• Rotational stocking and production of Italian ryegrass on Argentinean rangelands

      Jacobo, E. J.; Rodriguez, A. M.; Rossi, J. L.; Salgado, L. P.; Deregibus, V. A. (Society for Range Management, 2000-09-01)
      The decreased carrying capacity of Argentinian Flooding Pampa rangelands through the reduction of density of C3 grasses may be partially attributed to continuous stocking. The objective of this study was to evaluated the effectiveness of rotational vs. continuous stocking to improve winter forage production by incrementing the density of Italian ryegrass (Lolium multiflorum Lam.). Under rotational stocking, ryegrass seedlings established almost 2 months earlier in the fall and tiller density was 3-fold higher in winter than under continuous stocking. Aerial net primary productivity of C3 grasses was approximately 2-fold greater under rotational compared with continuous stocking in the first and second years. This substantial increase in winter productivity supported almost 2-fold increase in stocking rate (from 0.6 to 1.0 AU ha-1).
    • Rotational vs. Continuous Grazing Affects Animal Performance on Annual Grass-Subclover Pasture

      Sharrow, S. H. (Society for Range Management, 1983-09-01)
      Performance of Romney ewes and their lambs grazing an annual grass-subclover hill pasture was evaluated under both five-paddock rotational and continuous grazing management treatments during 1977 and 1978. Live weight gains of ewes and lambs tended to be greater under rotational than under continuous grazing during the spring or fall green-feed periods. During the summer dry-feed period, however, sheep maintained their body weight better under continuous than under rotational grazing. These data support the hypothesis that rotational grazing most effectively improves animal performance during the green-feed period, perhaps through its regulation of pasture production.
    • Rotationally stocked beef cattle responses to daily and weekly residence

      Boyd, N. S.; Astatkie, T.; Fredeen, A. H.; Martin, R. C. (Society for Range Management, 2001-01-01)
      Rotational stocking is a component of intensive pasture management and involves the systematic movement of animals among paddocks to optimize harvest of digestible nutrients. The optimum period of residence time for beef cattle in a paddock has not been researched in Atlantic Canada. A series of experiments were conducted at the Nova Scotia Agricultural College during the 1994, 1995, and 1996 grazing seasons to determine if short residence times (1 day) or longer residence times (6 or 7 days) encouraged higher average daily gains (ADG) in beef cattle. In 1994 and 1995, Hereford steers were used, and in 1996, Hereford heifers were used to compare the effects of daily and weekly residence times. In the mid to late season of 1994, a preliminary study with fewer replicates than in 1995 and 1996 indicated that the steers with a daily and weekly residence time gained 1.18 and 1.09 kg animal-1 day-1, respectively. Based on these results the project was expanded with the hypothesis that daily residence times result in higher average daily gains compared with weekly residence times. In both 1995 and 1996, cattle ADG for the first part of the season was higher with weekly residence times and similar near mid-season. Near the end of the grazing season the trend reversed with the daily residence time producing a higher cattle ADG. The results of this study indicate that animal performance could be maximized by long rotation cycles during periods of rapid forage growth and short rotation cycles during periods of slow forage growth. In all years, animals were finished on pasture with no visible yellow fat.
    • Rough Agave Flowers as a Potential Feed Resource for Growing Goats

      Mellado, Miguel; Garcia, Jose E.; Pittroff, Wolfgang (Society for Range Management, 2008-11-01)
      The objective of this study was to evaluate the effect of different levels of rough agave (Agave scabra Ortega) flowers on dry matter intake (DMI), average daily gain (ADG), volatile fatty acid (VFA) production in the rumen, and particular serum metabolites and minerals of native3dairy growing goats (Capra hircus L.). Forty female goats with an initial weight of 11.1 +/- 1.9 kg (mean 6 SD) were used in a completely randomized design experiment that lasted for 84 d. Goats were fed a completely mixed ration (30% roughage, 70% ground corn [Zea mays L.] and soybean [Glycine max {L.} Merr] meal). Treatments consisted of offering goats (4 pens group-1, 2 goats pen-1) air-dry rough agave flowers, which replaced alfalfa (Medicago sativa L.) hay at 0% (control; T0), 25% (T25), 50% (T50), 75% (T75), and 100% (T100) of the of the roughage portion of the diet. Values of nutritional parameters for rough agave flowers were in vitro organic matter digestibility, 493 g kg-1; crude protein, 115 g kg-1; and metabolizable energy, 6.29 MJ kg-1 DMI. There were differences (P < 0.05) in ADG (range, 108-155 g d-1) between diets. Goats fed T0 had higher (P < 0.05) gains than goats fed T50 and T100. DMI was not affected by dietary treatments (range, 3.4% to 3.6% of body weight). Feed conversion ratio (FCR, defined as DMI/ADG) increased (P < 0.05) 27% with total substitution of alfalfa by rough agave flowers, in comparison with T0. Lower (P < 0.05) values of total VFA were obtained with T100, in comparison with all other dietary treatments. These results demonstrated that totally replacing alfalfa with rough agave flowers in diets did not affect DMI but decreased AGD and compromised FCR. Thus, rough agave flowers have the potential to partially replace alfalfa in diets for growing goats. 
    • Rough Fescue (Festuca scabrella Torr.) in Washington

