• Botanical Composition and Diet Quality of Cattle Under a Short Duration Grazing System

      Kirby, D. R.; Parman, M. (Society for Range Management, 1986-11-01)
      A study was conducted in 1981 and 1982 at the Dickinson Experiment Station Ranch Headquarters in the mixed grass prairie of western North Dakota to determine seasonal and daily cattle diets under a short duration grazing system. Significant seasonal decreases in crude protein (CP) and in vitro digestible organic matter (IVDOM) were determined both years of the study. Dietary CP did not meet lactating and/or dry, pregnant cow requirements throughout the grazing season either year. In 1981, no seasonal difference in dietary CP and IVDOM was determined between the initiation and termination of grazing on individual paddocks. Only one significant difference occurred in 1982 when dietary CP decreased significantly between the first and last day of grazing individual paddocks in fall. Grass dominated cattle diets both years of the study. The major grasses selected were western wheatgrass (Agropyron smithii), needle-and-thread (Stipa comata), and blue grama (Bouteloua gracilis). Cattle showed no consistent seasonal trend in grass or browse selection, while forbs decreased in diets as the grazing season advanced. Selection of forage species and plant classes by cattle while they occupied a paddock varied little during seasonal collection periods throughout the study.
    • Broadcasting Grass Seed to Revegetate Sandy Soils

      Kocher, E.; Stubbendieck, J. (Society for Range Management, 1986-11-01)
      This study was conducted to determine the effects of tillage, irrigation levels, seed coating rates and species on grass establishment. Sand bluestem [Andropogon gerardii var. paucipilus (Nash) Fern.] and little bluestem [Schizachyrium scoparium (Michx.) Nash] seeds were coated with a lime and nutrient slurry at 3 rates and broadcast on abandoned cropland in the Nebraska Sandhills. A mixture of noncoated switchgrass [Panicum virgatum L.] and sand lovegrass [Eragrostis trichodes (Nutt.) Wood] was also broadcast. Three levels of irrigation were applied during the seeding year. Seedling establishment was higher on the disked areas than on nontilled areas. Establishment increased as irrigation level increased. Establishment of sand bluestem and little bluestem were similar, while establishment of the switchgrass-sand lovegrass mixture was less. Under the conditions of this experiment, seed coating rate had no influence on establishment.
    • Cattle Responses to Continuous and Seasonal Grazing of California Annual Grassland

      Ratliff, R. D. (Society for Range Management, 1986-11-01)
      An 8-year (1961-1968) study at the San Joaquin Experimental Range, in the Sierra Nevada foothills in central California, compared continuous, repeated seasonal, and rotated seasonal grazing on native range, and continuous grazing on sulfur-fertilized range. Cow and calf weight responses showed continuous grazing of annual grassland range to be most productive for cow-calf production. At birth, no advantage of one grazing treatment over another was found among calf weights. At the start of the adequate green forage season, calves under both continuous grazing treatments (native and fertilized) averaged 15 kg heavier than calves under rotated seasonal grazing; calves on continuously grazed fertilized range averaged 12 kg heavier than calves under repeated seasonal grazing. At weaning, calves under continuous grazing treatments averaged 25 kg heavier than calves under seasonal grazing treatments. No advantage of one grazing treatment over another was found among mature cow weights.
    • Determining Range Condition from Frequency Data in Mountain Meadows of Central Idaho

      Mosley, J. C.; Bunting, S. C.; Hironaka, M. (Society for Range Management, 1986-11-01)
      Although a useful method for monitoring changes in species composition, frequency sampling does not provide herbage production or cover data needed to use existing range condition guides. Responding to this need, frequency sampling procedures were investigated for determining range condition. Eighteen mountain meadow sites were sampled with 100 nested frequency quadrats. These quadrats had 5 plot sizes contained (nested) within 1 frame: 5×5 cm, 10×10 cm, 25×25 cm, 25×50 cm, and 50×50 cm. Rooted frequency of occurrence within each plot size was recorded by species. Discriminant analysis related a site's frequency data to its known range condition class, resulting in 2 range condition guides for mountain meadows based on frequency data. One guide was formulated with data from the 10×10-cm quadrat size, and a second guide was based on summed data from the 4 largest plot sizes. Both guides had equal resolution, correctly classifying 15 of 18, or 83%, of sites examined. Our procedures should prove valuable in developing condition guides based on frequency data in other areas and in other vegetation types.
    • Disappearance of Forage Under Short Duration and Seasonlong Grazing

