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Dissertations / Theses on the topic 'Agricultural Science'
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Morgan, Alan Christian. "Teaching leadership in agricultural science behavioral factors that influence secondary agricultural science leadership instruction /." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0006619.
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Kiriakopoulos, Nektarios. "Science and technolology : the case of Greek agriculture and agricultural industry." Thesis, University of Reading, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401423.
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Henke, Christopher R. "Working the mission : science and industry in California agriculture /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC IP addresses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p9984806.
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Cherry, Jenny Dee. "Ohio Secondary Agricultural Educator Perceptions of Integrating Science." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1300772663.
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Malekana, Marumo Moses. "Factors influencing the choice of agricultural science as a school subject." Diss., University of Pretoria, 1999. http://hdl.handle.net/2263/30399.
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Agriculture plays an important role as the basis of economic development of many countries. One of the ingredients for accelerating agricultural development is the provision of adequate knowledge through education. Schools where agricultural science is taught play an important role, but the problem that gave rise to this study is the lacking interest and poor performance in agricultural science. The main aim of this study was to investigate factors that may influence the choice of agricultural science as a school subject. In order to attain this aim, six high schools in the Temba District were sampled to represent urban, semi-urban and rural schools. All agricultural science pupils and, for purposes of comparison, forty five pupils doing physical science and twenty seven from home economics were interviewed. The overall image of agriculture appeared quite positive in that 62 percent of the students rated it as high or very high, and only the medical practitioner received a higher average status rating than the agricultural professional. The findings indicated that non-agriculture students had the most intensive association with a farming background, which seems to indicate that a close association with agriculture is a deterrent rather than an incentive to choose agriculture as a school subject. Exposure to agricultural science as a school subject appeared to increase the interest in the study of agriculture at tertiary level, although the possibility that the interest in tertiary studies in agriculture stimulated the choice of agriculture science as a school subject, cannot be ruled out. Amongst agricultural science pupils there is general agreement that agriculture provides good access to tertiary education, although physical science was rated much higher. The assessment of teachers does not favour agricultural science. Agricultural science teachers were assessed significantly lower as far as personality, teaching quality, accessibility and knowledge is concerned. However, the less the influence and assessment of the teacher, the bigger the influence of parents appeared to be. Somewhat alarming is the finding that about 20 percent of respondents claimed to have been forced to study agricultural science at school. Those that received counselling did not have a better image of agriculture, which seems to indicate that agriculture is not a field of study recommended by teachers during counselling.Dissertation (M Inst Agrar (Extension))--University of Pretoria, 1999.
Agricultural Economics, Extension and Rural Development
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Slaydon, Sunny Leigh. "Agricultural science students' perceptions and knowledge of hearing loss." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3095.
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Wallace, Joyce Rene 1962. "Agricultural literacy of seventh and eighth grade science teachers." Thesis, The University of Arizona, 1995. http://hdl.handle.net/10150/278478.
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The purpose of this study was to ascertain the Agricultural Literacy level of seventh and eighth grade science teachers in Arizona, New Mexico, Utah and Colorado. Respondents were tested in the eleven areas encompassing the definition of agricultural literacy as reported by Frick, Kahler and Miller study in the Agricultural Education Journal, Summer 1991. Findings of the study included: (1) science teacher in middle and junior high schools are not agriculturally literate according to the information gained from questions in the eleven concept areas proposed by Frick, Kahler, and Miller (1991); (2) There is no difference in the agricultural literacy level of science teachers in Arizona, Colorado, New Mexico, and Utah; (3) Gender does not affect the agricultural literacy level of science teachers; (4) Education in Agriculture does not affect the agricultural literacy level of science teachers; (5) There is no difference in agricultural literacy level of rural and urban science teachers; (6) Agricultural literacy is not changed in teachers who have lived on a farm or ranch after their eighth birthday.
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Rocka, Timothy Dee. "Future agricultural systems competencies of beginning Texas agricultural science teachers as determined by agricultural education professionals and administrators of agricultural education programs a Delphi study /." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969/174.
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Majid, M. Shaheen. "Effectiveness of Malaysian agricultural libraries." Thesis, City, University of London, 2000. http://openaccess.city.ac.uk/20113/.
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Evaluation studies can help libraries to find out their strengths and weaknesses and use this knowledge for re-orienting their collections, services and facilities to effectively meet the information needs of their users. The purpose of this study was to explore the information needs and seeking behaviour of agricultural scientists in Malaysia and how effectively their needs are satisfied by their libraries. The study investigated some major factors that were considered important in effectively meeting the information needs of these scientists. Five major agricultural institutions in Malaysia participated in the study. Data was collected through two questionnaires and follow-up interviews with selected respondents and library staff. The user survey questionnaire provided data on information needs and seeking behaviour of respondents, their assessment about the adequacy of library collections, services and facilities, and their overall perceptions about library effectiveness. The library survey questionnaire furnished data from the participating libraries on their manpower, budget, collections, physical resources, library services, and resource sharing activities. The population of the study comprised 1,328 individuals. Proportionate stratified random sampling technique was used to generate random samples. A total of 332 questionnaires were distributed and 234 useable questionnaires were received back with an overall response rate of 70.5 percent. The study found that research and review articles were the most preferred sources for getting up-to-date information. Interaction . with professional colleagues was also considered important for information exchange. Libraries were more extensively used during two important stages of research, i.e., proposal development and report writing. Although a majority of the respondents personally visited their library they, however, sent their junior researchers andlor para-professionals for getting photocopies of articles, checking out books or getting information from the sources already known to them. The use of IT-based information sources and facilities was very low, although a majority of the respondents possessed reasonably good computing skills. Among the Internet applications, e-mail was the most popular while other Internet-based sources and facilities were used infrequently. A positive relationship was found between perceptions about library effectiveness and assessment of participants of the adequacy of library collections, equipment and physical resources. Other factors having a positive impact on the perception about library effectiveness were: involvement in the selection of library materials; notification of current materials; adequate promotion; convenient library location; staff attitude; and participation in user education programmes. The level of resource sharing among Malaysian libraries was quite high as nearly 74 percent of the interlibrary loan and document delivery requests of the participating libraries were met locally. However, only a minimal resource sharing was found among the participating libraries and libraries in the ASEAN countries. Although the participating libraries agreed in principle to participate in a resource sharing scheme, they felt that it should be the prerogative of the participating library to decide its level of co-operation and with which library to share its resources. It means that these libraries were in favour of a "loose" library co-operation network. A big difference was found between the number of document delivery requests made by these libraries to international sources and the number of such requests received by them from overseas, confirming one-way flow of information. Most of the document delivery requests were made to the BLDSC. Malaysian agricultural scientists, as compared to scientists in developed countries, made considerably less number of interlibrary loan and document delivery requests. A positive relationship was found between the availability of funds in research projects for literature procurement and the number of document delivery requests made. The study concludes that agricultural libraries in Malaysia were to some extent meeting the information needs of their scientists, although a disparity among these libraries was quite evident. However, the financial crisis of 1997 has severely affected the performance of these libraries. Library collections, services and facilities considered reasonable at the time of this study may quickly become inadequate due to the lack of funds to sustain them. Therefore, agricultural libraries in Malaysia need to develop appropriate strategies for surviving in the rapidly changing environment. Major recommendations of the study are: development of a formal resource sharing scheme for agricultural libraries in Malaysia, putting holdings information of these libraries on the Internet to facilitate resource sharing, making subscriptions to full-text electronic journals, more library co-operation among ASEAN countries, and the conduct of intensive user education programmes.
