en la estación experimental de Santa Rita cerca de Tucson, Arizona, EUA. Se encontró después de 30 años de observaciones que el zacate Lehmann Lovegrass (Eragrostis lehmanniana Nees A-68) tiene buena adaptación a las zonas de 1,100 a 1,500 metros de altura y que tengan precipitación pluvial de 225 a 325 mm. Las siguientes ventajas y desventajas fueron encontradas: 1) Existe menor palatabilidad del zacate en el verano y mayor en el invierno que los zacates nativos. 2) El forraje seco dura mas que los nativos de un año a otro por lo tanto su uso es ventajoso para sequías. 3) Es muy agresivo ya que puede reemplazar las especies nativas e invadir montes de mezquite y tierra quemada. 4) Puede resistir el pastoreo pesado y continuado por todo el año.
    • Larger Pits Aid Reseeding of Semidesert Rangeland

      Slayback, R. D.; Cable, D. R. (Society for Range Management, 1970-09-01)
      Broad, shallow intermediate pits have proved to be longer lasting than conventional pits on semidesert range in the 6- to 8-inch summer rainfall zone in southern Arizona. Rainfall penetration averaged twice as deep in the pits as on adjacent flats. Herbage production of buffelgrass averaged 2 1/2 times as high, over a 4-year period, on the intermediate pits as on conventional pits, and five times as much as on similar adjacent untreated range.
    • Large Seeds Produce More, Better Alkali Sacaton Plants

      Knipe, O. D. (Society for Range Management, 1970-09-01)
      Larger seeds of alkali sacaton germinated better and faster than the smaller sizes. Seedlings from larger seeds emerged from deeper depths and had a higher growth rate.
    • Land Management Policy and Development of Ecological Concepts

      Jameson, D. A. (Society for Range Management, 1970-09-01)
      As ecological concepts become incorporated into the training and background information of professional land managers, they also become incorporated into land management policies. Recent developments in ecology, such as nutrient cycling studies and computer simulation of complex processes, have a favorable climate for acceptance. Possible applications should be carefully studied by land managers.
    • Lana Vetch for Medusahead Control

      Mac Laughlan, R. S.; Miller, H. W.; Hoglund, O. K. (Society for Range Management, 1970-09-01)
      Medusahead is invading California and western Oregon rangeland at an alarming rate. Overseeding with Lana vetch, a self-perpetuating annual legume, appears to be one of the most practical controls. Because Lana vetch can be successfully established without seedbed preparation it offers a practical method of controlling medusahead on rough terrain. Increased production and improved quality of forage from infested annual grass range are the result.
    • Influence of Site on Mesquite Mortality from 2,4,5-T

      Dahl, B. E.; Wadley, R. B.; George, M. R.; Talbot, J. L. (Society for Range Management, 1971-05-01)
      Soil temperature at the 18-inch depth was the most important factor affecting response of honey mesquite to 2,4,5-T application. Temperatures at this depth in the high 60's F or low 70's F resulted in no mesquite kills with the best results obtained if temperatures were over 80 F. Phenological development was essentially as important with plants having mature leaves and seed pods being easiest to kill. Trees with small and blooming spikes and those without flowers or pods were hardest to kill with 2,4,5-T. Other variables usually considered important, such as soil moisture, were important only in combination with other variables. Mesquite trees growing on upland and sandy sites are apparently more susceptible to 2,4,5-T largely because the soil is usually several degrees F warmer than bottomland and clay sites.
    • Influence of Secondary Succession on Honey Mesquite Invasion in North Texas

      Scifres, C. J.; Brock, J. H.; Hahn, R. R. (Society for Range Management, 1971-05-01)
      Quantitative vegetational relationships are reported for an exclosure protected from domestic livestock since 1941. Only 14 percent of the honey mesquite (Prosopis glandulosa Torr. var. glandulosa) stand recorded in 1941 remained in 1968. Age estimation indicated that no honey mesquite plants established after 1959. Average height of surviving honey mesquite plants was 0.5 m. Herbaceous vegetation within the exclosure is presently dominated by tobosa (Hilaria mutica (Buckl.) Benth.), buffalograss (Buchloe dactyloides (Nutt.) Englem.) and vine-mesquite (Panicum obtusum H.B.K.). An adjacent, grazed area where the honey mesquite has been removed by hand periodically during the last 27 years is dominated by annual herbs and tobosa./El estudio se llevó a cabo en la estación experimental de la Universidad de Texas A & M cerca de Spur, Texas, E.U.A. Se encontró que el número de plantas de mezquite (Prosopis glandulosa Torr. var. glandulosa), dentro de una exclusión protegida de pastoreo desde el año 1941, fué solo 14% del número original. Conforme los análisis de edad de los árboles de mezquite, no hubo plantas nuevas desde el año de 1959. Los zacates buenos aumentaron en abundancia y es posible que su competencia impidiera el establecimiento de plantas nuevas de mezquite.
    • Influence of Rootplowing and Seeding on Composition and Forage Production of Native Grasses