      Kirby, D. R.; Pessin, M. F.; Clambey, G. K. (Society for Range Management, 1986-11-01)
      A study was conducted in 1982 and 1983 at the Dickinson Experiment Station, North Dakota, in the mixed grass prairie to determine the effects of short duration grazing (SDG) and repeated seasonlong grazing (RSLG) by cattle on graminoid, forb, and half-shrub disappearance. Five range sites were delineated within each grazing treatment and evaluated for forage availability and disappearance. Graminoid disappearance was similar, regardless of grazing treatment, each year of the study. However, forb disappearance (i.e., utilization) increased three-fold in 1982 and more than two-fold in 1983 on the SDG treatment as compared to the RSLG treatment. Half-shrub availability and disappearance were negligible both years of the study. Spatial distribution of grazing among range sites on treatments must be evaluated with caution due to limitations in study design. Treatments were not equal-sized or replicated, and area, productivity potential, and distribution of range sites within treatments varied. Despite these limitations, no consistent pattern of site preference was discernible on either grazing treatment. In addition, a greater stocking rate (75%) and density (1400%) on the SDG treatment did not improve grazing distribution as measured by forage disappearance among the diverse range sites present.
    • Effect of Herbicides and Handweeding on Establishment of Kleingrass and Buffelgrass

      Bovey, B. W.; Meyer, R. E.; Merkle, M. G.; Bashaw, E. C. (Society for Range Management, 1986-11-01)
      In the greenhouse, kleingrass [Panicum coloratum (L.) 'Selection 75'] and buffelgrass [Cenchrus ciliaris (L.) 'Nueces'] were tolerant of preemergence application of butylate (S-ethyl bis(2-methylpropyl)carbamothioate) and early postemergence sprays of barban (4-chloro-2-butynyl 3-chlorophenylcarbamate) and siduron [N-(2-methylcyclohexyl)-N′-phenylurea]. Kleingrass tolerated early postemergence sprays of bromoxynil (3,5-dibromo-4-hydroxybenzonitrile), but bromoxynil injured buffelgrass. In the field, the most promising treatments for kleingrass establishment, compared with handweeding, included postemergence sprays of 2,4-D [(2,4-dichlorophenoxy)acetic acid], preemergence application of siduron, and ropewick application of glyphosate [N-(phosphonomethy)-glycine]. Once established, kleingrass seedlings tolerate extreme drought during the growing season where weeds had been controlled.
    • Effect of Season and Regrazing on Diet Quality of Burned Florida Range

      Long, K. R.; Kalmbacher, R. S.; Martin, F. G. (Society for Range Management, 1986-11-01)
      Diet crude protein and in vitro organic matter digestibility (IVOMD) of diets of esophageally fistulated steers were compared for a pasture grazed June to September ("summer" pasture) and again in January to March ("winter-regraze") with a pasture grazed in "winter-only". The longevity of improvement in diet quality due to burning also was measured. Grass and forb yields were determined before and after grazing. Dietary crude protein and IVOMD were greater (P<0.05) on the summer (8.4% and 47%) as compared to the winter-only pasture (6.7% and 32%) in both years. Diet protein concentration of the winter-regraze pasture (7.6%) was not different (P>0.05) from summer or winter-only diets in both years. IVOMD in diets from the winter-regraze (36%) was intermediate and significantly different from the summer and winter-only pasture in the first year. Diet IVOMD in the second year was not different (P>0.05) on the winter-regraze (34%) and winter-only (32%) pastures. Diet quality was not different (P>0.05) in summer (8.2% protein, 46% IVOMD) beginning 4 months after a burn as compared to forage quality in summer 16 months after the burn (8.5%, 47%, respectively). Compared to grazing in winter only, grazing in summer may improve digestibility of forage from range when that range is regrazed the following winter, but protein and energy of the summer range will be deficient for lactating cows.
    • Effect of Time of Grazing in First Crop Year on Subsequent Productivity of Russian Wildrye

