Remote sensing application in biomass crop production systems in Oklahoma

Foster, Anserd Julius Oklahoma State University 2013 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

This study was conducted to evaluate the combined effects of nitrogen and cropping systems on biomass yield and quality and to describe the spatial variation of biomass yield, soil carbon and nitrogen within a switchgrass field. Field plots at Stillwater and Woodward in Oklahoma consisting of five nitrogen treatments and three cropping systems were used for the nitrogen x cropping system study and an 8 ha switchgrass field at Chickasha, Oklahoma was used to describe the spatial variability at fine (2.5 m sampling distance) and coarse scale (10 m sampling distance). Remote sensing technique was used to monitor biomass yield and quality to better understand N requirement and usage for production. Semivariogram were used to evaluate spatial variability of the soil parameters and biomass yield. The results of this study showed that maximum yield was produced at both locations with less than 84 kg N ha 1 and high biomass sorghum has potential to produce biomass yield > 20 Mg ha 1 under normal conditions in Oklahoma. The study results also showed that perennial grass systems are more reliable sources of biomass yield, especially under adverse climatic conditions of Oklahoma. Final biomass yield of high biomass sorghum could be predicted using both broadband (aerial photograph) and narrowband (GreenSeeker) normalized difference vegetation index (NDVI) from July to close to harvest, while biomass yield in the perennial grass was best predicted during June to July. Comparing simple ratios and best narrowband indices with partial least square regression (PLSR) models suggested that while PLSR calibration models produced significantly lower error and higher r2 for predicting biomass yield and N concentration within a growing season, the simple ratios and best narrowband indices were more stable and reliable when used for prediction across growing seasons. Spatial pattern in switchgrass field was described using both ground and aerial imagery. The NDVI computed from aerial imagery provided good precision at the fine scale in describing the spatial distribution of switchgrass yield. Remote sensing application in biomass production systems can greatly improve prediction models for predicting biomass yield and quality in feedstock materials with use of optimal hyperspectral narrowband.

Optical and human assessment of winter wheat cultivars for competitiveness against jointed goatgrass, and characterizing Oklahoma jointed goatgrass-winter wheat hybrids

Stone, Amanda Elizabeth Oklahoma State University 2003 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

<italic>Scope and method of study</italic>. Characteristics other than mature height contribute to competitive ability of wheat, but the literature has not identified any other useful traits. Twenty-four winter wheat cultivars were seeded with and without jointed goatgrass (<italic>Aegilops cylindrica </italic> Host.) in five environments, 1999–2001. Wheat stand density, forage yield, height at Zadocks 32, 37, and 91, spike density, and yield were measured. Additionally, mature height, spike density, spikelet production, and spikelet density of jointed goatgrass were measured. An Oklahoma State University sensor was used to record incident and reflected wavelengths from the canopy of the 24 winter wheat cultivars grown with and without jointed goatgrass, 1999–2001. Normalized difference vegetative index (NDVI) was calculated. The introduction of imazamox tolerant winter wheat has increased interest in jointed goatgrass-winter wheat hybrids [<italic>Aegilotriticum sanctiandreae</italic> (Degen) Soó]. However, little is known about such hybrids in Oklahoma. Hybrid plants were collected from central Oklahoma, 2000 to 2002, for characterization and germination. <italic>Findings and conclusions</italic>. Yields of the 24 wheat cultivars, at four environments were not affected by jointed goatgrass competition. Cultivars varied substantially in their ability to suppress jointed goatgrass spikelet production. Wheat stand density varied greatly and appeared to be related to competitive ability. Wheat forage production, height at Zadocks 32 and 91, and spike density were minor factors in suppressing jointed goatgrass spikelet production. Wheat height at Zadocks 37 was inversely related and wheat yield was variably related to jointed goatgrass spikelet production. NDVI was useful in estimating spike density, spikelet production, and spikelet density of jointed goatgrass, as well as estimating stand density and forage yield of the wheat cultivars grown without jointed goatgrass. NDVI was variable in estimating wheat height at Zadocks 32, 37, and 91, wheat spike density, and wheat yield. When the published morphological characteristics of the 24 wheat cultivars were considered, estimations improved. When certain stress factors such as plant diseases and late season drought were absent, correlations approached 0.9. Hybrid plants varied in mature height and spike length. Hybrid spike color was darker than mature wheat spike color and mature hybrid spikes disarticulated intact, unlike jointed goatgrass. Wheat cultivars varied in hybrid production ability.