      Mathis, G. W.; Kothmann, M. M.; Waldrip, W. J. (Society for Range Management, 1971-01-01)
      Effects of rootplowing, with or without seeding, on forage production and composition of native grasses were determined on a deep upland range site. Percent composition of stoloniferous species, particularly buffalograss, was reduced initially and after 6 growing seasons by the rootplowing treatments. Frequency counts indicated a reduction of Texas wintergrass on rootplowed plots (seeded and nonseeded) compared to an undisturbed, native check area. This reduction the first growing season was attributed to the competitive effect of sorghum almum introduced in the seeding mixture. Unsuccessful establishment of other seeded grasses (sideoats grama and switchgrass) appeared to be related to poor seedbed preparation, competition from sorghum almum plants, and below normal rainfall immediately after seeding. Rootplowing decreased grass production. After 6 growing seasons, significantly less forage per acre was produced on rootplowed-seeded plots than on nonrootplowed plots. Differences in forage production were related to plant composition and density. /// El estudio fué empezado en el año de 1964 en el rancho experimental de Texas en el Municipio de Throckmorton; el diseño incluyó testigo; y se pasó arado para desenraizar sin la siembra y se pasó arado para desenraizar con la siembra. Después de 6 años los dos tratamientos disminuyeron la producción de forraje y composición de zacates deseables. El zacate sorghum almum (Sorghum almum) apareció en la siembra. El arado desenraizador controló el mezquite (Prosopis glandulosa var. glandulosa).
    • Infiltration and Erosion Studies on Pinyon-Juniper Conversion Sites in Southern Utah

      Gifford, G. F.; Williams, G.; Coltharp, G. B. (Society for Range Management, 1970-11-01)
      Infiltration and sediment data from small-plot studies (325 infiltrometer plots) utilizing high intensity simulated rainfall indicate that areas cleared of pinyon-juniper trees and seeded to grass in southern Utah generally show no consistent decrease or increase in sediment yields or infiltration rates at a given point. Of 14 sites studied, four indicated decreased infiltration rates and two indicated increased infiltration rates during one or more time intervals at specific points on the treated areas; one site had significantly less sediment yield and two sites had significantly higher sediment yields from points on the treated areas. These results nearly parallel those obtained during similar studies of 14 pinyon-juniper sites in central Utah.
    • Increasing Utilization of Weeping Lovegrass By Burning

      Klett, W. E.; Hollingsworth, D.; Schuster, J. L. (Society for Range Management, 1971-01-01)
      Burning increases the production and cattle preference of weeping lovegrass. A winter burn increased spring and summer herbage yields of weeping lovegrass 14% and utilization 53%. Burning increased crude protein from 3.6% on untreated lovegrass to 7.6% on unfertilized burned plots. It increased crude protein content from 5% on unburned fertilized plots to 10.5% on burned fertilized plots. Forty-four pounds per acre nitrogen fertilization increased crude protein but had little effect on forage production and utilization. /// Weeping lovegrass (Eragrostis curvula (Schrad.) Nees) tiene buena adaptación a varios climas y suelos, especialmente suelos arenosos. Este zacate tiene menor palatabilidad. Este estudio se llevó a cabo en la granja experimental de Texas Tech cerca de Amarillo, Texas, E.U.A., se demostró que puede aumentar la palatabilidad del zacate con quema. La quema durante invierno aumentó la producción de forraje en un 14%, la intensidad de pastoreo en un 53%, y el contenido de proteína en un 3.4%. La fertilización de nitrógene a 44 Kgs/Ha. aumentó el contenido de proteína pero no influyó en la producción de forraje ni en la palatabilidad del zacate.
    • In Vitro Digestibility of Native Grass Hay

      Karn, J. F.; Clanton, D. C.; Rittenhouse, L. R. (Society for Range Management, 1971-03-01)
      Method of storage had a greater effect on the in vitro dry matter digestibility (DMD) of native grass hay than either storage time or date of cutting. The nutritive value of native hay was maintained better by storing it in round bales than by storing it in windrows, bunches or letting it remain standing. The first 60 days in storage was the period when native hay had the greatest loss of nutritive value regardless of storage method. There was an interaction of cutting date and year on DMD. The early cut hay in 1962 had a higher DMD (42.7%) than the late cut hay (40.3%). There was no difference in 1963 (40.6 vs. 40.1%).