Browsing Journal of Range Management, Volume 52, Number 1 (January 1999) by Subjects
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Central Nevada riparian areas: Physical and chemical properties of meadow soilsDespite the importance of soil characteristics for classifying riparian ecosystem types and evaluating ecosystem or range condition, little information exists on western riparian area soils or the factors that influence them. We examined the effects of drainage basin geology and water table depth on soil morphology and soil physical and chemical properties of meadow sites in central Nevada. We described and analyzed the soils of meadows that occurred in 4 drainages with different geology and that exhibited high water tables (0 to -20 cm from the surface), intermediate water tables (-30 to -50 cm), and low water tables (-60 to -80 cm). Pedons of high water tables sites had thick Oe horizons, dark, fine-textured A horizons, no B horizons, and lower C horizons high in coarse fragments. In contrast, pedons of low water tables sites were characterized by deep, dark and organic-rich A horizons, cambic B horizons, and deep rooting profiles. High water tables sites had higher organic matter, total nitrogen, cation exchange capacity, and extractable potassium, but lower pH than low water table sites. Also, high water table sites had lower percentage sand, lower bulk densities, and higher soil moisture retention. The importance of organic matter was evidenced by strong positive product moment correlations for organic matter and total nitrogen, cation exchange capacity, and extractable potassium. Significant differences in pH, extractable potassium and extractable phosphorus existed among drainages that were explainable largely from the parent materials. Drainages with chert, quartzite, and limestone had higher silt and clay, neutral pH, and high levels of extractable phosphorus. Drainages formed in acidic volcanic tuffs, rhyolites and breccia were characterized by coarser textured soils and low pH and extractable phosphorus. In riparian areas, soil water table depth interacts with soil parent material to significantly affect soil morphology and soil physical and chemical properties. Because these factors vary over both large and small spatial scales, differences among sites must be carefully interpreted when classifying ecosystems or evaluating ecosystem condition.
Yield and feeding of prairie grasses in east-central AlbertaInformation on the yield of grasses as the plants mature is useful to optimize grazing potential and quality hay production. The objectives of this study were to compare the yield and feeding value of 11 common prairie grasses over 2 yearly cycles of growth and determine which of the grasses may require supplementation to meet nutrient requirements of grazing cattle. Dry matter yield (DM), crude protein (CP), acid detergent fiber (ADF), calcium (Ca), and phosphorus (P) values were obtained for brome (Bromus inermis [L.]), creeping red fescue (Festuca rubra [L.]), crested wheatgrass (Agropyron cristatum [L.] Gaertn), intermediate wheatgrass (Agropyron intermedium (host) Beauv), meadow foxtail (Alopecurus pratensis [L.]), orchardgrass (Dactylis glomerata [L.]), pubescent wheatgrass (Agropyron trichophorum Link. richt), streambank wheatgrass (Agropyron riparium Scriba &Smith), slender wheatgrass (Agropyron trachycaulum Link Malte), tall fescue (Festuca arundinacea Schreb), and timothy (Phleum pratense [L.]) at weekly intervals from June to September, in 1992 and 1993. Most grasses reached maximum yields at week 8 in 1992 (drought year) and week 12 in 1993 (normal year). Herbage mass yields (g/0.25m2 at week 8 in 1992 (highest to lowest yielding) were crested wheatgrass (235), intermediate wheatgrass(210), pubescent wheatgrass(173), brome(161), slender wheatgrass(152), meadow foxtail(114), Tall fescue(110), timothy(101), orchardgrass(83), creeping red fescue(56), and streambank wheatgrass(50). Herbage mass yields pattern of the grasses in 1993 was similar to that in 1992 except for crested wheatgrass and brome which ranked first and fourth in 1992 but ranked fifth and second, in 1993, respectively. Quality declined in all grasses as they matured. The average CP content of grasses declined from 24% to 13% in 1992 and from 21.5% to 12.1% in 1993 but were adequate to meet crude protein requirements of growing, pregnant or lactating grazing cattle. The Ca levels in all grasses were adequate for all classes of cattle on pasture but the low P levels of 0.11% in both years indicate that growing, pregnant or lactating cattle grazing on these pastures would require P supplementation.