Now showing items 1-20 of 23

    • Impact on Associated Vegetation of Controlling Tall Larkspur

      Cronin, E. H. (Society for Range Management, 1976-05-01)
      Herbicide treatments that effectively control tall larkspur also convert the tall-forb community to a grass-dominated community. The composition of the grass community is determined more by the grazing system imposed on the treated area than by the herbicide treatments. Early grazing reduces mountain brome and increases letterman needlegrass. With protection from grazing, the converted grass community can produce abundant high-quality forage and watershed cover superior to that of the former larkspur-dominated tall-forb community.
    • Factors Involved in the Decline of Annual Ryegrass Seeded on Burned Brushlands in California

      Papanastasis, V. (Society for Range Management, 1976-05-01)
      The effect of amount of mulch, nitrogen fertilizer, and clipping frequency was studied on herbage and seed production of annual ryegrass (Lolium multiflorum Lam.) seeded on a burned brushland in California. The experiment was continued for 2 years but, in the second year, actual grazing by meadow mice (Microtus californicus) was substituted for the clipping treatment. Available nitrogen in the soil was found deficient in both years but the deficiency was more pronounced in the relatively dry year. Meadow mice reduced herbage and seed yields significantly in the second year. It is concluded that the decline of annual ryegrass in burned brushlands is associated with a corresponding decline through immobilization of available soil nitrogen released by brush burning.
    • Establishment, Production, and Protein Content of Four Grasses in South Texas

      Polk, D. B.; Scifres, C. J.; Mutz, J. L. (Society for Range Management, 1976-05-01)
      Old World bluestem and Selection 75 Kleingrass established stands more rapidly and produced more topgrowth the year of seeding than did Bell Rhodesgrass or green sprangletop at three locations in South Texas. Based on crude protein content of foliage at maturity, the grasses ranked Selection 75 Kleingrass > Bell Rhodesgrass, green sprangletop > Old World bluestem. Old World bluestem foliage contained only slightly more than 6% crude protein at maturity. However, crude protein content of Old World bluestem, Bell Rhodesgrass, and green sprangletop decreased only slightly from maturity to dormancy. Selection 75 Kleingrass crude protein levels in foliage dropped from about 13% at maturity to less than 9% during dormancy.
    • Efficiency of Converting Nutrients and Cultural Energy in Various Feeding and Grazing Systems

      Cook, C. W.; Denham, A. H.; Bartlett, E. T.; Child, R. D. (Society for Range Management, 1976-05-01)
      Yearlong total confinement and partial confinement feeding were compared to conventional range grazing to determine the cultural and digestible energy expended to produce a kilocalorie of dressed-carcass meat from weaner calves and the protein consumed to produce a pound of red-meat protein. The range groups required the least amount of cultural energy to produce a kilocalorie of meat and the total confined groups required the most. The total confined system on a low level of nutrition, where calves were weaned early, converted digestible energy most efficiently but converted digestible protein least efficiently, whereas range groups converted digestible energy least efficiently and digestible protein most efficiently.
    • Effect of Temperature and Photoperiod on Germination and Survival of Sand Bluestem

      Stubbendieck, J.; McCully, W. G. (Society for Range Management, 1976-05-01)
      Results obtained from studies with controlled environments gave an indication of responses of G-1773 sand bluestem (Andropogon hallii Hack.) germinating caryopses and seedlings to several different temperature and photoperiod combinations. Germination was favored by relatively high alternating temperatures and was not affected by absence of light. Survival of this accession was affected by both photoperiod and temperature. Survival was favored by 12-hour photoperiods and was inversely related to increasing temperature. These data indicate that this accession of sand bluestem may respond more favorably to fall seeding than to spring seeding.
    • Dynamics of the Root System of Blue Grama

      Ares, J. (Society for Range Management, 1976-05-01)
      Field experiments were conducted to determine dynamics of the root system of blue grama (Bouteloua gracilis) during the 1973 growing season at the US/IBP Pawnee Site in northern Colorado. Differentiation and growth of blue grama roots were recorded in field conditions by means of windows in excavations. Roots began to grow and differentiate a short time before leaf growth was apparent. Desiccation of soil in the mid-growing season resulted in death and subsequent decomposition of 30% to 60% of the newly formed roots. Massive root growth occurred when soil water potential was high near the end of the growing season. Roots were separated into morphological categories by microscopic analysis of soil samples on May 15, near the beginning of the growing season, and on August 9, near the end of it. Young nonsuberized roots, so important in water absorption, were concentrated in regions of the soil profile where soil water potential was high. An empirical model of root growth and development in B. gracilis is derived from the data.
    • Drought Resistance of Blue Grama as Affected by Atrazine and N Fertilizer

