• 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.
    • 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.
    • 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.
    • 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).
    • 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.
    • 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.
    • 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.
    • Crude Protein, Crude Fiber, Tannin, and Oxalate Concentrations of 33 Astragalus Species

      Davis, A. M. (Society for Range Management, 1982-01-01)
      Plant introduction collections grown at the Western Regional Plant Introduction Station for preliminary evaluation and seed increase were evaluated for crude protein, crude fiber, tannin, oxalates, and readily detectable alkaloids. Sixty-eight Astragalus accessions representing 33 species and 1 unidentified accession had a range of 8.2 to 24.2% crude protein, 11.3 to 28.6% crude fiber, 4.2 to 10.0 mg/g tannin, and 0.15 to 1.10% oxalates. Species with more than 18% crude protein and less than 28% crude fiber (i.e., comparable to good quality alfalfa (Medicago sativa) hay) and acceptable levels of tannin and oxalate were A. canadensis, P.I. 19978 and A. siliquosus, P.I. 330696. None of the accessions tested gave a positive Dragendorff reagent color test for alkaloids. Some of the species reported are known to be selenium accumulators and/or contain toxic nitro-compounds that may be damaging to grazing animals. A. siliquosus is a species that contains nitro-compounds and will accumulate selenium.
    • Comparison of Four Methods to Estimate the Dissolved Nitrogen Fraction in Range Plants

      Simonson, D. J.; Hansen, R. M.; Trlica, M. J. (Society for Range Management, 1982-01-01)
      Aboveground biomass of four range species was collected at several phenological stages and total nitrogen was determined. The dissolvable nitrogen fraction within these samples was estimated utilizing four techniques: (1) in vivo nylon bag digestion in a rumen-fistulated Bison bison; (2) in vitro Tilley and Terry plus pepsin; (3) neutral detergent fiber; and (4) laboratory detergent fiber. Total nitrogen concentration in all plant species studied was highest during early growth and decreased with advancing maturity. A similar amount of nitrogen was removed from dead or dormant plant materials using any technique, but significantly more nitrogen was removed from green succulent material utilizing the nylon bag technique than was removed with the three laboratory assays. The amount of nitrogen removed from plant foliage was highly correlated among techniques. Equations were developed to predict nitrogen losses with the nylon bag technique using dissolved nitrogen values obtained from any of the other three techniques.
    • Chemical Quality and Sediment Content of Runoff Water from Southeastern Montana Rangeland

      Neff, Earl L. (Society for Range Management, 1982-01-01)
      Chemical quality of surface runoff water from rangeland sites with fine-textured soils in southeastern Montana was good to excellent with average total dissolved solids<300 mg/liter. This quality is better than that of most municipal water supplies in the same geographic area. Erosion from these sites was also low, averaging <1,500 kg/ha per year.
    • Chemical Composition of Native Range Grasses Growing on Saline Soils of the South Texas Plains

      Everitt, J. H.; Alaniz, M. A.; Gerbermann, A. H. (Society for Range Management, 1982-01-01)
      During the growing seasons of 1976 and 1977, six native range grass species and a composite of miscellaneous grasses growing on Saline Clay and Rolling Hardland range sites (both sites have saline soils) in south Texas were analyzed for percentage content of crude protein (CP), P, Ca, Mg, K, and Na. Levels of CP, P, K, and Na were generally highest after periods of adequate rainfall in late spring, summer, and early fall and lowest in late fall as the grasses went into dormancy. Levels of Ca and Mg remained relatively stable through the growing season and showed little relationship to rainfall. Grasses from the Saline Clay site had slightly higher levels of the chemical constituents than those grasses from the Rolling Hardland site.
    • Cattle Grazing Influence on a Mountain Riparian Zone

      Roath, L. R.; Krueger, W. C. (Society for Range Management, 1982-01-01)
      A combination of management and physical topographic constraints caused cattle to concentrate on the riparian zone early in the grazing season in 1977 and 1978. A large percentage of cattle days and vegetation utilization on the riparian zone occurred in the first 4 weeks of the grazing period. Utilization on herbaceous vegetation was 76 and 72% in 1977 and 1978, respectively. Impact of grazing on the most prevalent species, Kentucky bluegrass was minimal. Shrub use increased with increased maturity of herbaceous vegetation. Utilization of major shrubs was not excessive in either year, and very likely had no long-term effects on either the abundance or vigor of the shrubs.
    • Cattle Diets in the Blue Mountains of Oregon, I. Grasslands

      Holechek, J. L.; Vavra, M.; Skovlin, J.; Krueger, W. C. (Society for Range Management, 1982-01-01)
      Esophageally fistulated cows were used to determine cattle diets on grassland range in northeastern Oregon in 1976, 1977, and 1978. Idaho fescue, bluebunch wheatgrass, and Sandberg bluegrass were the most common species in the diets. Forb consumption declined while grass consumption increased with seasonal advance from late spring to fall. Food habits depended largely on phenological development of forage species. Forbs were preferred over grasses early in the grazing season; then after forbs reached maturity, cattle were selective for the plants that remained green. Diet similarities were compared between periods within years, and between years within periods. When diets were pooled into late spring, early summer, late summer and fall groups, late spring diets were least similar to the others. Diet variation from year to year was also less later in the grazing season. Utilization of Idaho fescue and bluebunch wheatgrass should be considered in grazing management decisions on grasslands in the Blue Mountains.
    • Brush Control with Herbicides on Hill Pasture Sites in Southern Oregon

