• A Method for Measuring Soil Erosion and Deposition with Beta Particle Attenuation

      Alldredge, A. W.; Whicker, F. W. (Society for Range Management, 1972-09-01)
      A method utilizing beta particle attenuation was developed for measuring soil erosion and deposition in a shortgrass plains ecosystem. This method used a sealed strontium-90 source located below ground level. Soil erosion and deposition was observed by fluctuations in detected count rates using a portable Geiger Mueller counting system. Initial results indicate that quantitative measurement of soil depth fluctuations in amounts considerably less than one millimeter and over a period of a few weeks are possible. Data are presented from application of this method in six soil series under heavy, moderate, and light summer grazing treatments.
    • Electric Shears for Plot Harvesting

      Daigger, L. A. (Society for Range Management, 1972-09-01)
      Battery powered electric shears can reduce hand labor required to harvest small forage plots. Extra rechargeable batteries extend capacity to operate shears for several hours. Such shears will clip alfalfa and native range grasses more uniformly than when harvested with conventional hand sickle.
    • Herbicide Interactions in Control of Sand Shinnery Oak

      Scifres, C. J. (Society for Range Management, 1972-09-01)
      Silvex was the most effective herbicide for reducing sand shinnery oak (Quercus havardii Rydb.) density and increasing grass production in the Rolling Plains of Texas. Combinations of silvex or 2,4,5-T with picloram controlled more sand shinnery oak than expected (synergistic) and substantially increased grass production. Picloram and 2,4-D (1:1) at 0.5 lb./acre total were additive and less effective than other phenoxy:picloram combinations. Combinations of dicamba with 2,4,5-T or silvex were usually additive.
    • Energy Fixation and Precipitation-Use Efficiency in a Fertilized Rangeland Ecosystem of the Northern Great Plains

      Wight, J. R.; Black, A. L. (Society for Range Management, 1972-09-01)
      Results of a 2-year study conducted on the mixed prairie near Sidney, Montana, indicated that high rates of nitrogen (N) fertilization accompanied by phosphorus (P) were necessary to obtain maximum levels of energy fixation. Total energy fixed over a 2-year period (1969-70) by the above-ground portion of native vegetation was 1136 kcal/ m2 or 2384 lb./acre yield equivalent. Single applications of 100, 300, and 900 lb./acre of N increased the level of energy fixation 1.6-, 2.2-, and 2.0-fold, respectively, when applied without P; 1.7-, 3.2-, and 2.8-fold, respectively, when applied with 100 lb. P/acre; and 2.0-, 3.0-, and 3.3-fold, respectively, when applied with 200 lb. P/acre. The high N-P treatment decreased the grass plus sedge portion of total yield from 77 to 70% in 1969, but increased it from 61 to 98% in 1970. Increased growth of individual plants and changes in species composition accounted for the high levels of energy fixation by the fertilized vegetation. Precipitation-use efficiency for the 1970 growing season was 110 lb./acre/inch on the unfertilized plots and 336 lb./acre/inch on the high N-P treatment plots.
    • Estimating Forage Production from Shrub Ring Widths in Hot Creek Valley, Nevada

      Davis, J. B.; Tueller, P. T.; Bruner, A. D. (Society for Range Management, 1972-09-01)
      Floristic and soil factors on 60 sites in the shadscale and sagebrush zone in Hot Creek Valley, Nevada were sampled to derive one or more equations for estimating production on those sites. The factors were analyzed by an all possible correlation followed by stepwise regression with production as the dependent variable. Many of the factors correlated significantly with production, but widths of growth rings of shrubs accounted for most of the variation in production. Thus, ring widths of big sagebrush, bud sagebrush, shadscale, common winterfat, and spiny hopsage were used to derive regression equations to estimate forage production. Big sagebrush and shadscale ring widths varied exponentially with production, while a linear relationship expressed the regression of production on ring widths for the other shrubs. The linear regression probably represents only a portion of the complete curve. The methods of collection and analysis of shrub rings to derive production estimation equations could probably be extended to other areas within the Great Basin.
    • Factors Affecting Germination, Emergence and Establishment of Sand Bluestem

