The effects of animal impact on soil chemical and physical properties as well as range condition were measured over a 5-year period to test the hypothesis that animal impact can improve the nutrient and water status of the soil and promote grassland succession. A seventeen-pasture short-duration grazing system was established in 1981 on 972 ha. The pastures were stocked on average with 278 cows with calves from 1982 to 1986, which was about twice to triple the recommended rate of 0.8 AUM/ha. Increased grazing pressure reduced range condition as reflected by a loss of desirable species such as rough fescue (Festuca scabrella Torr.). Soil moisture was always higher in soils of ungrazed exclosures. Soil bulk density increased while hydraulic conductivity decreased with grazing. Litter was not significantly incorporated into the soil with hoof action. Chitin-N, as a measure of fungal biomass, decreased significantly under the increased grazing pressure. The hypothesis that animal impact would improve range condition was rejected since impact, in the manner applied during the study, resulted in retrogression of the grasslands.

Supplemental irrigation generally increased seedling density the seeding year; however, this response was not maintained the year following seeding. Above-average precipitation minimized the importance of irrigation the seeding year. Seeding mixture appeared important with a 6- and 4-species mixture providing better establishment than a 2-species mixture. This was apparently due to the relatively large proportion of switchgrass (Panicum virgatum L.) in the 2-species mixture and its generally poor establishment. The reduced seeding rate resulted in better stand establishment than the recommended rate on a tilled seedbed (1.1 and 0.7 seedlings/0.1 m2, respectively), while neither seeding rate provided an acceptable stand (>0.5 seedlings/0.1 m2) with the no-till treatment in small plot evaluations. Seedbed tillage also resulted in a higher seedling density than no-tillage (1.3 and 0.5 seedlings/0.1 m2, respectively) for the production-level field trial. Seedling density was doubled with depth bands (1.2 vs. 0.6 seedlings/0.1 m2). These results suggested that a tilled seedbed on sandy cropland with adequate moisture results in successful stands. A native, warm-season grass mixture (4 or more species) is recommended with a seeding rate of 15 PLS/0.1 m2 using equipment with depth bands.

Perennial grass establishment on abandoned cropland in the Nebraska Sandhills is difficult due to low soil fertility, organic matter, and water holding capacity and high potential erodibility. Establishment is further complicated by unpredictable precipitation and weed competition. Two warm-season grasses: sand bluestem [Andropogon gerardii var. paucipilus (Nash) Fern.] and switchgrass (Panicum virgatum L.); and 2 cool-season grasses: smooth brome (Bromus inermis Leyss.) and intermediate wheatgrass [Thinopyrum intermedium (Host) Barkw. & D.R. Dewey subsp. intermedium] were evaluated with spring-seeded field trials. Seedbed preparation [untilled, disced, and dead oat (Avena sativa L.) cover (DOC)] effect on seeded grass and nonseeded species densities was evaluated in 1985 and 1986 at 2 locations on Valentine sands (Aquic Ustipsamment). In 1985 1 site was irrigated. Both sites were dryland in 1986. Stand failure (< 5 seedlings/m2) occurred on the dryland site in 1985 due to low, erratic precipitation. Stands evaluated in June 1986 on plots established with irrigation in 1985 had 38, 46, and 61 plants/m2 for the untilled, disced, and DOC seedbeds, respectively. The disced or DOC seedbeds were required for successful (>10 plants/m2) dryland seedings in 1986 at both locations. Irrigation the establishment year minimized risk of stand failure and allowed the use of any seedbed preparation or grass species studied. Sand bluestem was the only species to establish both years. However, if a dryland seeding of a cool-season species is desired, intermediate wheatgrass appeared more adapted than smooth brome.

Air temperature or growing degree-days (GDD) are known to influence morphological development of grass, but the effects of grazing history on grass morphological development has not been established. Morphological development of 5 species located on moderately and heavily grazed mixed prairie sites near Mandan, North Dakota, was determined 3 times per week from beginning of growth in spring to heading. The species were western wheatgrass [Pascopyrum smithii Rydb. (Löve)], blue grama [Bouteloua gracilis (H.B.K.) Lag. ex Griffiths], needleandthread (Stipa comata Trin. and Rupr.), green needlegrass (S. viridula Trin.), and prairie junegrass [Koeleria pyramidata (Lam.) Beauv.]. Regression analysis of growth stage with GDD was linear and statistically significant for prairie junegrass (R2=0.62), green needlegrass (R2=0.96), and needleandthread (R2=0.95), and nonlinear for blue grama (R2=0.95) and western wheatgrass (R2=0.97). Prior grazing management had little effect on this relationship. The number of leaves and accumulated GDD required to produce those leaves varied by each species: prairie junegrass (4 leaves, 520 GDD), needleandthread (4 leaves, 640 GDD), green needlegrass (4 leaves, 800 GDD), blue grama (5 leaves, 1,300 GDD), and western wheatgrass (6 leaves, 1,450 GDD). Based on the species and conditions of this study, plant growth stage can be predicted from accumulated GDD and used for predicting grazing readiness and in development of forage growth models.

