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1
Liu, Yingmei. "Effective Modeling of Nutrient Losses and Nutrient Management Practices in an Agricultural and Urbanizing Watershed." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/40398.
Abstract:
The Lake Manassas Watershed is a 189 km2 basin located in the Northern Virginia suburbs of Washington, DC. Lake Manassas is a major waterbody in the watershed and serves as a drinking water source for the City of Manassas. Lake Manassas is experiencing eutrophication due to nutrient loads associated with agricultural activities and urban development in its drainage areas. Two watershed model applications using HSPF, and one receiving water quality model application using CE-QUAL-W2, were linked to simulate Lake Manassas as well as its drainage areas: the Upper Broad Run (126.21 km2) and Middle Broad Run (62.79 km2) subbasins. The calibration of the linked model was for the years 2002-05, with a validation period of 2006-07.
The aspects of effective modeling of nutrient losses and nutrient management practices in the Lake Manassas watershed were investigated. The study was mainly conducted in the Upper Broad Run subbasin, which was simulated with an HSPF model. For nutrient simulation, HSPF provides two algorithms: PQUAL (simple, empirically based) and AGCHEM (detailed, process-based). This study evaluated and compared the modeling capabilities and performance of PQUAL and AGCHEM, and investigated significant inputs and parameters for their application. Integral to the study was to develop, calibrate and validate HSPF/PQUAL and HSPF/AGCHEM models in the Upper Broad Run subbasin.
â One-variable-at-a-timeâ sensitivity analysis was conducted on the calibrated Upper Broad Run HSPF/PQUAL and HSPF/AGCHEM models to identify significant inputs and parameters for nutrient load generation. The sensitivity analysis results confirmed the importance of accurate meteorological inputs and flow simulation for effective nutrient modeling. OP (orthophosphate phosphorus) and NH4-N (ammonium nitrogen) loads were sensitive to PQUAL parameters describing pollutant buildup and washoff at land surface. The significant PQUAL parameter for Ox-N (oxidized nitrogen) load was groundwater nitrate concentration. For the HSPF/AGCHEM model, fertilizer application rate and time were very important for nutrient load generation. NH4-N and OP loads were sensitive to the AGCHEM parameters describing pollutant adsorption and desorption in the soil. On the other hand, plant uptake of nitrogen played an important role for Ox-N load generation.
A side by side comparison was conducted on the Upper Broad Run HSPF/PQUAL and HSPF/AGCHEM models. Both PQUAL and AGCHEM provided good-to-reasonable nutrient simulation. The comparison results showed that AGCHEM performed better than PQUAL for OP simulation, but PQUAL captured temporal variations in the NH4-N and Ox-N loads better than AGCHEM. Compared to PQUAL, AGCHEM is less user-friendly, requires a lot more model input parameters and takes much more time in model development and calibration. On the other hand, use of AGCHEM affords more model capabilities, such as tracking nutrient balances and evaluating alternative nutrient management practices.
This study also demonstrated the application of HSPF/AGCHEM within a linked watershed-reservoir model system in the Lake Manassas watershed. By using the outputs generated by the HSPF/AGCHEM models in the Upper Broad Run and Middle Broad Run subbasins, the Lake Manassas CE-QUAL-W2 model adequately captured water budget, temporal and spatial distribution of water quality constituents associated with summer stratification in the lake. The linked model was used to evaluate water quality benefits of implementing nutrient management plan in the watershed. The results confirmed that without the nutrient management plan OP loads would be much higher, which would lead to OP enrichment and enhanced algae growth in Lake Manassas.Ph. D.
2
Habersack, Mathew James. "Evaluation of Nutrient and Pathogen Losses From Various Poultry Litter Storage Methods." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/34373.
Abstract:
Considerable concern has developed over the possible pollution from poultry litter storage methods. This study was conducted to evaluate three different storage scenarios; covered stockpiles, uncovered stockpiles, and litter sheds. The stockpiles were monitored over two rainfall simulation events, in both the Ridge and Valley and the Piedmont physiographic provinces, with both surface and subsurface flows analyzed. An observational study, where subsurface water was sampled for a nine-month period was conducted using six litter sheds, three in each of the above provinces. Samples were analyzed for nutrients, fecal coliforms, and solids.
Concentrations of NHx, TKN, OP, TP, VSS, and FC in surface runoff from uncovered litter piles were all statistically higher than that from covered piles, with NO3 being the exception. However, increased runoff volumes originating from the covered litter piles caused mass loadings from both covered and uncovered piles to be similar enough that statistical significance was not obtained, except in the case of FC.
