Master of Science / Department of Agricultural Economics / Kevin Dhuyvetter / Land accounts for more than 75% of a farm operation’s total assets and thus knowledge of land values are very important to landowners. However, many other parties, including lenders, appraisers, investors, and researchers also have significant interest in land markets. Over the past few decades, land prices in Kansas have increased significantly for many different reasons. The main objective of this research is to estimate the impact of various factors on Kansas land values using a hedonic regression model. In cooperation with the Property Valuation Department (PVD) of the Kansas Department of Revenue, farmland market transactions from 1986 to 2009 were obtained for this study. Hedonic models were estimated using Ordinary Least Squares to determine the impact of interest rates, urban areas, location, parcel size, and income on nominal and real Kansas land values. The estimated nominal and real models explained 24.1% and 17.2% of the variation in land prices, respectively, and the results from this study are generally consistent with previous research. This research went further into investigating the relationship between PVD data and United States Department of Agriculture (USDA) surveyed data. Results from this study indicate that USDA surveys significantly underestimate the true market for land prices across Kansas.

Master of Science / Department of Agricultural Economics / Hikaru Hanawa Peterson / Over the past few decades, the prevalence of obesity and diet-related diseases has steadily increased and become a major public health concern. Part of the problem has been attributed to the large quantity of unhealthy (energy-dense) foods U.S. consumers include in their diets. Statistics on food environment suggest that some areas and households have easier access to fast food restaurants and convenience stores but limited access to supermarkets. Limited access to nutritious food and relatively easier access to less nutritious food have been shown to lead to poor diets and, ultimately, to obesity and diet-related diseases. These issues may more negatively affect some communities than others, particularly rural communities as they tend to be further away from food outlets compared to urban areas. Counties are classified as food deserts based upon the percentage of residents living below the federal poverty line and the percentage of residents residing more than one mile from a supermarket. This definition excludes many viable food outlet options, including smaller independently-owned groceries. With rural residents being at a greater disadvantage, it becomes important to consider smaller groceries as an alternative for these communities. The level of social capital may be an indicator of an area’s willingness to support its community. The social environment of rural communities can be characterized as having a high degree of interconnectedness within the community, so that “everybody knows everybody else” (Beggs, Haines, & Hurlbert, 1996). This unique social network in rural communities facilitates the buildup of social capital, which incorporates reciprocity and the willingness to do things for members within the network. This study finds a negative relationship between obesity and social capital in nonmetropolitan counties, as well as a negative relationship between obesity rates and rural grocery stores. These conclusions lend insight into ways to decrease the level of obesity in rural areas.

Master of Science / Department of Plant Pathology / Megan Kennelly / Dollar spot disease of turfgrass, caused by the fungus Sclerotinia homoeocarpa, is the most economically important disease of intensively managed turfgrass such as creeping bentgrass (Agrostis stolonifera) in golf course fairways and putting greens. While several cultural management practices can lessen the severity of the disease, fungicide applications are necessary to manage the disease to acceptable levels. Host resistance is another avenue of improving the quality of turfgrass in response to dollar spot disease, but more information on cultivar susceptibility levels is necessary. Many fungicides are available to control dollar spot, but S. homoeocarpa has shown resistance to both demethylation inhibitor (DMI) and benzimidazole class fungicides. The objectives of this thesis were: (1) to evaluate 15 cultivars of creeping bentgrass under putting green and fairway management for both overall quality and disease severity of dollar spot in the presence and absence of fungicide applications; (2) to determine the sensitivity of Kansas S. homoeocarpa isolates to the DMI fungicides propiconazole, metconazole, tebuconazole, and triticonazole using in vitro mycelia growth assays; (3 to determine a best discriminatory dose concentration for each DMI fungicide that will provide for rapid testing of relative sensitivity, and (4) to sequence the entire β-tubulin gene of several resistant and sensitive isolates to determine mutations associated with resistance. There were differences in turfgrass quality among the 15 cultivars at putting green height but not fairway height. There were no significant differences in disease. In the fungicide resistance assays, the mean EC50 values were 0.0163, 0.038, 0.0612, and 0.0994 µg/ml for metconazole, propiconazole, tebuconazole, and triticonazole, respectively. Correlations were significant and positive for all pairwise comparisons of log10EC50 values. Regressions using discriminatory concentrations tested were significant. The most predictive concentrations were 0.01, 0.05, 0.05, and 0.10 µg/ml a.i, for metconazole, propiconazole, tebuconazole, and triticonazole, respectively. The entire β-tubulin gene was sequenced for four resistant and four sensitive isolates. The resistant isolates all harbored a substitution of alanine for glutamic acid at codon 198 (E198A).

