• N and P fertilization on rangeland production in Midwest Argentina

      Guevara, J. C.; Stasi, C. R.; Estevez, O. R.; Le Houérou, H. N. (Society for Range Management, 2000-07-01)
      Low soil nutrient status may be the major limiting factor to forage production in rangelands of the Mendoza plains 4 years out of 10. We studied vegetation responses to annual applications of N and P on such rangelands. Fertilizer application rates were 0 or 25 N and 0 or 11 P (kg ha-1) in a factorial arrangement. Dry matter production of grasses and palatable shrubs and crude protein (CP) content of grasses were determined annually from 1996 to 1998. Experimental plots received rains of 189, 278, and 346 mm during the 3 study years compared to mean growing season rainfall of 258 mm. Forage production was increased by N+P fertilization only in 1998 (1,390 vs 980 kg ha-1, P 0.05), producing 16.5 kg forage kg-1 N applied. Crude protein concentration was increased by N fertilization in 1997 (6.3 vs 5.3%, P < 0.05) and N+P application increased in 1998 (6.8 vs 5.7%, P < 0.05). Nitrogen and P application increased seasonal rain-use efficiency when the rainfall exceeded 300 mm. In 1998, the increase of grass production per kg N applied with and without P was 18.4 and 12.4 kg, respectively. The break-even point between rain and nutrients as the main primary production determinant on sandy soils in the central Mendoza plains is around 400 mm year-1 instead of 300 mm in other arid lands of the world. The value of meat increment derived from the N fertilization, with and without P application (US 0.07 ha-1 year-1 kg-1 N) was lower than the fertilizer cost (US 0.87 kg-1 N). A 5-fold increase in forage yields would be required to offset the cost of fertilizer. Fertilizer application did not increase forage production enough to be profitable for cattle production at present fertilizer and meat prices.
    • N, P, And K Fertilization of Tall Fescue (Festuca arundinacea Schreb.) Overseeded Range in Eastern Oklahoma

      Mitchell, R. L.; Ewing, A. L.; McMurphy, W. E. (Society for Range Management, 1985-09-01)
      A native hay meadow in northeastern Oklahoma was overseeded with tall fescue (Festuca arundinacea Schreb.) and fertilized for 6 years with N in August and February to encourage tall fescue growth in late fall and early spring, thus extending the green forage season. The effect of P and K fertilizer on forage yield and plant nutrient concentration was determined. Cool-season N fertilization (112 kg/ha) nearly doubled tall fescue yield and increased forage nitrogen concentration without altering warm-season grass production. Additions of P (15, 29 kg/ha) and K (28, 112 kg/ha) increased cool-season forage yield marginally and increased fertilizer N recovery but had no desirable effect on forage N, P, and K content. Tall grass decreaser species were dominant at the end of the study. Available soil P increased with P fertilization and available soil K increased with K fertilization.
    • N-alkane as an internal marker for predicting digestibility of forages

      Sandberg, R. E.; Adams, D. C.; Klopfenstein, T. J.; Grant, R. J. (Society for Range Management, 2000-03-01)
      Independent digestion trials with 5 forages were conducted to compare n-alkane with indigestible acid-detergent fiber (IADF) as internal markers to predict in vivo dry matter digestibility (digestibility). Forages were mixed grasses from subirrigated meadow (meadow), meadow regrowth (regrowth), native range (range), mature mixed grass hay from meadow, and alfalfa (Medicago sativa L.) hay. Meadow, regrowth, and range diets were immature grasses harvested 0.5 hours before feeding. Feces from the meadow hay and alfalfa hay trials were divided to compare freeze drying and oven drying (60 degrees C). All diets were subjected to in vitro fermentation for 0, 48, or 96 hours. N-alkane was separated from samples by 4.5-hour saponification with alcoholic KOH followed by extraction with n-hexane. Indigestible ADF was measured by 96-hour in vitro fermentation followed by ADF extraction. Digestibility estimated by markers was compared with in vivo digestibilities. N-alkane based digestibilities were lower (P < 0.01) than in vivo digestibility for all diets. N-alkanes provided higher estimates of digestibilities than IADF for meadow (P < 0.01), regrowth (P = 0.06), and alfalfa hay (P = 0.06), and lower digestibility for meadow hay (P = 0.02). Digestibilities calculated using n-alkanes for range tended to be higher (P = 0.14) than IADF values. Freeze drying increased (P < 0.01) the amount of n-alkane extracted from alfalfa hay, but did not affect (P = 0.1) the amount extracted from meadow hay. N-alkane disappeared (P < 0.001) from residue collected after 48 hours of in vitro fermentation, but no additional disappearance (P = 0.78) was evident at 96 hours. Neither marker was completely recoverable, although recovery of n-alkane was higher than indigestible ADF for 4 of the 5 forages tested.
    • Nail-Board Method of Root Sampling

