• Decomposition of Common Curlymesquite Herbage on Edwards Plateau Rangeland, Texas

      George, J. F.; Smeins, F. E. (Society for Range Management, 1982-01-01)
      Decomposition of common curlymesquite herbage from a continuously, heavily grazed pasture and one pasture of a 4-pasture deferred rotation grazing system was investigated on the Edwards Plateau of Texas. Decomposition of herbage in litterbags was similar for both pastures. Approximately 40% of the original herbage weight was lost during the 345-day study. Average decomposition rate was 2.19 mg/g/day. Rate of decomposition during a 238-day period was significantly related to antecedent potential evaporation and precipitation since the preceding collection date and cumulative time. Percentage nitrogen and percentage ash content increased while percentage carbon and carbon/nitrogen ratio decreased over time in the decomposing herbage.
    • Defoliation Impacts on Quality and Quantity of Forage Harvested from Big Sacaton (Sporobolus wrightii Munro)

      Haferkamp, M. R. (Society for Range Management, 1982-01-01)
      Forage quality and quantity and stand vigor of big sacaton were evaluated for seven defoliation systems during 1977 and 1978. Big sacaton plants were either shredded monthly, shredded in spring/midsummer, spring/early summer, spring, spring/late summer/fall, midsummer/fall, or late winter. Forage quality of big sacaton was improved by defoliation during both years. With few exceptions, crude protein content was highest in plants defoliated the previous month. IVDOM contents were also improved by defoliation. Digestibility decreased to below 50% in early summer in nonshredded plants and in mid summer in all plants regardless of prior defoliation treatment. IVDOM increased to above 50% in late summer and fall in plots defoliated the previous month. Forage harvests during the growing season were greatest from plots that were defoliated three or more times and were defoliated in the fall. The least amounts of forage were harvested from the plots defoliated in spring, spring/early summer and spring/midsummer. In the fall and winter the nonshredded and spring defoliated plots supported relatively large amounts of forage, and the spring/early summer and spring/midsummer plots supported intermediate amounts of forage for winter grazing. Stand vigor was maintained best by brief periods of defoliation in the spring or spring/early summer, followed by defoliation of old forage in late winter. Vigor appeared to be decreased by early fall defoliations to a 7.5 cm stubble height. The spring/early-summer system provided large amounts of high quality forage and maintained stand vigor. This system defoliated plants when soil moisture was usually adequate for plant regrowth, provided nutritious forage during the growing season and provided adequate standing forage for fall and winter grazing and protection against damage due to low temperature.
    • Dietary Overlap between Sheep, Cattle, and Goats When Grazing in Common

      Squires, V. R. (Society for Range Management, 1982-01-01)
      The chemical and botanical composition of the diets of esophageally fistulated sheep, cattle, and goats was monitored over a period of 1 year at intervals of approximately 2 months. The animals were grazing together in a poplar box (Eucalyptus populnea) woodland community with an understory of shrubs, chiefly Cassia and Eremophila spp., and an herbaceous field layer of grasses and forbs. Diet quality, as assessed by in vitro digestibility, was highest for sheep in all seasons. The degree of dietary overlap, and hence potential competition, was greatest between goats and cattle. Both goats and cattle had a high proportion of browse plants in their diets. Discussion centres on the degree of overlap in the diets and the complementarity of grazing under common-use.
    • Effect of Range Condition on the Diet and Performance of Steers Grazing Native Sandhills Range in Nebraska

      Powell, D. J.; Clanton, D. C.; Nichols, J. T. (Society for Range Management, 1982-01-01)
      Two areas of native Sandhills range were used to determine the effect of range condition on the quality of diet and performance of grazing steers. Pasture 1 was in high good-excellent condition (75%), pasture 2 was in low good condition (58%). Pastures were stocked according to recommended rates. At the end of the grazing trial, utilization was full (54%) for both pastures. The grazing trial was continuous from June 1 to September 22, 1978. Three 2-year-old esophageal fistulated and 3 intact yearling steers were used in each pasture for diet and fecal collections during a 5-day-period once each month. Ten Hereford yearling steers were used to measure weight gains in each pasture. Diet samples were analyzed for in vitro organic matter digestibility (IVOMD) and crude protein (CP). Fecal production divided by indigestibility was used to predict intake. IVOMD was 58.6 and 63.4% and CP was 10.2 and 9.4% for pasture 1 and 2, respectively. Differences were not significant (P<.05). IVOMD and CP declined (P<.01) from period 1 through period 4 in both pastures. IVOMD decreased (P<.05) more during the grazing trial in pasture 1 (high good-excellent condition) than pasture 2 (low good condition). Organic matter intake (OMI) was lower (P<.05) for pasture 1 (74 g/kg W^.75) than for pasture 2 (83 g/kg W^.75). OMI was lower (P<.05) in period 4 than in previous periods. OMI was not different (P>.05) between fistulated and intact steers. Average daily gains (.78 and .72 kg) per day for pastures 1 and 2, respectively were not different (P>.05).
    • Effects of Two Years of Irrigation on Revegetation of Coal Surface-Mined Land in Southeastern Montana

