• Floating Sheets of Foam Rubber for Reducing Stock Tank Evaporation

      Dedrick, A. R.; Hansen, W. R.; Williamson, W. R. (Society for Range Management, 1973-11-01)
      Foam rubber sheet stock, 48 inches wide and 3/16 inch thick, was lap jointed, using a contact cement, to fabricate three floating covers. Their performance was evaluated on 24-and 30-foot diameter water-storage tanks. Generally, field performance was satisfactory. Minor problems observed included: pecking by birds, temporary clogging of bailing holes, and separation of the cover from an ice surface. None of these problems are expected to cause cover failure. The estimated cost of saving potentially evaporated water in a 4-foot per year evaporation zone ranges from $1.80 to $2.00 per 1,000 gallons. Such a cost may be justifiable when compared to costs of alternate means of producing or saving an equal amount of water.
    • How to Prepare a Range Soil Monolith

      Donaldson, Norman C.; Beck, Dewayne J. (Society for Range Management, 1973-11-01)
      Step-by-step instructions are given for preparation of range soil and vegetation monoliths. These are slices of range vegetation and soil mounted on boards for demonstrations and educational purposes. A complete list of materials needed for preparation of monoliths is described.
    • Model Development for a Deferred-grazing System

      Smith, R. C. G.; Williams, W. A. (Society for Range Management, 1973-11-01)
      A model of the early growth of an annual pasture and liveweight response of grazing sheep was built using first order differential equations to study the practice of deferred grazing. The dynamic behavior of the system over time was simulated by solving the equations on a computer. The model is an interpretative representation of a subterranean clover pasture in Western Australia and relates to a specific site and set of seasonal conditions. Use was made of the literature and a recent grazing experiment to develop the model. Herbage growth is estimated from known relationships with radiation received, leaf area exposed, soil moisture, and herbage removed by grazing. Change in soil moisture is estimated from rainfall and pan evaporation data. Defoliation is based on stocking rate, pasture weight, and pasture height to account for the effects of animal numbers and availability of pasture. Liveweight change of the consuming animal is calculated as a function of intake, digestibility, and the partitioning of metabolizable energy between maintenance and weight change. Validation of the model by results observed in the grazing experiment is presented.
    • Mortality in Crested Wheatgrass and Russian Wildrye

      McLean, A.; van Ryswyk, A. L. (Society for Range Management, 1973-11-01)
      Mortality in crested wheatgrass and Russian wildrye near Kamloops, B.C., was observed in spring, 1970, and appeared to result from lower than average soil moisture reserves the previous season. Damage was heavy on a silt loam that graded to loamy fine sand at 50-cm depth but was negligible on a uniform sandy loam overlying cobbly loamy sand. Field moisture levels below 25-cm depth in the soil were greater on the sandy loam site than on the silt loam in spring, 1970. In that year, crested wheatgrass reached seed-set stage on the former, but inflorescences did not emerge from the boot on the latter site, where significant mortality occurred. No other published account of severe mortality of established stands of these grasses has been found.
    • Runoff and Sediment Yields from Runoff Plots on Chained Pinyon-Juniper Sites in Utah

      Gifford, G. F. (Society for Range Management, 1973-11-01)
      Runoff and sediment production from a chained pinyon-juniper site in both southeastern and southwestern Utah was measured from about June 6 to October 1 over a 5-year period (1968-1972) using .04-hectare (0.11 acre) runoff plots. Treatments evaluated included chained-with-debris-windrowed, chained-with-debris-in-place, and natural woodland. All treatments were fenced to exclude livestock. Runoff events occurred at both sites during only 2 years (1968, 1970) of the study. Results indicate that chained-with-windrowing plots yield from 1.2 to 5 times more water during a runoff event than respective woodland plots. Runoff from debris-in-place plots was equal to or less than that measured from the natural woodland for all storms. Runoff data and sediment indexes indicate that when runoff exceeds about 0.1 cm from the woodland, from 1.6 to 6 times more sediment can be expected from windrowed sites than from adjacent woodland. Sediment yields from debris-in-place sites were similar to those from adjacent unchained woodland for all storms during this study.
    • Satellite Imagery for Assessing Range Fire Damage in the Nebraska Sandhills

      Seevers, Paul M.; Jensen, Peter N.; Drew, James V. (Society for Range Management, 1973-11-01)
      Initial imagery from the first Earth Resources Technology Satellite indicates that satellite-acquired data is of value in determining the location and extent of range fire in the Sand Hills region of Nebraska. Preliminary results suggest that it can also provide a tool for monitoring soil erosion by wind and evaluating the recovery of vegetation in burned areas.
    • Seasonal Change in Nutritive Value of Bluestem Pasture

      Rao, M. R.; Harbers, E. F.; Smith, E. F. (Society for Range Management, 1973-11-01)
      Esophageally fistulated steers were used to determine organic matter intake and digestibility of bluestem pastures during the summer grazing season. Following a 48-hour total fecal collection period, esophageally fistulated steers were used to collect grazed samples of native pastures during June, July, August, September, and October. Esophageal samples were higher in ash and crude protein and lower in crude fiber, N-free extract, and acid detergent fiber than were hand-clipped samples. In vitro dry and organic matter digestibilities were higher in forage collected by cattle than in hand-clipped forage. Multiple regression equations were developed to predict in vitro digestibility. Only crude protein and acid-detergent fiber were highly correlated with digestibility. Average daily intakes of organic matter, digestible crude protein, and digestible energy by steers on pasture were estimated from fecal nitrogen regression established from hay trials. Protein apparently became limiting about mid-July and energy in late August. The positive effects of burning were increased forage yield and weight gain with lowered lignin content.
    • Soil Moisture Patterns on Two Chained Pinyon-Juniper Sites In Utah

