• Genetic Variability for Characters Affecting Stand Establishment in Crested Wheatgrass

      Asay, K. H.; Johnson, D. A. (Society for Range Management, 1983-11-01)
      Experiments were conducted in the laboratory (growth chamber) and field to determine the: (1) magnitude of genetic differences in crested wheatgrass [Agropyron cristatum (L.) Gaertn. and A. desertorum (Fisch. ex Link) Schult.] for characteristics related to seedling establishment on semiarid range and (2) effectiveness of laboratory procedures to estimate relative performance of breeding lines in the field. Significant differences were found among 175 crested wheatgrass progeny lines for seedling emergence, seedling height, seedling dry weight, and fall stand in the analyses of data combined over 2 field locations. The soil at both study sites was a Xerallic Calciorthids. The genetic variance among progenies comprised over 50% of the total phenotypic variance for most traits in the combined analyses of variance. Seedling emergence in the spring was positively related to fall stands (r = 0.54** to 0.61**). In growth chamber experiments involving 168 progeny lines, significant genetic variation was detected in seedling recovery after exposure to drought stress in 3 of 4 experiments. The genetic variance comprised over 50% of the total phenotypic variance in 5 of 6 instances in the combined analyses of the field data and in 3 of the 4 laboratory experiments. In general, laboratory determinations of seedling emergence under drought stress and seedling recovery after drought were not significantly related to seedling establishment in the field. A relatively close correlation between seed weight and all plant responses measured in the field (r = 0.46** to 0.57** in the pooled data) suggests that preliminary screening on the basis of seed weight appears promising.
    • Pronghorn Reactions to Winter Sheep Grazing, Plant Communities, and Topography in the Great Basin

      Clary, W. P.; Beale, D. M. (Society for Range Management, 1983-11-01)
      The winter distribution of pronghorn over a 142-km2 area on the Desert Experimental Range was significantly related to sheep grazing during the current winter, presence of black sagebrush, and topographic characteristics. Even moderate sheep use during the dormant period left grazing units relatively unfavorable for pronghorn until spring regrowth-at least on ranges where key pronghorn forage plants were in short supply. Winter use areas preferred by pronghorn were above the valley bottoms in rolling to broken topography where black sagebrush communities were evident. Movement characteristics of pronghorn have allowed many of them to readily locate rested grazing units, and, therefore, avoid severe dietary competition with sheep.
    • Relationship Between Selected Factors and Internal Rate of Return from Sagebrush Removal and Seeding Crested Wheatgrass

      Shane, R. L.; Garrett, J. R.; Lucier, G. S. (Society for Range Management, 1983-11-01)
      One alternative in increasing western range forage production is sagebrush removal and seeding crested wheatgrass. Of primary importance when considering such investments is economic profitability. Using internal rate of return (IRR) as a measure of economic profitability, a range improvement computer budget program (RIBPRO) was used to calculate IRR's for a specific ranch example. Factors associated with high IRR's are a constant forage production function over time, agricultural conservation payments, a 30-year or older stand, approximately 80 ha or more of improved range, low initial user cost/ha, and high additional kg of forage/ha.
    • Residual Effects of Liquid Digested Sludge on the Quality of Broomsedge in a Pine Plantation

      Dunavin, L. S.; Lutrick, M. C. (Society for Range Management, 1983-11-01)
      Broomsedge (Andropogon virginicus L.) is generally looked upon with some disfavor as a weed but has been utilized for grazing. Liquid digested sludge (LDS) has been tested as a fertilizer on tree plantations where broomsedge comprises a portion of the understory. Broomsedge samples were collected 4 years after treatment of a slash pine (Pinus caribaea More.) plantation with LDS containing 0, 21.6, 40.5, 62.1, 83.7, and 102.6 t/ha of dry solids. Sludge was applied both as a top application and incorporated prior to tree planting. Crude protein (CP) of grass samples was generally increased with an increase in sludge application. In vitro organic matter digestibility (IVOMD) appeared to decrease with increased sludge application under conditions of top application only. The understory at the 0 and 21.6 t/ha-rates of sludge was about 67% broomsedge. At the higher sludge rates, the understory was only 10% broomsedge or less.
    • Evaluating Management Alternatives with a Beef Production Systems Model