      Stubbendieck, J.; McCully, W. G. (Society for Range Management, 1972-09-01)
      Response of sand bluestem seed units (florets) to three rates of cotton-bur mulch and treatment with an organic mercury pathogenicide was measured by germination, emergence and establishment. All rates of cotton-bur mulch improved soil moisture conditions, but heavier rates formed a physical barrier to the emergence of grass seedlings. More than three times as many plants became established from florets treated with a pathogenicide than from untreated florets.
    • Fate of Fertilizer Nitrogen Applied to a Northern Great Palins Rangeland Ecosystem

      Power, J. F. (Society for Range Management, 1972-09-01)
      A field study was conducted at Mandan, North Dakota to provide information on the fate of fertilizer nitrogen (N) in a Northern Great Plains rangeland ecosystem. Mixed prairie grasses were fertilized with up to 540 kg N/ha applied (a) all in one year, (b) divided equally among 3 years, or (c) divided equally among 6 years. Up to 200 kg fertilizer N/ha was immobilized the first year in grass roots, soil organic matter, and fixed ammonium combined, plus gaseous losses (no leaching occurred). Immobilization and losses increased to about 350 kg fertilizer N/ha after 3 to 4 years, and remained rather constant thereafter. About half the immobilized N was found in the grass roots at the termination of the experiment. Collectively these results indicate that addition of high N rates to grasslands results in saturating the capacity of the soil-plant system to immobilize N. The system can then be maintained in an N-saturated condition if annual fertilizer additions plus mineralization equals immobilization plus irreversible losses. Thus, N can be eliminated as a growth-limiting factor, providing maximum grass production from the available water supply.
    • Flushing of Range Ewes by Supplementation, Drylot Feeding, or Grazing of Improved Pasture

      Torell, D. T.; Hume, I. D.; Weir, W. C. (Society for Range Management, 1972-09-01)
      The lambing performance of range ewes was compared with that of similar ewes which were supplemented for 17 days prior to and the first 17 days of breeding (four years), were fed in drylot (four years), or grazed an improved pasture (two years) over the same period. Supplementation (2.25 kg alfalfa pellets/ewe/week, fed twice weekly) did not improve lambing performance, but drylot feeding (1.82 kg alfalfa hay/ewe/day) increased the number of lambs born/ewe present at lambing from 101 to 128% (P < 0.001). Access to improved pasture also increased lambing percentage (from 110 to 138) (P < 0.01). Current feed costs, and availability and alternative uses of an area of improved pasture will determine which of the two effective treatments is most likely to result in the greatest net returns from flushing. The observed flushing effect was associated mainly with the live-weight change over the flushing period, rather than any static live-weight effect. For every kg increase in the weight gain during flushing, lambing % increased by about 8%.
    • Canada's Rangeland Resource—A Look Ahead

      Johnston, A. (Society for Range Management, 1972-09-01)
      Canada's cattle population is expected to increase from its present 13.7 million head to about 16.5 million head by 1980. About 5.3 million acres of additional pasture will be required to feed the extra cattle and most of it will come from land presently in grain. Range managers will be more concerned than formerly with cultivated pastures and hayland and the integration of these with native range.
    • Construction and Use of an Inexpensive Rain Gauge

      Ohlenbusch, P. D. (Society for Range Management, 1972-09-01)
      An inexpensive, wind-proof rain gauge was devised for measuring precipitation at remote locations. The gauge can be constructed from a funnel, gasoline can and assorted lumber and metal. Gauges in use over one year have withstood winds in excess of 50 miles per hour. Ease of installation and minimal maintenance requirements make the gauge desirable for remote or inaccessible locations that are visited infrequently. Protection from livestock may be necessary if rubbing is a problem.
    • Guidelines for Grazing Sheep on Rangelands Used by Big Game in Winter

      Jensen, C. H.; Smith, A. D.; Scotter, G. W. (Society for Range Management, 1972-09-01)
      A big game winter range in northen Utah was grazed with domestic sheep to ascertain what seasons and intensity of use would maximize utilization of herbs and minimize utilization of shrubs which provide the majority of forage for big game in winter, thus minimizing forage competition between big game and sheep. In late spring and early summer sheep ate mostly herbs. The light utilization of shrubs resulted in little or no reduction in forage production by shrubs at the end of the growing season. After mid-July, sheep heavily utilized bitterbrush (Purshia tridentata), the most desirable and abundant shrub for big game in this area. Grazing after mid-July reduced the volume of bitterbrush forage available for big game proportionately to the percentage utilization observed. There was no evidence that subsequent annual productivity of established plants was impaired by any of the grazing systems imposed.
    • Influence of Repeated Annual Burning on a Medusahead Community