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Powell, Kelly Lynn. "Denitrification in Agricultural Headwater Ditches." The Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392978328.
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Jung, Mun-Yhung. "Effects of carotenoids and tocopherols on the chlorophyll sensitized photooxidation of soybean oil." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1382551295.
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Vigorito, Anthony J. "Agricultural biotechnology, corporate hegemony, and the industrial colonization of science /." The Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486459267522341.
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Tobler, Emily. "A Needs Assessment of Arizona Agricultural Education Equine Science Curriculum." DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/7294.
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Like any other agricultural industry, many different career paths in the equine field are becoming more technologically advanced. To adapt to technological progress, current standards need to be integrated into school-based agricultural education courses to properly train and teach students about current industry standards. In addition to equine science curriculum development, emphasis must also be focused on providing assistance to secondary-school-based agriculture teachers so they can effectively teach industry-based equine science objectives in their programs.
The equine curriculum objectives were measured in terms of perceived importance by equine professionals and post-secondary equine educators as well as Arizona school-based agriculture teachers. Further, the Arizona school-based agriculture teachers indicated their self-perceived ability to teach the objectives. Demographics for each group (equine industry professionals and Arizona school-based agriculture teachers) were also collected. A Borich needs assessment was calculated to prioritize areas needed for professional development of school-based agriculture teachers.
Recommendations include the importance of bringing secondary-school-based agricultural education equine science curricula in line with industry standards. Further, providing professional development to secondary-school-based agriculture teachers is key to increasing teachers’ competence and ability to teach industry-based equine science.
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Taechatanasat, Pornchai. "A multilanguage blended learning approach for Thai agricultural science students." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2018. https://ro.ecu.edu.au/theses/2055.
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Agriculture plays a vital role in the economy of Thailand. Recent government initiatives such as “Smart Agriculture” have been undertaken to improve agriculture and the uptake technologies in both agriculture and agricultural education. The inclusion of Thailand in ASEAN group of nations has also lead to a greater push for university education to be delivered in English and for students to develop a greater proficiency in English. Computer technology has been used for teaching in many disciplines including agricultural science. Language barriers, challenges in the uptake of new technologies in agriculture, and the disadvantages of the traditional classroom learning are some of the factors that can limit the learning of new technology by Thai agriculture students. Multilanguage Blended Learning System which combines classroom learning environment and online learning environment has been proposed as a viable solution for improving the effectiveness of these learners. This research study was carried out to answer the question: “What is the effectiveness of multilanguage blended learning in the context of Thai agricultural science education?” This was answered by addressing the following sub questions 1. What barriers exist in traditional delivery of agricultural science education in Thailand? 2. Are multilanguage blended learning environments an effective approach to teaching agricultural science courses to Thai students? 3. What factors determine the effectiveness of multilanguage blended learning systems to improve learning in agricultural science courses? 4. What are the key principles to achieve effectiveness in a blended learning environment for Thai agricultural science education? A review of relevant literature identified a number of limitations in overcoming language barriers in learning and limitations found in research into multilanguage blended learning. The review of literature provided a definition of MBLS in order to clarify the scope and meaning of MBLS. LMS tools and their examples were also reviewed to provide knowledge in using LMS. The factors influencing the design of multilanguage learning management system and concepts and examples in designing multilanguage learning management system were examined. A case study was carried of students, lecturers and online learning experts from three universities in Thailand. The 374 student participants and other participants were selected from King Mongkut’s Institute of Technology Ladkranang (KMITL), King Mongkut’s University of Technology North Bangkok (KMUTNB), and Rajamangala University of Technology Phra Nakhon (RMUTP). A case study was conducted based on a mixed-method research methodology. Both quantitative and qualitative data techniques were used for the data analysis. This study utilized a two-treatment counterbalanced design with 374 students which consisted of students from seven groups from the three universities. Questionnaires, achievement tests, a Moodle tracking system and interviews were used as the research instruments of the study. A situational analysis was carried out using information from broad perspective to specific factors in relation to blended learning in agriculture in Thailand. The analysis presented the current situation that affected the blended learning system when the MBLS was tested. The findings from situational analysis were used for designing MBLS to suit the Thai students learning styles. The development of the MBLS used a process which consisted of four steps; software specification, software design and implementation, software validation and software evolution. The software process was used for designing MBLS. Activities and the resource teaching tools which provided in Moodle LMS were presented. The architecture of MBLS which consisted of four blocks; LMS, content in English language, translation tools, and content in other languages. Course content, Google, and ImTranslator add-on was selected to use in the MBLS. The research results from achievement test indicated that the achievement test all four groups did not clearly indicate that blended learning or classroom learning has higher efficiency. System logs from MBLS that indicated the behaviours in accessing MBLS of students at normal rate. The frequencies in accessing MBLS of students depend on the number and type of activities that lecturers assigned to students. The results of analysis of student experiences of using MBLS indicated that the overall satisfaction of students in using MBLS is high. The mean score of students’ satisfaction that was categorised in three aspects: the content, delivery medium, multilanguage tools indicated participant students satisfy in learning with MBLS. One-Way MANOVA was used to analyse how students in each groups rated satisfaction in content, delivery medium, and multilanguage tools. Univariate and MANCOVA in SPSS were used to analyse the relationship between student groups and the ability in using MBLS system of students. The findings from multivariate linear regression model equations of each group and model of all student who learning with MBLS indicated that Y’ = –0.657 – 0.027X +1.198X2 –0.069X3 is the equation of the student’s satisfaction. The model shows how students’ satisfaction of content, delivery medium, and multilanguage tools effected to students. Findings from interviews and participant observation were presented as a number of themes. The data from observed students’ behaviour, lecturers’ behaviour, web administrator’s behaviour, and course designers’ behaviour were presented. The data from student interviews was analysed into seventeen themes. The themes were categorized into five groups based on the process in developing MBLS. The data from the lecturer interviews were analysed into eighteen themes. The themes from lecturer interviews were also categorized into five groups based on the process in developing MBLS. A MBLE framework was proposed for an effective approach to assist agricultural science student that integrated LMS and translation technology in teaching. The MBLE consisted of 4 phases: preparation, implementation, teaching, and completion. The MBLE framework was designed in a top down design which the low layer is considered as fundamental of upper layer. Each phases have divided into 10 steps: surveying requirements, planning MBLE, seeking cooperation, designing MBLE, selecting tools, preparing ICT system, implementing MBLS, teaching through MBLE, evaluating, and complete model of MBLE. The research highlighted the barriers which exist in traditional delivery of agricultural science education in Thailand, factors determine the effectiveness of multilanguage blended learning systems to improve learning in agricultural science course, and key principles to achieve effectiveness in a blended learning environment for Thai agricultural science education are presented. This study has proposed, created, and used a novel concept of blended learning system that integrated LMS with novel translation tools in blended learning environment. Multiple factors influencing teaching in MBLS has been studied. The study contributes other lecturers, course designer, and web administrator in designing MBLS.
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Dowden, Bobbie. "Ultrastructural Effects of Sethoxydim on the Intercalary Meristem of Johnsongrass (Sorghum Halpense)." TopSCHOLAR®, 1985. https://digitalcommons.wku.edu/theses/2266.
