• 14 Years of Rabbitbrush Control in Central Oregon

      Mohan, J. M. (Society for Range Management, 1973-11-01)
      Fourteen years (1956 to 1970) of chemical control for rubber and green rabbitbrush using the ester forms of 2,4-D produced consistent control, ranging from 85 to 98% on rubber rabbitbrush. The amount of new twig growth, soil moisture, rate and methods of application, total seasonal twig growth, and subsequent drought conditions proved critical for effective kills. Selective kills were achieved by manipulation of these factors. Site potential and response to changes that result from chemical control must be recognized. "Drainage Effect" is a complex of thermal drafts, topography, and soil differences that can adversely influence the percentage of rabbitbrush control achieved.
    • 14- Vs. 42-Paddock Rotational Grazing: Aboveground Biomass Dynamics, Forage Production, and Harvest Efficiency

      Heitschmidt, R. K.; Dowhower, S. L.; Walker, J. W. (Society for Range Management, 1987-05-01)
      Research was initiated at the Texas Experimental Ranch in 1981 to quantify the effects of 2 stocking densities, equivalent to 14- and 42-paddock rotational grazing (RG) treatments, on aboveground biomass dynamics, aboveground net primary production (ANPP), and harvest efficiency of forage. Baseline data were collected in 1981 from 3 adjacent 30-ha paddocks in a 14-paddock, cell designed RG treatment. Near the beginning of the 1982 growing season the center paddock was subdivided into three, 10-ha paddocks to establish the RG-42 treatment. Stocking densities in the 14- and 42-paddock treatments were 4.2 and 12.5 AU/ha, respectively, from March 1982 to June 1984 and 3.0 and 9.1 AU/ha from June to November 1984. During 1981, estimated ANPP in the two RG-14 paddocks averaged 4,088 kg/ha as compared to 5,762 in the single RG-42 paddock. Following subdivision, ANPP in the RG-14 paddocks averaged 2,533 kg/ha as compared to 2,670 kg/ha in the RG-42 paddocks. Although ANPP varied significantly among the 4 years of the study it was not affected by density treatment. Likewise, harvest efficiency varied among years but was unaffected by density treatment. Average harvest efficiency over the 4 years was about 42%. Aboveground biomass dynamics were also generally unaffected by density treatments.
    • 14- Vs. 42-Paddock Rotational Grazing: Forage Quality

      Heitschmidt, R. K.; Dowhower, S. L.; Walker, J. W. (Society for Range Management, 1987-07-01)
      Research was initiated at the Texas Experimental Ranch in 1981 to quantify the effects of 2 livestock densities on forage quality in a rotational grazing (RG) treatment. Livestock densities evaluated were equivalent to 14 and 42-paddock RG treatments. Baseline data were collected in 1981 from 3 adjacent 30-ha paddocks in a 465-ha, 14-paddock, cell designed RG treatment stocked at a rate of 3.6 ha/cow/year. Near the beginning of the 1982 growing season the center paddock was subdivided into three, 10-ha paddocks to establish the RG-42 treatment. Herbage standing crop was harvested before and after each grazing event during the 40-month period, separated by species or species group into live and dead tissue, and each fraction analyzed for percentage crude protein (CP) and organic matter digestibility (OMD). Livestock density had minimial effect on forage quality. Live tissue was of higher quality than senesced tissue regardless of plant species. Increases and decreases in overall quality during grazing periods were positively associated with rates of plant growth. Number of periods when forage quality increased or decreased during grazing and magnitude of change were unaffected by treatment. Lack of significant treatment effects on forage quality is attributed to the general absence of significant treatment effects on forage production, species composition, and live/dead ratios.
    • 1990 President's Address: SRM Today and Tomorrow

      Bedell, Thomas E. (Society for Range Management, 1990-03-01)
    • 30 Years of Vegetal Change Following Burning of Sagebrush-Grass Range

      Harniss, R. O.; Murray, R. B. (Society for Range Management, 1973-09-01)
      A sagebrush-grass range was burned according to plan in 1936. Long-term results show that sagebrush yields have increased while most other important shrub, grass, and forb yields have decreased. Evaluation by subspecies of sagebrush was helpful in interpreting sagebrush behavior. The return of sagebrush shows the need for planning sagebrush control on a continuing basis for maximum forage qualities.
    • A 3-Year Evaluation of Taste Aversion Coyote Control in Saskatchewan

