• A cow-calf vs yearling substitution ratio for shortgrass steppe

      Forero, L.; Rittenhouse, L. R.; Mitchell, J. E. (Society for Range Management, 1989-07-01)
      Managers often deal with the problem of herd replacement of one animal class by another. A preliminary study suggested that steers could be substituted for cow-calf pairs on shortgrass steppe on a weight:weight basis. This ratio was tested on 2 pairs of pastures, one dominated by native shortgrass steppe and the other by a seeded stand of sideoats grama (Bouteloua curtipendula (Michx.)Torr.). The pasture sizes were set so the cow-calf pastures were 1.8 times larger than the steer pastures to allow equal herd sizes for the 2 classes of animals. Adequacy of stocking was determined by equalizing utilization. The actual stocking ratios of 1.79 steers to 1 cow-calf pair on the native pastures and 1.78 steers to 1 cow-calf pair on the seeded pastures resulted in no significant differences in utilization or standing crop of remaining forage after the grazing season ended. Season-long, the 90% confidence bounds of the steer-weight:pair-weight ratio was 0.981-1.035 and 0.968-0.985 for native and seeded pastures, respectively. This ratio provides an acceptable initial stocking rate guide for those wishing to change from cow-calf to steer operations, or vice versa, on the shortgrass steppe.
    • Bio-economic evaluation of stocking rate and supplementary feeding of a beef herd

      Seligman, N. G.; Noy-Meir, I.; Gutman, M. (Society for Range Management, 1989-07-01)
      The effect of varying price ratios between liveweight and supplementary feed on the optimum stocking rate (SR) of a beef herd on range is analyzed in relation to the net value of weaned calf live weight. While the basis for determining optimum stocking rate is generally the value of production and costs per unit area, the animal performance per se is often a major management criterion, especially where the capital investment in livestock is high and where risk avoidance is an important consideration. Consequently, equations expressing the net value of beef production per unit of land and per animal unit are formulated as a function of SR. Parameter values for the equations were taken from a grazing trial conducted in the Galilee in Israel where a beef herd was maintained yearlong on native range 5 years at 3 different SR's, 0.50, 0.67, and 0.83 cows/ha. The animals were supplemented ad libitum with poultry litter during the dry summer months. During the transitional period between the opening rains and range readiness, poultry litter was enriched with 20% barley grain. In addition, straw was given at an average rate of 80 to 375 kg/ha in the intermediate and highest stocking rates. Over the range of SR's studied, it was shown that when supplementary feed and other per animal costs are high, net value of production per unit area of range declines with SR even though total production increases. On the other hand, when fixed range and management costs are high, the net economic benefit per cow increases with SR even though production per cow decreases. It is concluded that the optimum SR for a given situation depends not only on the input/out price ratios but also on the criterion for evaluating economic value that is most revelant to the manager.
    • Characterization of seed germination and seedling survival during the initial wet-dry periods following planting

      Frasier, G. W. (Society for Range Management, 1989-07-01)
      Combined greenhouse, laboratory, and field studies were conducted to develop techniques which could be used to characterize seed germination and seedling survival of a plant species when subjected to various wet-dry watering sequences following seeding. A procedure was developed to utilize daily seedling count data to estimate the minimum number of seeds which germinate under specific wet-dry watering sequences. These seed germination percentages are used to adjust laboratory/greenhouse results to more accurately predict field results. Results showed no consistent relationships or patterns between germination percentages derived from filter paper experiments and percentages obtained from the seedling count procedure. The germination percentages, determined from seedling emergence data, were used to normalize seedling survival numbers for 3 wet-dry watering sequences determined in greenhouse experiments. With the adjustment for actual seed germination rates occurring in the greenhouse and field, the number of seedlings surviving the wet-dry watering sequences in the greenhouse could be used to estimate the number of seedling surviving the same watering sequences in the field.
    • Establishment of seven high yielding grasses on the Texas High Plains

