• Variability of Miserotoxin Concentration in Timber Milkvetch

      Majak, W.; McLean, A. (Society for Range Management, 1975-09-01)
      The variability in miserotoxin concentration of 120 individual timber milkvetch plants was determined in the bud, flower, and pod stages of growth on rough fescue grassland, parkland, and Douglasfir zone locations. Although a broad dispersion in miserotoxin levels was evident within each sampling unit of ten plants, the grassland samples exhibited the greatest toxicity with an exceptional level (10.17 +/- 1.13%) occurring during the bud stage. The bud stage of the parkland samples yielded intermediate concentrations (5.22 +/- 1.18%) while forest plants contained lower miserotoxin levels (4.08 +/- 0.95% to 2.49 +/- 0.47%). A decline in miserotoxin levels occurred during the bud-to-pod interval at the grassland and parkland sites, but significant differences were not apparent between the progressive stages of growth at the forest locations. The timber milkvetch toxicity patterns based on the variability of individual plants confirmed previously described trends derived from composite sampling.
    • Trends of Nonstructural Carbohydrates in the Stem Bases of Switchgrass

      Smith, D. (Society for Range Management, 1975-09-01)
      Carbohydrate reserves in the stem bases of switchgrass (Panicum virgatum L.) reached their minimum percent in the spring growth, and in the regrowth after cutting, when the young tillers began to initiate their elongation (jointing). Cutting or grazing at this stage would weaken the plants as compared with cutting at the flowering stage, or later, when carbohydrate reserves have been restored to a high level.
    • Titratable Acids in Opuntia ficus-indica L

      Samish, Y. B.; Ellern, S. J. (Society for Range Management, 1975-09-01)
      Accumulation of acidity in spiny and spineless Opuntia joints fluctuated daily due to crassulacean acid metabolism (CAM) in Golan Height and coastal plain. The acidity reached higher concentrations in the young joints, especially during early morning hours, before the plants were exposed to sunlight. Changes in acidity were more pronounced in the chlorenchyma than in the water-accumulating tissues. These findings provide information on the rate and time of photosynthesis of these plants and may enable the feeding of livestock on Opuntia, while acid levels taken in by livestock are kept low to reduce a cause of diarrhea. The acidity is lower on sunny warm days, during late afternoons, in shriveled, old joints which had been exposed to full sunlight or were excised and stored in light. It may, therefore, be better to let cattle feed on the shriveled Opuntia before the start of the rainy season and use shrubs such as Atriplex halimus, which is better suited after onset of the first rain, as complementary perennial feed.
    • Thiourea Solution Temperature and Bitterbrush Germination and Seedling Growth

      Neal, D. L.; Sanderson, H. R. (Society for Range Management, 1975-09-01)
      Antelope bitterbrush (Purshia tridentata (Pursh) DC.) seed is commonly soaked in a solution of thiourea to break seed dormancy for spring planting. "Warm" thiourea solutions have been reported to cause seedling deformities. To determine what range of "warm" temperature solutions can cause deformities, four seed collections were treated at 18 temperatures (30 degrees F to 200 degrees F) in increments of 10 degrees F. Normal germination and seedling growth resulted between 60 degrees F and 140 degrees F. Below 60 degrees rate of germination declined slightly, but seedling growth was normal. Seedling deformities began to show up above 140 degrees F, and germination decreased rapidly. Deformities consisted of annular cracks around the hypocotyls and detached root caps. Solution temperatures between 60 degrees F and 140 degrees F are recommended.
    • Seedling Growth of Three Switchgrass Strains

      Perry, L. J.; Moser, L. E. (Society for Range Management, 1975-09-01)
      Seedlings of Pathfinder, Nebr. 28, and experimental ey switchgrass (Panicum virgatum L.) strains were grown in a growth chamber and harvested 1, 2, 3, 4, 6, 8, and 10 weeks following emergence for detection of seedling growth differences among strains. Leaf areas and dry weights of leaf blade and stem axis (stem and leaf sheath) generally increased significantly with each harvest from 4 to 10 weeks. Stem axis and leaf blade dry weights were significantly greater with Pathfinder and ey, respectively, than with Nebr. 28. Final leaf area was significantly greater with ey than with the other strains. Thus, Nebr. 28 (early-maturing) would be less competitive with weeds during establishment than Pathfinder or ey (both are late-maturing). Relative growth rate (RGR), net assimilation rate (NAR), and leaf area ratio (LAR) were similar for all strains, although at the first harvest Nebr. 28 had a lower LAR than the other two strains. RGR, NAR, and LAR generally declined with each successive harvest. The strains appeared to have the same capacity to produce above ground biomass but photosynthate partitioning differed as indicated by leaf and stem comparisons.
    • Seeding Rate-Cover Relationships of Annual Ryegrass Seeded on Burned Brushlands