      Gustavson, C. R.; Jowsey, J. R.; Milligan, D. N. (Society for Range Management, 1982-01-01)
      Taste aversion programs using lithium chloride (LiCl) in sheep baits and carcasses have been applied in Washington to one sheep herd for 2 years; applications have been made in California and in Saskatchewan on 46 herds over 3 years. Ten of these 46 herds were available for statistical analysis, indicating a significant reduction in the percent of sheep lost to coyotes. All applications have suggested reduced sheep losses to coyotes (Canis latrans). This method of predation control may cost less than traditional techniques, save sheep, and should allow coyotes to carry out positive functions in the ecosystem.
    • A Basis for Conservation Lease of Rangeland on the Edwards Plateau

      Huss, D. L. (Society for Range Management, 1955-09-01)
    • A Basis for Relative Growth Rate Differences Between Native and Invasive Forb Seedlings

      James, Jeremy J.; Drenovsky, Rebecca E. (Society for Range Management, 2007-07-01)
      The ability of invasive plants to achieve higher relative growth rates (RGR) than their native counterparts has been widely documented. However, the mechanisms allowing invasives to achieve higher RGR are poorly understood. The objective of this study was to determine the basis for RGR differences between native and invasive forbs that have widely invaded nutrient-poor soils of the Intermountain West. Six native and 6 invasive forbs were seeded in pots in a greenhouse, and 4 harvests were conducted over a 2-month period. These 4 harvests were used to calculate RGR and the components of RGR, net assimilation rate (rate of dry matter production per unit leaf area), leaf area ratio (LAR, leaf area per unit total plant mass), leaf mass ratio (the proportion of biomass allocated to leaves), and specific leaf area (SLA, leaf area per unit leaf biomass). Mean RGR of the 12 study species ranged between 0.04 and 0.15 g g-1 d-1 but was significantly higher for invasive forbs compared to native forbs (P = 0.036). The higher RGR achieved by invasive forbs was due mainly to a greater SLA and LAR. This indicates that invasive forbs achieved higher RGR than natives primarily by creating more leaf area per unit leaf mass, not by allocating more biomass to leaf tissue or by having a higher net rate of dry matter production. A high degree of variation in RGR, SLA, and LAR was observed in native forbs, suggesting that the ability to design weed-resistant plant communities may be improved by managing for specific functional traits as opposed to functional groups. 
    • A Behavioral Study of Angora Goats on West Texas Range

      Askins, G. D.; Turner, E. E. (Society for Range Management, 1972-03-01)
      Behavior of four Angora goats was studied in sixteen observation periods for four seasons on a west Texas range. The goats consistently fed during two definite daylight feeding periods: (a) early morning, and (b) late afternoon to dusk. Bedding generally occurred whenever darkness became evident and little or no feeding activity was observed between that time and daybreak. The four goats differed somewhat in their behavioral activities, but were remarkably similar in their vegetation preference. Seasonal difference seemed to have an important effect upon both vegetative preference and behavioral activities./Cuatro cabras fueron marcadas y sus actividades fueron observadas a través del año. Las cabras mostraron un patrón de actividades sistemático a través del año. Empezaron el día levantándose y rumiando por un tiempo breve, seguido por una época de pastoreo de tres horas, luego por 30 minutos de descanso y después pastoreo otra vez hasta mediodía. Tomaron agua y descansaron en la sombra durante medio día hasta tres horas antes de la puesta del sol. Comieron otra vez por tres horas o sea hasta en la noche cuando tomaron agua otra vez y comieron sal, seguido por descanso por toda la noche. Aproximadamente de 34.4% de su tiempo de pastoreo fué con gramíneas y 65.6% fué ramoneo. Parece ser que las estaciones del año tienen un importante efecto en la preferencia del forraje pastoreado, y las actividades de las cabras.
    • A Capacitance Meter for Estimating Forage Weight

      Fletcher, J. E.; Robinson, M. E. (Society for Range Management, 1956-03-01)
    • A Case Study Evaluating Economic Implications of Two Grazing Strategies for Cattle Ranches in Northwest Argentina

      Quiroga, R. Emiliano; Blanco, Lisandro J.; Ferrando, Carlos A. (Society for Range Management, 2009-09-01)
      In the Argentinean Chaco Arido region, cattle production based on cow-calf operations is the principal source of agricultural income, and rangeland is the main forage source for cattle. Traditional grazing strategy (TGS, high stocking rate and continuous grazing) is considered the main cause of current rangeland degradation. Research shows that rangeland and cattle production improvements are possible when using a conservative grazing strategy (CGS, moderate stocking rate and rest rotation grazing). The aim of this research was to compare the effects of TGS and CGS applications on economic results for a cattle ranch in the region. To achieve this objective we used an approach that included estimations of forage and cattle production, and economic results. The study period was 1972/73–1983/84. Results showed that during the study period forage production and herd size were almost doubled with CGS, but maintained with TGS. The difference in net income between CGS and TGS (in Argentinean pesos, ), increased linearly from negative (–2.88 ha-1) to positive (4.48 ha-1) in the first 4 yr, and then was maintained at positive values (averaging 4.48 ha-1). Data suggest that CGS leads to higher productivity and better economic results than TGS in the medium and long terms. 
    • A Case Study for Optimal Allocation of Range Resources