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This investigation represents one of the first electron microscopic studies on determining the mode of action of the chemical herbicide sethoxydim, 2-[-1-(ethoxydimino)butyl] -5-.2-(ethiothio)propyl]-3- hydroxy-2-cyclohexen-1-one. Samples were excised from the intercalary meristem of johnsongrass (Sorghum halpense) at time intervals of 1,3, 6,12,24,36,48,60, and 72 hours and examined using electron microscopy. Transmission electron micrographs revealed that cellular activity shows alterations or abnormalities as early as six hours. Membranes show deterioration at this time and chloroplasts contain densely staining starch granules. As time intervals increase, cellular degradation becomes more evident. Nuclear membranes extend outward into the cytoplasm in various types of cells. After 72 hours, the protoplasm demonstrates plasmolysis. The cell walls, plasma membranes, and plasmodesmata are also influenced by the sethoxydim treatment. Scanning electron micrographs were studied for the effects on vascular bundles and the surrounding tissue. The results were similar to those found by transmission electron miscroscopy.
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Martin, Mark. "Herbicide Effects on Cultivars of Soybeans [Glycine Max (L.) Merr.]." TopSCHOLAR®, 1985. https://digitalcommons.wku.edu/theses/2585.
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Breeding herbicide-tolerant cultivars is a means of extending herbicide utilization. In 1983 and 1984, 20 soybean [Glycine max (L. Merr] cultivars were screened for their reactions to the following herbicides: metribuzin 4-amino-6-(tert)-butyl-3-(methylthio)-astriazin-5-(4H)-one]; vernolate (S-propyl dipropylthiocarbamate); and fluchloralin [N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl) aniline]. Each herbicide was applied at the recommended rate X, 2X, and 4X in 1983. An 8X rate was added in 1984. The recommended rates (X) for the herbicides were as follows: metribuzin 0.42, vernolate 2.80, and fluchloralin 1.12 kg/ha. The cultivars were Pella, Pixie, Cumberland, Williams, Essex, Union, Semmes, Tracy, Tracy M; North American Plant Breeders 350, 68225, 420, and 330; Northrup King 8069 and 8047; and Farmers Forage Research 339, 340, 560, and 561.
Plant vigor, height, and herbicide injury were the criteria used in estimating herbicide effects. Statistical differences were found among herbicides, rates, and cultivars. Also, there were significant interactions involving herbicides x rates, herbicides x cultivars, rates x cultivars, and herbicides x rates x cultivars. Although not always statistically significant, average vigor ratings decreased with increased herbicide application rate. Pronounced differences in the study results for the two years, likely reflecting rainfall patterns, were evidence of uncontrolled variability. However, a small number of the cultivars exhibited herbicide tolerance.
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Miller, Amelia J. "Evaluating Michigan's Food, Agriculture, and Resources in Motion (FARM) Science Lab as a Modality for Agricultural Literacy." DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7470.
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Michigan’s Food, Agriculture, and Resources in Motion (FARM) Science Lab is a 40-foot mobile classroom outfitted with 10 learning stations including scientific equipment and iPads. This quasi-experimental study analyzed preexisting data provided by Michigan Agriculture in the Classroom to evaluate the effectiveness of the FARM Science Lab mobile classroom as a method of teaching agriculture-themed, standards-based lessons to third- through fifth-grade students in order to increase their understanding of agriculture. From January through June 2018, more than 1,258 students participated in these lessons and completed the pretest and posttest and 72 teachers completed the post survey. Research questions not only addressed student learning but also teacher’s perceptions of the mobile classroom program and measured differences between rural, suburban and urban student populations.
Four lessons were offered to students in third through fifth grade during the time of this study. Each lesson had a unique pretest and posttest provided to each school by Michigan Agriculture in the Classroom using Google Forms. Students and teachers participated in the agricultural lessons within existing classroom groups; therefore, this was not a random sample of either population. During the timeframe of this study, all sections of each grade level for each participating school were engaging in FARM Science Lab programming; therefore, no control groups were used in this research. The student and teacher data were analyzed using standard statistical tools including t-tests and Cohen’s d.Difficulty and item discrimination values provided more confidence in the reliability of the question as a measure of knowledge change after participation in the FARM Science Lab intervention.
Results indicated there were statistically significant differences in knowledge between pretest and posttest scores for nearly all grade level/lesson groups. Each individual question was analyzed for statistically significant change in addition to overall test scores. Some questions did not see statistically significant changes from pretest to posttest for each group. These results suggested the FARM Science Lab was making a difference in students’ agricultural understanding, at a basic knowledge level, after a short intervention. The assessment questions tested the recall of facts rather than an understanding of a whole concept about science or agriculture. Teacher surveys indicated the FARM Science lab did address appropriate educational standards for their respective grade levels. Teachers also believed agriculture could be very effectively used to contextualize science concepts. The final research question addressed differences in rural, suburban and urban student gains from pretest to posttest. The FARM Science Lab did not visit any urban schools during the time of this study. Of the grade/lesson groups which did have a rural and suburban population to compare, there were some differences in scores between students’ responses in each geographic location. These populations were small therefore these differences may not be generalized to the larger population.
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Ford, Richard Kirby. "Preparation to teach agricultural mechanics: a qualitative case study of expert agricultural science and technology teachers in Texas." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3138.
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Since federal legislation in 1917 and the widespread program growth in the 1930s,
agricultural mechanics has been a major part of the high school agricultural science and
technology curriculum. Local programs integrated individual problem -solving, practical
applications of mathematics and technical science skills in to the curriculum. However,
recent financial constraints and a perceived lack of interest have led to reductions in course
offerings in agricultural mechanics in some universities that are responsible for the
maintenance and future of the disciplinary area. These curricular issues gave rise to a
research problem examining the perspectives of successful agricultural science and
technology teachers of agricultural mechanics and the education and experiences that were
associated with their success. This study used qualitative measures to identify factors that
enabled certain agricultural science and technology teachers who were more noted in
teaching of agricultural mechanics to be more successful than their peers. It examined
factors that motivated teachers to excel and examined the influences that determined what
portions of the curriculum were included or deleted. Finally, this study focused on the recommendations of experts regarding improvements for future teaching of high school
agricultural mechanics. Data were collected, analyzed, and reported using accepted a
qualitative protocol to develop emergent themes.
Successful agricultural science and technology teachers agreed that their
undergraduate course work did not adequately prepare them to teach the current
curriculum. Unanimously, the respondents expressed a concern for the lack of depth,
scope, and technical skills in agricultural mechanics currently being taught to future
agricultural science teachers. This concern for the pre-service curriculum led teachers to
agree that the three-week agricultural mechanics certification workshop is essential for
successful instruction of agricultural mechanics. Furthermore, teachers espoused a formal
mentoring program to aid the professional development of agricultural science and
technology teachers. The respondents alluded to the need for more quality workshops on
the part of the Texas Education Agency, the VATAT professional organization and the
agricultural education community as a whole to improve the quality, scope, depth, and
technical skills in the instruction of Agricultural Science and Technology in the high schools
of Texas.
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Bornn, Luke. "Modeling latent correlation structures with application to agricultural and environmental science." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42834.