      Kothmann, M. M.; Smith, G. M. (Society for Range Management, 1983-11-01)
      Simulation techniques were utilized to study alternative management practices for cow-calf operations in the Coastal Prairie of Texas. Data obtained over a 6-year period from a cooperating ranch were used to validate a beef production model successfully. Management practices evaluated with the model included fall, winter, spring, and split (fall-spring) calving seasons, July 1 and October 1 weaning dates, and two levels of nutrition. Eight combinations of these practices were simulated. Winter calving increased death losses of calves compared to fall and spring at the base nutritional level. Fall calving increased weaning weights, whereas spring calving increased the present calf crop. Fall calving with improved nutrition resulted in the highest level of calf production. Resource limitations frequently prevent screening many management combinations by field research techniques. Simulation can be a valuable aid for integrating and extending experimental data and for selecting the most promising combinations of practices for field testing.
    • Effects of Soil Moisture on Burned and Clipped Idaho Fescue

      Britton, C. M.; Clark, R. G.; Sneva, F. A. (Society for Range Management, 1983-11-01)
      Idaho fescue (Festuca idahoensis) plants were burned and clipped under 2 soil water regimes. Treatments were applied to plants in late August and mid-October located in eastern Oregon. Results indicated that watering plants either before or after burning produced no beneficial effects as measured by changes in basal area or yield. Regardless of treatment, plant damage was greater with late August as contrasted to mid-October treatment dates. These data do not support the opinion that high soil moisture is necessary prior to fall burning of sagebrush-bunchgrass communities.
    • Effects of Late Season Cattle Grazing on Riparian Plant Communities

      Kauffman, J. B.; Krueger, W. C.; Vavra, M. (Society for Range Management, 1983-11-01)
      Livestock impacts on riparian plant community composition, structure, and productivity were evaluated. After 3 years of comparison between fall grazed and exclosed (nongrazed) areas, 4 plant communities out of 10 sampled displayed some significant species composition and productivity differences. Two meadow types and the Douglas hawthorne (Crataegus douglasii) community type had significant differences in standing phytomass. These also were utilized more heavily than any other communities sampled. Shrub use was generally light except on willow (Salix spp.)-dominated gravel bars. On gravel bars, succession appeared to be retarded by livestock grazing. Few differences were recorded in other plant communities sampled, particularly those communities with a forest canopy.
    • Impacts of Cattle on Streambanks in Northeastern Oregon

      Kauffman, J. B.; Krueger, W. C.; Vavra, M. (Society for Range Management, 1983-11-01)
      Impacts of a late season livestock grazing strategy on streambank erosion, morphology, and undercutting were studied for 2 years along Catherine Creek in northeastern Oregon. Streambank loss, disturbance, and undercutting were compared between grazing treatments, vegetation type, and stream-meander position. No significant differences were found among vegetation types or stream-meander location. Significantly greater streambank erosion and disturbance occurred in grazed areas than in exclosed areas during the 1978 and 1979 grazing periods. Over-winter erosion was not significantly different among treatments. However, erosion related to livestock grazing and trampling was enough to create significantly greater annual streambank losses when compared to ungrazed areas.
    • Genetic Differences in Resistance of Range Grasses to the Bluegrass Billbug, Sphenophorus Parvulus (Coleoptera: Curculionidae)