      Depuit, E. J.; Skilbred, C. L.; Coenenberg, J. G. (Society for Range Management, 1982-01-01)
      Responses of reseeded vegetation in the first two growing seasons (1978 and 1979) to irrigation on topsoiled sodic mine spoils are presented. In terms of above-ground productivity and stand composition, irrigation significantly promoted growth of seeded perennial grasses and legumes in total. This stimulation was most pronounced in 1979 for the cool-season grasses, slender wheatgrass, smooth bromegrass and western wheatgrass and the invading cool-season legume yellow sweetclover. Other cool-season grasses and warm-season grasses were stimulated by initial irrigation, but were either unaffected or retarded (due to competitive relationships) by continued irrigation. Productivity of invading annual weeds was significantly curtailed by irrigation by 1979. Although differences in composition occurred, total stand productivity was similar for irrigated and nonirrigated plots in 1978, a year of above-average precipitation. In 1979, a drier year, total stand productivity was nearly three times higher under irrigation than nonirrigation. In the first year of study (1978), a higher measured index of stand structural diversity occurred under irrigation. This relationship became reversed in 1979, with higher structural diversity in nonirrigated plots. Root biomass was significantly higher in nonirrigated than in irrigated plots. This difference between irrigation and nonirrigation was most pronounced in the applied topsoil zone. Root distribution was skewed towards shallowest soil depths under irrigation to a far greater extent than under nonirrigation.
    • Energy Biomass from Large Rangeland Shrubs of the Intermountain United States

      Van Epps, G. A.; Barker, J. R.; McKell, C. M. (Society for Range Management, 1982-01-01)
      Large individual plants within a few species of rangeland shrubs were studied in several Intermountain States for their potential use in establishing biomass fuel energy plantations. Their locations were based on reports in the literature, suggestions from various range researchers, and personal knowledge. Biomass and other shrub physical characteristics plus site data were recorded for big sagebrush (Artemisia tridentata), fourwing saltbush (Atriplex canescens), big saltbush (A. lentiformis), greasewood (Sarcobatus vermiculatus), rubber rabbitbrush (Chrysothamnus nauseosus), and spreading rabbitbrush (C. linifolius) in 34 locations. Samples of current year's growth and woody tissue were analyzed for burning qualities (heat of combustion, sulfur, moisture, and ash content). Greatest biomass per plant of the individuals sampled was found in greasewood with fourwing saltbush, rubber rabbitbrush, and sagebrush following in decreasing order. Burning qualities varied among the species analyzed. The heat of combustion of the woody material from all shrubs was approximately 4500 Kcal/kg, but current year's growth varied considerably among species.
    • Fertilization of a Native Grassland in the 'Depresion del Rio Salado', Province of Buenos Aires: Herbage Dry Matter Accumulation and Botanical Composition

      Ginzo, H. D.; Collantes, M.; Caso, O. H. (Society for Range Management, 1982-01-01)
      The objective of this study was the evaluation of herbage production and botanical composition of a native grassland, ("flechillar"), of the Salado River Basin fertilized, during 3 years, with 0, 381, or 762 kg ha-1 yr-1 of ammonium sulphate alone or combined with 0 or 208 kg ha-1 yr-1 of triple superphosphate. Annual dry matter accumulation of herbage, (ADMA), was restricted by a negative water-balance in the soil during the first experimental year. A linear response to ammonium sulphate rate, irrespective of triple superphosphate, was observed. In the following years the relationship between ADMA and ammonium sulphate became progressively quadratic, and it was manifest firstly in the plots fertilized with superphosphate. The response to superphosphate seemed to be due to an environmentally stimulated growth demand more than to a phosphorus deficiency in the soil. Ammonium sulphate promoted the growth of graminoids and decreased that of legumes and forbs. Superphosphate increased the proportion of legumes and ameliorated the detrimental effect of ammonium sulphate, but only few species reflected the effect of fertilization. Because (a) the sward reacted remarkably to the addition of a nitrogenous fertilizer, and (b) its main legume species, Medicago polymorpha, (annual), was scarce, it is suggested that the sward's herbage production could be substantially increased by its enrichment with perennial legumes provided that their growth and expansion were assisted by periodic additions of a phosphorous fertilizer.
    • Fertilizer Effects on Above- and Below-Ground Biomass of Four Species