Master of Science / Department of Agricultural Economics / Kevin Dhuyvetter / This research analyzes how crop farms can achieve a higher net income per acre than other operations by farming fundamentally differently than others. There are many factors that are important to the long-term viability of today’s crop operations, one of which is how farms profitability compares with other operations. This determines farms’ ability to compete for land, outlast other operations through periods of unprofitability, and produce crops at long run equilibrium prices. These factors are relevant in today’s crop production industry where farms sit on a segment of the agribusiness supply chain. Therefore, in the interest of providing farms relevant information to manage their operations, this research analyzes how farms can distinguish their performance from other operations by accessing land and equipment resources, production practices for growing crops, and focusing their management efforts differently than other operations. There are three parts to this analysis. First, farms are broken down by characteristics, practices, and management performances. Then an econometric analysis quantifies the integrated correlation between farms’ distinguished characteristics, practices, and management performances and their distinguished net incomes per acre. Next a standard deviation analysis measures the degree to which farms are capable of distinguishing particular characteristics, practices, and management performances from other operations. Lastly, the performance of farms over the 2001 to 2010 time period is used to quantify how feasible it is for farms to maintain particular differences from other operations. Data used in this analysis were provided by the Kansas Farm Management Association, Kansas State University’s Department of Agricultural Economics, and Kansas’s National Agricultural Statistics Service office. The results suggest the way farms distinguish their characteristics, practices, and management performances from other operations impacts how their net income compares to other operations. The econometric analysis found that relative farm size, share of rented acres, the value of overhead and equipment investment per acre, government payments, planting intensity, risk, and cost, yield, and price management performances were all significantly related to farms’ relative net income. In regards to farms’ comparative profitability, this suggests farms should be aware of how their characteristics, practices, and management performances compare to other operations. The results also suggest the degree to which and the consistency with which farms can distinguish particular characteristics, practices, and management performances are different from one another. Over the 2001 to 2010 period, Kansas farms distinguished their characteristics from other operations to a larger degree than they distinguished their practices and management performances. Farms also maintained differences in their characteristics more consistently than they maintained differences in their practices and management performances. This suggests farms that are actively seeking to distinguish their net income per acre from other operations should be aware of the degree and consistency with which they can maintain particular differences from other operations.