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In this thesis, we explore the issue of latent correlation structure in spatial and other correlated systems. Firstly, we propose a class of prior distributions on decomposable graphs, allowing for improved
modeling flexibility. While existing methods solely penalize the number of edges, the proposed work
empowers practitioners to control clustering, level of separation, and other features of the graph. Emphasis
is placed on a particular prior distribution which derives its motivation from the class of product partition
models; the properties of this prior relative to existing priors is examined through theory and simulation.
We then demonstrate the use of graphical models in the field of agriculture, showing how the proposed prior
distribution alleviates the inflexibility of previous approaches in properly modeling the interactions between
the yield of different crop varieties.
Secondly, we describe how spatial dependence can be incorporated into statistical models for crop yield
along with the dangers of ignoring it. In particular, approaches that ignore this dependence suffer in their
ability to capture (and predict) the underlying phenomena. Prior distributions are developed to accommodate the spatial
non-stationarity arising from distinct between-region differences in agricultural policy and practice. As a result, the model developed has improved prediction performance relative to existing models, and allows for straightforward interpretation of climatic effects on the model's output.
Lastly, we propose a novel approach to modeling nonstationary spatial fields. The proposed method works by expanding the geographic plane over which these processes evolve into higher dimensional spaces, transforming
and clarifying complex patterns in the physical plane. By combining aspects
of multi-dimensional scaling, group lasso, and latent variable models, a dimensionally sparse projection is found in which the originally nonstationary field exhibits stationarity. Following a comparison with existing methods in a simulated environment, dimension expansion is studied on a classic test-bed data set historically used to study nonstationary models. Following this, we explore the use of dimension expansion in modeling air pollution in the United Kingdom, a process known to be strongly influenced by rural/urban effects, amongst others, which gives rise to a nonstationary field.
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Jones, Kevin Edison. "The politics of new agricultural technologies : contesting risk, science and governance." Thesis, Brunel University, 2004. http://bura.brunel.ac.uk/handle/2438/7890.
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This thesis provides a sociological exploration of the politics of new agricultural technologies in the United Kingdom. It addresses some of the key issues involved in these politics, as well as how they are discussed and fought over. Conceptually it addresses these questions by focussing on issues of risk, science and governance. In doing so, this thesis situates the politics of GM crops and foods in relation to wider normative concerns about the cultural values, relationships and institutions shaping agriculture, and British society more generally. Empirically, this thesis applies a qualitative methodology, primarily relying on data generated from a series of in-depth interviews. Through these interviews active participants in the debate were able to express a variety of opinions about the risks and benefits of agricultural biotechnology. The interview data is further supplemented by some documentary evidence, particularly as relates to several government led initiatives addressing agricultural debates in terms of contestations over risk and knowledge. Key chapters in this thesis look at the way in which the debate over GM crops and foods has been shaped by perceptions of the role and values of the life-industry, science and the Government in developing and regulating biotechnology. Finally, this thesis also addresses how society, and practices of governance in particular, are able to accommodate these political issues in managing risk and regulating technological change.
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Jones, Mary Ellen. "Politically Corrected Science: The Early Negotiation of U.S. Agricultural Biotechnology Policy." Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/29868.
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This social history of science policy development emphasizes the impact on the agricultural community of federal policies regarding release of recombinant DNA (rDNA) organisms into the environment. The history also demonstrates that the U.S. Coordinated Framework for Biotechnology Regulation (1986) is based principally in political criteria, not solidly based in science as its proponents claimed. The power struggle among policy negotiators with incompatible belief systems resulted in a political correction of biotechnology. I also demonstrate that episodes in the rDNA controversy occur in repetitive and periodic patterns.
During the 1980s, the first rDNA microbial pesticide, Ice-Minus, struggled through a policy gauntlet of federal agency approval processes, a Congressional hearing, and many legal actions before it was finally released into the environment. At the height of the controversy (1984-1986), the Reagan Administration would admit no new laws or regulations to slow the development of technologies or hinder American international competitiveness. At the same time, Jeremy Rifkin, a radical activist representing a green world view, used the controversy to agitate for social and economic reform. Meanwhile, a group of Congressional aides who called themselves the "Cloneheads" used the debate to fight for more public participation in the science policy-making process.
Conflicting perspectives regarding biotechnology originated, not in level of understanding of the science involved, but in personal perspectives that were outwardly expressed as political group affiliations. The direction of federal biotechnology policy was influenced most successfully by politically best-positioned individuals (what I call a "hierarchy effect") who based decisions on how biotechnology harmonized with their pre-existing beliefs. The success of their actions also depended on timing.
Historical events during the rDNA controversy followed the same periodic pattern--gestation, threshold, crisis/conflict, and quasi-quiescence--through two consecutive eras--the Containment Era (1970s) and the Release Era (1980s). These periods are modeled after Fletcher's stages through which ethical issues evolve (1990). However, an agricultural perspective on the debate reveals that such stages also occur in finer detail on repeating, overlapping, and multi-level scales. Knowledge of this periodicity may be useful in predicting features of future episodes of the rDNA controversy.Ph. D.
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Thompson, Gregory W. "Characteristics and implications of integrating science in secondary agricultural education programs /." free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9823332.
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Graham, Levar Desmond. "Factors that influcence African Americans to enroll in agricultural science programs." Master's thesis, Mississippi State : Mississippi State University, 2007. http://library.msstate.edu/etd/show.asp?etd=etd-11092007-163003.
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Scales, Jason A. "Assessment of teachers' ability to integrate science concepts into secondary agriculture programs." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4717.
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Thesis (Ph. D.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on February 29, 2008) Vita. Includes bibliographical references.
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Ibezim, Don Onwudiwe. "The integration of international agricultural concepts into agricultural science programs in the north central region of the United States /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487841975356834.
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Sivakumar, Gayathri. "Agricultural biotechnology and Indian newspapers." Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/1133.
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This study is designed to look into how agricultural biotechnology is covered by Indian newspapers. A through study of the literature showed that agricultural biotechnology is a much debated topic and there is a vast difference between the concerns expressed by its opponents in developed countries and those expressed by the opponents in developing countries. The research question was whether the sources used in an article determined the way in which this issue is framed. After conducting a content analysis of all articles written in Times of India between the time periods January 2001 - December 2003, it was found that the sources used did determine the way this issue was framed.
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Gowans, Kristina. "Effects of Animal Science Agricultural Education Course Completion on Urban High School Students' Career Choice." DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/2063.
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This study focused on testing the effects of agricultural education on urban high school students’ career choices. It looked into how students view agriculture, how they perceive their peers view agriculture, how their demographics are related to career choice, and if their career choice was changed to a different career upon completion of the study. The study showed a positive relationship between completing an agricultural education class in animal science and interest in going into an agricultural career. Further, females in the study were more likely to choose an agricultural career. After the completion of a school-based agricultural education program, both students and their peers had a more positive outlook on agriculture and its possibilities as a career. Students also increased their career self-efficacy score during the completion of an animal science agricultural education course. They became more confident in their ability to make decisions related to their future career.
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Sameipour, Sharmin Faraj. "Teachers’ Perceptions toward Sustainable Agriculture in an Ohio Science High School." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu149426481206391.
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Haque, S. M. Sirajul. "Afforestation effects on former agricultural soils." Thesis, University of Aberdeen, 1997. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU094706.