      Hyder, D. N.; Houston, W. R.; Burwell, J. B. (Society for Range Management, 1976-05-01)
      Two consecutive summer droughts in north central Colorado caused considerable thinning of blue grama (Bouteloua gracilis) stands, and N fertilizer accentuated the drought effects. However, atrazine, with or without N fertilizer, prevented serious thinning of stands. Consequently, investigations were initiated to test the hypotheses that atrazine created greater resistance to, or tolerance of, drying in crown tissues. Both hypotheses were rejected. It remains to be determined whether the combined effects of weed control, slower transpiration, and changes in root distribution by atrazine treatment may reduce water consumption and, thus, protect blue grama from drought.
    • Distribution of Nitrogen in Root Materials of Blue Grama

      Clark, F. E.; Campion, M. (Society for Range Management, 1976-05-01)
      Root materials of blue grama were compartmentalized into three categories-live, senescent, and detrital. Their mean N contents were 0.89, 1.90, and 2.56%, respectively. For each root category there were significant differences both with soil depth and time of sampling. Soil N differed significantly with depth but not across dates of sampling. The standing crop of root N was found to occur largely in senescent and detrital materials. Compartmentalization of the plant N belowground as well as that aboveground should promote more successful simulation of root growth dynamics and nutrient flows.
    • Decline of Prairie Dog Towns in Southwestern North Dakota

      Bishop, N. G.; Culbertson, J. L. (Society for Range Management, 1976-05-01)
      Aerial photographs for 1939 to 1972 were examined to evaluate the impact of rodent control programs and land use practices on prairie dog towns on a portion of the Little Missouri National Grasslands. Colonies were measured for three periods during the 33-year span and showed an 89% decline in number and a 93% decline in acreage. Average town size was not significantly affected during the decline and was not significantly different on federal land compared to private or state land. Colonies were largely eliminated on the best agricultural bottom lands but appeared to be more persistent near the undisturbed colonies in Theodore Roosevelt National Memorial Park. Reported sightings indicate that some black-footed ferrets have probably survived in the area. The new perspective has resulted in improved management for the two species.
    • An Inventory of Arthropods from Three Rangeland Sites in Central Montana

      Hewitt, G. B.; Burleson, W. H. (Society for Range Management, 1976-05-01)
      Three rangeland sites (mountain, foothill, and plains) in central Montana were surveyed for arthropods to determine their abundance and potential impact upon the vegetation. A vacuum quick trap (sampling method) showed that seven orders of arthropods were important on the basis of abundance and/or above-ground biomass: Acarina (mites); Thysanoptera (thrips); Collembola (springtails); Orthoptera (grasshoppers); Hemiptera (true bugs); Homoptera (leafhoppers and plant lice); and Hymenoptera (ants). The grasshoppers, true bugs, leafhoppers, and thrips consume parts of the plants and thus directly affect forage production. Springtails, mites (Oribatidae), and ants vary greatly in their habits and may affect forage production indirectly by breaking down organic matter in the soil or by affecting population densities of other insect species.
    • A Grazing Recorder Harness for Use with Zebu Type Cattle

      Gwynne, M. D.; Kingaby, G. P. (Society for Range Management, 1976-05-01)
      The hump, dewlap, and neck-curve of Zebu (Bos-indicus) cattle make it difficult to fit a stable harness which involves a neck-band. A harness design is described here which allows a vibracorder automatic grazing recorder to be correctly and securely positioned on the neck of these cattle. It has proved suitable for use with range-herded animals.
    • Vegetative Response under Various Grazing Management Systems in the Edwards Plateau of Texas

      Reardon, P. O.; Merrill, L. B. (Society for Range Management, 1976-05-01)
      Forage production under five different grazing management schemes was compared after 20 years of treatment in the Edwards Plateau region of Texas. Results from this study showed that: (1) a more dense ground cover does not always result in higher forage production; (2) forage yields and litter accumulation were lower on a natural area than under deferred rotation or light grazing; (3) greatest amounts of decreaser plants were found in deferred rotation pastures; (4) natural areas have limited value in range research since they do not respond in comparative patterns; and (5) the 4-pasture deferred rotation system produced the most desirable livestock and wildlife habitat for the Edwards Plateau region of Texas.
    • Vegetation Changes Induced by Prairie Dogs on Shortgrass Range

      Bonham, C. D.; Lerwick, A. (Society for Range Management, 1976-05-01)
      This study documented some effects of prairie dogs on a shortgrass type of the Central Plains Experimental Range approximately 35 miles northeast of Fort Collins, Colo., and an adjacent area. Prairie dogs changed the plant species composition of the two sites studied, but these changes were not all detrimental. Species diversity was greater and some plant species used by livestock were more abundant inside than outside the prairie dog towns.
    • Some Effects of Supplemental Grain Feeding on Performance of Cows and Calves on Range Forage

