Browsing Journal of Range Management, Volume 38, Number 6 (November 1985) by Subjects
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Prescribed Burning in the Loess Hills Mixed Prairie Southern NebraskaAbused rangelands dominated by introduced cool-season grasses and warm-season shortgrasses are common over much of the Mixed Prairie. Native decreaser species are primarily warm-season grasses and are present at only insignificant levels on abused rangeland in the Loess Hills of southcentral Nebraska. A single, late-spring, prescribed fire was evaluated as a method of improvement. The study area consisted of 3 tracts of plots located on Holdrege silt loam soil (Typic Argiustall) with an average annual precipitation of 550 mm. The vegetation on the tracts was in low range condition, with cool- and warm-season components being present in varying proportions on all tracts. In general, the dominant cool-season species were Kentucky bluegrass (Poa pratensis) and annual bromes (Bromus spp.), and the dominant warm-season species were blue grama (Bouteloua gracilis) and buffalograss (Buchloe dactyloides). Burning reduced the basal cover and herbage yields of cool-season species. This favored the warm-season component. The increaser short grasses generally exhibited higher herbage yields and basal cover on burned as compared to unburned plots. These results indicate that a single, late-spring, prescribed burn may have a limited potential as a range improvement practice in the Loess Hills of south central Nebraska.
Response of an Irrigated Cool- and Warm-Season Grass Mixture to Nitrogen and Harvest SchemeMaintaining a mixture of cool-and warm-season grasses under intensive management for season-long production is difficult, due to species shifts, especially to a dominance of cool-season grasses when heavy amounts of nitrogen (N) fertilizer are used. The objective of this study was to determine if high forage yields could be produced season long while maintaining a desirable balance of warm-and cool-season grasses. The study was conducted near Mead, Nebraska on a Sharpsburg silty clay loam (Typic Argiudoll). An irrigated mixture of 3 warm-season grasses and 1 cool-season grass, big bluestem (Andropogon gerardii Vitman), switchgrass (Panicum virgatum L.), and indian-grass [Sorghastrum nutans (L.) Nash] and smooth brome (Bromus inermis Leyss.) was fertilized at low (150 kg/ha), medium (250 kg/ha) and high (350 kg/ha) rates of N in split applications. Three harvest schemes were designed to either produce high quality forage or to maximize yield. Herbage yields showed a quadratic response with N level. A late May/mid July harvest scheme for the first and second cuttings did not produce as much forage as late May/late August or early June/late August harvest schemes. Population of smooth brome and other cool-season grasses declined with the higher N rates. Populations of warm-season grasses were not greatly affected by N level. Density of smooth brome increased under all harvest scheme treatments and the highest increase for other cool-season grasses was with a May 24/July 13 harvest scheme. Warm-season grasses maintained a steady density over the 3 years. Forage was produced from early May until late summer with an irrigated cool- and warm-season mixture. Fall production of smooth brome was minimal, although stand was generally maintained. Nitrate N accumulated in the soil under the medium and high N treatments.