      Hodgkinson, H. S.; Young, A. E. (Society for Range Management, 1973-01-01)
      In Washington, rough fescue occurs primarily north of the 47 degrees latitude and east of the Cascade Mountains. There are two large, well-represented areas. Other locations are represented by small areas, some containing only scattered plants. Rough fescue is very palatable and should be managed as the key species when it makes up more than 15% of the total plant composition. To maintain or improve good stands, no more than 50% of the annual current year's growth should be removed.
    • Rough Fescue Response to Season and Intensity of Defoliation

      McLean, A.; Wikeem, S. (Society for Range Management, 1985-03-01)
      Rough fescue (Festuca scabrella Torr.) was subjected to 10 clipping regimes which varied in time or intensity of defoliation. The experiment was repeated at 2 sites for 3 consecutive years. Plant survival and vigor were evaluated the summer following defoliation. Clipping treatments involving weekly defoliation to a 5-cm stubble height from mid May to late June resulted in the greatest injury. Reduced injury occurred when clipping ceased in May or when 10 or 15 cm of herbage was retained. Season long defoliation to 20 cm or clipping only in the fall caused no apparent damage. Cutting in the fall plus spring resulted in greater injury than spring clipping alone on plants clipped from mid May to late June but a fall clipping effect was not observed consistently on plants clipped in May plus fall.
    • 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.
    • Rumen Digestive Capability of Zebu Steers in Wet and Dry Seasons

      Hansen, R. M. (Society for Range Management, 1986-03-01)
      Most authors have suggested that the rumen's capability to digest foodstuff is influenced by the conditions resulting from microbial populations which are regulated by composition of the diets. Presumably the greatest ecological differences within the rumens of cattle grazing tropical semiarid range plants would be during wet and dry seasons. Rumen dry matter digestion indexes were determined by the nylon bag technique during wet and dry seasons for 4 different plant materials at the National Range Research Station near Kiboko, Kenya. The rumen digestive capability of 3 Zebu steers was not different between wet and dry seasons when these rumen fistulates selected their own foods from natural range vegetation.
    • 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)
    • Runoff and Erosion After Cutting Western Juniper

      Pierson, Fredrick B.; Bates, Jon D.; Svejcar, Tony C.; Hardegree, Stuart P. (Society for Range Management, 2007-05-01)
      Western juniper (Juniperus occidentalis spp. occidentalis Hook.) has encroached on and now dominates millions of acres of sagebrush/bunchgrass rangeland in the Great Basin and interior Pacific Northwest. On many sites western juniper has significantly increased exposure of the soil surface by reducing density of understory species and surface litter. We used rainfall and rill simulation techniques to evaluate infiltration, runoff, and erosion on cut and uncut field treatments 10 years after juniper removal. Juniper-dominated hillslopes had significantly lower surface soil cover of herbaceous plants and litter and produced rapid runoff from low-intensity rainfall events of the type that would be expected to occur every 2 years. Direct exposure of the soil to rainfall impacts resulted in high levels of sheet erosion (295 kg ha-1) in juniper-dominated plots. Large interconnected patches of bare ground concentrated runoff into rills with much higher flow velocity and erosive force resulting in rill erosion rates that were over 15 times higher on juniper-dominated plots. Cutting juniper stimulated herbaceous plant recovery, improved infiltration capacity, and protected the soil surface from even large thunderstorms. Juniper-free plots could only be induced to produce runoff from high-intensity events that would be expected to occur once every 50 years. Runoff events from these higher-intensity simulations produced negligible levels of both sheet and rill erosion. While specific inferences drawn from the current study are limited to juniper-affected sites in the Intermountain sagebrush steppe, the scope of ecosystem impacts are consistent with woody-plant invasion in other ecosystems around the world. 
    • Runoff and erosion in intercanopy zones of pinyon-juniper woodlands