      Marietta, K. L.; Britton, C. M. (Society for Range Management, 1989-07-01)
      The establishment of several high yielding grasses was examined on the Texas High Plains as an alternative to row crop agriculture. The species were Blackwell switchgrass (Panicum virgatum), El Reno sideoats grama (Bouteloua curtipendula), Morpa weeping lovegrass (Eragrostis curvula) and 4 old world bluestem selections including Caucasian (Bothriochloa caucasica), WW517 (B. intermedia var. indica), Ganada (B. ischaemum var. ischaemum), and WWspar (B. ischaemum var. ischaemum). Each species was seeded in mid-May 1981 and 1982 in Garza County on a fine sand and in Lubbock and Terry Counties on sandy loam soils. Number of seedlings 1 month after planting ranged from 129.7/m at Brownfield in 1981 to 7.5/m at Post in 1982. At the end of the first growing season, biomass ranged from 930 kg/ha at Lubbock in 1981 to 11 kg/ha at Post 1982. At the beginning of the second growing season, basal cover had increased, indicating these species were adapted to the winter conditions in the area. The seedings were successful, and adequate stands of all species were established the first year except for the 1982 Post planting. The year and location were the most important factors in establishment success during this study. There were differences among species, but no one species was superior over locations or years for all the characteristics measured. On the fine sand weeping lovegrass was superior.
    • Nutrient composition of selected emergent macrophytes in Northern Prairie wetlands

      Kirby, D. R.; Green, D. M.; Mings, T. S. (Society for Range Management, 1989-07-01)
      North Dakota's seasonal wetlands, covering 1.3 million ha, are an important forage resource especially during dry years. A study was initiated in south central North Dakota to determine forage quality of dominant emergent macrophytes. Ten species, American sloughgrass (Beckmannia syzigachne (Steud.) Fern.), tall mannagrass (Glyceria grandis S. Wats. ex A. Gray), common reed (Phragmites australis (Cav.) Trin. ex. Steud.), whitetop or sprangletop (Scolochloa festucacea (Willd.) Link), prairie cordgrass (Spartina pectinata Link), slough sedge (Carex atherodes Spreng.), spikerush (Eleocharis macrostachya Britt.), baltic rush (Juncus balticus Willd.), hardstem bulrush (Scirpus acutus Muhl.), and three square (Scirpus pungens Vahl.) were collected twice a month, from mid-May until mid-August then after first frost. After drying at 60 degree C, samples were separated to leaf and stem where applicable. Analyses included in vitro dry matter digestibility (IVDMD), crude protein (CP), and phosphorus (P). Although species and season differences occurred, IVDMD, CP, and P declined linearly with season in each plant species and part. Depending upon the species mix, wetland hay harvested between bloom and mature stages would be expected to average 47-49% IVDMD, 7.6-14.0% CP, and .17-.29% P. Harvested early, mixed species wetland hays would provide adequate nutrients for dry pregnant cows. However, energy and P supplementation may be necessary for late harvested wetland hays.
    • Opportunistic management for rangelands not at equilibrium

      Westoby, M.; Walker, B.; Noy-Meir, I. (Society for Range Management, 1989-07-01)
      We discuss what concepts or models should be used to organize research and management on rangelands. The traditional range succession model is associated with the management objective of achieving an equilibrium condition under an equilibrium grazing policy. In contrast, the state-and-transition model would describe rangelands by means of catalogues of alternative states and catalogues of possible transitions between states. Transitions often require a combination of climatic circumstances and management action (e.g., fire, grazing, or removal of grazing) to bring them about. The catalogue of transitions would describe these combinations as fully as possible. Circumstances which allow favorable transitions represent opportunities. Circumstances which threaten unfavorable transitions represent hazards. Under the state-and-transition model, range management would not see itself as establishing a permanent equilibrium. Rather, it would see itself as engaged in a continuing game, the object of which is to seize opportunities and to evade hazards, so far as possible. The emphasis would be on timing and flexibility rather than on establishing a fixed policy. Research under the state-and-transition model would aim to improve the catalogues. Frequencies of relevant climatic circumstances would be estimated. Hypotheses about transitions would be tested experimentally. Often such experiments would need to be planned so that they could be implemented at short notice, at an unknown future time when the relevant circumstances arise.
    • Response of a semidesert grassland to 16 years of rest from grazing