Assessing activity of the pecan nut casebearer, Acrobasis nuxvorella, (Lepidoptera: Pyralidae) in Oklahoma using synthetic pheromone and simulation models

Grantham, Richard Allen Oklahoma State University 2001 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

<italic>Scope and method of study</italic>. The purpose of this study was to evaluate a variety of tools that will enable Oklahoma pecan growers to make decisions about managing the pecan nut casebearer. Two existing biological models (Texas and Georgia) for predicting first entry of PNC larvae into fruit were field evaluated at seven sites using weather data supplied by the Oklahoma Mesonet. A new PNC pheromone was evaluated in two trap types and its efficacy compared to blacklights. The pheromone was also evaluated at three different heights in the pecan canopy to determine its affect on male PNC numbers. Final damage counts and two-day oviposition and larval damage counts were taken at the three heights to assess any height and/or pheromone effects. Data were analyzed using t-tests, SAS PROC MIXED, GLM, and REG. <italic>Findings and conclusions</italic>. The Texas model was consistently late in predicting the entry date for 1996 although three of the sites were within one day of the observed entry. The Georgia model was consistently early in predictions for 1996. Both models showed mixes of over and under predictions for 1997. Because the Texas model appears more stable over time, degree-day thresholds from it were established for PNC activity in Oklahoma. A new PNC pheromone was evaluated in Pherocon<super>®</super> II and IIID traps, and compared to blacklight catch. Results obtained from trapping the spring emergent generation revealed the Pherocon<super>®</super> II mean catch was significantly greater than the Pherocon<super>®</super> IIID or blacklight catch. Although the Pherocon<super>®</super> II trap appeared to catch more moths in the second and third flight periods, no significant differences were observed between means of tamp types in the F1 and F2 generations. Capture of PNC was evaluated based on height of pheromone traps. A direct relationship was found between height of the trap and moth catch. No significant trends in damage by height were observed in 1996. Damaged clusters in 1997 were significantly different at each height with increasing damage from the bottom to top of the pecan tree.

Effects of multistate species occurrence on community-based inference and applications

Bried, Jason Oklahoma State University 2015 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Species occurrence is a basic unit of community data, but occurrences tend to have multiple ecological states. Ecologists are often interested in breeding states, such as birds with or without nesting success, frogs with or without mating calls, and plants in flower/fruit vs. vegetative state. My thesis explored the effects of locally resident (autochthonous) vs. immigrant (allochthonous) species occurrence on community inference and applications, using adult Odonata (dragonflies and damselflies) and wetlands as a model system. The primary data came from standardized odonate surveys at non-forested wetlands in New York and Oklahoma, USA. I first had to determine how to split resident and immigrant occurrences (chapter I). The presence of final exuviae (molted exoskeletons of F-0 larvae) definitively indicates local autochthony in odonates. I estimated the probability of exuvia occurrence in relation to readily acquired adult survey information and discovered several indicators of species residency: tenerals (newly emerged) on at least two surveys, adults at any stage on at least four surveys, and counting >20 adults at least once. These criteria were used to separate resident from immigrant occurrences in subsequent chapters. Chapter II explored the general forms of classification analysis in community ecology including the identification of (meta)community structures and site grouping based on variation in species composition. I predicted gradient-structured resident occurrence vs. unstructured (random) immigrant occurrence, and predicted the resident occurrence would more effectively partition community variation than total (resident + immigrant) occurrence. Predictions were well supported, Clementsian-style turnover was prevalent, and species composition of resident adult damselflies appears useful for wetland classification. Chapter III explored additional community approaches including environmental gradient modeling, spatial-environmental hypothesis testing, and biological condition assessment. Resident occurrences reduced model selection uncertainty, enabled detection of environmental and spatial effects, and strengthened the signal of biological impairment. These findings indicate that local autochthony may be determined in standardized adult dragonfly surveys, and that multistate species occurrence can strongly influence community-level inference and applications.

Perceived effects of block scheduling on agricultural education programs in Oklahoma

Mills, Jeffrey Brian Oklahoma State University 2002 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