      Norris, L. A.; Montgomery, M. L.; Warren, L. E.; Mosher, W. D. (Society for Range Management, 1982-01-01)
      Silvex alone or with 2,4-D in a 1:1 ratio at about 3 to 4 kg/ha gave 60 to 100% control of many brush species including poison oak, Oregon oak, and maples. Picloram at 1 kg/ha plus 2,4-D at 4 kg/ha was most effective with respect to the amount of picloram; however, the mixture of 1 kg/ha plus 2 kg/ha respectively, was nearly as good. Complete pasture renovation in this area requires brush control, burning, fertilization, and seeding of desirable species. Picloram and 2,4-D disappear from soils in 29 months with no significant leaching into the soil profile at these study sites. Herbicide discharge in streamflow was small, representing 0.35% and 0.014% of applied picloram and 2,4-D. We believe that nearly all of the herbicide discharged from these watersheds represents residue deposited in dry stream channels or that mobilized by fall rains from adjacent streambanks. Significant overland movement of herbicides from upslope did not occur on these study areas. The probability of crop damage from irrigation with water from these watersheds is low.
    • Bottom Sediment: a Reservoir of Escherichia coli in Rangeland Streams

      Stephenson, G. R.; Rychert, R. C. (Society for Range Management, 1982-01-01)
      Escherichia coli concentrations of bottom sediment and overlying water were determined from a variety of streams in southwestern Idaho by a one-step most probable number technique. Results show E. coli concentrations of bottom sediments to be from 2 to 760 times greater than from the overlying water. E. coli concentrations of bottom sediment were found to be resuspended following disturbance simulation and a rainstorm event, contributing to pollution of the overlying waters. It is, therefore, suggested that microbial analysis of bottom sediments be considered a part of water-quality evaluations for rangeland streams.
    • Biomass Estimation in a Young Stand of Mesquite (Prosopis spp.), Ironwood (Olneya tesota), Palo Verde (Cercidium floridium, and Parkinsonia aculeata), and Leucaena (Leucaena leucocephala)

      Felker, P.; Clark, P. R.; Osborn, J. F.; Cannell, G. H. (Society for Range Management, 1982-01-01)
      Simple methods for estimating standing biomass in a stand of tree legumes containing the genera Prosopis, Cercidium, Olneya, Leucaena, and Parkinsonia are reported. Fresh and dry biomass were related to height and stem diameter measurements for 212 leguminous trees ranging in biomass from 0.04 to 17.8 kg using linear regression. The dry matter content of the above-ground biomass of these genera ranged from 40 to 56% and the stem dry matter percentage ranged from 70 to 96%. The best functional form of the model was log10 dry weight (kg) = 2.55 log basal diameter (cm)-1.25, which had an r2 of 0.956 for 212 samples.
    • An Esophageal Fistula Dilator

      Anderson, D. M.; Mertz, D. L. (Society for Range Management, 1982-01-01)
      An esophageal fistula dilator is described. The tool can be used to exert an even pressure around the fistula perimeter to stretch a shrunken fistula and allow the successful insertion of a closure device larger in diameter than that of the original fistula. With this instrument the process of enlarging the esophageal fistula is accomplished immediately in a time-saving, efficient manner compared to increasing the diameter of the fistula gradually by periodically increasing the diameter of the closure device.
    • A Method for Forecasting Potential Losses from Grasshopper Feeding on Northern Mixed Prairie Forages

      Hewitt, G. B.; Onsager, J. A. (Society for Range Management, 1982-01-01)
      Information on the potential loss of forage that might be expected from grasshopper feeding in a given season would benefit ranchers and land managers if the loss could be estimated in the spring before peak forage production. A method was developed for forecasting such losses on the northern mixed prairie when most species of grasshoppers are in the 3rd and 4th instars. The method is based on the assumptions that forage losses (forage consumed + destroyed) are directly proportional to grasshopper size and density and that during the period between the 3rd instar and death, which usually does not exceed 46 days, density decreases linearly to 0. Using feeding ratios (weight of forage destroyed/weight of adults), losses/day were calculated for each of 26 grasshopper species and for 3 groups of species separated by weight. Forecasted loss estimates for any population can be estimated if the density and species are determined, or a loss of 43 mg/grasshopper feeding day could be used as a general average if species cannot be identified. Forecasted losses are related to grasshopper density and to observed losses at one site in Montana during a 3-year period.
    • A Durable Livestock Exclosure for Herbage Production and Utilization Sampling

      Hinnant, R. T.; Kothmann, M. M. (Society for Range Management, 1982-01-01)
    • A Dissimilarity Coefficient and Its Use

      Bonham, C. D. (Society for Range Management, 1982-01-01)
      A coefficient of dissimilarity was used to test hypotheses concerned with standing crop of individual plant species occurring on two soil types and subjected to two levels of cattle grazing. It was concluded that variations in relative biomass of individual species changed with grazing, but biomass by species did not vary over the growing season on deep sandy soils.