No abstract

Smooth bromegrass is a commonly used cool-season pasture grass that responds favorably to annual spring fertilization, but annual fertilizer applications require annual inputs of both time and expense. This study was conducted to determine if interseeding legumes into established smooth bromegrass pasture is a viable alternative to spring fertilization. Steers (Bos taurus) were rotationally grazed in either fertilized smooth bromegrass pastures or smooth bromegrass pastures interseeded with legumes. Data were collected on forage production, forage available at the beginning of each grazing rotation, steer weight gain, and the number of grazing days. Total forage production for the growing season was not different between the pasture types, but fertilized pasture had greater available forage early in the growing season and interseeded pasture had greater forage production late in the growing season. Season-long average daily gain of steers was not different between pasture types, but daily gains were greater in interseeded pasture late in the growing season and may be linked to proportionally greater abundance of legumes late in the season. Beef production ac -1 was higher in interseeded pastures, largely due to increased days of grazing. We found that interseeding legumes into established pasture can be a viable alternative to annual spring fertilization and may outperform fertilized pasture depending on the metric and growing conditions.

The Rainwater Basin region in Nebraska is critically important stopover habitat for spring waterfowl migrations, but the ability of these sites to produce sufficient food for migrating waterfowl is endangered by the invasion of reed canarygrass (Phalaris arundinacea L.). This species produces thick litter layers and abundant aboveground biomass, reducing germination and seedling survival of the annual plant species responsible for much of the seed production in the area. Cattle grazing often is used as a management tool in the Rainwater Basin to slow or reverse reed canarygrass invasion and to improve growing conditions for more desirable plant species. However, there has been little research on the impact of grazing on these factors. We studied the impacts of one-time, early-season (between April and June) cattle grazing on the abundance of reed canarygrass, bare ground, and litter. We hypothesized that cattle grazing would result in reduced reed canarygrass by the end of the 2-yr study, and that grazing would increase the abundance of bare ground and decrease the abundance of litter. Because grazing was expected to improve conditions for seed germination, we expected to find higher species richness in grazed areas. We found that grazing did not reduce the abundance of reed canarygrass, but the application of early-season grazing for two consecutive years did reduce litter and increase bare ground. Litter abundance decreased by 7.5% in ungrazed plots and litter increased by 8.6% in grazed plots. Bare ground in grazed plots increased 10.7% in grazed plots but decreased 1.2% in ungrazed plots. Species richness was not affected by grazing during this study. We concluded that grazing, as utilized in this study, is not sufficient to reduce reed canarygrass abundance, but can be used to mitigate some of the negative impacts of reed canarygrass invasion. Resumen La región de la cuenca hidrológica Rainwater Basin en Nebraska es un hábitat sumamente importante de escala para las migraciones de aves acuáticas de primavera. Sin embargo, la capacidad de estos sitios para producir suficientes alimentos para aves acuáticas migratorias está en peligro por la invasión de canarygrass (Phalaris arundinacea L.). Estas especies producen capas gruesas de materia orgánica y abundante biomasa aérea, reduciendo la germinación y la sobrevivencia de las especies anuales que son las que producen gran parte de la semilla en el área. El pastoreo de ganado se utiliza frecuentemente como una herramienta en esta cuenca hidrológica con el fin de reducir o retroceder la invasión de canarygrass y para mejorar las condiciones de crecimiento de especies más deseables. No obstante, hay poca investigación sobre el impacto del pastoreo sobre estos factores. Por lo que investigamos los efectos del pastoreo aplicado una sola vez al inicio del crecimiento (entre Abril y Junio) sobre la abundancia del reed canarygrass, suelo desnudo y mantillo orgánico. Formulamos la hipótesis que el pastoreo del ganado daría como resultado una reducción en reed canarygra...

Establishing vegetation on roadsides following construction can be challenging, especially for relatively slow growing native species. Topsoil is generally removed during construction, and the surface soil following construction ("cut-slope soils") is often compacted and low in nutrients, providing poor growing conditions for vegetation. Nebraska Department of Transportation (NDOT) protocols have historically called for nitrogen (N) and phosphorus (P) fertilization when planting roadside vegetation following construction, but these recommendations were developed for cool-season grass plantings and most current plantings use slower-establishing, native warm-season grasses that may benefit less than expected from current planting protocols. We evaluated the effects of nitrogen and phosphorus fertilization, and also topsoil amendment, on the foliar cover of seeded and non-seeded species planted into two post-construction roadside sites in eastern Nebraska. We also examined soil movement to determine how planting protocols and plant growth may affect erosion potential. Three years after planting, we found no consistent effects of N or P fertilization on foliar cover. Plots receiving topsoil amendment had 14% greater cover of warm-season grasses, 10% greater total foliar cover, and 4-13% lower bare ground (depending on site) than plots without topsoil. None of the treatments consistently affected soil movement. We recommend that NDOT change their protocols to remove N and P fertilization and focus on stockpiling and spreading topsoil following construction.

Understanding of Sandhills prairie, the most expansive sand dune region stabilized by perennial grasses in the Western Hemisphere, is limited by lack of long-term vegetation data. We used a 26-year dataset to evaluate Sandhills prairie responses to yearto-year variation in precipitation, temperature, and cattle stocking rate. Basal cover, a measurement that is constant seasonally and used to detect long-term changes in bunchgrass vegetation, was measured in 38-40 permanent plots positioned along four transects spanning 769 ha from 1979 to 2007. Across this period, total basal cover averaged 2.4 % and was dominated by warm-season grasses (81.1 %). Schizachyrium scoparium (little bluestem), the dominant warmseason bunchgrass, consisted of 60.0 % relative basal cover. Warm-season grass and total basal cover responded positively to lag 3-year growing season precipitation indicating delayed responses to improved growing season conditions, but these variables also were positively associated with stocking rate. The positive responses may be due to slow spread of warmseason grasses by vegetative structures in response to favorable growing conditions in light to moderately stocked rangeland. Despite its dominance, however, warm-season grass cover had no influence on cover of other functional groups providing weak support for competition as regulator of Sandhills prairie composition. Forb cover was best related in a negative manner to 3-year running mean total precipitation, a surprising result that maybe signaling factors governing basal responses in prairie remain largely unresolved. Woody species cover, however, was positively associated with mean growing season temperatures indicating potential of these to spread under warming scenarios.