      Holt, N. W.; Lawrence, T.; Kilcher, M. R. (Society for Range Management, 1986-11-01)
      Russian wildrye (Elymus junceus Fisch.) is an important range-land grass. It is slow to establish and could be damaged by grazing too soon after seeding. To test this hypothesis the effect of date of first grazing on the productivity of a newly established Russian wildrye pasture was determined for the first crop year, that is, the year after establishment, and 3 subsequent years at Swift Current, Saskatchewan. In the first crop year the grazing days per hectare with yearling steers was 134 days and 138 kg/ha total liveweight gain was obtained for a grazing period beginning on 15 June. When grazing was started 1 May or 1 August, carrying capacity was not different but beef production was 60 and 84 kg/ha, respectively. In the second year, when all pastures were grazed continuously from 4 May, the greatest number of days grazing were obtained when grazing had been delayed until 1 August the previous year. However, date of first grazing in the first production year did not affect liveweight gain in the second year nor liveweight gain or grazing days in the subsequent 2 years of grazing with steers. It was concluded that grazing of newly established Russian wildrye pastures should be delayed in the first crop year until the plants are fully headed (about mid-June).
    • Effects of Season and Stage of Rotation Cycle on Hydrologic Condition of Rangeland Under Intensive Rotation Grazing

      Warren, S. D.; Blackburn, W. H.; Taylor, C. A. (Society for Range Management, 1986-11-01)
      Infiltration rate and sediment production were measured over a 2-year period on an intensive rotationally grazed pasture. Measurements were taken prior to the movement of livestock onto the pasture, soon after their removal, and approximately midway through the subsequent rest period of each rotation through the system. Midgrass-dominated interspaces were characterized by significantly higher infiltration rates and lower sediment production than shortgrass-dominated interspaces. Infiltration rate declined and sediment production increased following the short-term intense grazing periods inherent in the rotational system. The detrimental effect was significant during periods of drought or winter dormancy, but not during periods of active growth. Soil characteristics relating to higher hydrologic condition were significantly more stable during the growing season, providing greater resistance to and resilience from the damaging impact of livestock activity.
    • Enhancing Germination of Spiny Hackberry Seeds

      Fulbright, T. E.; Flenniken, K. S.; Waggerman, G. L. (Society for Range Management, 1986-11-01)
      Establishment of spiny hackberry (Celtis pallida Torr.) in plantings for wildlife has been hampered by low seed germination. We evaluated methods for enhancing germination of spiny hackberry by subjecting seeds to: (1) chemical scarification with 2.9 mol liter-1 H2O2, 0.71 mol liter-1 NaOCl, and concentrated (18 mol liter-1) H2 SO4; (2) rinsing with water; (3) 0, 0.3, 1.4, 2.9, and 4.3 mmol liter-1 gibberellic acid (GA); (4) 0.02 mol liter-1 KNO3; (5) mechanical scarification, or (6) moist heat (30 degrees C) followed by moist prechilling at 7 degrees C for 2 weeks. Untreated seeds exhibited higher percent germination in the light than in the dark. Percentage germination at 30 degrees C and germination rate were increased in the light and in the dark by either 1.4 mmol liter-1 GA or 3 days of moist heat (30 degrees C) followed by a 2-week moist prechill at 7 degrees C. A combination of mechanical scarification + 1.4 mmol liter-1 GA + 3 days moist heat (30 degrees C) followed by moist prechilling for 2 weeks at 7 degrees C increased germination from 1% (controls) to 49%. Germination varied slightly with seed source, but a large proportion of all lots was dormant. Spiny hackberry seeds can be treated with a combination of mechanical scarification + 1.4 mmol liter-1 GA + 3 days moist heat (30 degrees C) followed by moist prechilling for 2 weeks at 7 degrees C before planting to increase percentage and rate of germination.
    • Establishment of Range Grasses on Various Seedbeds At Creosotebush [Larrea Tridentata] Sites in Arizona, U.S.A. and Chihuahua, Mexico