In vivo digestibility trials were conducted to evaluate the influence of shrubs containing low and high levels of soluble phenolic/-tannins on digestibility and nitrogen retention by Angora goats. Each of 6 shrubs and alfalfa hay (Medicago sativa L.) were fed to goats at 30% (dry matter basis) of the diet in a barley straw-prairie hay mixture. The mixture was regulated so that all diets contained about 8% crude protein. High soluble phenolic shrubs used included big sagebrush (Artemisia tridentata Nutt. ssp. tridentata), gray oak (Quercus grisea Liebm.), true mountain mahogany (Cercocarpus montanus Raf.), and one-seed juniper (Juniperus monosperma [Engelm.] Sarg). Low-soluble phenolic species included common winterfat (Ceratoides lanata [Pursh.], J.T. Howell), fourwing saltbush (Atriplex canescens [Pursh.], Nutt.), and alfalfa. Nitrogen digestibilities of winterfat, gray oak, mountain mahogany and one-seed juniper diets were less (P<.05) than the alfalfa controls, but big sagebrush did not differ (P>.05) compared with the alfalfa control. Retained nitrogen (g/d) differed (P<.05) only among alfalfa, juniper, and mountain mahogany diets. Goats fed juniper had greater (P<0.05) retained nitrogen than the alfalfa control. Shrubs high in soluble phenolics, with the exception of big sagebrush, had elevated fecal nitrogen losses, but reduced urinary nitrogen losses compared with the alfalfa control. Forage organic matter intake (% body weight) and nitrogen intake (g/d) were correlated more highly with nitrogen retention than dietary crude protein (%) or digestible protein (%). Present data indicate that protein found in palatable native shrubs is assimilated with similar efficiency to that in alfalfa hay if these shrubs are consumed at moderate levels.

Herbage yields in a newly planted slash pine (Pinus elliottii Engelm.) Plantation were measured annually for 26 years. Total herbage yield initially increased in response to removal of the previous forest canopy. Thereafter, yield decreased steadily as the canopy of the developing pine plantation closed until it leveled off at about age 20. The maxima function described trends in yield for most species and groups of species. Accurate herbage yield estimates over time allow managers of forested rangeland to plan cattle stocking rates or arrange for alternative sources of forage.

The effects of N fertilization on spotted knapweed (Centaurea maculosa Lamarck) and competing vegetation were studied at 2 sites in western Montana during 1981 through 1984. The N was applied 1 time at each site at rates of 56, 112, 224, and 448 kg/ha. Spotted knapweed biomass showed a significant, positive yield response to N at all rates at both sites during the year of application. The only response by spotted knapweed to N in succeeding years was in the second year at Site 1 where a significant response was detected at the 448 kg N/ha rate. Competing vegetation at Site 1 (primarily quackgrass, Agropyron repens (L.) Beauv.) in the first year showed a significant, positive response to N, while competing vegetation at Site 2 (primarily crested wheatgrass, Agropyron cristatum (L.) Gaertn.) did not respond to N in the first year. No response by competing vegetation to N in succeeding years at either site was detected. There was a significant relationship between percent knapweed and N rate at both sites in the year of N application, but not in succeeding years. These results suggest that N fertilization, by itself, as a cultural control approach to knapweed may be impractical, and could contribute toward the increase of knapweed when used in some of the plant communities normally associated with spotted knapweed on rangeland in western Montana.

Tule elk (Cervus elaphus nannodes) reintroduced to Point Reyes, Calif., in 1978 exhibited gross signs of copper deficiency by June 1979. Copper levels in liver (mean = 5.9 ppm) and serum (0.42 ppm) of elk at Point Reyes were below levels in adult tule elk from other locations in California (liver, mean greater than or equal to 80 ppm; serum, mean greater than or equal to 1.4 ppm). These levels were consistent with documented copper deficiency in wild and domestic ruminants. Copper serum levels increased in response to copper enriched dietary supplements and declined after the elk stopped eating the supplements. Analysis of plant and soil samples showed both are deficient in copper and normal in molybdenum and sulfur-sulfates. Deficiency in plants and soils at Point Reyes are probably due to low copper levels in the underlying granitic parent material.

The Surface Mining Control and Reclamation Act of 1977 requires that surface-mined land be revegetated with "the same seasonal variety", meaning species of the same season of growth as the species native to the area. Our objective was to compare season-of-grazing use of pastures comprised of introduced cool-season species with pastures comprised of a mix of native warm- and cool-season species. The study was conducted on surface-mined land near Center, North Dakota, dominated by smooth bromegrass (Bromus inermis Leyss.) and alfalfa (Medicago sativa L.) and on adjacent unmined mixed prairie. Pastures were 1.86 ha in size and stocked with 2 yearling steers (Bos spp.) each. Grazing was started in May or June and ended in late September or early October for 96 days in 1982 and 126 days each in 1983, 1984, and 1985. Liveweight gain increased from mid June through August and then remained constant on all pastures. Herbage dry matter yield from reclaimed pastures was equal to or greater than yield from native pastures each year. The season-of-grazing use was no different for reclaimed cool-season pastures than for native mixed prairie, and there was no evidence that species with the same growing season as those native to the area were necessary to provide season-long grazing use. Cool-season forage species are easier to seed, establish, and less expensive to buy and can be used to revegetate surface-mined land for season-long grazing use.

Recording and management of field or laboratory data can be aided through use of a data logging computer. Data are electronically transferred from the data logger to a larger computer for statistical analysis, eliminating re-entry from field sheets and reducing the potential for error. Laptop computers offer advantages over specialized data loggers, but require a software program to function efficiently as a data logger. Range research uses might include recording plant sample weights, recording livestock weights and condition scores, plant growth measurements, and frequency counts. A flexible data entry program accommodating several experimental designs was written in BASIC for creating analysis-ready data files, using either keyboard or RS-232 data input.