Soil water samples from litter stockpiles did not show a statistically significant treatment effect for concentration data, but uncovered piles did exhibit higher nitrogen concentration estimates than the covered piles. Sample collection frequency showed a statistically significant increase in the number of samples that could be obtained from the edge lysimeter under uncovered litter piles from the Piedmont experimental site. This result indicates uncovered piles are releasing the precipitation absorbed during the rainfall simulation into the sub-surface environment.
In the storage shed study, a greater number of samples were collected per attempt at the Piedmont sheds compared to those at the Ridge and Valley site. While both areas were undergoing a significant drought, Piedmont porous-cup lysimeters yielded samples 63% of the time, compared to 10% for Ridge and Valley lysimeters. Lysimeters located near the edge of the shed were also more likely to yield a sample than those in the center or a background location. Unknown interferences within the litter shed samples prevented three laboratories from obtaining valid nutrient concentrations.Master of Science
3
Hollinger, Eric, of Western Sydney Hawkesbury University, and Faculty of Environmental Management and Agriculture. "Links between management of a market garden and stormwater losses of sediment, nitrogen and phosphorus." THESIS_FEMA_XXX_Hollinger_E.xml, 1998. http://handle.uws.edu.au:8081/1959.7/306.
Abstract:
Market gardening is commonly characterised by intensive cultivation, high inputs of both organic and inorganic fertilisers, chemical over/misuse, frequent irrigation, and a low degree of soil cover. While market gardening is readily perceived to be detrimental to waterways, there is remarkably little data to quantify the impacts. Soil and nutrient loss in stormwater runoff varies with soil type, climate and production systems. Therefore local data are needed to determine the impact of market gardening on the Hawkesbury-Nepean. This should lead to a better understanding of how land management influences runoff quantity and quality so that practices can be improved. Objectives of this research were to : quantify sediment, N and P loss and assess the implications for waterways; relate sediment, N and P losses to specific land management practices and assess their impacts on profitability; and, reflect on this research in terms of extension and adoption of better land management. An 8.8 ha property with 6.6 ha of market garden was used as a case study in the Hawkesbury-Nepean Catchment. Soil samples were collected at the beginning and end of the study. Sediment core samples were collected from the drainage channel. A rainfall simulator was used to compare runoff volume from green manure and bare fallow beds. The research produced several recommendations for the extension and adoption of improved land management. In order to reduce sediment, N and P losses in stormwater, the primary focus should be on improving soil and nutrient management, in particular matching fertiliser inputs more closely to nutrient requirements. The secondary focus should be on utilising structural measures, in particular farm dams, to prevent pollutants from entering waterways. The outcome should be decreased costs to the farmer and decreased impacts on waterways. The use of N-fixing green manure to decrease the use of poultry manure should be explored.Master of Science (Hons)
4
Loper, Shawna. "Effects of compost and tillage on soils and nutrient losses in a simulated residential landscape." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0041298.
5
Griffith, Keegan. "Impact of a Winter Rye Cover Crop on Edge-of-Field Nutrient Losses and Corn Silage Production." ScholarWorks @ UVM, 2019. https://scholarworks.uvm.edu/graddis/1011.
Abstract:
Cover crops have the potential to reduce environmental impacts of corn production. The objective of this study was to quantify differences in nitrogen (N) and phosphorus (P) loading between corn plots with or without a winter rye cover crop (Secale cerale). Four field plots (30 x 46 m) in Chazy, NY with edge-of-field monitoring were used for the study. Two plots were randomly assigned a rye cover crop treatment and planted with a grain drill at a rate of 112 kg ha-1 after corn silage harvest in 2015 and 2016. Continuous water flows were monitored from surface runoff and tile drain hydrologic pathways dur-ing runoff events. Soluble reactive P (SRP), total P (TP), nitrate-N, total N (TN), and to-tal suspended solids (TSS) concentrations were measured and multiplied by runoff vol-umes to estimate nutrient export. Surface runoff from rye plots had lower nutrient loss compared to control plots. Cumulative nitrate-N exports were similar between treatments (15.7 vs. 14.8 kg nitrate-N ha-1 for rye and control, respectively). Cumulative TN exports were numerically higher for control plots compared to rye plots, (18.8 vs. 21.4 kg TN ha-1). Cumulative TP and SRP exports (surface + tile) for rye were 2.2 and 3-fold greater than control plots, (0.51 vs. 1.19 kg TP ha-1 and 0.33 vs. 0.96 kg SRP ha-1). Total P and SRP loads in surface runoff were 3.0-fold greater for control plots compared to rye plots (0.36 vs. 1.12 kg TP ha-1 and 0.32 vs. 0.94 kg SRP ha-1). TSS load in surface runoff was numerically higher for control plots compared to rye (5.7 vs. 20.6 kg ha-1). Cumulative surface runoff was 1.8-fold greater in control plots compared to rye plots (112.6 mm vs. 207.7 mm), while cumulative tile runoff was numerically higher in rye plots compared to control (83.2 mm vs. 66.1mm). Snowmelt events contributed the majority of phosphorus losses (96% of SRP and 92% of TP), emphasizing the need to implement management techniques that reduce P transport risk during the non-growing season. Winter rye re-duced snowmelt TP export by 3-fold compared to the control plots (0.33 kg TP ha-1 and 1.03 kg TP ha-1). The winter rye cover crop planted after corn silage harvest effectively reduced erosion and P transport in surface water runoff compared to corn silage left fal-low after harvest. In addition to significantly reducing P exports, farms have the option of harvesting rye as a forage crop and double cropping with corn. In this way, more total forage is possible for the farm in addition to offering environmental conservation and wa-ter quality benefits.