      Asay, K. H.; Hansen, J. D.; Haws, B. A.; Currie, P. O. (Society for Range Management, 1983-11-01)
      Significant differences in plant resistance to larvae of the bluegrass billbug, Sphenophorus parvulus Gyllenhal (Coleoptera: Curculionidae), were found among and within range grass species and interspecific hybrids in nurseries at the Decker, Mont., surface mine and on a site near Miles City, Mont. Slender wheatgrass (Elymus trachycaulus) and related species were particularly susceptible. Crested wheatgrass (Agropyron cristatum and A. desertorum), thickspike wheatgrass (E. lanceolatus), Russian wildrye (Psathyrostachys juncea), and salina wildrye (Leymus salinae) were among the species with a relatively high degree of resistance to the insect. Clonal lines of the Et. repens × Et. spicata hybrid differed significantly in resistance. Over 50% of the total phenotypic variation among the hybrid lines was attributed to genetic effects, indicating that selection for resistance would be effective.
    • Long-Term Effects of Big Sagebrush Control on Vegetation and Soil Water

      Sturges, D. L. (Society for Range Management, 1983-11-01)
      Herbaceous productivity of mountain big sagebrush (Artemisia tridentata spp. vaseyana) areas sprayed with 2,4-D (2,4-dichlorophenoxyacetic acid) was nearly twice that of untreated areas 10 years after spraying, while the number of sagebrush plants on treated areas was 4% of that before spraying. Soil at the Wyoming study site was a Youga loam (Argic Cryoboroll). On treated areas, soil water depletion from the surface 0.9 m of soil slightly exceeded that of untreated areas beginning the third year after spraying when herbaceous vegetation had fully responded to release from sagebrush competition. Water depletion in soil 0.9 m to 1.8 m deep was substantially less on sprayed areas compared to unsprayed areas. Seasonal water depletion in the surface 1.8 m of soil was reduced 31% the year of treatment, and about 7% between 5 and 11 years after treatment. Mathematical relationships were developed to predict the effect of sagebrush control on seasonal water depletion in the surface 1.8 m of soil, the surface 0.9 m of soil, and soil 0.9-1.8 m deep.
    • Management Considerations to Enhance Use of Stock Ponds by Waterfowl Broods

      Rumble, M. A.; Flake, L. D. (Society for Range Management, 1983-11-01)
      Use of 36 livestock watering ponds by mallard (Anas playtrhynchos), blue-winged teal (A. discors), and total broods was tested against 32 habitat variables from 1977 and 1978. Pond size, shallow water areas with submersed vegetation, number of natural wetlands in a 1.6-km radius, and emersed vegetation composed of smartweed (Polygonum spp.) and spikerush (Eleocharis spp.) were associated with increased use of ponds by total broods. When analyzed by species, small grain on the surrounding section and height and density of shoreline vegetation were associated with increased use of ponds by mallard broods; percent of shoreline with trees and percent arrowhead (Sagittaria spp.)/water plantain (Alisma spp.) were associated with decreased use of ponds by mallard broods. Percent river bulrush (Scirpus fluviatilis)/burreed (Sparganium spp.) was associated with decreased use of ponds by blue-winged teal.
    • Edaphic Factors Influencing the Control of Wyoming Big Sagebrush and Seedling Establishment of Crested Wheatgrass

      Cluff, G. J.; Young, J. A.; Evans, R. A. (Society for Range Management, 1983-11-01)
      The physiographic position and taxonomic identity of soils of a Wyoming big sagebrush (Artemisia tridentata spp. wyomingensis)/grassland community were determined. Surface soil materials from each identified soil were analyzed for a variety of chemical and physical properties. Areas of each soil were either burned, sprayed with 2,4-D [(2,4-dichlorophenoxy) acetic acid], or plowed for sagebrush control and seeded to crested wheatgrass (Agropyron desertorum cultivar Nordan). Spraying and plowing resulted in significantly (p=0.05) different sagebrush mortalities of 75 and 62% averaged over all soils with brush mortality being much higher on some soils than others. Burning resulted in 100% sagebrush mortality on all soils. Seedling establishment of crested wheatgrass was significantly higher on plowed than sprayed soils with 9 and 6 seedlings per meter of row, respectively. Soils of burned areas averaged 5 seedlings per meter of row on a dry year. Most seedlings were established on loamy soils regardless of the method of brush control. Multiple regression analyses of edaphic factors were used to develop equations predicting brush mortality and seedling establishment in sprayed and plowed areas. Soil series descriptions include data which could be used in making such predictions.