Master of Science / Department of Grain Science and Industry / Cassandra Jones / In two experiments, conditioning time and temperature of swine feed were altered to determine effects of starch, vitamin retention, and swine growth performance. A third experiment evaluated methodologies for estimating gelatinized starch in swine feed. Across all experiments, diet formulation was constant. In Exp. 1, treatments were arranged in a 2 × 3 factorial design plus a control, including 2 conditioning temperatures (77 vs. 88°C) and 3 conditioner retention times (15, 30, and 60 s). A mash diet was added for a total of 7 treatments. Total starch was affected by conditioning temperature (P = 0.04) but not time (P = 0.50). Similar results were observed for gelatinized starch (P = 0.005 and 0.65, respectively). Sample location also affected total starch (P = 0.0002) and gelatinized starch (P = 0.0001), with the greatest increase in gelatinization occurring between conditioned mash and hot pellets. Conditioning alone did not influence gelatinization as evidenced by similar values between cold and hot mash (P > 0.05). Neither conditioning temperature nor time affected vitamin concentrations (P > 0.50). A portion of these treatments were then fed to 180 nursery pigs (PIC 327 × 1050; initially 12.6kg) in an 18-d study. Treatments included: 1) non-processed mash (negative control); 2) pelleted diet conditioned for 30 s (positive control); 3) pelleted diet conditioned for 15 s and reground; 4) pelleted diet conditioned for 30 s and reground, and 5) pelleted diet conditioned for 60 s and reground. Observed growth performance differences appear to be due to feed form, not conditioning time. Average daily gain and G:F did not differ (P > 0.12) between treatments, but ADFI was decreased (P = 0.03) as expected for pigs fed the positive control pelleted diet compared to all other diets. There were no differences (P > 0.05) in any growth performance variables amongst the three conditioning temperatures. In Exp. 3, it was determined that the method developed by Mason et al. (1982) was the best indicator of gelatinization in livestock feed. In summary, feed form, but not conditioning time affected gelatinized starch and swine growth performance.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Donghai Wang / Grain sorghum is the second major starch-rich raw material (after corn) for bioethanol production in the United States. Most sorghum feedstock for bioethanol production is normal non-tannin sorghum. Waxy sorghum and tannin sorghum are rarely used due to lack of scientific information about waxy sorghum fermentation performance and the way to increase fermentation efficiency of tannin sorghum. The main objectives of this study were to investigate the fermentation performance of waxy sorghum and to improve fermentation efficiency of tannin sorghum using techniques such as germination and ozonation treatments. The ethanol fermentation performance on both waxy sorghum and tannin sorghum were evaluated using a dry grind ethanol fermentation procedure. Fermentation efficiencies of tested waxy sorghum varieties ranged from 86 to 93%, which was higher than normal (non-waxy) sorghum varieties. The advantages of using waxy sorghums for ethanol production include less energy consumption, higher starch and protein digestibility, shorter fermentation time, and less residual starch in distillers dried grains with solubles (DDGS). Results from germination study showed germination significantly increased fermentation efficiency of tannin sorghum. The laboratory results were further confirmed by those from five field-sprouted grain sorghum samples. Significantly increased free amino nitrogen (FAN) contents in sprouted sorghum samples accelerated the ethanol fermentation process. Results from both laboratory-germinated and fieldsprouted samples demonstrated that germination not only increased fermentation efficiency (higher than 90%) but also reduced fermentation time by about 50%, which could result in energy saving and increased production capacity without additional investment. The excellent performance of sprouted sorghums may provide farmers a new market for field-sprouted sorghum (poor quality as food or feed) in a bad year. A previous study showed ozone had a strong connection to degradation of lignin macromolecules. The hypothesis was that ozone treatment may also reduce tannin activity and increase fermentation efficiency of tannin sorghum. Results showed that the ethanol production performance (ethanol yield, fermentation efficiency, and fermentation kinetics) of the ozone-treated, tannin sorghum flours was significantly improved compared with the untreated control. The other effects of ozonation on sorghum flour include pH value decrease, discoloration, and inactivation of tannin. In summary, these studies showed sorghum, no matter it was waxy, field-sprouted, or tannin sorghum, can be an excellent feedstock for ethanol production.

Master of Agribusiness / Department of Agricultural Economics / Michael Langemeier / This thesis examines flour moisture control and how this control can be an effective tool for cost minimization in a flour mill. Specifically, this thesis discusses the economic rationale behind the value of moisture control, the variables associated with moisture control, options for controlling those variables, the current control strategies, the decision process used to examine moisture control options, analysis of the solution, and implementation of optimal control strategies. In the area of optimal control strategies, two outcomes were generated in the thesis. The first outcome involved collecting data and developing a better understanding of the factors impacting flour moistures. The second outcome was to create a spreadsheet tool for use in the flour mill that would allow operators to determine an optimal water set point that would bring about a desired flour moisture taking into consideration the variables effecting flour moisture and their status at a given time. Both outcomes have been met and are outlined in detail in the thesis. It is understood that the conclusions of this thesis do not represent an end to the flour moisture control challenge and that more research is needed in order to implement further control measures. Work that remains to be done in order to achieve even better moisture control is also outlined in this thesis.