6
Webber, David Franklin. "Vegetative filter strip buffer effects on runoff, sediment, and nutrient losses from a grazing and windrow composting site." [Ames, Iowa : Iowa State University], 2007.
7
Formaglio, Greta [Verfasser]. "The effect of reduced management intensity on soil nutrient dynamics in a large-scale oil palm plantation: soil nitrogen cycle, asymbiotic nitrogen fixation and nutrient leaching losses / Greta Formaglio." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://d-nb.info/121533852X/34.
8
Nummer, Stephanie Ann. "Assessing the Effects of Conservation Practices and Fertilizer Application Methods on Nitrogen and Phosphorus Losses from Farm Fields – A Meta Analysis." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1470394645.
9
Ciccaglione, Julia Serafina. "Characterization of soil erosion processes and nutrient losses associated with previously forested areas, the Colonarie River Watershed, St. Vincent, West Indies." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0026/MQ31337.pdf.
10
Kugbe, Joseph [Verfasser]. "Spatio-temporal dynamics of bush-fire nutrient losses and atmospheric depositional gains across the Northern savanna region of Ghana / Joseph Kugbe." Bonn : Universitäts- und Landesbibliothek Bonn, 2012. http://d-nb.info/104305636X/34.
11
Thomas, A. D. "The effects of fire and different logging practices on nutrient losses in overland flow from eucalyptus and pine forests, northern Portugal." Thesis, Swansea University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.639187.
Abstract:
This thesis presents data on nutrient losses in overland flow and eroded sediment after fire in Eucalyptus globulus and Pinus pinaster forests on schist bedrock in the Águeda Basin, northern Portugal. The principal aims were: i) to determine the effects of fire on nutrients in overland flow and eroded sediment during the immediate post-fire period, ii) to evaluate the effects of various post-fire logging techniques on nutrient losses, and iii) to examine the causes of temporal and spatial variability in overland flow and eroded sediment nutrient losses. A total of 11, 8 x 2m bounded plots were used to quantify overland flow, soil and nutrient losses from slopes under burnt and unburnt eucalyptus and pine stands. The plots were monitored for an initial period of 8 months before treatments were applied to simulate the effects of different logging techniques. The results show that fire has a substantial impact on nutrient losses. The main findings of the research are: i) overland flow responses at the burnt sites were significantly greater than at the unburnt sites and the high responses were sustained for at least 2 and 3 years at the eucalyptus and pine sites respectively, ii) solute losses in overland flow were negligible at the unburnt sites but increased substantially at the burnt sites because of increased overland flow and availability of nutrients at the soil surface, iii) nutrient losses in eroded sediment were also greater from the burnt sites because of greater erosion and enrichment of the eroded material, iv) post-fire logging techniques resulting in large amounts of litter debris on the slopes in eucalyptus plantations and delayed logging of scorched pine trees to allow needlefall were found to be effective at reducing eroded sediment nutrient losses. The implications of fire-enhanced nutrient losses on soil fertility and forest productivity are discussed.
12
Spence, Porche' La Phyl. "Effects of Lawn Maintenance on Nutrient Losses via Overland Flow and the Comparison of Nitrous Oxide Flux from Three Residential Landscapes A Case Study." NCSU, 2009. http://www.lib.ncsu.edu/theses/available/etd-11032009-142926/.
