A metabolism trial was conducted to compare the nutritional value of: 1)"Quickstand" bermudagrass [Cynodon dactylon (L.) Pers.], 2)caucasian bluestem [Bothriochloa caucasia (Trin.) C.E. Hubb], 3)tall fescue (Festuca arundinacea Schreb.), and 4)orchardgrass (Dactylis glomerata L.). The warm-season grasses (bermudagrass and bluestem) were higher (P < .01) in fiber components than the cool-season grasses (tall fescue and orchardgrass). Bluestem was lower (P < .001) in CP, hemicellulose, and ash, and higher in NDF (P < .001), ADF (P < .001), cellulose (P < .001), and lignin (P < .01) than bermudagrass. The warm-season grasses were lower in the apparent digestibility of DM (P < .001), NDF (P < .01), ADF (P < .05), cellulose (P < .05), and hemicellulose (P < .01) than cool-season grasses. Apparent digestibility of NDF (P < .001), ADF (P < .001), cellulose (P < .01), and hemicellulose (P < .01) was higher for bluestem than bermudagrass. Fescue was higher (P < .001) in apparent digestibility of DM and CP and lower (P < .01) in apparent digestibility of NDF, ADF, cellulose, and hemicellulose than orchardgrass. Lambs fed bluestem had lower (P < .05) N retention than those fed bermudagrass, when expressed as g/d. Lambs fed fescue had higher (P < .001) N retention, than those fed orchardgrass. When expressed as a percent of intake or absorption, N retention values were similar among treatments. The results of this study suggest that cool-season grasses are of higher nutritional value than warm-season grasses. / Master of Science

The lack of consistent summer pasture supply is a major limitation to livestock production in the mid-Atlantic region. Perennial warm-season grasses might provide a solution if managed for high quality. Experiments were conducted on separate well-established stands of Caucasian bluestem and 'Cave-in-Rock' switchgrass at the Kentland Farm near Blacksburg, VA. Stages of grass maturity at harvest simulating pasture and hay systems were tested. Six interseeded legume species and two grass monoculture checks, one with 56 kg N/ha applied in spring and after each harvest, the other with no N, were imposed as sub-plots. Legume species included alfalfa, red clover, sericea lespedeza, annual lespedeza, Illinois bundleflower, and purple prairieclover. Inter-seeded legumes contributed a significant amount to yield and quality of perennial warm-season grasses in the legume-establishment year. In the year after establishment, grass mixtures with alfalfa, red clover, and, for switchgrass, sericea lespedeza yielded as much forage as N-fertilized grasses. Alfalfa and red clover altered the distribution of yield of the grasses, and may not be as compatible with perennial warm-season grasses as sericea lespedeza in the long-term. Interseeded legumes improved quality considerably in the second year. / Master of Science

Master of Science / Department of Agronomy / Walter H. Fick / Kevin Price / Caucasian bluestem [Bothriochloa bladhii (Retz) S.T. Blake] is a perennial, C4 warm-season bunchgrass that was first introduced in 1929 from Russia as a potential forage crop in the Great Plains. Due to its invasiveness and tolerance of drought and grazing pressure, Caucasian bluestem can out-compete native prairie species. Research has shown that this species, when compared to native tallgrass species in the Flint Hills of Kansas causes decreased cattle weight gains because of its poor forage quality relative to tallgrass prairie species. Traditional methods of plant data measurements and mapping are costly and time consuming. Use of remotely sensed data to map and monitor the distribution and spread of this plant would be most useful in the control of this aggressive invader. Spectroradiometer data were collected over the 2009 growing season to determine if and when Caucasian bluestem was spectrally unique from native tallgrass prairie species. Observations were made from June through September as the plants were going into a senescent state. Reflectance data were measured approximately every two weeks or when clear/near clear sky conditions prevailed. Statistical analyses for differences in spectral characteristics were conducted to determine the optimal spectral bands, indices and timing for discriminating Caucasian bluestem from native tallgrass species. Difference in reflectance for spectral reflectance of bands 760 nm, 940 nm, 1,070 nm, and 1,186 nm were found to be statistically significant on the June 17th and June 30th sampling dates. The following band ratios and indices were found to be significantly different between Caucasian bluestem and native range on the June 17th collection date: Simple Ratio, Modified Normalized Difference Index, Normalized Phaeophytinization Index, Plant Index 1, Normalized Water Difference Index, Water Band Index, Normalized Difference Nitrogen Index, and the Normalized Difference Lignin Index. Findings of this study suggest that Caucasian bluestem can be spectrally discriminated from native tallgrass prairies of the Flint Hills in Kansas if the measurements are collected in mid to late June. Statistical analyses also showed differences between treatments for percent litter, grass, and forb basal cover.