      Wilcox, B. P. (Society for Range Management, 1994-07-01)
      In semiarid pinyon-juniper environments, the principal mechanisms of redistribution of water, sediments, nutrients, and contaminants are runoff and erosion. To study the phenomena underlying these mechanisms, we established six 30-m2 plots, in intercanopy zones, for monitoring over a 2-yr period (1991-1993). Two of the plots were severely disturbed; 4 were undisturbed. We measured the most runoff from these plots during mid summer (generated by intense thunderstorms) and late winter (from snowmelt and/or rain-on-snow). Runoff accounted for 10 to 28% of the water budget over the 2-yr period—a higher proportion than that observed in most other pinyon-juniper woodlands, which is probably explained by the smaller scale as well as the higher elevation of our study area. Runoff accounted for 16% of the summer water budget the first year, with above-average precipitation (and thereby higher soil moisture content) and 3% the second year, when precipitation was about average. Winter runoff was substantial both years as measured on the small scale of our study (no winter runoff was observed in the nearby stream channel). Interestingly, even though precipitation was lower the first winter, runoff was higher. This may be because snowmelt set in about 20 days earlier that year—while the soils were still thoroughly frozen, inhibiting infiltration. Differences between disturbed and undisturbed plots were most evident in the summer: both runoff and erosion were substantially higher from the disturbed plots. On the basis of our observations during this study, we suggest that the following hypotheses proposed about runoff and erosion in other semiarid landscapes are also true of pinyon-juniper woodlands: (1) Runoff amounts vary with scale: runoff decreases as the size of the contributing ares increases and provides wore opportunities for infiltration. (2) The infiltration capacity of soils is dynamic; it is closely tied to soil moisture content and/or sod frost conditions and is a major determinant of runoff amounts. (3) Soil erodibility follows an annual cycle; it is highest at the end of the freeze-thaw period of late winter and lowest at the end of the summer rainy season, when soils have been compacted by repeated rainfall.
    • Runoff and Reservoir Quality for Livestock Use in Southeastern Montana

      Soiseth, R. J. (Society for Range Management, 1975-09-01)
      Runoff and reservoir waters from the Pierre Shale Plains in southeastern Montana were fresh (< 1,000 mg/liter of TDS) to slightly saline (1,000 to 3,000 mg/liter of TDS) and were rated good to fair for livestock use. However, as water levels drop, mainly through evaporation, waters in some reservoirs could become moderately saline (3,000 to 10,000 mg/liter of TDS) and should not be used if other waters are available.
    • Runoff and Sediment Yields from Runoff Plots on Chained Pinyon-Juniper Sites in Utah

      Gifford, G. F. (Society for Range Management, 1973-11-01)
      Runoff and sediment production from a chained pinyon-juniper site in both southeastern and southwestern Utah was measured from about June 6 to October 1 over a 5-year period (1968-1972) using .04-hectare (0.11 acre) runoff plots. Treatments evaluated included chained-with-debris-windrowed, chained-with-debris-in-place, and natural woodland. All treatments were fenced to exclude livestock. Runoff events occurred at both sites during only 2 years (1968, 1970) of the study. Results indicate that chained-with-windrowing plots yield from 1.2 to 5 times more water during a runoff event than respective woodland plots. Runoff from debris-in-place plots was equal to or less than that measured from the natural woodland for all storms. Runoff data and sediment indexes indicate that when runoff exceeds about 0.1 cm from the woodland, from 1.6 to 6 times more sediment can be expected from windrowed sites than from adjacent woodland. Sediment yields from debris-in-place sites were similar to those from adjacent unchained woodland for all storms during this study.
    • Runoff and soil loss in undisturbed and roller-seeded shrublands of semiarid Argentina

      Aguilera, M. O.; Steinaker, D. F.; Demaria, M. R. (Society for Range Management, 2003-05-01)
      Vegetation influences runoff and soil losses in semiarid environments. In shrublands of Central Argentina, grazing has resulted in a reduction of plant cover, an increase in the proportion of bare soil, and eroded soils. Patterns of runoff and soil losses affected by seeding cultivated grasses were evaluated. We investigated the effects of roller-seeding of Cenchrus ciliaris L and the influence of microsite cover-type on the dynamics of water erosion. Evaluated cover-types were: bare soil, shortgrass cover, and tallgrass cover. Evaluations were performed 2 growing seasons after roller-seeding. The experimental design was a split-plot, replicated 3 times using a portable rainfall simulator. After simulation runs of 45 min at an average rate of 110 mm hour-1, runoff of tallgrass cover was the least, whereas bare soil and shortgrass cover had similar values (ca. 60%). However, both types of grass cover reduced soil splash compared to the bare soil cover-type. An exponential function between runoff and soil loss suggested that increasing runoff beyond 60% produced an abrupt rising of sediment loss. Roller-seeding did not influence runoff or sediment loss at the microsite-scale. Nevertheless, roller-seeding reduced the proportion of area covered by microsites prone to erosion (bare soil and shortgrass cover-types) at the whole plot level. We propose that any management tool that promotes the replacement of bare soil and shortgrasses by tallgrasses should reduce runoff and increase forage productivity via amelioration of hydrologic conditions of the rangeland site. Conversely, overgrazing will result in more bare soil, increasing runoff, and further intensifying the loss of sediments by detachment.
    • Runoff from simulated rainfall in 2 montane riparian communities