      Young, J. A.; Evans, R. A.; Robison, J. (Society for Range Management, 1972-09-01)
      Three annual burnings near Alturas, California, did not result in a decrease in medusahead. Medusahead increased and downy brome decreased after burning. No changes were observed in perennial grass populations in relation to burning. Changes in densities of annual grasses due to burning apparently were not a result of destroying caryopses; but probably were caused by alteration of the seedbed environment.
    • Production and Persistence of Common Carpetgrass in Relation to Site and Harvest Frequency

      Wolters, G. L. (Society for Range Management, 1972-09-01)
      On a range in central Louisiana, maximum production of carpetgrass and total herbage was obtained by harvesting once or twice per season. Carpetgrass and forbs increased in percent botanical composition with frequent harvests, while bluestems and other grasses increased with infrequent harvests. Site did not significantly affect herbage production.
    • Range Management in the United States for the Next One to Three Generations

      Clawson, M. (Society for Range Management, 1972-09-01)
    • Salt Tolerance and Cation Interaction in Alkali Sacaton at Germination

      Hyder, S. Z.; Yasmin, S. (Society for Range Management, 1972-09-01)
      Salt tolerance and cation interaction in alkali sacaton (Sporobolus airoides Torr.) was studied during the germination stage. Germination was inhibited at a concentration of 275 meq/liter of sodium chloride. Mannitol and other salts at iso-osmotic pressure restricted germination in the following decreasing order: MgCl2, KCl, CaCl2, NaCl, and mannitol. Inhibitory effects of magnesium on germination were partially counteracted by calcium and sodium. Greater recovery in germination was noted by addition of calcium than sodium in seeds previously treated with a high concentration of magnesium chloride. The role of sodium and calcium in counteracting magnesium effects has been discussed. It is also concluded that specific effects of salts are more important than osmotic effects on the seed germination of this species.
    • Three Methods of Determining Diet, Utilization, and Trampling Damage on Sheep Ranges

      Laycock, W. A.; Buchanan, H.; Krueger, W. C. (Society for Range Management, 1972-09-01)
      Esophageal fistula sampling and ocular utilization estimates gave similar figures for dietary composition and for percentage utilization by sheep for most plant species in the tall-forb type. The paired-plot method gave higher utilization figures than the above methods because it estimated not only herbage eaten, but also that trampled. As a result, this method overestimated the dietary composition of species most susceptible to trampling damage; trampling accounted for one-half to two-thirds of the herbage removed by grazing.
    • Vegetation Changes as a Result of Soil Ripping on the Rio Puerco in New Mexico

      Aldon, A. F.; Garcia, G. (Society for Range Management, 1972-09-01)
      Soil ripping in 1963 effectively reduced runoff on the San Luis watershed of the Rio Puerco, New Mexico, and caused a favorable shift in forage production from galleta to alkali sacaton. Ripping effects on runoff are short-lived, but forage production patterns may persist for 10 years.
    • Western Coneflower—A Noxious Species?

      Florez, A.; McDonough, W. T.; Balls, L. D. (Society for Range Management, 1972-09-01)
      In laboratory tests, dilute foliar extracts of western coneflower (Rudbeckia occidentalis Nutt.) inhibit germination and seedling growth of seeded grasses as do those of some supposedly innocuous species. Under natural conditions on aspen range, measurements of plants of mountain brome growing in close association with coneflower gave doubtful evidence of suppressed growth. Large doses of dried aerial parts of coneflower force-fed to sheep produced no evidence of toxicity or other distress. We found no evidence of coneflower posing any special threat on mountain range, except as a relatively unpalatable increaser species.
    • Some Factors Influencing Tolerance to Moisture Stress of Three Range Grasses

      Schlatterer, E. F.; Hironaka, M. (Society for Range Management, 1972-09-01)
      Pre-conditioning of bluebunch wheatgrass, squirreltail and Thurber stipa plants by exposure to different temperatures and watering schedules affected their tolerance to moisture stress. Plants conditioned under high or low temperatures were more resistant to moisture stress than plants conditioned at moderate temperature. Plants grown in fertile mound soil were less conditioned to withstand moisture stress than those grown in less fertile intermound soil.