<italic>Scope and method of study.</italic> The purpose of this study was to determine Oklahoma Agricultural Education teachers' perceptions of block scheduling and to examine its effects on secondary Agricultural Education programs in the state. Combinations of qualitative and quantitative methods were used to determine perceptions of Agricultural Education instructors toward block scheduling. The triangulation method was used to assist in eliminating bias relative to the qualitative nature of the study. Participants in the study were 51 Agricultural Educators in the State of Oklahoma currently on a block schedule. Each participant was mailed a short answer survey related to questions concerning their individual perceptions of the block schedule. Based on selected criteria, five Agricultural Educators were interviewed to determine their in-depth perceptions and attitudes toward a block Schedule. <italic>Findings and conclusions.</italic> Initially, fifty-five percent of the respondents indicated they were opposed to the block schedule. This initial response shifted to fifty-three percent agricultural instructors indicating they favored the block schedule over a traditional schedule, after experiencing the block schedule. The most significant impact of the block schedule was on the teaching strategies of Agricultural Educators. According to those interviewed, four out of five indicated they had adjusted their teaching styles to a more activity-based style of instruction. Three of the five indicated they were also utilizing more evaluation techniques in their daily instruction. Survey responses indicated the block schedule had caused a negative impact on student SAE projects. However, the interviews neither supported a positive nor a negative impact. Based on the survey information sixty percent of the programs had an increase in enrollment. In addition, four of the five Agricultural Educators interviewed indicated an increase in student enrollment.

The Effects of Prescribed Fire on Black Bear Forage Availability, Resource Selection, and Distribution in the Interior Highlands

Yaklin, Danielle M Oklahoma State University ProQuest Dissertations & 2017 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Black bears (Ursus americanus) were extirpated from Oklahoma in the early 1900's but have recolonized the eastern part of the state since they were reintroduced into Arkansas in the 1950's and 1960's. Bears now occur in fragmented, human-dominated areas that are managed for human interests. Forest management practices such as prescribed fire have been shown to be beneficial for wildlife by opening up the canopy and allowing more light to penetrate to the understory, stimulating forage production. Because bears must gain substantial fat reserves to last through winter and are highly dependent on seasonal food sources, I investigated the effects of prescribed fire on the availability of key black bear forage items and subsequent bear movements and resource selection in the Ouachita Mountains of southeast Oklahoma. To determine whether prescribed fire positively or negatively affected common black bear forage items, I surveyed soft mast, ants, and hard mast within prescribed burn units in the Ouachita National Forest in Oklahoma between May 2014 and January 2017. I used GPS locations from 60 black bears collared between May 2014 and August 2016 in resource selection functions to determine if bears selected areas of a particular time since fire. Lastly, I used GPS locations from collared black bears in the Ozark and Ouachita Mountains of Oklahoma in ecological niche models to predict future range expansion westward into Oklahoma. Forage production was highly variable and species-specific. Soft mast was influenced by year, topography, land cover and prescribed fire, but ants and hard mast were not influenced by fire. Bears seemed to select burned areas with more soft mast, but that was variable by sample year. Bears selected hardwood-dominated forests more in autumn when hard mast was important in their diets. Niche models demonstrated bears used forests and higher elevations similarly to resource selection results. Bears have the potential to expand their range farther west in Oklahoma, although areas of expansion will be fragmented and likely have low population density.

Dynamics of understory shortleaf pine (Pinus echinata Mill.) and hardwood after thinning shortleaf pine forests in the southeastern United States

Kc, Anup Oklahoma State University 2016 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The shortleaf pine (Pinus echinata Mill.) population is consistently declining in southeastern United States. Shortleaf pine forests are thinned frequently to improve the growth and development of residual stands. But, the effect of thinning on growth and development of understory woody-plants in long term has not been extensively studied. We assessed the effects of thinning, overstory shortleaf pine characteristics, climatic, and topographic factors on shortleaf pine regeneration applying various predictive modeling techniques. We applied decision tree models to predict shortleaf pine regeneration. We also developed, evaluated, and compared the performance of three other predictive models to predict shortleaf pine regeneration. We used understory shortleaf pine data that were collected from shortleaf pine forests of Arkansas and Oklahoma spanning a period of 25 years following thinning and hardwood control treatments. The shortleaf pine densities have declined in every subsequent measurement since the first measurement of understory trees in 1996. Thinning treatments played a significant role on the understory shortleaf pine density. The decision tree model using the Gini criteria as the splitting rule to predict the shortleaf pine regeneration had a low misclassification rate of 7.6 percent. The decision tree model can be an efficient tool to make shortleaf pine stand management decisions. The best performing logistic regression model showed precipitation, plot age, site index, and overstory thinning were the significant inputs affecting shortleaf pine regeneration with validation misclassification rate of 8 percent. The best performing artificial neural network model predicted the shortleaf pine regeneration with validation misclassification rate of 7.6 percent, and cumulative lift of 5, 2.5 and 1.66 at depth of 20, 40 and 60 respectively. An artificial neural network model performed best to predict the shortleaf pine regeneration. Poor shortleaf pine regeneration performance over decades in study sites suggests the future of shortleaf pine dominated forests is questionable unless further regular silvicultural treatments are applied. We recommend continual hardwood removal every 10-15 years to obtain the satisfactory understory shortleaf pine regeneration in shortleaf pine forests of Arkansas and Oklahoma.