      Brady, W. W.; Stromberg, M. R.; Aldon, E. F.; Bonham, C. D.; Henry, S. H. (Society for Range Management, 1989-07-01)
      Grazing was eliminated from the Appleton-Whittell Research Ranch Sanctuary, located in south-central Arizona, in 1968. Long-term changes in canopy cover of vegetation were evaluated between 1969 and 1984, and comparisons were made between ungrazed and grazed plant communities in 1969. Long-term changes included both increases in species richness (diversity) and significant increases in canopy cover for midgrass, shortgrass, shrub, and forb species groups. Total vegetation cover was not significantly different on the grazed and ungrazed areas, but cover of midgrasses was significantly different. Increased cover of plains lovegrass (Eragrostis intermedia Hitchc.) on the ungrazed pasture was largely responsible for this difference. No differences in cover existed for the shortgrass, shrub, or forb species groups. Observations suggest that long-term (perhaps cyclical) changes in vegetation are occurring in addition to short-term influences of herbivory. Data do not support the hypothesis that continued animal impact is necessary to prevent ecosystem deterioration.
    • Response of established forages on reclaimed mined land to fertilizer N and P

      Reeder, J. D.; McGinnies, W. J. (Society for Range Management, 1989-07-01)
      A field study was conducted from 1981 through 1986 on an established stand of grass and legume species on topsoiled coalmine spoils in northwest Colorado to evaluate the effects of N and P fertilization on dry matter production, species composition, canopy cover, and forage crude protein and P concentrations. Fertilizer treatments included annual fall applications in 1981 through 1985 of: 0, 28, 56, 112, and 224 kg N ha-1; 56 kg P ha-1; and 112 kg N ha-1 + 56 kg P ha-1. Additionally, single fall applications of N were applied in 1981 through 1983 at rates of 0, 28, 56, 112, 224, and 448 kg N ha-1 to other plots that had not been previously fertilized. Plots were harvested at grass anthesis in 1982 through 1986. Fertilizer P significantly increased forage P concentration but did not significantly affect yield, crude protein concentration, or species composition. Fertilizer N did not significantly affect species composition or forage P concentration but did significantly increase dry matter production and crude protein concentration with increased N rate. Averaged over the 5 years of the study, annual application of 28, 56, 112, and 224 kg N ha-1 increased herbage production by 23, 19, 19, and 11 kg per kg N applied, respectively. On those plots receiving a single application of fertilizer N, significant increases in dry matter production with increased N rate were noted only during the first growing season after N fertilization. Significant yield response to carry-over fertilizer N was noted in the second (and occasionally third) growing seasons only at the 448 kg N ha-1 rate. The data indicate that annual applications of fertilizer N would be more effective than infrequent applications of high rates of N on these reclaimed mined lands.
    • Rooting characteristics of four intermountain meadow community types

      Manning, M. E.; Swanson, S. R.; Svejcar, T.; Trent, J. (Society for Range Management, 1989-07-01)
      Healthy meadow communities generally have excellent soil binding properties. However, belowground characteristics of these communities have seldom been evaluated. In 4 meadow community types (CTs) we measured root mass and root length density (RLD) at 10-cm intervals to 40 cm soil depth. The CTs occurred along a wet to dry soil moisture gradient. The ranking of CTs from wettest to driest was: Carex nebrascensis (CANE) > Juncus balticus (JUBA) > Carex douglasii (CADO) > Poa nevadensis (PONE). Total RLD and mass to 40 cm paralleled the order of soil wetness, i.e., there were more roots at the wetter sites. Values of total RLD and mass for the 4 CTs were: 95.6 cm cm-3 and 3,382 g m-2 respectively for CANE; 33.6 cm cm-3 and 2,545 g m-2 for JUBA; 25.7 cm cm-3 and 1,526 g m-2 for CADO; and 8.8 cm cm-3 and 555 g m-2 for PONE. Root mass and RLD declined with depth, a result consistent with other graminoid systems. The RLD values for CANE, JUBA, and CADO are exceptionally high compared to literature values from other graminoid plant communities. The high RLD of the wet CTs suggests that they have superior site-stabilizing characteristics.
    • Seed viability of alpine species: variability within and among years