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Long-term changes in soil profile characteristics and important soil physical, chemical and biological properties were evaluated and compared at 4 paired sites in NE Scotland, 44-61 years after the afforestation of agricultural soils planted with either Norway spruce (Picea abies (L.)) or Scots pine (Pinus sylvestris (L.)). At each paired site five profiles were studied in the afforested and five in the control agricultural soils. Comparison made between various properties in the pairs of soils showed a number of significant changes, which are summarised in Tables 2.18-2.20. The surface (O) horizon of the afforested soil could be differentiated into L, F and H horizons. The O horizon was rich in organic matter, crumb structured, porous and well-drained and was differentiated from the A horizon below by an irregular boundary. The A horizon was moderately well to excessively well-drained with a subangular blocky to crumb structure. This horizon was differentiated from the B horizon below by an irregular boundary. The agricultural soil profile was characterised by compact O and A horizons with a subangular blocky structure; each horizon was separated from the one below by a gradual, smooth horizon boundary. Afforestation increased the combined thickness of the O and A horizon by 0.21 cm yr-1. It caused a significant decrease in bulk density and had no effect on particle size distribution. At most sites % organic matter, C, C/N ratio, CEC and NH4+ concentration were higher and extractable P concentration lower in the O horizon and most of the A horizons of forest soils, compared to the agricultural soil. The concentration of N increased significantly in the O horizon. Soil pH, exchangeable Ca, Mg and K and % base saturation decreased significantly in most forest soil horizons compared to the agriculated soils. Exchangeable Na concentration increased in the B horizon. Accumulation rates of each element since afforestation were also calculated.
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Duke, John Killebrew. "Development of basic meat science standards for secondary agricultural education Delphi model /." Connect to this title online, 2009. http://etd.lib.clemson.edu/documents/1246558749/.
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Tanksley, Koli. "Soil, groundwater, and alfalfa yield response to manure and compost applications in an arid environment." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/280334.
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The assessment of environmental degradation from farming practices has received recent attention due to the concern for sustainable agriculture. The United States Department of Agriculture and the Environmental Protection Agency have set forth the Unified National Animal Feeding Operation Strategy to protect the nation's water resources from contamination. The Unified Animal Feeding Operation Strategy requires that field application of manure, a common fertilization method and manure disposal practice, may not exceed crop nutrient needs. This requirement necessitates studies to determine how the multiple variables involved interact so that farmers may comply with the regulation. In this research, the effects of the application of manure, both fresh and composted, on a production alfalfa (Medicago sativa L.) field was examined. Manure and compost were applied to a production alfalfa field to determine the impact on alfalfa yield, soil nutrient content, and the potential for nitrate leaching. A conventional "no nitrogen added" treatment was also maintained as a control. Manure and compost were applied after each harvest in amounts such that the amount of nitrogen removed in the alfalfa harvest was replaced with the same amount of nitrogen in manure or compost. Application rates varied from 35 to 476 kg nitrogen ha⁻¹ after each harvest. It was found that the finer particles of the compost incorporated into the soil profile better than the chunky form of the manure. Soil analysis down to 150 cm depth showed that the compost treatment plots contained nearly 3000 kg total nitrogen ha⁻¹, the manure plots contained about 1750 kg ha⁻¹, and the no nitrogen plots had approximately 1400 kg ha⁻¹. Final PO₄-P soil analysis revealed that compost plots contained about 125 kg PO₄-P ha⁻¹, manure plots had approximately 115 kg ha⁻¹, and no nitrogen plots had only 20 kg ha⁻¹. Alfalfa yield did not vary between treatments throughout the one and a half year study. Also, no detectable nitrate or phosphate was found in the leachate collected from each of the treatments.
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Jia, Xinhua. "Electrokinetic management of nitrate movement in drip irrigated soils." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280615.
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Nitrate contamination of surface and groundwater has become a serious concern in many agricultural areas throughout the world. The major source of nitrate contamination is believed to be nitrogen fertilizer from agricultural fields. Best Management Practices have been developed to guide fertilizer use and minimize nitrogen losses, but do not address control of nitrate movement from the crop root zone. It is proposed that an in-situ method, electrokinetics (EK), could be used to control nitrate movement, retaining it near the root zone. Lysimeter experiments were conducted to evaluate the effect of parallel electrodes on pH and nitrate distribution in field soils subjected to an electrical input. However, the expected results, increased nitrate retention, reduced sodium and calcium concentration and lower pH values near the anode, were not attained consistently in the test soils with and without Sudan grass. Small scale experiments in a vertical, partially saturated sandy soil column (25 cm height by 14 cm diameter) were conducted to evaluate the optimal EK parameters. After 80 mA current for 6 h the nitrate was retained near the anode, with the highest measured nitrate concentration of 7155 mg/L within 5 mm of the anode. The nitrate concentration at the cathode was 1/5 of the inflow solute concentration (221 mg/L). The pH was 11 near the cathode, 3.5 near the anode, and showed little changes in intermediate layers. The results demonstrate that in sandy soils nitrate can be strongly retained near the anode, even against gravity effect. As the percentage of illite clay in the soil increased, the EK effect decreased; due to the increase of fine clay particles both the transports of ions and the water were inhibited. The loam soil showed some increase in the nitrate concentration near the anode, but the clay soil showed no change. An increase of pH near the cathode was seen in all soils. The electrical potential analysis showed the sandy soil required the highest electrical potential 97.23 V, loam soil was 18.24 V and clay soil was 14.22 V.
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Boonmung, Suwanee. "Evaluation of DRIFTS technique with PLS regression for determination of added mineral nitrogen in soil." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/289864.
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Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) in both near infrared (NIR) and mid infrared (MIR) has been previously shown to be effective in quantifying soil nitrogen (N) concentrations when calibrated using numerous field soil samples. However, such an approach provides samples that likely contain substantial correlations between physical and chemical properties. To address these concerns, the performance of DRIFTS coupled with PLS regression in NIR regions, 5,000-4,000 cm⁻¹ (2,000-2,500 nm) and 6,500-5,500 cm⁻¹ (1,540-1,820 nm), and the M1R region, 3,400-2,400 cm⁻¹ (2,940-4,170 nm), was assessed first through analysis of the concentration of mineral N (ammonium (NH₄⁺) (0-50 ppm) and nitrate (NO₃⁻) (0-200 ppm)) artificially incorporated into a series of silica sand and clay samples with a consistent particle size. The influence of the reduction of sand particles to silt was also analyzed quantitatively. Subsequently, the Pima clay loam soil was evaluated and the concentration ranges of 0-200 ppm NH₄⁺ and 180-1,000 ppm NO₃⁻ were added in soil samples. All three regions provided good measurement of NH₄⁺ but the MIR region was significantly more useful for NO₃⁻ measurement in sand. The detection limits for the measurement of mineral N in sand with particle sizes within 212-300 μm using the MIR region were 9 ppm NH₄⁺ (7 ppm NH₄-N) and 36 ppm NO₃⁻ (8 ppm NO₃-N). For silt (particles less than 53 mum), the most effective model was the MIR region for both NH₄⁺ and NO₃⁻ measurements, yielding the detection limits of 15 ppm NH₄⁺ (12 ppm NH₄-N) and 50 ppm NO₃⁻ (11 ppm NO₃-N). The MIR region also performed reasonably well with soil samples but both NIR regions provided poor results. The detection limits for NH₄⁺ and NO₃⁻ measurements in soil were 100 ppm NH₄⁺ (78 ppm NH₄-N) and 330 ppm NO₃⁻ (75 ppm NO₃-N) with the correlation coefficients (R²) of roughly 80% and 90%, respectively. The spectral range of 2,900-2,400 cm⁻¹ was the effective common range for mineral N measurement in sand, silt, and soil samples.