Soil carbon, nitrogen, and physical properties in cropping systems of Oklahoma

Abreu, Silvano Luiz de Oklahoma State University 2011 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Soils across the State of Oklahoma where areas of conventional and long term no-till are under similar climate conditions and soil properties (same soil series) were sampled in 4 points of a transect across the field at 110 cm depth and divided in 5 different depths (0--10; 10--20; 20--40; 40--70; and 70--110 cm). Samples were air dried and sieved at 2mm mesh. Sixteen farm fields (eight no-till and eight conventional till) were sampled in the principal agricultural areas of Oklahoma. Also, two tillage experiments that have no-till and conventional till treatments combined with different crop rotations where sampled and compared as well. Organic C and total N were analyzed. Besides, bulk density was determined at each depth and sampling point in order to account for the amount of organic carbon and nitrogen storage in the soil profile. Results were analyzed by LSD comparing tillage system. Organic carbon and total nitrogen was analyzed by LECO analyzer and carbonates were analyzed so the amount of organic carbon can be calculated. Another chapter of the study analyzed the use of cover different cover crops; including forage radish, sunn hemp, pigeon pea, cowpea, and Austrian winter pea in cash crop rotations that included soybean, corn, and wheat. Grain yield, biomass, and soil physical properties were analyzed in two locations in Central Oklahoma. For most Oklahoma studied areas, no-till soils had higher organic carbon and total nitrogen stock in the soil profile than conventional till. Top soils no-till have also more carbon stock in no-till compared to conventional till soils. The increasing of crop intensity and diversity did not affect grain yield in the cash crops, but increased biomass production. After two years of rotations no effect of crop rotation or crop intensity was observed in soil physical properties.

The shared experiences of prospective agricultural education teachers: A phenomenology of supervised agricultural experiences

Whiddon, Ashley Seamon Oklahoma State University 2015 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The purpose of the qualitative, phenomenological study was to better understand SAE programs through the lived experiences from self-identified future agricultural education teachers in Oklahoma. Phenomenological methods were used to explore eight Oklahoma State University Future Agricultural Education Teachers Academy from each of the five agricultural education districts in the state. The research questions investigated the learning outcomes and experiences regarding SAE programs. Subjects in this study reported learning skills and external factors that attributed their SAE experiences. Four themes were revealed from the reported data to include: (a) subjects attain skills through SAE programs; (b) teachers have a great influence on subjects' SAE programs; (c) subjects have limited and narrow perceptions of SAE; and (d) subjects believe SAE programs diversify their experiences in agriculture. The essence was revealed that teachers determine learning through SAE programs, which provided the greatest opportunity for the acquirement of employability skills in the SBAE program. Recommendations were developed to address the findings and conclusions for each theme.

Growth performance of forest plantations on the western margin of their commercial range

K.C., Dipesh Oklahoma State University 2013 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The southern US contains some of the most productive plantation sites in the USA and Oklahoma is the western margin for several plantation species including sycamore (Platanus occidentalis), eastern cottonwood (Populus deltoides), loblolly pine (Pinus taeda L.), shortleaf pine (P. echinata Mill.), and pitch X loblolly pine hybrid (P. rigida X P. taeda). The long, hot summers and dry winters of Oklahoma provide an opportunity to compare the growth performance of these species at the edge of or outside of their natural range. The region is also prone to ice storms and glaze and pine plantations are negatively affected during such disturbances. Hence we carried out comparative studies on growth performance of different plantations in Oklahoma. One examined the growth performance and nutrient (nitrogen and phosphorus) uptake by sycamore and eastern cottonwood from a decommissioned swine lagoon in the north-central Oklahoma. The results showed that eastern cottonwood outperformed sycamore in both growth and nutrient uptake. The species showed the potential for removing a substantial amount of nutrients from the soil. In another comparative study between loblolly pine, shortleaf pine and pitch X loblolly pine hybrid in southeastern Oklahoma, loblolly pine outperformed both the other species, although shortleaf pine was native to the area. However, wood specific gravity was similar among the species. The final study examined simulated ice damage on loblolly pine stands which had previously undergone either thinning or thinning and pruning. Damaged trees had an average 2.4 m of the top removed. Four years after damage, the relative basal area decreased as the amount of live crown ratio loss increased. Thinned stands showed lower relative reduction in growth with the same level of crown damage than the non-thinned stands. Undamaged trees did not benefit from the opening caused by damaged trees. Unless the damage is severe, the stand can be allowed to recover after the thinning of the damaged trees.