      Bellows, R. A.; Thomas, O. O. (Society for Range Management, 1976-05-01)
      This study was conducted to determine the effects of supplemental grain feeding on reproductive performance of lactating range beef cows. Results indicated that feeding 3.86 kg grain either before or during lactation, or before and during the breeding season, decreased the fall pregnancy rate in supplemented cows compared to cows on range forage only. The high level of grain feeding reduced grazing time and subsequent forage intake and served as a substitute for the range forage rather than a supplement. A major part of the diet of dams grazing during the early spring period was new growth on western wheatgrass. This forage was available in limited amounts during this early time period, and the moisture content ranged from 65.3 to 82.1%, resulting in a low dry matter intake. Lactating dams lost 1.23 kg daily during this time period, but daily calf gains at this time averaged 0.71 kilograms. Thus, a major part of the nutrients consumed by the dam was being used for production of milk, and at least a portion of the milk was being produced at the expense of body tissue stores of the dam. This work indicates that the period from calving until adequate forage with a sufficient dry matter content is available to produce weight gains in the lactating dams should be considered a critical nutritional period. These findings indicate the need for studies to determine the most satisfactory methods of meeting the nutritional requirements of the lactating dam during this period.
    • Semiarid Rangeland Treatment and Surface Runoff

      Tromble, J. M. (Society for Range Management, 1976-05-01)
      Effects of pitting and rootplowing on surface runoff were determined on a desert shrub range in southeastern Arizona, and the time-dependent changes in the soil surface characteristics resulting from these practices were studied. Additional detention storage was provided by increased roughness in microtopography, thereby decreasing surface runoff when compared to the control. Rock and gravel were negatively correlated with surface runoff. Combining the two parameters showed a significant reduction in surface runoff. Increases in runoff were associated with exposed soil. Crown cover significantly reduced runoff. Litter was not significant in the reduction of runoff. Regulation of surface runoff is important for on-site rangeland improvements as well as reducing sediment yields.
    • Row Spacings of Russian Wildrye for Fall Pasture in Southern Saskatchewan

      Kilcher, M. R.; Heinrichs, D. H.; Lodge, R. W. (Society for Range Management, 1976-05-01)
      In southern Saskatchewan fall grazing resources become acutely short because little growth of grass occurs after early July. Russian wildrye (Elymus junceus) cures better than most other grasses and is therefore best for late fall pasture. Over a 9-year period cattle were grazed on stands of Russian wildrye that had been seeded in rows spaced 20, 40, or 60 cm apart. Two stocking rates were used. The animals were weighed periodically and were removed when losses in weight occurred. Up to 5 weeks of grazing were obtained where rows were 60 cm apart and when stocked at one animal on each .43 ha, compared to as low as 3 weeks where rows were only 20 cm apart and stocked at one animal on each .32 ha. Values for crude protein, digestibility, crude fibre and ether extract are given.
    • Response of Planted South Florida Slash Pine to Simulated Cattle Damage

      Hughes, R. H. (Society for Range Management, 1976-05-01)
      Seedling outplants injured to resemble damage by cattle the 6th, 18th, or 30th month after planting were observed until trees attained sapling size. Simulated browsing alone killed few trees, but combinations of damage increased losses and aggravated the stunting of trees. With factorial combinations which included varying degrees of defoliation, shoot removal, and stem breakage, plots with unclipped trees contained 1 1/2 to 4 times more basal area at the end of the study than trees that were totally defoliated. Without the other treatments, less than a full girdle of the stem was not detrimental.
    • Redberry Juniper Response to Top Removal

      Schuster, J. L.; George, J. (Society for Range Management, 1976-05-01)
      Redberry juniper (Juniperus pinchoti) sprouted vigorously from root crowns after removal of tops by cutting. Regrowth was least on trees cut from June through August, indicating that this is the optimum period for control by top removal. Production of sprouts was directly proportional to tree size.
    • Range Fertilization in the Northern Great Plains

      Wight, J. R. (Society for Range Management, 1976-05-01)
      Nutrient deficiency, primarily nitrogen (N), is a major plant growth-limiting factor on northern Great Plains rangelands. Applications of 30 to 50 lb N/acre/year have commonly doubled forage production with an N-use efficiency of about 20 lb dry matter/lb N applied, or in grazing situations about 1 lb beef/lb N applied. Range fertilization can also increase water-use efficiency and improve forage quality and palatability. With applications of 50 lb N/acre/year or less, changes in species composition are gradual and can largely be controlled by timing of fertilizer applications and by season and intensity of grazing. Drastic changes in species composition are usually limited to applications greater than 150 lb N/acre/year.