      Holechek, J. L. (Society for Range Management, 1982-01-01)
      Research was conducted in a greenhouse at Bozeman, Montana, and on coal mine spoils at Colstrip, Montana, in 1975 to determine production characteristics of four species when nitrogen and phosphorus fertilizer was applied at a low rate and when not applied. Aboveground biomass, belowground biomass, and the root to shoot ratio of fairway crested wheatgrass (Agropyron cristatum), critana thickspike wheatgrass (Agropyron dasystachyum), and fourwing saltbush (Atriplex canescens) were increased by fertilizer application. Root depths of crested and thickspike wheatgrass were increased by fertilizer application. Ranger alfalfa (Medicago sativa) responded differently to fertilizer application in the greenhouse and field experiments. Crested wheatgrass had a higher root to shoot ratio than the other three species when fertilizer was not applied. This may explain why this species has been successful in the Northern Great Plains.
    • Forage Good Enough for Cattle Production: When!

      Beaty, E. R.; Calvert, G. V.; Engel, J. E. (Society for Range Management, 1982-01-01)
    • Growth Response of Two Saltbush Species to Nitrate, Ammonium and Urea Nitrogen Added to Processed Oil Shale

      Richardson, S. G.; McKell, C. M. (Society for Range Management, 1982-01-01)
      Nitrate nitrogen promoted good growth of cuneate saltbush (Atriplex cuneata) and gardner saltbush (A. gardneri) on processed oil shale in a glasshouse pot experiment, but ammonium and urea nitrogen were not utilized effectively in growth.
    • Identification of Subspecies of Big Sagebrush by Ultraviolet Spectrophotometry

      Shumar, M. L.; Anderson, J. E.; Reynolds, T. D. (Society for Range Management, 1982-01-01)
      The three subspecies of big sagebrush (Artemisia tridentata) are dominant shrubs over much of the Intermountain West. Because the subspecies differ in palatability and habitat requirements, researchers and resource managers have become increasingly concerned with their identification. Subspecies have been identified by leaf morphology, ultraviolet (UV) fluorescence, or chromatography. Fluorescence of leaf extracts under short-wave UV light provides a convenient technique for distinguishing between A.t. vaseyana and the other two subspecies, but this technique will not distinguish between A.t. tridentata and A.t. wyomingensis. Chromatographic techniques can differentiate between all of the subspecies, but the methods are tedious. We describe a technique for distinguishing all three subspecies by UV spectrophotometry. Alcohol leaf extracts of the three subspecies produce relative absorbance graphs that differ markedly from one another between 230 and 280 nm.
    • Leaf Water Potentials of Perennial Grasses—Leaf Press and Pressure Chamber Evaluation

      Cox, J. R.; Hughes, H. G. (Society for Range Management, 1982-01-01)
      The leaf water potentials of blue grama [Bouteloua gracilis (H.B.K.) Griffiths] and western wheatgrass (Agropyron smithii Rydb.) transplants were measured using a pressure chamber and a leaf press. Combined water potentials for both species ranged from -5.34 to -26.05 bars for the pressure chamber and -5.52 to -16.24 bars for the leaf press. Trends between the to methods were more consistent for blue grama. Generally, large increases in leaf water potential measured with the pressure chamber were measured as small changes with the leaf press.
    • Long-Term Effects of Fertilization and Subclover Seeding on Northern California Annual Range

      Vaughn, C. E.; Murphy, A. H. (Society for Range Management, 1982-01-01)
      The long-term effects of P and S fertilizers and subclover seeding on northern California annual range production and composition were measured during a 20-year study. Following an initial calibration period, two pastures were seeded and fertilized; pasture A prior to the 1968 growing season and pasture B prior to the 1973 growing season. After treatment pasture A produced significantly more forage annually. It also produced significantly more winter forage, and winter and annual forage N than either of two adjacent untreated control pastures during the period from 1973 to 1979. This was due primarily to an increase in native legumes because subclover averaged only 7% of cover. Treatment on pasture B gave similar responses, but the relative increases in forage production were larger (annual production increased about 2,000 kg/ha compared to 1,200 kg/ha on pasture A), and winter forage N concentrations were significantly higher than on pasture A. This was due to the greater subclover component (36%) on pasture B. The significant increases in forage production and protein indicate that subclover seeding and appropriate fertilization are practical ways of improving utilization of northern California annual range.
    • Monoterpenoid Content of Pygmy Rabbit Stomach Ingesta