      Cox, J. R.; Martin-R, M. H.; Ibarra-F, F. A.; Morton, H. L. (Society for Range Management, 1986-11-01)
      Perennial grasses were seeded by drilling or broadcasting on 4 mechanical and 3 herbicidal weed control and/or seedbed preparation treatments at 4 semidesert grassland sites invaded by creosotebush (Larrea tridentata) in the Chihuahuan and Sonoran Deserts. The cultivars 'Cochise' Atherstone lovegrass (Eragrostis lehmanniana × Eragrostis trichophera) and 'Catalina' Boer lovegrass (Eragrostis curvula var. conferta) lovegrasses were initially established and persisted in 6 of the 8 plantings on disk plowed and disk plowed plus contour furrowed seedbeds. These grasses were established and persisted in 2 of the 5 plantings made in creosotebush stands treated with tebuthiuron [N-(5-(1,1-dimethylethyl)-1,3,4-thiadizol-2-yl)-N-N′-dimethylurea] at 0.5, 1.0, and 1.5 kg a.i/ha rates. Grasses established initially on two-way railed and land imprinted areas usually died within 3 or 4 years.
    • Gully Migration on a Southwest Rangeland Watershed

      Osborn, H. B.; Simanton, J. R. (Society for Range Management, 1986-11-01)
      Most rainfall and almost all runoff from Southwestern rangelands are the result of intense summer thunderstorm rainfall. Gully growth and headcutting are evident throughout the region. A large, active headcut on a Walnut Gulch subwatershed has been surveyed at irregular intervals from 1966 to present. Runoff at the headcut was estimated using a kinematic cascade rainfall-runoff model (KINEROS). The headcut sediment contribution was about 25% of the total sediment load measured downstream from the headcut; and the sediment contribution from the swale drainage above the headcut, as estimated from a depth-integrated pumping sampler, was about the same. Although more data are needed to quantify sediment contributions from other tributary watersheds, the total contribution from gully banks and headcuts on Walnut Gulch must be an important portion of the total sediment load.
    • Harbage Production Following Litter Removal on Alberta Native Grasslands

      Willms, W. D.; Smoliak, S.; Bailey, A. W. (Society for Range Management, 1986-11-01)
      Studies were conducted to determine the effects on herbage yield of removing mulch and standing dead plant litter during dormancy for up to 3 or more consecutive years. This information is required to obtain a better understanding of the implications of dormant season grazing on forage production. In 2 studies, mulch and standing litter were harvested at 3 or more annual frequencies from 2 × 2 m plots. One study was repeated in both the Fescue Prairie and Mixed Prairie communities and plant response was measured annually as the yield of herbage produced from treated and control plots. The second study was conducted in the Fescue Prairie on 3 sites and designed as a 3 × 3 Latin square. The treatments consisted of removing mulch and standing litter, removing and replacing this material, and a control. Estimates were made of the yield, species composition, and morphological characteristics of the grass. A third study was made, in the Fescue Prairie, by defoliating individual rough fescue (Festuca scabrella Torr. var. major Vasey) plants a single time, at 5 and 15 cm above ground, and comparing them with a control. Herbage yields decreased as the annual frequency of mulch and litter harvests increased in the Mixed Prairie but not in the Fescue Prairie. In the Mixed Prairie, yields declined to 43% of the control after 3 years of treatment. Removing mulch and standing litter from rough fescue plants resulted in shorter but a greater number of tillers than in the control. The results were similar after 1 or 3 years of treatment.
    • Hydrologic Characteristics of Vegetation Types as Affected by Livestock Grazing Systems, Edwards Plateau, Texas

      Thurow, T. L.; Blackburn, W. H.; Taylor, C. A. (Society for Range Management, 1986-11-01)
      Infiltration rate and sediment production were assessed in oak, bunchgrass and sodgrass vegetation types in moderate continuous (MCG), heavy continuous (HCG), and intensive rotation (short-duration, SDG) grazing systems and in a livestock exclosure (LEX). Infiltration rate was related to the total organic cover and bulk density characteristics of the site (R2 = .86). The amount of cover was more important than type, indicating that protection of soil structure from direct raindrop impact was the primary function of cover on infiltration. The SDG and HCG pastures had lower total organic cover with correspondingly lower infiltration rates compared to the MCG and LEX pastures. Bulk density, an indicator of soil structure, was significantly lower in oak mottes than in the grass interspace, but there was no significant difference between pastures. Sediment production was related to the total aboveground biomass and the bunchgrass cover of the site (R2 = .79). Obstruction to overland sediment transport and protection from the disaggregating effect of direct raindrop impact were the primary functions of the total aboveground biomass and bunch-grass cover. Total aboveground biomass was greatest in the oak motte and least in the sodgrass interspace, consequently the sod-grass interspace had the greatest amount of sediment production and the oak mottes had the least sediment production. Midgrass cover and total aboveground biomass in the MCG and LEX pastures was significantly greater than in the SDG and HCG pastures; thus sediment production from the MCG and LEX pastures was significantly lower than from the SDG and HCG pastures.
    • Nitrate Reductase Activity of Kleingrass (Panicum Coloratum L.) During Drought in the Northern Chihuahuan Desert