      Schuster, J. L.; Wasser, C. (Society for Range Management, 1964-03-01)
    • National Meetings Are Also for Students

      Sedgley, Ellis F. (Society for Range Management, 1953-09-01)
    • Native Clovers and their Chemical Composition

      Hamilton, J. W. (Society for Range Management, 1961-11-01)
    • Native forage quality, quantity, and profitability as affected by fertilization in northern Mexico

      Rubio, H. O.; Wood, M. K.; Gomez, A.; Reyes, G. (Society for Range Management, 1996-07-01)
      Fourteen treatments of nitrogen (N) and phosphorus (P) fertilizers were applied in an overgrazed eight rangeland in northern Mexico, during 1990 and 1991. Eight treatments were applied using ammonium nitrate as a source of N (60-0-0, 60-30-0, 60-60-0, 80-40-0, 120-30-0, 120-60-0, 120-90-0 and 180-60-0 kg ha-1), 2 treatments with ammonium sulfate (60-30-0 and 120-60-0 kg ha-1), 2 with urea (60-30-0 and 120-60-0 kg ha-1), only P (0-30-0 kg ha-1), and the control (0-0-0 kg ha-1). Triple superphosphate was applied as a source for P. The 80-40-0 treatment was included because it was the commonly recommended rate for the area. Fertilizers were applied at the beginning of the rainfall season (July) and forage was harvested in late October (1990) and mid-November (1991). Dry matter production, crude protein (CP) content, and in situ digestibility were determined. An economic analysis was used to obtain the best economic treatment for forage production. In 1990 with a precipitation of 377 mm, dry matter production was significantly affected for both source and rate of N. The maximum amount of dry matter was obtained with a rate of 120-90-0 kg ha-1 using ammonium nitrate. However, the best treatment in terms of economic return was 120-30-0 kg ha-1 as ammonium nitrate. Urea did not produce as well as other N source treatments. Crude protein was highest in treatments with the higher N, but no significant trend was evident. In situ digestibility was not affected by rate or source of N fertilizer. During 1991, precipitation was higher than in 1990. Significant differences were determined among N rates but not in N source. In fact, urea produced greater in dry matter production than other N sources at the same rate. The maximum amount of dry matter was obtained with the 180-60-0 treatment using ammonium nitrate with 4,190 kg ha-1, but the best economic treatments were the 120-30-0 and 60-0-0 with a marginal return rate of 377% and 355%, respectively. Results of CP and in situ digestibility were similar to those of 1990.
    • Native Forage Response to Clearing Low Quality Ponderosa Pine

      Thompson, W. W.; Gartner, F. R. (Society for Range Management, 1971-07-01)
      Clearing of low quality ponderosa pine in the foothills region of the Black Hills of South Dakota increased forage production 1,500 lb./acre on an east slope and 848 lb./acre on a west slope. Warm season grasses increased to a greater extent than did cool season grasses. If extensive areas were treated in this manner, management changes should be implemented to more efficiently use the increased production of warm season grasses. The increases in forage production plus the use or sale of removed timber should justify clearing low quality pine in this area. Pine reproduction will pose future management problems on cleared areas.
    • Native Grass and Crested Wheatgrass Production as Influenced by Fertilizer Placement and Weed Control

      Smika, D. E.; Haas, H. J.; Rogler, G. A. (Society for Range Management, 1963-01-01)
    • Native or seeded rangeland for cows with high or low milk production