      Chambers, J. C. (Society for Range Management, 1989-07-01)
      Percent of seeds filled for alpine grasses and seed viability and longevity for alpine grasses and forbs with different life history and physiological traits were evaluated for seeds collected in 1983, 1984, 1985, and 1986 on the Beartooth Plateau, Mont. Significant (p<0.001) differences existed in the percent of seeds filled for grass species and in the seed viability of both grass and forb species among years. The high variability in seed viability among years is attributed to the severe and unpredictable nature of the environment. Seed viability differed among species within most years. In general, grass species had lower and more variable seed viability than forb species. Low seed viability years for the grass species coincided with low seed fill years, indicating poor seed development. Longevity of seeds collected in 1983 varied among species and was related to seed characteristics and the overall life history and physiological traits of individual species. Seed longevity of species with life history and physiological traits typical of late seral species was shorter than that of species with traits typical of early seral species.
    • Soil climate and plant community relationships on some rangelands of northeastern Nevada

      Jensen, M. E. (Society for Range Management, 1989-07-01)
      Soil temperature and moisture data were collected between 1983 and 1986 on 1 forest and 11 sagebrush-dominated rangeland plant community types of the Humboldt National Forest in northeastern Nevada. Six soil parameters were used to contrast differences between the community types studied: mean annual soil temperature, mean summer soil temperature, starting date (i.e., when soil temperature at 0.5 m exceeded 5 degrees C), growing period (i.e., number of days when soil temperature and moisture were not limiting to growth), soil degree days (i.e., number of days that soil temperature at 0.5 m exceeded 5 degrees C), and growing period percentage (i.e., growing period/soil degree days). These soil parameters were effective in discriminating between most plant community types, yet their effectiveness varied considerably among types. Certain community types (e.g., mountain sagebrush [Artemisia tridentata Nutt. subspecies vaseyana]-bluebunch wheatgrass [Agropyron spicatum Pursh.]) occupy a wide range in soil temperature and moisture, which limits their indicator significance for predicting soil climate. Short growing periods of 25 to 150 days, characterize the rangeland plant community types studied. The onset of the growing period (starting date) occurs between 6 March and 1 July. Such information facilitates the determination of range readiness by plant community type in the study area.
    • Some effects of a rotational grazing treatment on cattle grazing behavior

      Walker, J. W.; Heitschmidt, R. K. (Society for Range Management, 1989-07-01)
      Research was conducted on the effects of rotational grazing (RG) compared to continuous grazing (CG) on the behavior of cattle grazing on rangelands. Different livestock densities in the RG treatments were created by varying the size of paddocks in a 465-ha, 16-paddock, cell designed RG treatment stocked at a rate of 3.6 ha/cow/yr. Paddock sizes of 30 and 10-ha were used to simulate RG with 14 (RG-14) and 42-paddocks (RG-42), respectively. The CG treatment consisted of a 248-ha pasture stocked at 5.9 ha/cow/yr. Data were collected using vibracorders, pedometers and observation to estimate time (min/day) spent: intense grazing, search grazing, trailing, or sleeping; distance walked (km/day), and individual animal space ( m2/animal) in grazing subherds. Total grazing time did not vary among grazing treatments, but the components of total grazing (i.e., intense and search grazing) did vary among treatments. Cattle in the RG-14 paddocks spent less time search grazing compared to the ones in the other treatments presumably because the rotational grazed paddocks were more uniform because of less mixing of live and dead forage. Search grazing was highest in the RG-42 paddocks which may be due to the high stock density in this treatment coupled with an attempt to maintain individual animal space. Grazing time tended to be longer the first day in a RG-14 paddock than the last. Time spent trailing and the distance walked increased as the frequency of rotation increased among the different treatments. Sleeping was similar among grazing treatments. Individual animal space within a grazing subherd decreased as the stock density increased because of the grazing treatment.
    • Succession of secondary shrubs on Ashe juniper communities after dozing and prescribed burning