      Frasier, G. W.; Trlica, M. J.; Leininger, W. C.; Pearce, R. A.; Fernald, A. (Society for Range Management, 1998-05-01)
      Riparian ecosystems are the final terrestrial zone before runoff water enters a stream. They provide the last opportunity to decrease non-point source pollution delivery to streams by removing sediments from overland water flow from uplands and roads. To quantify processes of sediment transport, filtration and deposition, it is necessary to determine runoff characteristics for the area. A rotating boom rainfall simulator was used to evaluate the effects of 3 vegetation height treatments (control, 10-cm stubble height, and clipped to the soil surface) in 2 montane riparian plant communities (grass and sedge) on runoff characteristics. Each rainfall simulation event consisted of 2 phases, a dry run of about 60 min followed by a wet run approximately 30 min later. There were no differences in time to runoff initiation for either dry or wet runs that could be attributed to vegetation height treatments for either plant community. It usually required more time for runoff to be initiated in the sedge community compared to the grass community. Generally, there were lower equilibrium runoff percentages from dry runs in the sedge community compared with the grass community. These differences were less during wet runs. Several runoff parameters had characteristics of runoff from water repellent soils. The organic layer on the soil surface exhibited signs of water repellency that reduced the water infiltration rate during the initial stages of a rainfall simulation. These results indicate that runoff and infiltration processes in the surface organic horizon of riparian zones may not respond in the classical manner. This characteristic has important implications if criteria developed in areas with less organic matter on the soil surface are used to manage overland flow in the zone. Additional studies are needed to fully describe infiltration and runoff processes in riparian plant communities.
    • Runoff prediction from sagebrush rangelands using water erosion prediction project (WEPP) technology

      Wilcox, B. P.; Sbaa, M.; Blackburn, W. H.; Milligan, J. H. (Society for Range Management, 1992-09-01)
      Runoff prediction is an important component of any process-based soil erosion model. In this paper we evaluate the runoff prediction capabilities of a new soil erosion model, WEPP, on sagebrush rangelands. Particular attention was given to the parameter estimation techniques used in WEPP to predict infiltration. Runoff volume predicted by WEPP is based on the Green and Ampt infiltration equation. Predicted runoff was compared to observed runoff from 90 large plot rainfall simulation experiments on sagebrush rangelands. There was a poor correlation between predicted and observed runoff when the Green and Ampt parameters were estimated using the parameter estimation techniques. Runoff prediction was improved when parameters were determined from field measurements. Additional refinement of the Green and Ampt parameterization techniques is needed for continued improvement of WEPP.
    • Runoff Water Quality from Varying Land Uses in Southeastern Arizona

      Schreiber, H. A.; Renard, K. G. (Society for Range Management, 1978-07-01)
      Surface runoff waters from three kinds of activity on rangeland were examined for suspended solids and some indicator chemical constituents. We compared ungrazed brush-covered rangeland with recently subdivided rangeland, originally and still partly brush-covered, but whose surface was disturbed by man's urbanizing influence. Water quality indicators showed the urbanized watersheds had poorer water quality. Comparisons between the two brush-covered watersheds and a third-grass-covered and grazed-were made only on the runoff water's dissolved constituents. Despite the grazing activity, the waters were of better quality. A contrast in the geology between the grass and brush areas suggested that mineral sources affected qualitative changes in the dissolved solids. Calcareous soils produced waters higher in Ca and total dissolved solids and lower in other cations. Phosphate in runoff averaged higher from the grass-covered, noncalcareous area than from the brush-covered calcareous watershed. We hypothesize now that the phosphate originated from soil sources, rather than from grazing activity. Nitrate levels were comparable in runoff from all the nonurban areas, but increased in runoff from the semiurban area. Thus, the nonagricultural complex of activities associated with a housing development was more detrimental to water quality than those from undisturbed or grazed rangelands.
    • Russian-Thistle (Salsola) Species in Western United States

      Beatley, J. C. (Society for Range Management, 1973-05-01)
      Russian-thistle populations in western United States consist of either of two species, or both, and are distinguishable at all stages in the field. Salsola pestifer is now replaced by an earlier name, S. iberica. The second species, S. paulsenii, prevails in many areas, especially in the southwest. Where growing together they appear to hybridize freely, resulting in populations exhibiting varying degrees of genetic introgression.
    • Ryegrass and Brush Seedling Composition for Nitrogen on Two Soil Types

      Gartner, F. R.; Schultz, A. M.; Biswell, H. H. (Society for Range Management, 1957-09-01)