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Uribe-Chavez, Armando. "A numerical model and semi-analytic equations for determining water table elevations and discharges in non-homogeneous subsurface drainage systems." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/289956.
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A free water surface finite element model was developed. The method was implemented with the Galerkin approach to solve the Laplace equation in the saturated region. It was developed in the object oriented Visual C ++ computer language to permit easy update and drawing of the adaptive mesh. For each time step, the new water table position was calculated based on flux across the water table, a Brooks-Corey equation mass balance for the unsaturated region, and an equation that calculates water table position for the saturated region. An equation was developed to calculate a drainage transfer coefficient, alpha, based on percentage of perforated area in the drain tube wall. The drainage transfer coefficient was incorporated into the finite element model as a Fourier boundary condition. To validate the finite element model, its results were compared with the Kirkham equation results for steady state recharge of three subsurface drainage systems. The finite element model was used to calibrate a semi-analytical frozen stream tube model for subsurface drainage of heterogeneous soils. The first step in the calibration procedure is to run the finite element model for steady state recharge and calculate the water table height divided by recharge rate (the stream tube resistance to flow) as a function of distance between drains. Least squares regression is used to fit a polynomial logarithmic equation, called the resistance function, to the stream tube resistance to flow vs. distance from the drain curve. A differential equation based on the principle of conservation of mass and application of Darcy's law to the frozen stream tube was solved to obtain an equation that calculates stream tube flow rate and final water table elevation as a function of the resistance function and initial water table elevation. An example was developed for a non-homogeneous subsurface drainage system to illustrate the use of the semi-analytical model to predict water table fall and discharge.
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Alam, Mohammed Monjurul. "Soil reaction forces on agricultural disc implements." Thesis, University of Newcastle Upon Tyne, 1989. http://hdl.handle.net/10443/996.
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Theoretical models for the prediction of the performance of wide cutting blades have been in existence for some time. These models characterise the soil as a rigid-plastic Mohr-Coulomb material and depend on advanced mathematical techniques developed for the solution of the complex equations of equilibrium of soil elements in two-dimensional plane-strain failure. Less rigorous techniques have been employed for developing mathematical models for the behaviour of deep narrow tines. In both cases the soil-implement contact boundary is assumed to be a plane surface of simple geometrical shape. The extension of these methods to deal with three-dimensional failure generated by curved loading boundaries is of comparatively recent origin. The soil failure patterns associated with disc soil cutting implements fall into this category. The thesis describes the development of a mathematical model for predicting the performance of such implements. The method employed follows the technique used by Godwin et al for reducing three-dimensional failure into two-dimensional components. The present analysis caters for discs implements having both inclination and disc angles. Soil contact in such implements takes place on complex curved surfaces and the geometry of these were analysed. These surfaces were approximated by plane elements which were then assumed to generate two-dimensional failure in planes parallel to the direction of translation of the disc. The rupture geometry and the forces acting on these elements are then computed using the Newcastle adaptation of Sokolovski's rigorous solution to soil failure. The force acting on the soil contact surface is then obtained by a version of the method of slices used for analysing slip surfaces. The model developed can predict the quasi-static soil reactions on disc implements from a knowledge of the disc geometry, soil properites and depth of cut. The computer programme was used to investigate the sensitivity of the input parameters to the final predicted results and this information was used to develop a set of non-dimensional force coefficients which can be used in a simple additive algebraic equation to predict the three orthogonal force components acting on the disc. Empirical correction factors have been devised to cater for deviations between these and computed valus and prediction to within 5 percent of the computer prediction are possible by this relatively simple method. In order to check the performance of this theoretical model a special dynamometer rig was designed and built to assess all three orthogonal force components acting on a disc tool. A single plough disc was tested in a loam soil and the computer prediction was in good agrement with experimental values. The model was also used to check other published experimental results and once again the prediction was good.
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Okusu, Haruko. "Rethinking science and society : risk assessment of agricultural modern biotechnology for developing countries." Thesis, University of Sheffield, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434539.
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Cohen, Benjamin R. "Notes from the Ground: Science and Agricultural Improvement in the Early American Republic." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/27318.
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This dissertation is an analysis of systematic studies of the land in the early American Republic, from the 1790s to the 1840s; more specifically, it explores the role scientific and technical practices played within that era's improvement ethic. I argue that science, as seen through the lens of agricultural chemistry and, to a lesser extent, geology, became an important, acceptable, and credible way to interact with early Republic land because it fit within the multivalent improvement ethic of that period. Through a study of the agricultural press, farmers’ diaries, and county and statewide scientific surveys, I examine how scientific and technical practices aided agricultural improvement, how they were promoted or resisted by local farmers, and in what ways they gained social credibility for interpreting and interacting with agrarian nature. Part I, “The Place of Science,” explores how science was interpreted by people. I there ask about the social, moral, instrumental, and literary places of agricultural science in rural culture. Part II, “The Science of Place,” asks instead how science interpreted the land, there studying county and state scientific surveys in Virginia. Underlying the entire work is an exposition of the georgic ethic (as distinct from the pastoral ethic), which emphasizes the labor-based means through which most rural peoples understood their land and ties the moral plea for cultural improvement to the material pursuit of agricultural progress.
The story herein introduces the production of an important set of conditions that allowed later scientific developments across the land to have meaning and significance: forms of communication, precedents of organization, field-tested modes of analysis, a tradition of improvement and experimentation, the long-standing search for solutions to soil exhaustion, increasingly mechanistic philosophies of soil composition, a market force to drive all of these, and a unique American political and agricultural environment into which the above could take shape. The lesson is not that the entirety of our modern scientific worldview can be traced to the activities of a disgruntled antebellum American farming class, but that this example of rural science and agricultural improvement provides a fruitful example of what it takes to make a scientific worldview. Thus, arguments about philosophical and conceptual bases for scientizing the land–topics of great importance in the fields of environmental history and various branches of science and technology studies–gain strength and plausibility by reference to the workings of antebellum agents who first argued over the value of using science to define their land.
By putting the circulation of agricultural science in the context of early Republic improvement-minded agents, we can better locate agrarian American culture into a post-Enlightenment setting, we are better equipped to recognize how everyday citizens came to treat scientific practices as legitimate means of interacting with their lands, and we have a more developed picture of how morality, materiality, and theory were wedded in the much-revered principles of practice and practicality. The sum of those points highlights how traditional means of managing the land, as with religious doctrine, almanac strictures, the lessons inherited through family lineage by generations of daily practice, or uncodified folk knowledge in general, were being complemented with or displaced by organized, methodical, and systematic–eventually, scientific–practices on the land.Ph. D.
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Lynch, Terence Lamont. "Factors Influencing the Enrollment of Minorities in Agricultural Science Programs at Virginia Tech." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/27147.
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This study examined the factors that influence minorities to enroll in agricultural science programs at Virginia Tech. Minorities have been and continue to be under-represented in most areas of the agricultural sciences. The presence of African-American and other minority students in the agricultural sciences is, therefore, very important. Enrollment numbers in programs across the country indicate that agriculture, does not appeal to many minority groups. Wardlow, Graham, & Scott (1995) noted that there is little doubt that minorities are underrepresented in academic departments at land-grant universities, professional roles in agricultural industries, and in governmental agencies such as the United States Department of Agriculture (USDA).
