Theses and Dissertations at Montana State University (MSU)
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Item Browse condition and trend on Montana ungulate ranges(Montana State University - Bozeman, College of Agriculture, 2002) Thompson, Scott KarlItem A comparison of line intercept, inferred point contact, and weight measurement methods on foothill grassland vegetation(Montana State University - Bozeman, College of Agriculture, 1961) Fisser, Herbert G.Item Comparison of three remote sensing techniques to measure biomass on CRP pastureland(Montana State University - Bozeman, College of Agriculture, 2013) Porter, Tucker Fredrick; Chairperson, Graduate Committee: Bok SowellBiomass from land enrolled into CRP is being considered as a biofuel feedstock source. For sustainable production, harvesting, and soil protection, technology is needed that can quickly, accurately and non-destructively measure biomass. Remote sensing of vegetation spectral responses, which tend to be highly responsive to changes in biomass, may provide a means for inexpensive, frequent, and non-destructive measurements of biomass at management relevant scales. A valuable resource for land managers would be a biomass measurement model that could non-destructively measure biomass at different phenological growth stages across multiple growing seasons. The objective of this study was to compare remote sensing-based biomass measurement models using the normalized difference vegetation index (NDVI) and bandwise regression remote sensing techniques to determine which model best measures biomass at different phenological growth stages over multiple growing seasons on CRP pastureland in central Montana. Biomass and plant spectral response measurements were collected over the 2011 (n = 108) and 2012 (n = 108) growing seasons on an 8.1 ha CRP pasture. Measurements were stratified by phenological growth stage and growing season. Half of the data was used to build each measurement model and the other half was used to test the power of each model to measure biomass. Remote sensing-based biomass measurement models were constructed using NDVI measurements from an active ground-based sensor, NDVI measurements from Landsat images, and band combination measurements from Landsat images. All biomass measurement models showed no difference between actual and estimated biomass values (p-value > 0.05). The biomass measurement model using NDVI measurements from Landsat images had the smallest margin of difference between estimated biomass and actual biomass (22 kg/ha + or - 96 kg/ha), followed by the combination of individual spectral bands from Landsat images (128 kg/ha + or - 71 kg/ha), and NDVI measurements from a ground based sensor (182 kg/ha + or - 94 kg/ha). Results indicate remote sensing-based biomass measurement models are accurate at measuring biomass at different phenological growth stages across multiple growing seasons. Land managers can implement remote sensing-based biomass measurement models into their land management strategies to quickly, accurately, and non-destructively measure biomass across a landscape.Item Winter cereals as a pasture-hay system in Montana(Montana State University - Bozeman, College of Agriculture, 2008) Hafla, Aimee Nicole; Chairperson, Graduate Committee: Dennis Cash.In 2006 - 2008 'Willow Creek' winter wheat and 'Trical 102' triticale were evaluated for biomass production and forage quality under grazing and hay systems in Montana. Forage cultivars of winter wheat and triticale were subjected to a single grazing event at three growth stages (vegetative, boot, or heading) in the late spring. Subsequent regrowth from each grazing event was harvested as hay. Growth of winter cereals was modeled with environmental conditions. Both cultivars reached 100% headed between accumulated growing degree day (base 5 C°) 1090 and 1245 (between July 7 and 13) during the three year trial. During this period, winter cereals experienced rapid forage growth, and grew 1.4 to 2.6 cm daily and produced 87 to 248 kg ha-1 daily. In two years, triticale had superior forage biomass compared to winter wheat. Forage quality of winter cereals was excellent at the vegetative stage of growth and declined until the final forage harvest dates. At all growth stages winter wheat and triticale had similar levels of forage quality. However, the rates of digestibility of winter wheat pasture and hay were greater than those of triticale. When grazed at increasing stages of maturity, winter cereals demonstrated variable forage regrowth yield and quality. Delaying grazing until later dates coincided with hot and dry growing season conditions and limited forage regrowth potential. Regrowth of grazed cereals declined in forage quality with advancing maturity. Nitrate concentrations were high enough to concern producers with pregnant livestock grazing in spring or when grazing regrowth. Grass tetany was found to be a potential risk to lactating livestock grazing early vegetative winter cereal forage. In a whole animal digestion trial, winter wheat hay was had similar digestibility when compared to traditional grass alfalfa hay, in a sheep maintenance diet. Winter cereals can offer producers a viable option for a pasture-hay system in Montana. Maximum total biomass was a single cutting of hay at anthesis and early grain development. Therefore, it will be necessary for livestock producers to consider total biomass, availability and cost of pasture and hay, and forage quality, when using a pasture-hay system in Montana.