      Adams, D. C.; Staigmiller, R. B.; Knapp, B. W.; Lamb, J. B. (Society for Range Management, 1993-11-01)
      Multiparous cows (n = 91, 1986; n = 92, 1987) were selected from 2 populations to obtain cattle with high and low milk production. After March-April calving, high and low producing cows grazed either native range (treatment 1) or seeded range (treatment 2) until weaning in September. Seeded range included paddocks of crested wheatgrass (Agropyron desertorum, Fisch. ex [Link]Schult), contour furrowed native range interseeded with "Ladak" alfalfa (Medicago Sativa L.), and Russian wildrye grass Psathrostachys juncea[Fisch.]Nevski.). In treatment 2, crested wheatgrass was grazed mid-April to 17 June, followed by contour furrowed rangeland 18 June to 5 August, and ended with Russian wildrye 6 August to weaning (mid-September). Data were analyzed as a split plot with treatment and year in the main plot and cow type in the subplot. Number of cows exhibiting estrus before the beginning of the breeding season and fall pregnancy rate were not influenced (P > 0.05) by range treatment. Twelve-hour milk production during May, June, August, and September ranged from 11.3 to 6.8 kg and 7.6 to 3.9 kg for high and low producing cows, respectively. Cows with high milk production lost body condition during and after the breeding season, whereas cows with low milk production maintained body condition during the same period. Live weight gain of calves was greater (P < 0.01) for cows with high production than cows with low production but was not affected (P > 0.05) by range treatment. We concluded that native and seeded ranges were of similar nutritive value for cows with high and low milk production and that cows with high milk production may have greater nutrient requirements during late summer-early fall than what was provided by native or seeded ranges. Protein may be the primary limiting nutrient in forages during the late summer for lactating cows grazing Northern Great Plains range.
    • Native Plant Growth and Seedling Establishment in Soils Influenced by Bromus tectorum

      Rowe, Helen I.; Brown, Cynthia S. (Society for Range Management, 2008-11-01)
      The invasion of 40 million hectares of the American West by cheatgrass (Bromus tectorum L.) has caused widespread modifications in the vegetation of semi-arid ecosystems and increased the frequency of fires. In addition to well-understood mechanisms by which cheatgrass gains competitive advantage, it has been implicated in reducing arbuscular mycorrhizal fungi (AMF) abundance and taxa diversity. We evaluated this possibility at a high elevation site in a two-pronged approach. To test whether cheatgrass changed native AMF communities in ways that affected subsequent native plant growth, we grew cheatgrass and native plants in native soils and then planted native plants into these soils in a greenhouse experiment. We found that cheatgrass-influenced soils did not inhibit native plant growth or AMF sporulation or colonization. To test whether soils in cheatgrass-dominated areas inhibited establishment and growth of native plants, cheatgrass was removed and six seeding combinations were applied. We found that 14.02 +/- 1.7 seedlings m-2 established and perennial native plant cover increased fourfold over the three years of this study. Glyphosate reduced cheatgrass cover to less than 5% in the year it was applied but did not facilitate native plant establishment or growth compared with no glyphosate. We conclude that cheatgrass influence on the soil community does not appear to contribute to its invasion success in these high elevation soils. It appears that once cheatgrass is controlled on sites with sufficient native plant abundance, there may be few lingering effects to inhibit the natural reestablishment of native plant communities. 
    • Native Plants Poisonous to Humans

      Steger, R. E. (Society for Range Management, 1972-01-01)
    • Natural Establishment of Aspen from Seed on a Phosphate Mine Dump

      Williams, B. D.; Johnston, R. S. (Society for Range Management, 1984-11-01)
      The natural reproduction of aspen (Populus tremuloides Michx.) from seed was discovered on a phosphate mine dump in southeastern Idaho. Aspen seedlings were found growing on areas that were essentially bare except for scattered plantings of containerized shrubs and trees. Aspen survival and growth was monitored for 4 growing seasons. Seedling density varied from 2 to 10 per m2, seedling heights varied from 16 to 81 cm, and survival rate was 73% at the end of 4 growing seasons. No changes in the number of seedlings were noted after the second growing season.
    • Natural regeneration processes in big sagebrush (Artemisia tridentata)