Abstract:
Residential lawn management practices (mowing, fertilizer, irrigation, reseeding, and aeration) result in aesthetically appealing landscapes, but can result in nutrient losses via overland flow or gaseous losses to the atmosphere (e.g. nitrous oxide - N2O). The overall objective of this study was to determine the effect of lawn management on nutrient losses from residential lawns. The specific objectives were: modify a passive sampling system to determine nutrient loads due to overland flow from lawns; evaluate differences in overland flow frequency, volumes, and nutrient losses during rainfall events (⥠2.54 cm); and compare N2O losses following rainfall events. Three lawn schemes were studied: a high maintenance fescue (Festuca arundinacea) lawn (HMFL), a low maintenance fescue lawn (LMFL), and a mixed forested residential landscape (RFL). The modified passive sampling system allowed 100% recovery of overland flow and demonstrated that differences in maintenance influenced the overland flow frequency, volumes, and nutrient losses. The LMFL had the greatest overland flow volumes and nutrient unit area loads, although N and P concentrations in overland flow exceeded USEPA recommendations from all three lawns. Nutrient losses (g ha-1 yr-1) from all three residential landscapes were 1000 times less than fertilizer (kg ha-1 yr-1) and throughfall (kg ha-1 yr-1) inputs, due in part to the presence of well-structured soils (low bulk densities and high infiltration rates). Irrigation practices between the HMFL and LMFL explained the differences in overland flow volumes and nutrient loads, especially during the first half of the study when drought conditions existed at the study site (Cary, North Carolina). Lack of irrigation in the LMFL resulted in early dormancy, a minimal thatch layer and lower plant density, resulting in higher volumes of overland flow. Trends in the N2O losses from the HMFL and LMFL were associated with timing of fertilizer applications, presence or absence of irrigation, and seasonal growth patterns of the fescue. For the RFL, the presence of a decomposing litter layer limited N2O production. Well-maintained residential lawns, receiving recommended fertilizer N applications and frequent irrigation, reduce nutrient losses via overland flow but may provide optimum conditions for greater N2O fluxes.
13
Kalvelage, Tim Verfasser], Marcel M. M. [Akademischer Betreuer] Kuypers, and Hermann Werner [Akademischer Betreuer] [Bange. "Nitrogen Losses and Nutrient Regeneration in Oxygen Minimum Zones / Tim Kalvelage. Gutachter: Marcel M. M. Kuypers ; Hermann W. Bange. Betreuer: Marcel M. M. Kuypers." Bremen : Staats- und Universitätsbibliothek Bremen, 2012. http://d-nb.info/1071994158/34.
14
Göbel, Leonie Verfasser], Johannes [Akademischer Betreuer] [Isselstein, Daniela [Gutachter] Sauer, and Rainer Georg [Gutachter] Jörgensen. "Nutrient Response Efficiencies, Leaching Losses and Soil-N Cycling in Temperate Grassland Agroforestry and Open Grassland Management Systems / Leonie Göbel ; Gutachter: Daniela Sauer, Rainer Georg Jörgensen ; Betreuer: Johannes Isselstein." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://d-nb.info/1213096294/34.
15
Göbel, Leonie [Verfasser], Johannes [Akademischer Betreuer] Isselstein, Daniela [Gutachter] Sauer, and Rainer Georg [Gutachter] Jörgensen. "Nutrient Response Efficiencies, Leaching Losses and Soil-N Cycling in Temperate Grassland Agroforestry and Open Grassland Management Systems / Leonie Göbel ; Gutachter: Daniela Sauer, Rainer Georg Jörgensen ; Betreuer: Johannes Isselstein." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://d-nb.info/1213096294/34.
16
Fischer, Peter. "The degree of phosphorus saturation of agricultural soils in Brazil and Germany: New approaches for risk assessment of diffuse phosphorus losses and soil phosphorus management." Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/19589.