      Ray, I. M.; Sisson, W. B. (Society for Range Management, 1986-11-01)
      Plant nitrate (NO_3-N) uptake rates are often low in desert environments because soil nitrogen levels are typically low, and mineralization and nitrification of nitrogen is moisture-dependent. During drought, leaf tissue NO_3-N levels toxic to grazing animals can result because the enzyme responsible for NO_3-N reduction (nitrate reductase; NR) is repressed during plant water stress. Seasonal leaf NR activity (in vivo), and NO_3-N, total nitrogen, and leaf water (%) content of kleingrass (Panicum coloratum L.) plants growing in situ in the northern Chihuahuan Desert were determined. Total precipitation during the April through November growing season (11.5 cm) was 40% less than the long-term average (19 cm). This drought resulted in low NR activity, repressed plant growth, and water-stressed plants through most of the growing season. Seasonal and diurnal leaf NR activities were positively correlated (P<.05) with leaf water contents (%) and leaf water potentials, respectively. The latter correlation was significant only with young leaf tissue. Young leaf tissue reduced 29.6 micromol NO_3-N gDW-1 on 14 July when leaf water potentials exceeded -3.0 MPa. On 18 May, 7.1 micromol NO_3-N gDW-1 were reduced when older leaf tissue was present and leaf water potentials did not exceed -3.0 MPa. Leaf NO_3-N accumulated to levels toxic to livestock during August, September, and October. The stem plus leaf sheath component of the aboveground biomass was the primary site for NR activity, and nitrogen and biomass allocation during 6 phenological stages (second through fifth leaf stages, and boot and immature seed stages). Immature seeds comprised only 12.3% of the aboveground biomass and possessed 29.9% of the nitrogen and 62.2% of the total capacity of NO_3-N reduction.
    • Nutrition of Sheep Grazing Crested Wheatgrass Versus Crested Wheatgrass-Shrub Pastures During Winter

      Gade, A. E.; Provenza, F. D. (Society for Range Management, 1986-11-01)
      Grazing sheep on improved pastures during winter offers an economically attractive alternative to supplementation in sage-brush steppe ecosystems. We studied diet selection and nutrition of sheep grazing in crested wheatgrass (Agropyron desertorum) and crested wheatgrass-shrub (Kochia prostrata, Atriplex canescens, Purshia tridentata, Artemisia tridentata, Chrysothamnus nauseosus, Ceratoides lanata) pastures during early-January (period 1), mid-January (period 2), and late-January (period 3). Diet selection by esophageally fistulated sheep differed during each of the 3 periods because the amount of available forage changed with snow depth, trampling, and utilization. Sheep grazing crested wheatgrass (CW) pastures consumed diets that were about 55% mature grass and 45% green vegetative growth during periods 1 and 2, and 93% mature grass and 7% green vegetative growth during period 3. Sheep grazing crested wheatgrass-shrub (CWS) pastures consumed diets that were about one-half grass and one-half shrub during all periods. Organic matter intake (g kg BW ^ -.075), determined from total fecal output and in vitro digestibility estimates, were higher (P = 0.036) for sheep grazing CWS pastures than for sheep grazing CW pastures during periods 1 (38 vs. 28) and 3 (31 vs. 27), but were similar (P<0.10) during period 2 (28 vs. 26). Diets of sheep grazing CWS pastures contained more (P = 0.002) crude protein (%) than diets of sheep grazing CW pastures during periods 1 (9.0 vs. 5.8), 2 (7.3 vs. 6.6), and 3 (7.9 vs. 4.6). In vitro organic matter digestibilities (%) of diets of sheep in CW and CWS pastures were similar during period 1 (45 vs. 48), but higher (P = 0.001) for sheep grazing in CW pastures during periods 2 (46 vs. 29) and 3 (32 vs. 24). We stocked pastures heavily to accentuate differences between sheep diets in CW and CWS pastures during period 1-3; we believe results from period 1 best represent the potential nutritional benefits of shrubs on snowy winter ranges.
    • Nutritive Quality of Ceanothus Shrubs in California Mixed Conifer Forest

