• A Method for Estimating Economic Injury Levels for Control of Rangeland Grasshoppers with Malathion and Carbaryl

      Onsager, J. A. (Society for Range Management, 1984-05-01)
      A theoretical "average" rangeland grasshopper weighs 81.6 mg (dry weight) in the adult stage and consumes 9, 22, and 53 mg of forage/day in the 4th instar, 5th instar, and adult stages, respectively. Criteria for a computer program are presented whereby grazing pressure from grasshopper infestations can be predicted as a function of initial density and normal daily rate of survival. The benefits of a contemplated control measure may then be estimated through appropriate adjustment of the survival rate. By assigning dollar values to the worth of forage and cost of treatment, the lowest infestation that will justify control measures can be determined. The technique is demonstrated for 2 effective but dissimilar insecticides, malathion and carbaryl. By using actual treatment costs for 1981 control programs and by assuming that an AUM (364 kg of forage) saved from destruction by grasshoppers has a marginal value product of $14, it was calculated that grazing by grasshoppers must approach 0.25 AUM/ha before treatment becomes economical. If treatments are not applied before carrying capacity has been depleted by grasshoppers, then the forage that is saved cannot be harvested. Thus, early treatments with both chemicals are much more economical than late treatments.
    • Cattle Behavior on a South Florida Range

      Tanner, G. W.; Sandoval, L. D.; Martin, F. G. (Society for Range Management, 1984-05-01)
      Grazing, resting, defecating, and urinating behaviors of cattle (Zebu-European cross breeds) were monitored seasonally on a south Florida range from November 1980 through August 1981. Individual animals were continuously during daylight hours in a pasture containing 4 plant communities. Distributions of time spent grazing and resting and counted occurrences of excretion were significantly different among the 4 seasons. Grazing time in the 4 plant communities was not in proportion to their size. Cattle grazed more in those communities that had the best quality of forage available. Cattle grazed more in the freshwater marsh during fall but spent more time in the ecotone during spring and summer. Shade was not a requisite for resting sites, even during the warmest days. Excretion activities were more closely associated with grazing than resting.
    • Change in Bacterial Populations Downstream in a Wyoming Mountain Drainage Basin

      Skinner, Q. D.; Adams, J. C.; Beetle, A. A.; Roehrkasse, G. P. (Society for Range Management, 1984-05-01)
      Ten bacteriological tests were utilized to monitor different bacterial populations found in water samples taken from streams draining high mountain rangeland. Livestock grazing and recreation constituted the major uses of the study area. Vegetation types were typical of those found in other sub-alpine and alpine zones in the central Rocky Mountains. Results show differences in counts of bacteria between sampling sites along individual streams sampled with the exception of those organisms capable of reducing nitrate were not significant. A seasonal variation in the numbers of bacteria were found between streams. This variation is not fully explained by drainage basin areas or related to runoff. In contrast, within each stream counts varied with season and could be related to runoff. Bacterial populations which indicate fecal pollution were low and probably derived from animals not man. Wet meadows and bog areas under snow may be possible sources for sulfate reducing bacteria and those organisms capable of reducing nitrate.
    • Ecophysiological Studies of Eleusine indica (L.) Gaertn. and Sporobolus pyramidalis P. Beauv. at Ibadan, Nigeria

      Sharma, B. M. (Society for Range Management, 1984-05-01)
      Eleusine indica and Sporobolus pyramidalis are common grasses in the tropics, including Ibadan, Nigeria. The former is considered a good fodder when young, but the latter has low grazing quality. The objective of this study was to describe some of the morphological characteristics of these 2 prominent species. S. pyramidalis is a taller grass having more roots per culm and a longer inflorescence. Seeds of the 2 grasses germinated between 20 degrees C and 35 degrees C and emergence declined with increasing depth until it was zero at and 4 cm for E. indica and S. pyramidalis, respectively. S. pyramidalis had a higher rate of germination. The 2 species have stomata on both leaf surfaces, but the number is greater on the adaxial surface. Experiments indicate that E. indica is more tolerant and adaptable to biotic disturbances. The biomass contribution by E. indica and S. pyramidalis is estimated at 1,100 kg/ha 300 kg/ha, respectively.
    • Effects of Livestock Grazing on Infiltration Rates, Edwards Plateau of Texas