Abstract:
Diffuse Phosphor (P)-Austräge aus der Landwirtschaft tragen zur Gewässereutrophierung bei. Der Phosphorsättigungsgrad (DPS) ist ein etablierter Parameter, um das P-Austragsrisiko aus Böden zu erfassen. Ein bodentypunabhängiger Ansatz, der die Abschätzung des DPS durch eine einfache Standardmethode wasserlöslichen P (WSP) ermöglicht (WSP-DPS-Ansatz), wurde an europäischen Böden entwickelt. In der Dissertation wurde dieser Ansatz erstmalig: i) an tropischen Böden getestet und ii) dazu verwendet P-Austragsrisiken von Boden-P-Monitoringdaten und von landwirtschaftlichen Institutionen empfohlenen P-Gehalten abzuleiten. Neben dem DPS wurde der Einfluss der in Brasilien gängigen anorganischen Oberflächendüngung auf das Austragsrisiko mittels Laboranalysen und Feldstudien erfasst. Die Bodentypunabhängigkeit des WSP-DPS-Ansatzes wurde für Böden Brasiliens bestätigt. Infrarotspektroskopische Analysen lieferten eine Erklärung für relativ niedrige gelöste P-Konzentrationen im Oberflächenabfluss von Oxisols. Pedotransferfunktionen zwischen WSP und Methoden, die in Brasilien und Deutschland zur Abschätzung pflanzenverfügbaren P verwendet werden, ermöglichten die Berechnung von DPS-Werten aus Monitoringdaten. Erste DPS-Karten zeigten relative geringe Austragsrisiken für das Untersuchungsgebiet in Brasilien und hohe Risiken für Deutschland, die teilweise durch unterschiedliche empfohlene Boden-P-Gehalte erklärbar waren. Um mit einer einfachen und kosteneffizienten Methode sowohl die landwirtschaftliche Produktion als auch den Gewässerschutz zu berücksichtigen, wurden die Wasser- und CaCl2-Methode zur Abschätzung von pflanzenverfügbarem P mit dem WSP-DPS-Ansatz kombiniert. Dieser Ansatz könnte helfen die Herausforderungen zu lösen mit denen die Menschheit in den nächsten Jahrzehnten bezüglich P in der Landwirtschaft konfrontiert sein wird: Einer effizienten Nutzung der limitierten Ressource P und dem Schutz der Gewässer vor diffusen P-Einträgen.Diffuse phosphorus (P) losses from agriculture contribute to the eutrophication of surface waters. The degree of P saturation (DPS) is an established parameter for assessing the risk of P loss from agricultural soils. A soil type-independent approach for estimating the DPS by a simple standard method of water-soluble phosphorus (WSP; the WSP-DPS approach) was developed on European soils. In the thesis, the WSP-DPS approach was for the first time: i) tested on tropical soils and ii) used to derive P loss risks from soil P monitoring data and from recommended soil P levels by agricultural institutions. In addition to DPS, laboratory analyses and field studies were combined to assess the risk of P loss associated with the superficial application of inorganic fertilizer, which is commonly used in Brazil. The soil type-independency of the WSP-DPS approach was confirmed for soils of Brazil. Infrared spectroscopic analyses provided an explanation for the relatively low dissolved P concentrations in the surface runoff of Oxisols. Pedotransfer functions were determined between WSP and methods used to estimate plant-available P in Brazil and Germany and allowed for the transformation of soil P monitoring data into DPS values. The first DPS maps revealed relatively low P loss risks for the investigation area in Brazil and high risks for Germany. This difference was partly explainable by the recommended soil P levels in the two countries. To consider both agricultural production and the protection of surface waters in soil P management with a simple and cost-effective method, the soil test methods of using water and CaCl2 to estimate plant-available P and the WSP-DPS approach were combined. This approach could help to solve the challenges humanity faces regarding P in agriculture in the coming decades: An efficient use of the limited resource P and the protection of surface waters from diffuse P losses.
17
ROCHA, JUNIOR P. R. "Impact of soil management on water, sediments and nutrients losses: field, laboratory and modeling experiments." Universidade Federal do Espírito Santo, 2016. http://repositorio.ufes.br/handle/10/4892.
Abstract:
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Previous issue date: 2016-02-22Embora muito esforço venha sendo realizado, os estudos visando mitigar os efeitos da erosão ainda são insuficientes. Neste contexto a presente tese buscou estudar os efeitos do manejo do solo em dois grandes países produtores agrícolas, Brasil e Estados Unidos, focando nas particularidades encontradas em cada país. Os Capítulos 1 e 2 da presente tese tiveram como objetivo estudar os efeitos da recuperação ou renovação de pastagens sob diferentes manejos de solo (controle, escarificada, adubada, queimada, integração lavoura-pecuária e arada e gradeada em nível). Foram avaliados sob chuva natural as perdas de sedimento, água, nutrientes (Ca, Mg, P e K) e carbono orgânico (COT, C lábil, C menos lábil e C recalcitrante). Além disso, estudou-se qual compartimento (água ou sedimento) e granulometria de sedimento (maior ou menor que 0,250mm) perdeu mais nutriente e carbono. Para cada manejo foram calculados o fator cobertura e manejo do solo (fator-C) usado na Equação Universal de Perda de Solo (USLE/RUSLE), os valores calculados foram calibrados com os observados a campo. Nos Capítulos 3 e 4 o objetivo foi estudar o efeito da mudança de manejo do solo adotado na produção agrícola dos Estados Unidos (plantio direto, preparo em contorno, preparo do solo morro abaixo e solo exposto) avaliando a influência da alteração do manejo nas perdas de sedimento, água e P, sob chuva natural e simulada. Além disso, foram avaliados os efeitos destas práticas na rugosidade do solo com experimentos de chuva simulada, e a possibilidade de modelagem dos dados observado a campo utilizando o software WEPP (Water Erosion Predict Project). No capitulo 1 verificou-se de uma maneira geral que os manejos de pastagens que levam aos maiores valores de perda foram o controle (10,31 t ha-1 e 119,58 mm ou 9,1%) e a pastagem queimada (5,34 t ha-1 e 90,37 mm e 6,8%). Valores intermediários de perda foram de solo foram observados nos manejos de integração lavoura-pecuária (1,25 t ha-1 e 125,87 mm ou 9,5%) e escarificada (1,70 t ha-1 e 84,74 mm ou 6,4%). Os valores mais baixos de perdas de solo e água foram verificados nos manejos de pastagens arada e gradeada em nível (0,01 t ha-1 e 9,23 mm ou 0.7%) e adubada (0,31 t ha-1 e 32,47 mm ou 2,4%). Recomenda-se a utilização da adubação em pastagens estabelecidas na Mata Atlântica tendo em vista reduzir as perdas e elevar a produção de capim. O manejo da queima x e o manejo extensivo semelhante à pastagem controle devem ser evitados. Independente do manejo as maiores perdas de Ca (98,63 %), Mg (99,30 %), K (90,57 %) e P (65,29 %) estiveram associadas a água de escoamento, enquanto as maiores perdas de CO (79,93 %) estiveram associadas ao sedimento. Os sedimentos grossos (granulometria maior que 0,250 mm) foi responsável pela maior perda de Ca, Mg, K e CO, enquanto o a maior parte do P foi perdido pelo sedimento fino. No capitulo 2 verificou-se que os dados estimados pela USLE/ RUSLE utilizando o fator-C calculado foram próximos aos observados a campo. Recomenda-se o fator-C para estimativa de perda de solo em áreas de pastagens estabelecidas na Mata Atlântica. Os valores encontrados quando calculados em 4 meses foram: 0.007300 t ha t-1 ha-1 pastagem controle, 0.009700 t ha t-1 ha-1 pastagem escarificada, 0.001900 t ha t-1 ha-1 pastagem adubada, 0.017300 t ha t-1 ha-1 pastagem queimada, 0.0090 t ha t-1 ha-1 pastagem integração lavoura-pecuária e 0.000400 t ha t-1 ha-1 pastagem arada e gradeada. O fator-C calculado para 24 meses foram: 0.001380 t ha t-1 ha-1 pastagem controle, 0.002350 t ha t-1 ha-1 pastagem escarificada, 0.000470 t ha t-1 ha-1 pastagem adubada, 0.003210 t ha t-1 ha-1 pastagem queimada, 0.002240 t ha t-1 ha-1 pastagem integração lavoura-pecuária e 0.000110 t ha t-1 ha-1 pastagem arada e gradeada. No Capitulo 3 verificou que o manejo do solo com plantio direto deve ser mantido nos Estados Unidos tendo em vista evitar as perdas de sedimento e água, os menores valores foram observados neste manejo 0,45 t ha-1 e 152,35 mm. Quando não for possível manter todo o resíduo sob o solo o preparo em contorno deve ser adotado, isso porque neste manejo foi registrado o segundo menor valor de perdas 5,71 t ha-1 e 166,51 mm e a menor perda de P com 216.26 g ha-1. Os manejos de solo com a colheita total de resíduos (semelhante ao solo exposto) e o preparo do solo morro abaixo devem ser evitados onde foram registradas as maiores perdas de sedimento, água e P. Quando realizado a modelagem foi observado superestimação das perdas de água e subestimação das perdas de sedimento, recomendando mais pesquisas com modelagem, buscando uma melhor caracterização do solo ao longo do tempo. No Capitulo 4 observou-se que o preparo do solo em Contorno (7,03) e Morro abaixo (7,17) tiveram efeito na elevação da rugosidade do solo quando comparado aos manejos Plantio Direto (4,34) e Solo exposto (4,26). Este efeito levou a menor perda de água na chuva de menor intensidade (50 mm). No entanto nas perdas de sedimento a rugosidade teve pouco efeito, sendo mais importante a direção do preparo e o fator cobertura do solo, onde os valores totais de perda de sedimento foram: solo exposto 9,77 t ha-1; morro abaixo 8,85 t ha-1; preparo em contorno 1,30 t ha-1; e plantio direto 0,59 t ha-1.
18
Schwab, Elizabeth Rose. "Maumee River Watershed Farmers’ Perceptions of Nutrient Loss Risk." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1587662279052842.