      Papanastasis, V.; Biswell, H. H. (Society for Range Management, 1975-09-01)
      The relationship between seeding rate and cover of reseeded annual ryegrass (Lolium multiflorum Lam.) was studied for 3 years on a burned brushland near Berkeley, California. Five seeding rates were compared: 6, 11, 22, 34, and 45 kg/ha. During the first winter the percentages of cover from the high seeding rates were greater than those from the lower rates; however, the differences were eliminated in the spring as a result of more tillering in the areas of low seeding rates. Percentages of cover declined in the second and third years even though seed supplies were, respectively, 32-fold and double that of the first year. It is suggested that high rates of seeding be used after wildfires, where the objective is to have a good cover to protect bare soil against erosion during the winter months.
    • Sap Velocity Studies in Natural Stands of Pinyon and Juniper Trees

      Shaw, C. B.; Gifford, G. F. (Society for Range Management, 1975-09-01)
      Sap velocities in pinyon (Pinus edulis Engelm.) and juniper (Juniperus osteosperma (Torr.) Little) trees in southeastern and southwestern Utah were studied for 1 year using the heat-pulse technique. Measured velocities were related to nearby environmental factors and Dalton's simplified aerodynamic method for estimating evaporation from water. Sap velocity was independent of the dry weight of green biomass within both pinyon and juniper trees. From 90.5 to 99.0% and from 66.0 to 99.0% of the variability in diurnal sap velocities in pinyon and juniper trees, respectively, could be accounted for by using an 8-variable multiple regression equation. Dalton's equation accounted for 4.0 to 86.0% of the variability in diurnal sap velocities for both tree species on select days. Amount of variability in sap velocities explained by multiple regression equations was reduced markedly when sap velocities and environmental data were pooled over all sampling dates.
    • S-Triazine Herbicides Combined with Nitrogen Fertilizer for Increasing Protein on Shortgrass Range

      Houston, W. R.; Van Der Sluijs, D. H. (Society for Range Management, 1975-09-01)
      Three s-triazine herbicides (atrazine, simazine, and cyanazine) applied annually at 1.1 and 3.4 kg/ha to shortgrass range in northcentral Colorado, consistently increased protein concentration in range herbage for 3 years, 1970-72. Overall, herbage yields were not affected. Spring applications were slightly more effective than fall applications. Atrazine and simazine were about equally effective. However, herbage treated with simazine retained protein better into fall and winter than that treated with atrazine. Cyanazine was the least effective. Increases in protein from the three herbicides were additive to increases from N fertilizer applied at 22 and 45 kg N/ha, except in a drought year. During drought, 3.4 kg of atrazine or simazine combined with 45 kg N reduced herbage yields and yields of protein. The most practical treatment was a combination of 1.1 kg simazine and 22 Kg N/ha. Averaged over 3 years, this combination increased protein concentration 43% and yield of protein 35% in September.
    • Runoff and Reservoir Quality for Livestock Use in Southeastern Montana

      Soiseth, R. J. (Society for Range Management, 1975-09-01)
      Runoff and reservoir waters from the Pierre Shale Plains in southeastern Montana were fresh (< 1,000 mg/liter of TDS) to slightly saline (1,000 to 3,000 mg/liter of TDS) and were rated good to fair for livestock use. However, as water levels drop, mainly through evaporation, waters in some reservoirs could become moderately saline (3,000 to 10,000 mg/liter of TDS) and should not be used if other waters are available.
    • Root-Herbage Production and Nutrient Uptake and Retention by Bermudagrass and Bahiagrass