      D'Aquino, S. A. (Society for Range Management, 1974-05-01)
      A linear programming model was developed to help in the management of range resource systems. This analysis simultaneously considers per acre management costs and resulting per animal gross revenues. The management plan sets out a season-by-season use of land areas and associated forage resources with the objective of maximizing net dollar returns. Procedures developed in this study may also be applied to public resource management problems.
    • A Challenge to Stockmen and Range Officials

      Savage, D. A. (Society for Range Management, 1951-05-01)
    • A chamber design for measuring net CO2 exchange on rangeland

      Angell, R.; Svejcar, T. (Society for Range Management, 1999-01-01)
      Net carbon exchange of terrestrial ecosystems will likely change as atmospheric CO2 concentration increases. Currently, little is known of the annual dynamics or magnitude of CO2 flux on many native and agricultural ecosystems. Remoteness of many ecosystems has limited our ability to measure CO2 flux on undisturbed vegetation. Today, many plant ecologists have portable photosynthesis systems with which they make single-leaf photosynthesis measurements. Utility of this equipment is enhanced when canopy-level CO2 flux is also measured. We designed a portable 1-m3 closed chamber for use in measuring CO2 exchange in short statured vegetation with widely varied canopy structure. The design includes external ductwork equipped with doors which are used to open the chamber for ventilation with outside air between measurements. The chamber was tested on a Wyoming big sagebrush (Artemisia tridentata ssp. Wyomingensis Nutt.)/Thurber's needlegrass (Stipa thurberiana Piper) community using 10 plots equally divided between shrub and interspace. The ductwork and doors provided adequate ventilation to allow consecutive measurements of CO2 flux without removing the chamber from the plot. The chamber could differentiate CO2 flux between plots with sagebrush and those with grass only, even at relatively low fluxes. Net CO2 uptake per unit ground area was greater (P = 0.04) on sagebrush-grass plots (7.6 +/- 1.4 micromoles m-2 s-1) than on interspace plots without sagebrush (3.1 +/- 1.0 micromole m-2 s-1). Chamber and leaf temperature increased by an average of 0.5 and 1.2 degrees C, respectively, during measurements.
    • A Chemical-Fallow Technique for Control of Downy Brome and Establishment of Perennial Grasses on Rangeland

      Eckert, R. E.; Evans, R. A. (Society for Range Management, 1967-01-01)
      Downy brome was controlled with three soil-active herbicides: atrazine, EPTC, and IPC. Seedings were made 1 year after herbicide application. If fallow were effective during this year, soil moisture was conserved. Seeding in deep furrows resulted in superior seedling stands and greater 2nd and 3rd year production than did surface drilling. Performance of Amur intermediate wheatgrass was superior to Standard crested and Topar pubescent wheatgrasses.
    • A Common-Garden Study of Resource-Island Effects on a Native and an Exotic, Annual Grass After Fire