19
Skoog, Peter, and Henrik Bodin-Sköld. "Nutrients and runoff in a small catchment during spring 2010." Thesis, Linköping University, Linköping University, Department of Water and Environmental Studies, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-57611.
Abstract:
Eutrophication is an increasing problem in the Baltic Sea and is caused by an excess of nutrients in the water which are primarily transported with the runoff from cultivated land. The peninsula Vikbolandet in Östergötland is dominated by arable land and has stream outflows to the bays of Bråviken and Slätbaken. In this study five streams of Vikbolandet have been sampled during the spring flood period with the aim of connecting concentrations of nutrients in the streams with turbidity and runoff in the catchment. This analysis has then been related to the land use in the small catchment of Vadsbäcken in order to investigate the impact of land uses with areal losses of phosphorus. The results indicate that there are increasing concentrations of phosphorus downstream in the sites of Vadsbäcken and that the transported amounts of phosphorus increases with the spring flood and at a rainstorm event. It is shown that the distribution of agricultural blocks in the catchment of Vadsbäcken has a major impact on the nutrient leakage. There is a co-variation between turbidity and runoff during a rainstorm event and between particulate-bound phosphorus and runoff over time. A further aim has been to investigate possibilities for use of an easily managed, cost-effective environmental monitoring method for nutrient measurements in watercourses. Within four out of five streams at Vikbolandet there is a significant co-variation between turbidity and total phosphorus. Using field measurements of turbidity for environmental monitoring could provide a viable alternative for environmental monitoring of watercourses but will need further investigations of co-variation before being brought into use. Further, this study shows that the transport of phosphorus is underestimated in environmental monitoring
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Fontanive, Maicon. "Erosão hídrica em solo cultivado com aplicação de dejeto líquido de suínos." Universidade do Estado de Santa Catarina, 2016. http://tede.udesc.br/handle/handle/2470.
Abstract:
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Many of the existing swine production systems in southern Brazil, provide high production of pig slurry. This situation leads to management problems, storage, distribution and environmental pollution caused by the improperly disposal of this waste product. The objective of this work was to determine the effect of application of dose increase of pig slurry on physical and chemical attributes of a Cambisol, in the production of plant biomass and water erosion, under three crops and compare the results with those obtained in soil condition uncultivated and without waste, in Rio do Sul - SC. The treatments were the control (no tillage and zero dose) and the doses 0 (zero), 50, 100 and 200 m³ ha-¹ of pig slurry applied on the soil surface. The application was performed in three stages after the implementation of millet, oat and sunn hemp in plots of 15 x 2.0 m, bounded by galvanized sheet, with an average gradient of 23.3%. The samples of erosive rainfall were collected to quantify the soil loss, water and nutrients. Before and after the experiment, soil samples were collected to evaluate the physical and chemical properties. At the end of each cultivation, dry matter production of shoot was determined. The increase of pig slurry doses increased production of biomass in the cultivated area, due to the improved porosity and, in part, of calcium, phosphorus and potassium, especially in the soil surface. Therefore, the water erosion reduces, after three cycles of cultivation. Soil losses were more influenced than the loss of water. The Ca, Mg, P and K contents in runoff water are the largest in treatments with higher doses of pig slurry. In the 200-m3 h-1 of pig slurry dose, the total nutrients losses in runoff are greatest
A erosão hídrica é a principal causa de degradação do solo agrícola e do ambiente no entorno dos sistemas de produção, fortemente influenciada pelo manejo do solo que, por sua, vez, é influenciando pelas adubações, dentro outros fatores. A maior parte dos sistemas de produção de suínos no sul do Brasil propicia produção de dejeto em alta quantidade. O dejeto gera problemas de manejo, armazenamento, distribuição e poluição ambiental causada pela erosão hídrica devido ao descarte do produto de forma de adubação, de maneira inadequada. Com o experimento objetivou-se estudar o efeito de dejeto líquido de suínos (DLS) em atributos de um Cambissolo Háplico, na produção de massa vegetal da parte aérea das plantas (MS) e na erosão hídrica em solo cultivado, e comparar os resultados com os obtidos em condição de solo sem cultivo e sem dejeto, em Rio do Sul - SC. Os tratamentos foram constituídos em testemunha (sem cultivo e sem dejeto) e pelas doses 0 (zero), 50, 100 e 200 m³ ha- ¹ de DLS aplicado na superfície do solo em três momentos após a implantação das culturas de milheto, aveia preta e crotalária, em parcelas de 15 x 2,0 m delimitadas por chapas galvanizadas, com declividade média de 23,3%. Ao longo da pesquisa foram determinadas as perdas de água e solo por erosão e coletadas amostras de enxurrada resultantes de chuvas erosivas para, nelas, determinar as perdas de alguns nutrientes. Antes da instalação do experimento e após o final da pesquisa, amostras de solo foram coletadas para avaliar as propriedades físicas e químicas e, ao final de cada cultivo, determinou-se ainda a produção de MS das plantas cultivadas no experimento. Identificou-se que o DLS aumentou a MS com o aumento da dose de dejeto, devido à melhoria da porosidade e, em parte, dos teores de cálcio, fósforo e potássio, em especial na superfície do solo. Com isso diminuiu a erosão hídrica ao final de três ciclos de cultivo. Em relação à erosão, as perdas de solo (PS) foram mais influenciadas do que as perdas de água (PA); os teores de Ca, Mg, P e K na água de escoamento superficial foram maiores nos tratamentos com as maiores doses de DLS do que naqueles das menores doses. As perdas totais de nutrientes na enxurrada, no entanto, foram maiores apenas na dose 200 m3 ha-1 de dejeto do que nas demais
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Hobara, Satoru. "Biogeochemical consequences of biotic change in forest ecosystems : implications for nutrient loss." Kyoto University, 2002. http://hdl.handle.net/2433/149897.