The data collection in this study was through a survey developed by the researcher. The population in this study consisted of minority undergraduate and graduate students in the Minority Academic Opportunities Program (MAOP) and Minorities in Agriculture, Natural Resources, and Related Sciences (MANRRS) organization at Virginia Tech.
The respondents in this study selected agricultural science as a major due to their personal decision, input form family members and friends, and the guidance form a high school or faculty member. They also noted there was opportunity for them in the agricultural sciences and felt that professors, administrators and students within the department were fair and supportive. Financial assistance was an important factor in the student's decision enrolling in the program, and the majority of the respondents were receiving financial assistance. However, the respondents noted that they would be enrolled if they were not receiving financial assistance and felt they had the opportunity to succeed in the agricultural sciences at Virginia TechPh. D.
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Tantisantisom, Khumphicha. "Information dissemination for farming communities in Thailand." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2011. https://ro.ecu.edu.au/theses/428.
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The use of information and communication technology tools has been applied in many disciplines, including agricultural sectors. It may be applied in many modules such as data gathering, data processing, information management and information dissemination. One issue that cannot be neglected is the readiness of technology service users, or farmers in this case. It was found that most Thai farmers were poor and illiterate; therefore, offering them the best available tools and services may not be always what they would like to use. To answer the research questions, action research methodology was selected in this study to find a practical way to deliver agricultural information to Thai farmers. Groups of participants from two villages in a northern Thai province were targeted; as a result, case study methodology was also used in this study. Accordingly, a needs analysis using a survey technique, in conjunction with an analysis of the current situation and relevant documents, was conducted in order to find answers about the types of information truly required by Thai farmers. Additionally, questions about how Thai farmers currently received agricultural information, and factors affecting their information requirements, were to be answered. Then, information dissemination through the short message service on mobile phones was found to be the most appropriate alternative for Thai farmers in this study. The free-of-charge experimental service was offered to participating farmers for a period of eight weeks. After that the user satisfaction survey and group interviews were conducted to determine the effectiveness of the system framework. A number of findings and discussion points will be useful for policy makers, relevant government agencies and other researchers who attempt to conduct viable projects in the actual field. This study revealed that income, age and education were significant factors related to the success of the agricultural information dissemination project. Also, relationships between agricultural information extension workers and farmers affected the preferences for, and attitudes to, receiving information among Thai farmers. Subsequently, a new framework was proposed and was obtained comments from agricultural extension workers in order to improve the framework for a wider scale. Finally, the main objective of this research, which was to find out how information and communication technologies can be used to enhance information dissemination to Thai farmers, was achieved. In summary, these outputs are likely to be useful and workable in practice, together with collaborations with third parties such as local councils, mobile phone service providers or academic sectors.
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Lopez, Sabater Carlos Joaquin. "An empirical model of hydraulic roughness for overland flow." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/280353.
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This research has developed a method for estimating hydraulic roughness coefficients for overland flow models in a dynamic approach, to more effectively simulate runoff on natural, agricultural and urban slopes. The hydraulic roughness coefficients are then generated with a series of neural networks. First, a laboratory experiment was designed to explore the effects of soil microtopography, slope and Reynolds number on the magnitude of Darcy-Weisbach, Manning and Chezy roughness coefficients. It was found that three parameters were necessary to describe the soil surface microtopography. Neural networks developed in a preliminary phase were able to reproduce the roughness coefficients obtained in the laboratory experiment by using five predictor variables: bed slope, Reynolds number, and the three parameters used to describe the microtopography. However, these networks failed to generate roughness coefficients for different input variables (generalization). Second, more complex algorithms were developed as combinations of neural networks in parallel. The algorithm output, the sought hydraulic roughness estimate, was estimated with the arithmetic average of the individual network outputs. Results presented in this study demonstrate that combining multiple neural networks reduced the prediction error and improved on the generalization ability of the neural networks. It was also observed that the estimate accuracy was influenced by the characteristics of the dataset, and especially by the relationship between the roughness coefficient and Reynolds numbers. Finally, a field experiment was performed to explore the applicability of the algorithms. A numerical model based on the 1-D diffusion approximation to the Saint Venant equations was constructed, and two surface irrigations were performed to collect data to test the model estimates. The model was used under two scenarios: (1) with constant hydraulic roughness coefficients, and (2) using variable hydraulic roughness predicted with the algorithm. Discharge at the end of the plot and irrigation front advance estimated using both models matched the observations well. However, when using a variable hydraulic roughness, the front was initially delayed until there was a sufficient surface storage to push it forward. The methodology described in this research should be useful for 2-D overland flow models applied to natural slopes with unsteady rainfall.
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Fukumura, Kazunari 1956. "Electrokinetic nitrate removal from porous media." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/290595.
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Nitrate movement under simultaneous influence of hydraulic, electric and chemical gradients was investigated. A one-dimensional ion migration model was developed and compared with laboratory column experiments. Operation of subsurface drainage with an electrode was discussed as an application. The ion transport equation was developed utilizing non-equilibrium thermodynamics. Onsager's reciprocal relations were applied to reduce the number of linear phenomenological coefficients that relate flux to driving forces. Then phenomenological coefficients were expressed using known or measurable physical, chemical and electrical properties of solute and porous media. Developed equations were numerically solved by the Integral Finite Difference Method in one dimension. The numerical results were validated with analytical solutions of simple boundary conditions as well as the results obtained from laboratory column experiments for two or three applied gradients. Without water flow, nitrate concentration increased at the anode by 2.5 times after 100 hrs of 30 V application. Three initial concentrations, 10, 100 and 500 ppm NO₃-N, were tested. A log normal relation between elapsed time and relative concentration increase at the anode was obtained. Two flux rates (0.112 and 0.225 cm min⁻¹), and three inflow concentrations (100, 500 and 1000 ppm NO₃-N) were used to evaluate nitrate transport in the column. Nitrate concentration at the anode increased by 10 to 20% at the end of all experiments. However, the concentration in the column was same as inflow concentration. The application of electrokinetic nitrate removal by installed subsurface drainage with on-off (no flow then flush out) operation is recommended over a continuous flow approach. The numerical model results showed very low flux rates (i.e. 2.68 x 10⁻³ cm min⁻¹) are required for nitrate accumulation in a sand column, and the experimental results confirmed no accumulation at a flux rate of 0.112 cm min⁻¹.
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Malatji, Pholoso. "Processing of wood and agricultural biomass for gasification." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/2937.
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Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2009.ENGLISH ABSTRACT: Wood waste, when used for gasification is commonly pressed into briquettes, especially if no uniform particle size is available. This densification reduces problems of handling, storage and transportation and improves the combustion performance because of a more uniform fuel size. Briquettes have to be mechanically strong enough to be handled. Cohesive strength is provided by residual moisture and lignin present in the wood. The lignin acts as a natural binder. However, the briquetting process becomes more complicated if one wants to add other agricultural waste products that do not necessarily contain lignin as binders,, In this study we have investigated various briquetting process parameters, such as mixing ratios of briquettes containing wood chips, grape skins and chicken litter, moisture content and press time. The aim was to determine the optimum process parameters that allow the production of briquettes, containing a blend of biomaterials that are mechanically stable to allow further handling but yield high energy content at the same time.