      Hoover, Amber N.; Germino, Matthew J. (Society for Range Management, 2012-03-01)
      Plant-soil variation related to perennial-plant resource islands (coppices) interspersed with relatively bare interspaces is a major source of heterogeneity in desert rangelands. Our objective was to determine how native and exotic grasses vary on coppice mounds and interspaces (microsites) in unburned and burned sites and underlying factors that contribute to the variation in sagebrush-steppe rangelands of the Idaho National Lab, where interspaces typically have abiotic crusts.We asked how the exotic cheatgrass (Bromus tectorum L.) and native bluebunch wheatgrass (Pseudoroegneria spicata [Pursh] A. Lo¨ ve) were distributed among the microsites and measured their abundances in three replicate wildfires and nearby unburned areas. We conducted a common-garden study in which soil cores from each burned microsite type were planted with seed of either species to determine microsite effects on establishment and growth of native and exotic grasses. We assessed soil physical properties in the common-garden study to determine the intrinsic properties of each microsite surface and the retention of microsite soil differences following transfer of soils to the garden, to plant growth, and to wetting/drying cycles. In the field study, only bluebunch wheatgrass density was greater on coppice mounds than interspaces, in both unburned and burned areas. In the common-garden experiment, there were microsite differences in soil physical properties, particularly in crust hardness and its relationship to moisture, but soil properties were unaffected by plant growth. Also in the experiment, both species had equal densities yet greater dry mass production on coppice-mound soils compared to interspace soils, suggesting microsite differences in growth but not establishment (likely related to crust weakening resulting from watering). Coppice interspace patterning and specifically native-herb recovery on coppices is likely important for postfire resistance of this rangeland to cheatgrass./La variación suelo-planta en relación con la isla de recursos de las plantas perennes y los montículos intercalados con la presencia de inter-espacios relativamente desnudos es la mayor fuente de heterogeneidad en pastizales áridos. Nuestro objetivo fue determinar cómo pastos nativos y exóticos varían con montículos y espacios intermedios (micro-sitios) en aéreas quemadas y no quemadas, y los factores principales que contribuyen a tal variación en los pastizales de Artemisia de Idaho National Lab. Donde los inter-espacios típicamente tienen capas abióticas. Nos preguntamos cómo el pasto exótico cheatgrass (Bromus tectorum L.) y el pasto nativo bluebunch wheatgrass (Pseudoroegneria spicata [Pursh] A. Löve) se distribuyeron entre los micro-sitios, y medimos su abundancia en tres replicas de incendios forestales y áreas adyacentes no incendiadas. Se condujo un estudio común de jardín en el cual muestras de suelo de cada micro-sitio incendiado se sembró con semillas de cada especie para determinar el efecto de los micro-sitios en el establecimiento y crecimiento de los pastos nativos y exóticos. Las propiedades físicas del suelo se midieron como en un estudio típico de jardín para determinar las propiedades intrínsecas de la superficie de cada micro-sitio, y las diferencias en la retención de suelo en cada micro-sitio después de la transferencia de los suelos al jardín, para el desarrollo de las plantas, y para los ciclos de humectación/secado. En el primer estudio, sólo la densidad de bluebunch wheatgrass fue mayor en los montículos que en los inter-espacios en ambas áreas incendiadas y no incendiadas. En el experimento común de jardín, se presentaron diferencias en los micro-sitios relativos a las propiedades físicas del suelo, particularmente en la dureza de la corteza y su relación con la humedad, pero las propiedades del suelo no se afectaron por el crecimiento de las plantas. De igual manera en el experimento, ambas especies tuvieron iguales densidades pero mayor producción de materia seca en los suelos de los montículos comparado con los suelos de los inter-espacios, sugiriendo diferencias entre los micro-sitios en crecimiento pero no en establecimiento (probamente relacionado con el debilitamiento de la corteza como resultado del riego). Los patrones de los montículos e inter-espacios y específicamente la recuperación de herbáceas nativas en los montículos es probablemente importante para la resistencia de este pastizal a la invasión cheatgrass después de la presencia de incendios forestales.
    • A Comparative Study of Soils of Selected Creosotebush Sites in Southern New Mexico

      Valentine, K. A.; Norris, J. J. (Society for Range Management, 1964-01-01)
    • A Comparison of Average Variable Costs of Private vs. Public Land Ranches in Southeastern Montana

      Lacey, J. R.; Workman, J. P. (Society for Range Management, 1986-07-01)
      A study was conducted in southeastern Montana to determine the effects of federal range grazing on cattle ranch average variable operating costs per animal unit. Data were obtained through personal interviews in 1980 with 68 ranches in six southeastern Montana counties. T-tests were used to determine if the average variable costs per animal unit were less on ranches that rely on federal ranges than on ranches that do not. Annual variable costs per animal unit averaged $158 and $144, respectively, for ranches obtaining 0-4% and 5-51% of total forage from federal lands. However, this difference was not statistically significant. Regression analysis did indicate that variable costs per animal unit were significantly affected by the percentage of total ranch income from crop sales.
    • A Comparison of Continuous and Rotational Grazing

      Walton, P. D.; Martinez, R.; Bailey, A. W. (Society for Range Management, 1981-01-01)
      Continuous and rotational grazing of a brome-alfalfa-creeping red fescue pasture was compared at the University of Alberta Ranch in 1975, 1976, 1977, and 1978. Productivity, in terms of animal weight gain and dry-matter consumption, was studied together with changes in the sward composition. In 1977 and 1978 the weight gains from the rotationally grazed areas were nearly double those obtained from continuous grazing (218 vs 119 kg/ha). The percentage by weight of alfalfa in the sward increased under rotational grazing from 23 to 47%. The herbage in the rotationally grazed field was more digestible and contained more calcium, magnesium, copper, and crude protein than did that in the continuously grazed area. Animals in the continuously grazed fields spent 2.4 hours longer per day grazing than did the animals which were rotationally grazed.
    • A Comparison of Crested Wheatgrass and Native Grass Mixtures Seeded on Rangeland in Eastern Montana

      McWilliams, J. L.; Van Cleave, P. E. (Society for Range Management, 1960-03-01)