Master of Science / Department of Grain Science and Industry / Xuzhi Susan Sun / Large amount of fiberboard are used for packaging applications every year, which generate a large amount of solid wastes causing environmental pollution if these packaging materials are not recycled. Also, a large amount of wood are needed for making fiberboard, which is limited resource in the earth. Reducing the weight of fiberboard and recycling the fiberboard materials are two methods to save quantities of wood fiber in fiberboard manufacture, which benefit the environment and economy. Besides, most adhesives used for producing the fiberboard contain environmental hazardous chemicals. It is necessary to develop new technology to produce cellulosic fiberboards with environmental friendly bio-based adhesives. The soybean is an agricultural product, and its resource is abundant. Soybean protein is a bio- material that offers an alternative to the existing synthetic adhesives to reduce petroleum dependence of the U.S. energy strategy. The newly developed soy-based adhesive is also competitive in cost. Material cost based on food-grade soybean protein is around 20 cents/Lb. The cost of commercial PF resin is about 14 ~ 17 cents/Lb. Price of hot-melt adhesive for fiberboard is around $6/Lb. In this study, soybean protein was modified with sodium dodecyl sulfate as an adhesive for two bio-based fiberboards products, medium density fiberboard by dry processing and light weight cardboard by wet processing. The mechanical and water soaking properties of these cellulosic fiberboards were stronger than or as same as commercial solid fiberboard. This research suggests that these cellulosic fiberboards with modified soybean protein based adhesive have great potential as alternative to current commercial fiberboard.

Master of Science / Department of Animal Sciences and Industry / John A. Unruh / Forty-eight Brahman-cross male calves were fed to 26 mo of age and used to determine carcass cutability and meat quality characteristics of four muscles from intact bulls and steers castrated at 3, 7, or 12 mo of age grown under tropical pasture conditions. Longissimus lumborum (LL), Psoas major (PM), Gluteus medius (GM), and Semitendinosus (ST) steaks were aged for 2, 7, 14, or 28 d for Warner Bratzler shear force (WBSF) analysis. Live weight, carcass traits, and total subprimal yields were not affected by male sex condition. For PM, GM, and ST steaks, WBSF values were similar for steaks from intact bulls and steers castrated at all ages. For both PM and GM muscles, steaks aged for 28 d had the lowest (most tender) WBSF values and steaks aged for 2 d had the highest WBSF values. For the ST, WBSF values were highest for steaks aged 2 d. A treatment × aging interaction was detected for LL WBSF values. At 14 d of aging, LL steaks from steers castrated at 3 mo tended to have lower WBSF values than those from intact bulls. At 28 d of aging, steaks from steers had lower WBSF values than steaks from intact bulls and steaks from steers castrated at 3 mo tended to have lower WBSF values than steaks from steers castrated at 12 mo. For LL steaks from steers castrated at 3, 7 or12 mo, WBSF values linearly decreased with increased days of aging. Although all sensory panel data collected were not statistically different, LL steaks from steers castrated at 3 mo tended to have higher (more tender) scores for overall tenderness than steaks from intact bull. This study indicates that castration at 3 mo would be the recommended production practice as it provided the greatest improvement of LL tenderness over intact bulls with no differences in carcass traits or subprimal yields. The degree of improvement in tenderness due to aging is muscle dependent.

Estimating the size of an insect pest population in an agricultural field is an integral part of insect pest monitoring. An abundance estimate can be used to decide if action is needed to bring the population size under control, and accuracy is important in ensuring that the correct decision is made. Conventionally, statistical techniques are used to formulate an estimate from population density data obtained via sampling. This thesis thoroughly investigates an alternative approach of applying numerical integration techniques. We show that when the pest population is spread over the entire field, numerical integration methods provide more accurate results than the statistical counterpart. Meanwhile, when the spatial distribution is more aggregated, the error behaves as a random variable and the conventional error estimates do not hold. We thus present a new probabilistic approach to assessing integration accuracy for such functions, and formulate a mathematically rigorous estimate of the minimum number of sample units required for accurate abundance evaluation in terms of the species diffusion rate. We show that the integration error dominates the error introduced by noise in the density data and thus demonstrate the importance of formulating numerical integration techniques which provide accurate results for sparse spatial data.