      Rasmussen, G. A.; Wright, H. A. (Society for Range Management, 1989-07-01)
      Secondary brush species (found as minor components of the climax community and those from lower seral stages) have increased after most prescribed burns on the Edwards Plateau of Texas. Originally, most of this area was dominated by Ashe juniper (Juniperus ashei). Line and belt transects were used to estimate brush canopy cover and density on 4 soil series located on 5 topographical positions in untreated, tree dozed, and tree dozed plus prescribed burn areas. Total canopy cover and density were not correlated with time following dozing (13, 16, or 18 years) or burning (8, 9, 10, 12, 13, or 14 years). Recovery of brush canopy cover to untreated levels was dependent on the topographical location and treatment. Total brush canopy cover was not different (P lesser than or equal to 0.05) among untreated, dozed, and dozed plus burned treatments on the Speck soil series occurring on the plateau tops. However, brush canopy cover was reduced by burning on soil series occurring on the sideslopes (Oplin and Brackett variant series) and drainages. Species composition was altered with Ashe juniper being reduced approximately 80% on dozed plus burned areas. Flameleaf sumac did not occur on untreated areas but comprised an average of 38% of the woody cover on all burned areas. Other secondary brush species increased, the amount depending on the topographical position. Future management may have to include spot treatment on upland soil series where secondary brush species quickly increase.
    • Survival and agronomic performance of 25 alfalfa cultivars and strains interseeded into rangeland

      Berdahl, J. D.; Wilton, A. C.; Frank, A. B. (Society for Range Management, 1989-07-01)
      This study assesses survival and agronomic performance of 7-year-old stands of 25 alfalfa (Medicago sativa L.) cultivars and experimental strains interseeded into rangeland near Mandan, N.Dak. Associated grasses consisted primarily of crested wheatgrass [Agropyron desertorum (Link) Schulte.], western wheatgrass [Pascopyrum smithii (Rydb.) Löve], needle-and-thread (Stipa comata Trin. & Rupr.), and blue grama [Bouteloua gracilis (H.B.K.) Lag.]. Soil was a Chama silt loam (Typic Haplustolls), an upland soil with moderate water holding capacity. Each entry was replicated 4 times in a randomized complete block design in plots consisting of 3 interseeded rows 6.1 m long with 90 cm between rows. Alfalfa cultivars and experimental strains with a high proportion of falcata [M. sativa subsp. falcata (L.) Arcang.] parentage were better adapted to interseeding into rangeland at a semiarid site in the northern Great Plains than traditional hay-type cultivars which have a high proportion of sativa (M. sativa L. subsp. sativa) parentage. Sativa-types with high levels of known winterhardiness had low survival in this test. Seven years after plant establishment, the 12 falcata-type entries averaged 100% more plants or propagules m-2, 124% wider foliage spread of plant rows, and 68% more dry matter yield, respectively, than the 13 sativa-type entries. Traits associated with falcata parentage such as plant spread by root proliferation and broad crown development, dormancy during midsummer drought, and slow, decumbent regrowth may help to enhance alfalfa survival in semiarid rangeland in the Northern Great Plains. These traits have no known utility in more humid environments where maximum forage yields from multiple harvests is a primary objective.
    • Tree canopy effects on herbaceous production of annual rangeland during drought