AFRIKAANSE OPSOMMING: Wanneer houtafval vir vergassing gebruik word en die partikelgrootte daarvan varieer, word die materiaal normaalweg in ’n brikket gedruk. Brikketvorming vergemaklik opberging, hantering en vervoer. Weens die meer uniforme grootte en vorm van die brikkette is verbranding daarvan heelwat meer doeltreffend. Brikkette moet egter meganies sterk genoeg wees om hanteer te kan word. Die kohesiewe sterkte word deur residuele vog en lignien, wat as natuurlike bindmiddel in hout aanwesig is, verskaf. Indien ander materiale soos landbouafval, wat noodwendig geen lignien bevat nie egter gebruik word, word die brikketvormingsproses meer kompleks. In hierdie ondersoek is verskeie brikketvormingsparameters evalueer. Mengverhoudings van brikkette wat houtspaanders, druiwedoppe en hoendermis bevat, asook invloed van materiaalvoggehalte en druktyd is bestudeer. Die doel was om die optimale materiaal- en prosesparameters vas te stel wanneer ’n mengsel van biomateriale gebruik word om brikkette te lewer wat meganies sterk genoeg is maar steeds die hoogste energieopbrengs lewer.
Centre for Renewable and Sustainable Energy Studies
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Tso, Katherine Kit-Yan. "Effects of climate on agricultural productivity in China." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/40203.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (leaves 99-103).
by Katherine Kit-Yan Tso.
M.Eng.
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Choh, Chun Min Terence 1974. "Sustaining agricultural growth in China : a case for land privatization?" Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9314.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Political Science, 1999.Includes bibliographical references.
With the decollectivization of agriculture based on a system of private incentives, China's agricultural output increased significantly. After the successful implementation of the Household Responsibility System (HRS) in agrarian China after the 1978 economic reforms, agricultural productivity finally surpassed the levels in the early 1950s. This led to significant increases in Chinese peasants' real incomes but agricultural productivity began to decline after 1984 for a myriad of reasons. This thesis seeks to do two things. Firstly, it intends to account for the increases in agricultural output during the post-78 period and to explain the causes of agricultural stagnation after 1984. Secondly, having investigated the causes of agricultural growth and decline after the introduction of the HRS, I will deliberate the case for and against land privatization as a policy prescription to sustain agricultural growth in China.
by Chun Min Terence Choh.
S.M.
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Brooker, Michael R. "Physical and Chemical Characterization of Self-Developing Agricultural Floodplains." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1513778530623727.
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Falk, Jeremy M. "DESCRIBING COGNITIVE LEVEL OF INSTRUCTOR DISCOURSE, ATTITUDES, AND ASPIRATIONS, AND STUDENT CONTENT RETENTION DURING A SECONDARY ANIMAL SCIENCE UNIT OF INSTRUCTION." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1275400070.
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Velho, L. M. L. S. "Science on the periphery : A study of the agricultural scientific community in Brazilian universities." Thesis, University of Sussex, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371204.
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Tungate, Kimberly Denise. "Environmental factors influencing weed interference in agricultural systems." NCSU, 2004. http://www.lib.ncsu.edu/theses/available/etd-07072004-001526/.
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In all agricultural systems using few or no herbicides, cultural and mechanical techniques are crucial to economic viability. Further advances in non-chemical weed control will require in-depth knowledge of weed biology. The objective of new strategies likely will be to alter competitive interactions between crop and weed species. An important part of weed biology, and often the basis for competitiveness, is species response to the environment. Environmental conditions differ greatly in different parts of the world. In agricultural systems, the low nitrogen status of some soils requires most crops to be amended. Weed populations can experience a wide range of fertilization regimes from year to year due to different crop rotations. Fertilization patterns in a rotation can lead to differential growth and reproductive performance of weeds and competitiveness with crops. In research described in the first two chapters, we attempt to determine the extent that lowering parental nutrition would impact weed growth, reproduction, and offspring vigor. The purpose was to begin evaluating benefits of controlling nitrogen fertility in agronomic systems on low fertility soils. Another environmental factor that could influence weed competitiveness is temperature. The significance of temperature responses will become increasingly important in the future. Global climate change models are predicting increases in the earth?s average surface temperature between 1.4- 5.8 ºC during the 21st century. As temperatures increase it is conceivable that warmer temperatures will alter competitive balance between crop and weed species, intensifying weed pressures. The expression of temperature response also will be a function of other interacting factors such as the ability to acquire water and nutrients. Resource acquisition is controlled to a large extent by root growth and interactions with soil microorganisms. The third chapter of this thesis is focused on temperature responses of selected plant species from an agroecological system. The purpose was to begin assessment of possible climate change effects on weed competitiveness. All of our experiments made extensive use of the weed Senna obtusifolia due to its importance in crops in the Southeastern U.S.
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Thiesen, Thais H. Ms. "A Framework for assessing Alternative Agro-Ecosystems: finding Multi-Functional Solutions for Sustainable urban landscapes." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/3042.
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Creating sustainable urban landscapes in light of growing population pressures requires interdisciplinary multi-functional solutions. Alternative agro-ecosystems described as food forests, permaculture gardens, and/or edible landscapes among others could offer potential ways to address the social, economic and ecological goals of various stakeholders simultaneously. The present research used a unique rubric, the Permaculture and Agro-ecosystems Sustainability Scorecard (PASS) that combines existing agricultural and landscape sustainability indicators in order to assess alternative agro-ecosystems. The rubric evaluates provisioning, regulating, supporting and cultural ecosystem services such as pollinator presence, biodiversity, pesticides and fertilizer use, carbon sequestration and human interactions. The PASS was used to score twelve sites in South Florida that meet specific criteria in the small farm, residential and public space categories. The results showed that the majority of the sites scored highest in the supporting services provided, followed by regulating and cultural services and lowest in the economic services category.
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Gonzalez, Cesar. "Response of Three Cultivars of Bell Pepper (Capsicum Annuum L.) to Mulching & Irrigation." TopSCHOLAR®, 1988. https://digitalcommons.wku.edu/theses/2411.
Full textAbstract:
The effect of black polyethylene mulching and drip irrigation on the yield and quality of three cultivars of bell pepper was studied during the 1987 growing season. This study was conducted on a Pembroke silt loam soil on the Western Kentucky University Farm in Bowling Green, Kentucky. The experimental design was a split-plot arranged in randomized complete blocks in four replications with treatment as the main plot and cultivars as the sub-plot.
'California Wonder,' 'Lady Bell F1 Hybrid: and' Keystone Resistant Giant' cultivars of bell pepper were established in the field during the last week of May. The cultivars were grown using black polyethylene, with application of irrigation (no mulch) and without irrigation or mulch (check) Irrigation was initiated in early August and continued throughout the remainder of the growing season; the amount per application was 158.8 m3/ha.
At harvest, mature green fruit were removed from the plant, weighed, and classified as grade I or II. There were significant differences at the 5% level in the yield of the cultivars. There were significant differences at the 5% levels among the yields of the treatments. the higher yield was obtained with irrigation, followed by the use of mulch. The better yield under each of the three treatments was obtained with the cultivar Lady Bell.
The production of grade II peppers Was higher than the production of grade I peppers, the average yield was 48.82 MT/ha, and 21.99 MT/ha, respectively. The yield of bell pepper grade II was higher in all three treatments.