      McCalla, G. R.; Blackburn, W. H.; Merrill, L. B. (Society for Range Management, 1984-05-01)
      The influence of short duration grazing (SDG), moderate continuous grazing (MCG), heavy continuous grazing (HCG), and grazing exclusion on infiltration rates of midgrass and shortgrass-dominated communities was evaluated over a 20-month period on the Texas Agricultural Research Station, located near Sonora in the Edwards Plateau, Texas. A combination of cattle, sheep, and goats were used in each grazing treatment. Infiltration rates were consistently less in the midgrass (bunchgrass) than in the shortgrass (sodgrass) community. The HCG pasture was severely overgrazed and infiltration rates were reduced to about one-half those in the MCG pasture. The midgrasses in this pasture were destroyed after 26 months of overgrazing. Infiltration rates in the SDG pasture, stocked at double the recommended rate, decreased during the study period. Infiltration rates in the SDG pasture shortgrass community, near the end of the study, approached those in the HCG pasture. The greatest infiltration rates for both communities were maintained in the MCG pasture. Infiltration rates for the midgrass community remained relatively stable during the study when the general trend in the SDG and HCG pastures was toward reduced infiltration rates. The nongrazed pasture subsequent to the 1980 drought had a general increase in infiltration rates.
    • Effects of Planting Depth and Soil Texture on the Emergence of Four Lovegrasses

      Cox, J. R.; Martin, M. H. (Society for Range Management, 1984-05-01)
      We studied the emergence of 4 lovegrass accessions planted at 0.0, 0.5, 1.0, 1.5, and 2.0 cm depths in Pima silty clay loam, Sonoita silty clay loam, and Comoro sandy loam soils in a greenhouse. Catalina boer lovegrass (Eragrostis curvula var. conferta Nees) emergence was superior to A-84 boer lovegrass, A-68 Lehmann lovegrass (Eragrostis lehmanniana Nees) and Cochise lovegrass (Eragrostis lehmanniana Nees X E. trichophera Coss & Dur.) in all soils and at all depths. Approximately 75% of the radicles of germinating Lehmann and A-84 boer lovegrass seeds failed to penetrate the surface of the 3 soils when surface sown. Lehmann lovegrass seed planted below the surface failed to emerge in the 3 soils.
    • Evaluation of Air Threshing for Small Lots of Winterfat Fruits

      Booth, D. T.; Griffith, L. W. (Society for Range Management, 1984-05-01)
      Air threshing, using an air gun scarifier, is an improved method for threshing small lots of winterfat [Eurotia lanata (Pursh) Moq.; Ceratoides 1. (Pursh) J.T. Howell] fruits for laboratory analysis. The technique is faster than hand threshing and causes insignificant damage to the seed in contrast to hammer mill threshing which damages about 25% of the seed.
    • Fire Temperatures and Physical Characteristics of a Controlled Burn in the Upper Sonoran Desert

      Patten, D. T.; Cave, G. H. (Society for Range Management, 1984-05-01)
      Fire temperatures at 4 vertical locations within 3 desert microhabitats were measured during a controlled burn using both temperature pellets and thermocouples. Examples of maximum air temperatures (30 cm) during the fire were 138 degrees C in open interspaces, 352 degrees C within a shrub, and 442 degrees C under a palo verde tree. Fire temperatures among other levels and microhabitats varied considerably. Environmental conditions during the fire were monitored. Soil water repellency at 4 vertical locations within 3 microhabitats showed minimal changes after burning. Soil surface albedo increased by 5% following the fire resulting from 70% perennial plant cover removal and subsequent white ash release. Soil and air temperatures did not vary significantly after the fire when compared to an unburned control.
    • Forage Yield and Quality of Dryland Grasses and Legumes

      White, L. M.; Wight, J. R. (Society for Range Management, 1984-05-01)
      A 7-year study was conducted on forage yield, digestibility, and crude protein of 7 species of grass, 3 cultivars of alfalfa, and cicer milkvetch at Sidney, Mont., from 1975 through 1981. Forage quality was inversely proportional with forage yield. Crude protein concentration of legumes and grasses decreased 0.8 and 1.25 percentage units, respectively, while dry matter digestibility decreased 1.5 to 2.3 percentage units per every 1,000 kg/ha increase in forage yield. Meadow bromegrass and reed canarygrass produced the least forage from the second through seventh years of the study. Neither forage yield nor quality differed among the 3 creeping-rooted alfalfas: 'Rambler', 'Drylander', and 'Orenberg'. Russian wildrye, Altai wildrye, and green needlegrass produced the most forage during the 1980 drought, and the alfalfas, pubescent wheatgrass, and meadow bromegrass produced the least. Cicer milkvetch and reed canarygrass died during the 1980 drought. Forage digestibility of the alfalfas was 5 to 6 percentage units higher than that of the grasses, and the alfalfas also produced more digestible forage per unit of land. The crude protein concentration of alfalfas was almost twice that in grasses, and alfalfa produced almost twice as much crude protein per unit of land (kg/ha).
    • Forage Yield of Japanese Honeysuckle after Repeated Burning or Mowing

