• Influence of Date of Planting on Emergence of Cultivars of Trifolium hirtum All. and Triflium subterraneum L.

      Evans, R. A.; Kay, B. L.; Young, J. A. (Society for Range Management, 1976-07-01)
      Emergence by seven cultivars of rose clover (Trifolium hirtum All.) and eight cultivars of subclover (T. subterraneum L.) was studied in relation to date of planting in a plant community on cismontane California annual range. Numerous dates of planting were used in each of three growing seasons, from 2 months before to 2 months after the first rain in the fall. The temperature in the seedbed was monitored hourly from the first planting date through clover emergence. The seeded clovers, including seeds of all previous plantings, germinated at the time of the first effective rains. Where seeds were exposed to high soil temperatures (30-50°C), early fall planting generally reduced seedling emergence in cultivars of rose clover, but enhanced or did not affect emergence in subclover. In 2 of the 3 years, seeding after the first rain gave significantly lower emergence. Maximum seedbed temperatures below 10°C allowed only very limited emergence.
    • Impact of Wildfire on Three Perennial Grasses in South-Central Washington

      Uresk, D. W.; Cline, J. F.; Rickard, W. H. (Society for Range Management, 1976-07-01)
      In a south-central Washington sagebrush-bluebunch wheatgrass community, bluebunch wheatgrass responded to burning by increased vegetative and reproductive performance. Burning decreased the vegetative and reproductive vigor of Cusick bluegrass and Thurber needlegrass.
    • Grazing and Debris Burning on Pinyon-Juniper sites—Some Chemical Water Quality Implications

      Buckhouse, J. C.; Gifford, G. F. (Society for Range Management, 1976-07-01)
      During 1973 and 1974 a water quality study was conducted in San Juan County, southeastern Utah. Water quality data were collected from the study location which had been chained to remove pinyon-juniper vegetation six years earlier. Debris burning and livestock grazing treatments were studied. An "undisturbed, natural" woodland was left adjacent to the treatments in order to serve as a control area. Following burning, significant increases in potassium and phosphorus were observed in overland flow from infiltrometer plots. No significant treatment changes were detected for sodium, calcium, or nitrate-nitrogen. No treatment differences due to grazing were detected at the soil surface following cattle use (stocking rate was 2 ha/AUM).
    • Foods of Free-Roaming Horses in Southern New Mexico

      Hansen, R. M. (Society for Range Management, 1976-07-01)
      Seasonal foods of free-roaming wild horses were determined in southern New Mexico by microhistological analyses of fecal samples. The most important forages consumed annually by wild horses were Russianthistle (29%), dropseed (21%), mesquite (16%), and Junegrass (12%). Seasonal differences in the percentages of the diets were found for mesquite, Junegrass, and saltbush.
    • Fast Filter for In Vitro Studies

      Dietz, D. R.; Messner, H. E. (Society for Range Management, 1976-07-01)
      A crucible for filtering plant material is made by modifying an aluminum 35-mm film canister to hold the filter, composed of glass wool fiber and nylon curtain mesh. Cleaning and preparation of the conister for a new test is simplified by disposing of the used filter and inserting a new one. Comparison with sintered glass crucibles showed no significant differences in in vitro digestible dry matter values.
    • Expressing the Competitive Relationship between Wyoming Big Sagebrush and Crested Wheatgrass

      Rittenhouse, L. R.; Sneva, F. A. (Society for Range Management, 1976-07-01)
      Crested wheatgrass production was negatively correlated with Wyoming big sagebrush crown cover. Each 1% increase in sagebrush crown cover was associated with a decline in crested wheatgrass production equivalent to 3.3 to 5.2% of its potential within the range of cover measured. Expression of this relationship in the above manner may enable sounder economic analysis than conventional methods now used.
    • Estimating Potential Downy Brome Competition after Wildfires

      Young, J. A.; Evans, R. A.; Weaver, R. A. (Society for Range Management, 1976-07-01)
      To plan for revegetation and management of big sagebrush communities burned in wildfires, wildland managers need guidelines for estimating potential downy brome competition. A bioassay technique was used to determine the density of viable downy brome caryopsis in relation to burn and seedbed characteristics. The amount of unburned organic matter was found to be the characteristic most highly correlated with potential populations of downy brome. By determining the relative cover of ash and unburned organic matter, land managers can estimate potential reinfestation of downy brome and thus determine best weed control-seeding techniques in wildfire rehabilitation.
    • Effects of Cattle Grazing and Wildfire on Soil-Dwelling Nematodes of the Shrub-Steppe Ecosystem