      Beaty, E. R.; Tan, K. H.; McCreery, R. A.; Jones, J. B. (Society for Range Management, 1975-09-01)
      Studies were conducted to determine the effect of clipping and N fertilization practices on dry matter yield and macro-element uptake and retention of Bermudagrass and Bahiagrass grown on Inceptisols. Field experiments were conducted from 1963 to 1971 using a Montevallo soil sprigged with three varieties of Bermudagrasses and seeded with two varieties of Bahiagrasses. The results indicated that Bahiagrass outyielded Bermudagrass in root and herbage production. The root-herbage ratio of Bermudagrass increased with increasing N fertilization, whereas this ratio decreased for Bahiagrass. Bermudagrass differed from Bahiagrass in N, P, K, Ca and Mg content. The Ca and Mg content in both roots and herbage of Bermudagrass decreased with N fertilization, but similar N fertilization increased these nutrient elements in Bahiagrass. There was a positive correlation between N content and K/Ca molar ratio in Bermudagrass herbage.
    • Reducing Erosion Hazard on a Burned Forest in Oregon by Seeding

      Anderson, E. W.; Brooks, L. E. (Society for Range Management, 1975-09-01)
      A burned private forest was revegetated by seeding to grasses, legumes, shrubs, and trees. The sequence of events in carrying out this stabilization program provides a guideline for others handling similar situations; timeliness and ecological adaptation of species used is important. A field study (1969-72) compared results obtained on three ecological sites. A satisfactory vegetational cover was established by seeded grass the first year after seeding on all three sites, whereas natural revegetation did not provide satisfactory cover on an unseeded area in 4 years. Common legumes seeded for deer forage did not survive, indicating the need for additional study of species adaptation. Broadcasting tree seed was a failure. Seeded grasses apparently suppressed development of some native shrubs, which was detrimental to wildlife habitat. Herbage production on seeded areas was about four times greater than on the unseeded area. Two years of soil loss from seeded watersheds totaled less than 5 tons per acre as measured by the amount of sediment in debris basins. Fire-killed ponderosa pine snags were most susceptible to windthrow; grand fir was the least.
    • Plant Response and Livestock Weight Changes on Big Bluegrass Range Grazed during Late Fall, Winter, and Early Spring

      Currie, P. O. (Society for Range Management, 1975-09-01)
      Yearling heifers grazing Sherman big bluegrass ranges in Colorado during the cold winter period gained weight during late fall with or without a protein supplement, but they gained less than animals that grazed native range and received 1/2-lb protein/day. During winter and early spring, animals lost weight in most pastures. Exposure as well as kind and quantity of forage and feed available evidently influenced livestock weights. Grazing was not detrimental to Sherman big bluegrass during any period from late fall to early spring, and stands improved during the study. For most effective use, big bluegrass should replace native range for fall grazing in a management system. More animals could be carried over winter, or a set number of animals could be overwintered on fewer acres.
    • Number of Fistula Samples Needed for Determination of Sheep Diet on Sagebrush-Grass Range

      Harniss, R. O.; Price, D. A.; Tomlin, D. C. (Society for Range Management, 1975-09-01)
      Sheep diet was examined in the spring season on sagebrush-grass range in northeastern Idaho. Balsamroot and bluegrasses were the preferred plant species. The number of esophageal fistula samples needed for estimating the botanical and chemical components was determined. Botanical samples were more variable than chemical samples indicating a greater number of botanical samples for the same precision.
    • Interseeding Shrubs in Cheatgrass with a Browse Seeder Scalper

      Guinta, B. C.; Christensen, D. R.; Monsen, S. B. (Society for Range Management, 1975-09-01)
      Four browse species and a mixture of the four were interseeded into a uniformly dense cheatgrass stand with a browse seeder-scalper on deer winter range south of Manti, Utah. Four different width–4-, 8-, 16-, and 24-inch-scalping attachments were used to determine their relative effectiveness in reducing competition between cheatgrass and developing shrub seedlings. Scalping with the wider attachments resulted in substantial increases in shrub seedling survival. Reduction of cheatgrass density was most marked during the first growing season following planting. Thereafter, cheatgrass fully reoccupied first the narrower and then the wider scalps. In terms of numbers of plants surviving after 5 years, antelope bitterbrush, Nevada ephedra, and the mixture proved most responsive to increases in scalp width. Cliffrose and fourwing saltbush were less so. Herbage production of individual shrubs regardless of species showed no response to increasing scalp width. However, production for an entire plot where the effect of number of plants was included increased markedly with increases in scalp width. Cheatgrass competition, although it limited growth of all the planted shrubs, was less limiting to fourwing saltbush than to the other three shrubs.
    • Influence of Grazing on Crude Protein Content of Blue Grama