      Kie, J. G. (Society for Range Management, 1986-11-01)
      Mule deer (Odocoileus hemionus) in the Sierra Nevada rely heavily on mountain whitethorn (Ceanothus cordulatus, Kell.) and deerbursh (C. integerrimus, H&A) as summer forage. In this study, mountain whitethorn leaves, deerbrush leaves, and deerbush twigs were collected from shrubs growing in full sun every 2 weeks during summer, and from shrubs growing under a range of overstory crown closures during late summer-early fall. Samples were analyzed for calcium, phosphorus, crude protein, in vitro digestible dry matter (IVDDM), gross energy, digestible energy, and sequential fibers. Summer samples of all 3 forages had adequate concentrations of calcium, apparently adequate concentrations of crude protein, and inadequate concentrations of digestible energy and phosphorus for growth and development in deer. IVDDM values were lower than expected based on fiber content alone, suggesting high concentrations of digestion-inhibiting compounds. In general, forage quality declined as summer progressed. Crown closure and shrub age had only minor effects on forage quality, but significant annual differences were found in several variables in both species. Under conditions common to the southern Sierra Nevada, annual differences in precipitation may have been more important than available light in determining forage quality. Forage deficiencies in late summer may have a substantial adverse affect on newly weaned fawns. Marginal forage quality with respect to certain nutrients suggests the need to further explore deer nutritional ecology on summer and other seasonal ranges in the Sierra Nevada.
    • Soil Hydrologic Response to Number of Pastures and Stocking Density Under Intensive Rotation Grazing

      Warren, S. D.; Blackburn, W. H.; Taylor, C. A. (Society for Range Management, 1986-11-01)
      Infiltration rate and sediment production were measured for 2 years on 3 pastures from an intensive rotational grazing system. The pastures were 32, 24, and 16 ha in size. Stocking rate was held constant but stocking density at any given point in time varied due to pasture size. Stocking densities were 0.68, 0.51, and 0.32 ha/AU, respectively. Within the respective treatments, midgrass interspaces exhibited significantly higher infiltration rates and lower sediment production than shortgrass interspaces. Overall, the pasture grazed at the highest stocking density produced the lowest infiltration rates and the greatest sediment loss. However, there was no consistent trend in hydrologic responses over time and the differences appeared to be the result of random selection of a poorer condition site on 1 or 2 occasions rather than the result of stocking density. Regardless of whether the pasture grazed at the highest stocking density was in similar or poorer hydrologic condition in terms of treatment response, the data do not support the hypothesized beneficial hydrologic advantages of increased stocking density via manipulation of pasture size and numbers. Rest, rather than intensive livestock activity, appears to be the key to soil hydrologic stability. The potential for altering the length of the rest period is greatest where the number of pastures is small. Therefore, very little benefit in terms of soil hydrologic condition should be expected from large increases in the number of pastures within rotational grazing systems.
    • The Influence of Livestock Trampling Under Intensive Rotation Grazing on Soil Hydrologic Characteristics

      Warren, S. D.; Thurow, T. L.; Blackburn, W. H.; Garza, N. E. (Society for Range Management, 1986-11-01)
      Infiltration rate decreased significantly and sediment production increased significantly on a site with a silty clay surface soil devoid of vegetation following periodic trampling typical of intensive rotation grazing systems. The deleterious impact of livestock trampling generally increased as stocking rate increased. Damage was augmented when the soil was moist at the time of trampling. Thirty days of rest were insufficient to allow hydrologic recovery. Soil bulk density, aggregate stability, aggregate size distribution and surface microrelief were related to the soil hydrologic response of the trampling treatments.