      Gifford, G. F.; Shaw, C. B. (Society for Range Management, 1973-11-01)
      Soil moisture patterns were studied under chaining-with-windrowing, chaining-with-debris-in-place, and natural woodland at one site each in both southwestern and southeastern Utah. Results of the study indicate the greatest moisture accumulation occurred under the debris-in-place treatment (as compared to woodland controls), during the first 6 months of each year at Milford and regardless of season at Blanding. The woodland had the least soil moisture throughout most of each year. Most moisture flux took place in the upper 60- to 90-cm of soil profile, with only minor changes occurring at greater depths. Differences in soil moisture patterns have been attributed to changes in microclimates due to chaining, different rooting depths and length of growing season, mulching effect of litter on the debris-in-place treatment, and possible differences in snow accumulation. Variation in vegetation density on the chained treatments did not influence soil moisture patterns. There was no evidence of deep seepage on any chaining treatment at either site.
    • Soil Moisture Response to Spraying Big Sagebrush the Year of Treatment

      Sturges, D. L. (Society for Range Management, 1973-11-01)
      Spraying big sagebrush with 2,4-D in Wyoming reduced soil moisture loss 24% between June 24, the treatment date, and September 30. All of the reduction accrued by August 4, during the time of active vegetative growth. Moisture was measured to a 6-ft depth and 83% of the reduction was located in soil 2 to 6 ft deep.
    • Soil Physical and Physico-chemical Variability Induced by Atriplex nummularia

      Sharma, M. L. (Society for Range Management, 1973-11-01)
      Spatial variability in two soils supporting 10-year old stands of saltbush (Atriplex nummularia) was examined by evaluating various soil physical and physico-chemical properties under and between the plants. The differences in soil properties between these two positions were mostly significant for the surface layer (0-7.5 cm) but only in a few cases for the 7.5-15 cm layer. No differences were observed below this depth. Presence of A. nummularia resulted in increased electrolyte concentration, higher sodium adsorption ratio, and higher levels of exchangeable sodium and organic matter in the surface soil. Standard laboratory measurements showed that these physico-chemical changes induced a significant deterioration in the structure of the surface soil under the plants as indicated by reduced aggregate stability, poorer drainage, and lowered hydraulic conductivity. Field studies suggested that the bulk density of the surface soil was reduced under the plants but that water penetration and storage in the profile after rains remained unaffected. Probable reasons for these effects are discussed.
    • Southern Pine Overstories Influence Herbage Quality

      Wolters, G. L. (Society for Range Management, 1973-11-01)
      A cover of young longleaf or slash pines increased protein and phosphorus and decreased nitrogen-free extract in herbage on pine-bluestem range. Under protection from grazing, the proportion of big bluestem in the herbage stand increased more on forested than cutover land. Herbage decreased about 15 lb/acre for every 1 ft2 increase in pine basal area.
    • Vegetation Changes between 1943 and 1965 on the Shortgrass Plains of Wyoming

      Lang, R. (Society for Range Management, 1973-11-01)
      Ground cover estimates on permanently marked plots in East Central Wyoming were compared between 1943 and 1965. On grazed native range plots, shortgrasses increased and midgrasses decreased when comparing 1965 to 1943. Plots in exclosures showed a decrease in shortgrass cover and an increase in cover of midgrasses. Generally, big sagebrush (Artemisia tridentata) and plains pricklypear (Opuntia polyacantha) increased markedly on both open and exclosure plots. Due to excessive grazing pressure, the total perennial grass cover on a section of abandoned farmland was nearly 35% less in 1965 than in 1943.
    • Water Harvesting Efficiencies of Four Soil Surface Treatments

      Rauzi, L.; Fairbourn, M. L.; Landers, L. (Society for Range Management, 1973-11-01)
      Water harvesting efficiency of four soil surface treatments was studied for 5 years at Gillette, Wyoming, and the Central Plains Experimental Range near Nunn, Colorado. The surface treatments consisted of rangeland, salt (NaCl), plastic covered with pea gravel, and asphalt roll roofing. Average water harvesting efficiencies ranged from 5% on rangeland at Gillette to 105% from the asphalt roll roofing treatment at the Central Plains Experimental Range. Spring and fall snowstorms resulted in water harvesting efficiencies of over 100% at the Central Plains Experimental Range. Precipitation was highest in April, May, and June and lowest in August.
    • Wax-treated Soils for Harvesting Water

      Fink, D. H.; Cooley, G. W. (Society for Range Management, 1973-11-01)
      Shortage of water for livestock often limits the carrying capacity of rangeland. Water harvesting can provide extra water. Paraffin wax was applied as granules or flakes on the surface of two experimental watershed plots and allowed to melt and spread in the hot desert sun to form a hydrophobic soil surface, which then readily shed water. The wax-treated plots yielded an average of 90% precipitation runoff, compared to only 30% runoff from two untreated plots and to 100% runoff from a butyl-covered plot.