      Stransky, J. J. (Society for Range Management, 1984-05-01)
      Japanese honeysuckle (Lonicera japonica) plantings were burned, mowed, or left untreated in February 1973, and again in March 1978, to measure forage yields from honeysuckle after repeated treatments and to determine whether burning or mowing confines honeysuckle to food plots and prevents accumulation of large, impenetrable mats. Two growing seasons after the 1st treatment, total honeysuckle yield (kg/ha) was greatest on controls and least on burned plots. One and two growing seasons after the 2nd treatment, yield on the mowed plots was significantly greater than that on the control or burned plots. However, honeysuckle formed large, solid mats on control and mowed plots due to the numerous, intertwined runners, while burning reduced the dense growth between plants making them accessible to white-tailed deer (Odocoileus virginianus).
    • Grass Species Adaptability in the Southern High Plains—A 36-Year Assessment

      Eck, H. V.; Sims, P. L. (Society for Range Management, 1984-05-01)
      A 36-yr old species adaptation test was evaluated and the relative quality of some persisting native and introduced grass species was determined. The site was Conlen loam on the Rita Blanca National Grassland in Dallam County, Texas. Of the 25 species planted, only yellow bluestem (Bothriochloa ischaemum),1 Caucasian bluestem (Bothriochloa caucasica), and galleta (Hilaria jamesii) tended to dominate the plots on which they were originally planted. Yellow and Caucasian bluestem had spread into plots planted to other grasses but galleta had spread very little. Yellow bluestem was as high or higher in protein, mineral content, and digestibility (IVDMD) than the other grasses analyzed [Caucasian bluestem, galleta, sideoats grama (Bouteloua curtipendula), blue grama (Bouteloua gracilis), and western wheatgrass (Agropyron smithii)]. The contents of Caucasian bluestem and galleta were not significantly different from those of yellow bluestem, except that galleta was lower in IVDMD, especially when mature. These 3 grasses merit consideration in range seeding programs on Conlen and similar soils in the Southern High Plains.
    • Horses and Cattle Grazing in the Wyoming Red Desert. II. Dietary Quality

      Krysi, L. J.; Sowell, B. F.; Hubbert, M. E.; Plumb, G. E.; Jewett, T. K.; Smith, M. A.; Waggoner, J. W. (Society for Range Management, 1984-05-01)
      Botanical composition of horse and cattle diets from fecal analysis and nutrient quality of hand-harvested forages used by these herbivores were evaluated to assess dietary quality during the summer and winter seasons of 1981 in the Wyoming Red Desert. Dietary crude protein estimates averaged 7.5 +/- 0.1% and 9.0 +/- 0.5% during the summer for horses and cattle, respectively. Dietary crude protein estimates in the winter were lower, averaging 6.1 +/- 0% and 6.0 +/- 0% for horses and cattle, respectively. Estimated dietary calcium levels for both herbivores were high through the summer and winter, while dietary phosphorus levels appear to be deficient during both seasons. Average in vitro dry matter disappearance coefficients for horses and cattle during the summer were 52 +/- 2% and 52 +/- 2%, respectively. During the winter these values dropped to 39 +/- 1% and 40 +/- 1% for horses and cattle, respectively.
    • Marginal Benefits of Grazing and Agricultural Practices on a Mexican Ejido

      Jameson, D. A.; Armijo-T., J. R.; Medina-T., J. G.; Nava-C., R. (Society for Range Management, 1984-05-01)
      The ejidos, or communal farms, of northeastern Mexico traditionally produce cattle, goats, corn, and beans. In addition, several plant species are gathered for sale as food, fiber, or other uses. The present governmental policy is to provide price supports for the gathered plants as an incentive for families to remain on the ejidos. An alternative to this program is a program of grazing land improvements to provide increased forage for cattle and goats. On the Ejido Noria de Guadalupe in the state of Zacatecas, analysis of the marginal contribution of increments of labor clearly shows that improvement of grazing would be more effective in attracting families to the ejidos than the present practice of price supports but would result in some challenging changes in social organization./Los ejidos o predios comunales del norte de Mexico se caracterizan por ser productores de ganado vacuno y caprino, y en menor escala, productores de maiz y frijol. Como una actividad adicional se realizan colectas de ciertas especies nativas de las cuales se obtiene fibra, hule, productos quimicos y alimento para humanos. La politica actual del gobierno consiste en subsidiar estas actividades para proporcionar empleo y fortalecer el arraigo al ejido. Una alternativa al programa actual consiste en incrementar la produccion de forraje, mediante una serie de mejoras en el manejo total del ejido. En el caso especifico del ejido Noria de Guadalupe, Zac., el analisis demuestra que los margenes de contribucion, debido a un incremento en la fuerza de trabajo, son mayores para las actividades de pastoreo bajo las condiciones propuestas que la practica de subsidio vigente en la actualidad. Sin embargo, esta nueva propuesta demanda desafientes combios en la organizacion productiva del ejido para que sea congruente con las estrategias de manejo propuestas.
    • Pickup grass seed stripper