      White, S. M.; Welch, B. L.; Flinders, J. T. (Society for Range Management, 1982-01-01)
      During mid-January 1979, ingesta samples were collected from the stomachs of ten wild pygmy rabbits. The ingesta samples were analyzed for big sagebrush and monoterpenoid content. Big sagebrush comprised 97% of the material in the ingesta and was the only forage containing monoterpenoids. Monoterpenoid content of the ingesta was only 23% of expected levels. This major loss (77%) of monoterpenoids may occur during mastication. Loss of monoterpenoids from mastication by pygmy rabbits was measured in an airtight rabbit chamber. Twelve times more monoterpenoids were recovered during the rabbit feeding trials (big sagebrush and rabbit) than during the control tests (big sagebrush only).
    • Nitro Compounds in Introduced Astragalus Species

      Williams, M. C.; Davis, A. M. (Society for Range Management, 1982-01-01)
      Leaves of foreign Astragalus species were examined for the presence and type of poisonous aliphatic nitro compounds. Twenty-two (24%) of the 92 species examined tested positive for nitro compounds and 70 (76%) tested negative. Three nitro-bearing species, Astragalus bodeanus Fisch., Astragalus isfahanicus Boiss., and Astragalus siliquosus Boiss. synthesized 3-nitro-1-propanol (3-NPOH). The other nitro-bearing species synthesized 3-nitropropionic acid (3-NPA). Ten taxonomic sections had a high percentage of nitro-bearing species. Chemotaxonomic relationships in Astragalus suggest that most, if not all, of the other species in these 10 sections would synthesize nitro compounds.
    • Preliminary Study of Some Insects Associated with Rangeland Shrubs with Emphasis on Kochia prostrata

      Moore, T. Blaine; Stevens, Richards; McArthur, E. Durant (Society for Range Management, 1982-01-01)
      The introduced and potentially useful range shrub Kochia prostrata (prostrate kochia) and its naturalized herbaceous congener K. scoparia (annual kochia) both appear to be excellent hosts for the lygus bug (Lygus desertinus). However, lygus bugs were abundant only on concentrated Kochia stands and not on K. prostrata growing intermixed with other plant species. Therefore, it is recommended that prostrate kochia be planted in mixtures with other plant species in range rehabilitation projects so that high insect populations are not encouraged. Lygus bugs spend much of the summer on both Kochia species but move to associated plants when the associates flower. Although lygus bugs were found in abundance on prostrate kochia, no major damage to the plant was evident. Prostrate kochia apparently is not the overwintering egg host-plant for lygus bugs. On prostrate kochia, seven other identified insect species (six families) as well as several unidentified taxa were also collected. These additional species were mostly short-time residents in low numbers. Flea beetles (Psylloides punctulata) were occasionally abundant.
    • Prescribed Burning during Winter for Maintenance of Buffelgrass

      Hamilton, W. T.; Scifres, C. J. (Society for Range Management, 1982-01-01)
      Neither a single burn during late winter nor a second burn 2 years later reduced the density of mixed brush dominated by blackbrush acacia, honey mesquite, and twisted acacia which had invaded buffelgrass seedings on the South Texas Plains. Based on canopy cover and height, most woody species had recovered to preburn status after two growing seasons. Buffelgrass responded by a flush of spring growth during the year of burning and cumulative herbage production exceeded that of unburned areas for three growing seasons after the single burn. However, during dry growing conditions, less buffelgrass herbage was produced on burned than on unburned areas. A second burn tended to increase buffelgrass herbage production compared to the single burn. However, when moisture became limiting, less herbage was also produced on the twice-burned areas. Disappearance of buffelgrass, attributed primarily to grazing, closely paralleled herbage production, with the greatest disappearance occurring the first growing season after the burn.
    • Rangeland Management and the Environment

      Baumer, M. (Society for Range Management, 1982-01-01)
      Management of the rangelands of the world for multiple use is a complicated process. Rangeland productivity can be increased by several means. However, some of these means have undesirable ecological consequences. There is a need for integration of range ecosystems management on a world-wide scale under an ecological framework.
    • Reseeding by Eight Alfalfa Populations in a Semiarid Pasture

      Rumbaugh, M. D. (Society for Range Management, 1982-01-01)
      Eight alfalfa populations were seeded in a dryland pasture in northern Utah. Densities of mature plants, seeds, seedlings, and 1-year-old plants were measured in each of 3 years. The populations did not differ for mature plant stands or seed production. There was a higher rate of seedling survival for populations that primarily originated from Medicago sativa rather than M. falcata. All populations had some one-year-old plants persisting to replace mature plants killed by disease or rodents.