      Smolik, J. D.; Rogers, L. E. (Society for Range Management, 1976-07-01)
      A comparison was made between nematode density and biomass values in grazed, ungrazed, and burned areas within a shrub-steppe community located on the Arid Lands Ecology Reserve in south-central Washington. Highest total population biomass values on grazed, ungrazed, and burned areas were 405, 502, and 400 $mg/m^{2}$, respectively. There were not consistent differences in density or biomass values between treatments, resulting in the conclusion that short-term effects associated with cattle grazing and burning had little impact on soil-dwelling nematodes.
    • Effect of Prescribed Burning on Sediment, Water Yield, and Water Quality from Dozed Juniper Lands in Central Texas

      Wright, H. A.; Churchill, F. M.; Stevens, W. C. (Society for Range Management, 1976-07-01)
      Prescribed burning was applied to six miniwatersheds that were each paired with an unburned watershed. Erosion losses, runoff, and water quality were unaffected on level areas, but adverse effects lasted for 9 to 15 months on moderate slopes and for 15 to 30 or more months on steep slopes. Rates of erosion losses stabilized within 18 months on all slopes when vegetative cover reached 63 to 68%.
    • Cultural Energy Expended in Range Meat and Fiber Production

      Cook, C. W. (Society for Range Management, 1976-07-01)
      Range livestock production requires more cultural energy than commonly believed. However the cultural energy expended for range meat and fiber is considerably less than that required in confined fattening procedures. Complementing rangelands with dryland forages offers great promise in decreasing the cost of fossil fuel to produce a pound of red meat for human consumption, compared to feedlot fattening.
    • Clipping Effects on Dry Matter Yields and Survival of Basin Wildrye

      Perry, L. J.; Chapman, S. R. (Society for Range Management, 1976-07-01)
      Effects of frequency and height of clipping basin wildrye over a 4-year period on yield and plant survival in the fifth year were studied. Yield and survival were reduced with close and frequent clippings (6 vs 9 week frequencies and 15 vs 30 cm heights), but growth stage at the first clipping did not significantly reduce either yield or survival. We conclude that reduced yield and survival in response to the clipping treatments are due to a previously reported decline in plant vigor, which is related to levels of carbohydrate reserves.
    • Caloric Content of Rocky Mountain Subalpine and Alpine Plants

      Andersen, D. C.; Armitage, K. B. (Society for Range Management, 1976-07-01)
      Caloric equivalents for aboveground parts of Rocky Mountain subalpine and alpine herbaceous plants averaged 4,859 cal/g ash-free oven-dry weight. Ash content averaged 9.8% for 17 forbs. Both caloric content and ash content ranged higher than values for alpine species from New Hampshire.
    • Botanical Composition of Eland and Goat Diets on an Acacia-grassland Community in Kenya

      Nge'the, J. C.; Box, T. W. (Society for Range Management, 1976-07-01)
      A study of goat and eland diets on the Kiboko Range Research Station, Kenya, showed that diets of both animal species consisted of leaves from relatively few plant species. Six of the 41 species available consistently provided the bulk of the diets of both goats and elands. Although elands utilized a wide variety of plants, they consumed a larger proportion of grasses than goats. Elands are mixed feeders (grazers and browsers), grazing both during the wet and dry period. The diets of both kinds of animals were more diverse during the growing season (February through May), compared to the dry season (July through October). This reflected the greater variety of available forage during the wet season.
    • Bahiagrass Regrowth and Physiological Aging

      Sampaio, E. V. S. B.; Beaty, E. R.; Ashley, D. A. (Society for Range Management, 1976-07-01)
      Pensacola Bahiagrass (Paspalum notatum Flugge) grows by adding new phytomers to the terminal ends of vegetative stolons. A new phytomer and its attached leaf is added on average each 7 to 12 days during growth as long as the tiller is vegetative. The new leaf is supplied with energy primarily for the first 2 to 3 days of growth and, from 3 days of age until fully expanded at 12 days, photosynthates are retained by the leaf. After 12 days, exports are made to other sinks in the sheath, stolon, root, and new tillers. An investigation was completed in which (a) shoot growth (leaves) of plants fertilized with 0, 100, or 300 kg/ha of N were measured for length and clipped at the top of the stolon daily or weekly until the stolons died, (b) photosynthesis rate of leaves of different ages was determined, and (c) photosynthesis was correlated with leaf chlorophyll, and N content by weeks. Thirteen weeks of daily or weekly clipping were required to kill the stolons and regrowth amounted to 749 to 850 kg/ha of dry leaves. Total length of shoot regrowth per square meter ranged between 13 to 22 m for the 13 weeks and was negatively related to N application rate. Photosynthesis started dropping after approximately 25 days, but leaf N and chlorophyll contents were relatively stable for the first 45 days. After 45 days of age all three factors declined rapidly until leaf death occurred 60 ± 6 days after initiation. Stolons live much longer than do leaves.
    • An Evaluation of Barrel Medic (Medicago truncatula) as an Introduced Pasture Legume for Marginal Cropping Areas of Southeastern Australia