      Dalrymple, R. L. (Society for Range Management, 1984-05-01)
      Several methods of grass seed harvest exist. One method that performs well for farm and ranch circumstances is a homemade pickup grass seed stripper. This stripper affords a means of economical seed harvest for many grass seeds.
    • Responses of Birds, Rodents, and Vegetation to Livestock Exclosure in a Semidesert Grassland Site

      Bock, C. E.; Bock, J. H.; Kenney, W. R.; Hawthorne, V. M. (Society for Range Management, 1984-05-01)
      Livestock have been excluded from a 3,160-ha range in southeastern Arizona since 1968. Compared to an adjacent continuously grazed area, in 1981-82 a protected upland site supported 45% more grass cover, a comparatively heterogeneous grass community, and 4 times as many shrubs. Grama grasses (Bouteloua spp.) were equally common in and outside the exclosure, while a variety of other species, especially plains lovegrass (Eragrostis intermedia) and Arizona cottontop (Trichachne californicum) were much more abundant on the protected site. The grazed area supported significantly higher numbers of birds in summer, while densities did not differ in winter. Rodents were significantly more abundant inside the protected area. Species of birds and rodents more common in the grazed area included those typical of more xeric lowland habitats and those preferring open ground for feeding. Species more common on the protected site were those which characterize semidesert or plains grasslands, and which prefer substantial grass or shrub cover. Grazing appeared to favor birds as a class over rodents.
    • Ruminal Digestion Consistency of Zebu Cattle

      Hansen, R. M.; Whittington, D. L.; Child, R. D.; Wanyama, J. M. (Society for Range Management, 1984-05-01)
    • Seasonal Foods of Blacktail Jackrabbits and Nuttall Cottontails in Southeastern Idaho

      MacCracken, J. G.; Hansen, R. M. (Society for Range Management, 1984-05-01)
      The diets of blacktail jackrabbits (Lepus californicus) and nuttall cottontails (Sylvilagus nuttalli) were estimated by examination of fecal pellet botanical composition. The deficiencies of fecal analysis are noted, but dietary trends and relative importance of forage plants are accurate. Cluster analysis combined leporid pellets into 2 distinct groups based on botanical composition, representing feeding during spring-summer and fall-winter periods. Seven variables (plant species) accounted for significant differences (P<0.05) within and among the leporids studied in seasonal food selection. Generally, grasses and forbs were most abundant in blacktail jackrabbit and nuttall cottontail pellets during the spring-summer period, whereas shrubs were most abundant during the fall-winter period. Diet similarity was greatest between blacktail jackrabbits and nuttall cottontails during the same season. Diversity of forage consumed was greatest for both leporids during spring-summer periods. Habitat segregation minimizes competition for forage between the leporids studied. Livestock grazing appears to limit leporid population density rather than alter leporid food habits.
    • Semen Characteristics and Behavior of Grazing Bulls as Influenced by Shade

      Coleman, S. W.; Meyerhoeffer, D. C.; Horn, F. P. (Society for Range Management, 1984-05-01)
      The efficiency of shades to provide bulls relief from heat stress was studied during the summers of 1977 and 1978. The shades were constructed from steel pipe with expanded metal roof covered with baled straw. Ambient and blackbulk temperatures were more variable in 1977 than in 1978. No consistent influence of shade availability was observed in behavior of the bulls, though during 1978, less time was spent grazing by bulls with access to shade. During both years, standing time was greater (P<.10) by bulls without access to shade. Bulls made little use of the shades in August and September. In 1977, semen motility, movement rate, and percentage live sperm cells were greater (P<.10) from bulls provided shade. Bulls without shade showed a trend for higher numbers of aged acrosomes and abnormal sperm cells. General semen quality was lower in 1978, but no consistent effect of shade was noted, except that abnormal sperm cells were lower from bulls with access to shade. During both years, semen motility was decreased and percentage of abnormal sperm cells was increased 2- to 3-weeks after blackbulb temperatures approached 45 degrees C for several consecutive days.