      Uresk, D. W.; Sims, P. L. (Society for Range Management, 1975-09-01)
      Grazing intensities of light, moderate, and heavy by cattle did not affect the protein content of blue grama herbage in northeastern Colorado. Crude protein content of live herbage changed with phenological development and with season, but no change occurred in dead herbage. During the early vegetative growth period, a high of 18% crude protein occurred in the plant tissues. Additional precipitation during the growing season did not appear to affect the content of protein in herbage.
    • Increased Range Forage Production by Reseeding and the Chemical Control of Knapweed

      Hubbard, W. A. (Society for Range Management, 1975-09-01)
      Diffuse knapweed and spotted knapweed on the lower ranges of the interior of British Columbia can be controlled by 8 oz/acre of picloram (4 amino-3,5,6, trichloropicolinic acid). Crested wheatgrass was not seriously affected by the chemical. Crested wheatgrass significantly increased forage production over the check areas when protected from grazing by domestic animals.
    • Effects of Nitrogen Fertilization, Burning, and Grazing on Reserve Constituents of Big Bluestem

      Rains, J. R.; Owensby, C. E.; Kemp, K. E. (Society for Range Management, 1975-09-01)
      During 1972 and 1973, the effects of nitrogen fertilization, burning, and grazing on total nonstructural carbohydrate (TNC) and nitrogen reserves of big bluestem (Andropogon gerardi Vitman) were studied in the Kansas Flint Hills. TNC and nitrogen reserves were lowered when growth exceeded photosynthetic production and nutrient assimilation. TNC reserves were lowest in unburned, heavily fertilized, pastures; nitrogen in storage organs increased linearly as nitrogen fertilization was increased. TNC was higher in burned than in unburned pastures, regardless of fertilization rate. Increasing the grazing rate when nitrogen fertilization was increased had little effect on reserves at senescence.
    • Effect of Surface-applied Sulfuric Acid on Growth and Nutrient Availability of Five Range Grasses in Calcareous Soils

      Ryan, J.; Stroehlein, J. L.; Miyamoto, S. (Society for Range Management, 1975-09-01)
      In a greenhouse pot study, the application of concentrated sulfuric acid to two calcareous soil surfaces significantly increased growth of five range grasses: Lehmann lovegrass (Eragrostis lehmanniana Nees.), Wilman lovegrass (E. superba Peyr.), atherstone lovegrass (E. atherstonei Stapf.), weeping lovegrass (E. curvula (Schrad.) Nees.), and blue panicgrass (Panicum antidolale Retz.). These species varied in their response to soil applied phosphorus (P), iron (Fe), and sulfuric acid. The effectiveness of H2SO4 was attributed principally to increased solubility of these elements. Sulfuric acid, being produced in large quantities in the Southwest, may prove to be a suitable alternative to existing Fe and P fertilizers.
    • Effect of Site and Fertilization on Protein Content of Native Grasses

      Goetz, H. (Society for Range Management, 1975-09-01)
      Protein content of selected native range grass and sedge species was followed during the course of the growing season over a 6-year period on four major range sites in western North Dakota. The study included three rates of nitrogen fertilizer plus some added treatments of phosphorus alone and in combination with nitrogen during the study. Protein content varied appreciably between the same species on different sites, different species on the same site, and between the same species on the same site due to fertilization. Certain species were inherently high in protein content (Agropyron smithii), while others were intermediate (Stipa comata and Stipa viridula), and still another was comparatively low (Bouteloua gracilis). The presence of nitrogen fertilizer generally increased protein content of all species regardless of level of treatment or site; the magnitude of increase, however, varied greatly between sites and species. Decline in protein content is progressive in all species with the advance in maturity regardless of fertilizer treatment level or site. However, the rate of protein loss is accelerated with fertilization and becomes more rapid with a decline in summer moisture. Cool-season species show a more rapid protein loss than was observed from warm-season Bouteloua gracilis. The length of the grazing period when forage values remain near the minimum protein requirement is appreciably extended on some sites with certain species, especially Bouteloua gracilis. Proper range management must take into consideration the potential of each major range site and the inherent species capabilities to produce and maintain a high level of protein for an extended period of grazing.