      Michalk, D. L.; Beale, J. A. (Society for Range Management, 1976-07-01)
      The potential of barrel medic (Medicago truncatula) as a possible improved pasture legume for introduction to marginal cropping areas was examined with breeding Merino ewes at four stocking rates. Although the dry matter production was similar to that of natural pasture, the proportion of barrel medic, ranging from 5 to 30%, was higher than that of naturalized medics in adjacent natural pasture areas. However, although barrel medic persisted in the pasture under all stocking treatments, it was unable to compete with barley grass (Hordeum leporinum), which invaded the pasture soon after establishment. While the pasture could support 5 ewes per hectare under favourable seasonal conditions with only moderate supplementary feeding in winter, it could not adequately support any stocking rate under drought conditions without considerable supplementary feeding. Annual wool production per head declined significantly with increased stocking rate and adverse seasonal conditions. Stocking rate did not affect lamb growth rates, but drought caused a high lamb mortality rate. The usefulness of barrel medic at Trangie is questionable, since it did not significantly improve either carrying capacity or lamb growth rates above that of natural pasture. At the same time, lucerne pastures under rotational management were able to support higher stocking rates and improve lamb growth above those of either barrel medic or natural pasture.
    • A Supporting Device for Use with Stepwise Thermal Sensors

      Probasco, G. E.; Bjugstad, A. J.; Pierce, R. W. (Society for Range Management, 1976-07-01)
      A mechanical supporting device is described for use with stepwise thermal sensors. The sensor stand was used for estimating temperatures at various levels below, within, and above the burning fuel.
    • Variable Germination Response to Temperature for Different Sources of Winterfat Seed

      Moyer, J. L.; Lang, R. L. (Society for Range Management, 1976-07-01)
      Superior sources of winterfat seed for range revegetation should be sought, but a clearer concept of what constitutes a "superior" type is necessary. Laboratory germination temperature response of seed collected from three sources was determined. Some positive reactions to 5 degrees C prechilling were observed 13-16 weeks after collection. When the same seedlots were subjected to constant temperatures of 5 degrees C, 10 degrees C, and 20 degrees C, seed from plants originating at the lower elevations (Simla, Colorado and Pine Bluffs, Wyoming) germinated best at the lower temperatures, unlike seed collected from a Laramie, Wyoming source. Kinetic studies of germination verified that rates varied among the seedlots, but were not associated with differences during any particular stage of germination. Different temperature responses between seedlots could have practical implications regarding stand establishment.
    • Twenty Years of Changes in Grass Production Following Mesquite Control and Reseeding

      Cable, D. R. (Society for Range Management, 1976-07-01)
      Production of native perennial grasses and seeded Lehmann lovegrass was measured periodically for 21 years on a semidesert area where velvet mesquite was controlled by 2,4,5-T aerial spray and on an adjacent unsprayed area to determine how mesquite control would affect grass production and how long the effect would last. Grass production on the sprayed area increased dramatically during the first 5 years in a time-dependent relationship in response to the higher levels of available soil moisture. During the last 12 years, changes in lovegrass production were associated with changes in summer rainfall of the current and previous summers and of the intervening winter (2 separate variables). Because of the strong competition from lovegrass, native grass production during the last 12 years did not show its usual relationship with summer rainfall, but decreased gradually and consistently on both the sprayed and unsprayed areas. At the end of the study period, native grasses provided only 10% of the total perennial grass production on the sprayed area and 20% on the unsprayed. Increased grass production, resulting from the mesquite control treatment and seeding, paid for the treatment within 4 years, and the sprayed area was still producing more grass than the unsprayed area 20 years later.
    • Toxicity of Bassia hyssopifolia to Sheep

      James, L. F.; Williams, M. C.; Bleak, A. T. (Society for Range Management, 1976-07-01)
      Bassia hyssopifolia, an introduced annual, is toxic to sheep. Signs of poisoning in sheep dying from acute bassia intoxication included weakness, incoordination, tetany, and coma. The toxic principle is probably an oxalate. On the basis of oxalate content, bassia is more toxic than halogeton (Halogeton glomeratus), another oxalate-producing plant. Bassia hyssopifolia should not be further seeded or allowed to increase, and care should be taken when grazing livestock on existing stands.
    • The Effects of Weather Modification on Northern Great Plains Grasslands: A Preliminary Assessment

      Perry, D. A. (Society for Range Management, 1976-07-01)
      Possible effects of weather modification on Northern Great Plains Grasslands are examined using published reports on community-water relations. It is concluded that (1) long-term incremental forage production will be governed by the effect of added water on nutrient cycling rates; (2) community composition will change, but the nature of the change will depend on the timing of added precipitation; and (3) increased forage in the absence of increased nitrogen may have a neutral or negative effect on livestock weight gains.