      Schlaepfer, D. R.; Lauenroth, W. K.; Bradford, J. B. (Society for Range Management, 2014-07)
      Big sagebrush, Artemisia tridentata Nuttall (Asteraceae), is the dominant plant species of large portions of semiarid western North America. However, much of historical big sagebrush vegetation has been removed or modified. Thus, regeneration is recognized as an important component for land management. Limited knowledge about key regeneration processes, however, represents an obstacle to identifying successful management practices and to gaining greater insight into the consequences of increasing disturbance frequency and global change. Therefore, our objective is to synthesize knowledge about natural big sagebrush regeneration. We identified and characterized the controls of big sagebrush seed production, germination, and establishment. The largest knowledge gaps and associated research needs include quiescence and dormancy of embryos and seedlings; variation in seed production and germination percentages; wet-thermal time model of germination; responses to frost events (including freezing/thawing of soils), CO2 concentration, and nutrients in combination with water availability; suitability of microsite vs. site conditions; competitive ability as well as seedling growth responses; and differences among subspecies and ecoregions. Potential impacts of climate change on big sagebrush regeneration could include that temperature increases may not have a large direct influence on regeneration due to the broad temperature optimum for regeneration, whereas indirect effects could include selection for populations with less stringent seed dormancy. Drier conditions will have direct negative effects on germination and seedling survival and could also lead to lighter seeds, which lowers germination success further. The short seed dispersal distance of big sagebrush may limit its tracking of suitable climate; whereas, the low competitive ability of big sagebrush seedlings may limit successful competition with species that track climate. An improved understanding of the ecology of big sagebrush regeneration should benefit resource management activities and increase the ability of land managers to anticipate global change impacts. © 2014 The Society for Range Management.
    • Natural Reproduction of Winterfat (Eurotia lanata) in New Mexico

      Woodmansee, R. G.; Potter, L. D. (Society for Range Management, 1971-01-01)
      In situ ecological factors influencing the natural reproduction of the important Western browse species winterfat (Eurotia lanata) were investigated in central and west-central New Mexico from summer 1967 to spring 1969. Seed of winterfat germinated in late winter and early spring on all slopes and in soils varying widely in origin and texture. Survival was greatest on disturbed soils which supported low vegetation that afforded some shelter but little shading for seedlings. The disturbed soils indicated greater moisture availability. Seedlings were tolerant to competition, and were often found in living clumps of grass. A comparison of vegetation on heavily grazed and protected ranges indicated winterfat was susceptible to heavy grazing, and reproduced when on protected or lightly grazed range dominated by low-growing grasses.
    • Natural Sources of Nitrogen and Phosphorous for Grass Growth

      Miles, A. D. (Society for Range Management, 1958-05-01)
    • Nature and Successional Status of Western Juniper Vegetation in Idaho

      Burkhardt, J. W.; Tisdale, E. W. (Society for Range Management, 1969-07-01)
      Western juniper invasion of sagebrush-bunchgrass vegetation in southwestern Idaho was verified. The invasion started about 1860 and is continuing at present. Juniper was found to be climax on rocky ridges and rimrocks where soil development is limited. Seral juniper stands were found on the deeper soils of valley slopes and bottoms. These sites were previously occupied by productive sagebrush-grass stands. It appears that juniper control would be more beneficial on invaded sites than on climax juniper sites.
    • Nature of Phytomer Growth in Blue Grama

      Stubbendieck, J.; Burzlaff, D. F. (Society for Range Management, 1971-03-01)
      The pattern and relative growth rates of the individual phytomers of blue grama were determined. A mature blue grama shoot from the site had an average of 13 complete phytomers. The first six phytomers appeared to be initiated in the growing season prior to the one in which the plant reached maturity. Internodal elongation of over 100 mm in a period of two weeks was not uncommon. In most instances the internodes did not elongate before the sheath and blade reached maximum length. The leaf of the last phytomer was initiated just prior to the middle of June. Mature sheath length varied from 15 mm in phytomer 13 to nearly 80 mm in phytomers 11 and 12. Blade length varied from 4 mm in phytomer 2 to 134 mm in phytomer 10.
    • Navajo Use of Mixed-breed Dogs for Management of Predators

      Black, H.; Green, J. S. (Society for Range Management, 1985-01-01)
      Seventy-two Navajo ranchers were questioned about the role of mixed-breed dogs with their flocks. Navajos call their dogs "sheep dogs" but, unlike sheep dogs used by other ranchers to assist in herding and moving the flocks, Navajo dogs function primarily as guardians of sheep and goats to whom they have developed social bonds. This attraction is a result of raising dogs essentially from birth in visual, olfactory, auditory, and tactile association with sheep and goats. A minimum of handling of pups reduces the likelihood that they will bond strongly to humans. Mixed-breed dogs of the Navajo appear to exhibit all behavioral traits believed to be important in protecting flocks from predators, especially coyotes: they are attentive, defensive, and trustworthy. If ranchers choose to employ dogs, the rather simple Navajo recipe for training may serve them well. Mixed-breed dogs could be quickly deployed in a variety of ranching situations to help reduce predation on livestock.