      Frost, W. E.; McDougald, N. K. (Society for Range Management, 1989-07-01)
      Seasonal herbaceous production was measured beneath tree canopies of blue oak (Quercus douglasii Hook & Arn.), interior live oak (Quercus wislizenii DC), and digger pine (Pinus sabiniana Dougl.), and in adjacent open grassland during 2 drought years (1986-87 and 1987-88) at the San Joaquin Experimental Range, California. Early and mid-growing season herbaceous production was variable, with no increase in production beneath the canopies the first year and a 60 to 150 kg/ha increase the second year compared to the herbage produced in open grassland. Peak standing crop was about 1,000 kg/ha greater beneath blue oak canopies than in open grassland in both years. Peak standing crop beneath interior live oak canopies was about 700 and 1,000 kg/ha greater than in open grassland the first and second years of the study, respectively. Peak standing crop beneath digger pine canopies was about 500 kg/ha greater the first year and similar the second year to that of the open grassland.
    • Variability for Ca, Mg, K, Cu, Zn, and K/(Ca + Mg) ratio among 3 wheatgrasses and sainfoin on the southern high plains

      Kidambi, S. P.; Matches, A. G.; Griggs, T. C. (Society for Range Management, 1989-07-01)
      The objective of this study was to determine the variability of Ca, Mg, K, Cu, Zn, and K/(Ca+Mg) ratio in 'Jose' tall wheatgrass [Thinopyrum ponticum (Podp.) Barkw. & D.R. Dewey], 'Luna' pubescent wheatgrass [T. intermedium subsp. barbulatum (Schur.) Barkw. & D.R. Dewey], and 'Hycrest' crested wheatgrass [Agropyron cristatum (L.) Gaertn. × A. desertorum (Fisch. ex Link.)]. Each grass was grown alone and in paired rows with 'Renumex' sainfoin (Onobrychis viciifolia Scop.) on a Pullman clay loam soil (a fine, mixed thermic Torrertic Paleustoll). Each species or mixture was evaluated under 3 cutting schedules in 1985 and 1986 and their mineral concentrations were compared to the recommended daily requirements of beef cattle. The concentration of minerals was similar in grasses grown as monocultures and in binary mixtures. The concentrations of all minerals and the ratio varied with harvest time, phenological stage, and year. Therefore, seasonal dynamics of mineral concentrations should be kept in mind when evaluating the mineral status of different forages. Among grasses, Hycrest had a better mineral profile for beef cattle than Luna or Jose. Sainfoin had higher concentrations of Ca, Mg, Cu, and Zn and much lower K/(Ca+Mg) ratio than the grasses. Hence, sainfoin-Hycrest mixtures may provide mineral concentrations more in balance with beef cattle requirements and help alleviate the problem of hypomagnesemia.
    • Vegetational response to herbicide treatment for brush control in Tanzania

      Msafiri, D. N.; Pieper, R. D. (Society for Range Management, 1989-07-01)
      Dense stands of small trees restrict understory production and provide suitable habitat for tsetse-fly in many areas in Tanzania. Three methods (ring barking, cut stump and frilling) of applying a mixture of esters of 2,4-D (2,4-dichlorophenoxy acetic acid) and 2,4,5-T (2,4,5-trichlorophenoxy acetic acid) for tree control were compared. There were no significant differences in mortality (P<0.10) of Combretum species among the application methods. Mortalities for all species ranged from 37 to 48%. Applications in June had pronounced effects on Combretum molle and Combretum ternifolium on the reddish-brown soil and black soils sites, respectively. Combretum binderanum on the reddish-brown soil site tended to respond differently in June and December to cut stump and ring barking treatments. Overall, Combretum molle and Combretum ternifolium were more susceptible to the herbicide treatments than was Combretum binderanum. Total herbage standing crop in the reddish-brown soil site was not affected by method or the season of herbicide application (P>0.10). On the black soil site Andropogon gayanus and forbs produced more herbage standing crop under the ring barking treatment in June compared to the control. Percent composition of Panicum infestum on the reddish-brown soil site was higher in the June herbicide applications than that in December applications. On the black soil site, composition of Andropogon gayanus was significantly lower in the December ring barking treatment than in the control, whereas forb composition was significantly higher (P<0.10) in the June ring barking treatment compared to the control. The frilling treatment applied in June appeared to give the most positive response for management objectives.