Abstract:
Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第9605号
農博第1233号
新制||農||841(附属図書館)
学位論文||H14||N3637(農学部図書室)
UT51-2002-G363
京都大学大学院農学研究科森林科学専攻
(主査)教授 菊澤 喜八郎, 教授 小﨑 隆, 教授 武田 博清
学位規則第4条第1項該当
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Muller, Fernando. "Volatilização de amônia com o uso de dejetos de suínos com pH modificado." Universidade Estadual do Oeste do Paraná, 2018. http://tede.unioeste.br/handle/tede/3950.
Abstract:
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In western Paraná the production of pigs in feedlot system is in a large scale, resulting in a wide production of manure with a high power of environmental pollution if not treated correctly. The use of this manure as biofertilizers may be an interesting alternative for the agricultural sector by providing nutrients to plants, especially nitrogen. In addition, the biofertilizer can improve soil fertility by increasing its organic matter. However, after the application of nitrogen to the soil, gaseous losses of this nutrient may occur, denominated ammonia volatilization, which can be intensified by different factors. Thus, the objective of this work was to evaluate the fertilization of soybean with liquid swine manure and the loss of nitrogen by volatilization after the application of it with different pHs. The work was conducted in two experiments. The first one was conducted in the 2015/2016 under no-tillage system with soybean crop. On the day of sowing, the treatments were composed of three doses of liquid swine manure (48; 96 and 144 m3 ha-1), plus additional treatments, which were the control (without fertilization) and a treatment with mineral fertilization (300 kg ha-1 of NPK formulation 04-30-10). The productivity of grains, green stems, heights of plants and one hundred grain mass were analyzed. The second work was conducted in a greenhouse during the period from October to December 2017. The ammonia volatilization was evaluated according to the adjusted pH of the liquid swine manure, being 3.0; 4.0; 5.0; 6.0 and 7.4 (natural manure). Further, two additional treatments were evaluated: natural manure + agricultural gypsum and the control (without application of manure). In order to capture the volatilized ammonia, Sale type collectors were used, with a static free semi-open chamber. The volatilization flow, accumulated volatilization and percentage of ammonia loss were analyzed. The mineral fertilization of soybean crop can be replaced by fertilization with liquid swine manure, mainly in high fertility soils. The fertilization with 48 m³ ha-1 was able to supply the nutritional need of the soybean crop according to the productivity obtained. The application of liquid swine manure with natural pH (7,4) provided high losses of ammonia, around 46 % higher. With the acidification of the manure by adjusting the pH around 3 to 5, a great reduction to 5 % of loss of nitrogen by volatilization was observed.
No oeste do Paraná a produção de suínos em sistema de confinamento é de grande escala, resultando em alta produção de dejetos, com grande potencial para poluição ambiental se não tratados de forma correta. A utilização desses dejetos como biofertlizante pode ser uma alternativa interessante para o setor agrícola pelo fornecimento de nutrientes às plantas, principalmente o nitrogênio. Além do mais, a aplicação do biofertilizante pode melhorar a fertilidade do solo pelo incremento da matéria orgânica. Entretanto, após a aplicação de nitrogênio no solo podem ocorrer perdas gasosas desse nutriente, principalmente sob a forma de amônia. Esse processo é denominado volatilização e pode ser intensificado por diferentes fatores. Assim, o trabalho teve por objetivo avaliar a adubação da soja com dejetos líquidos de suínos e a perda de nitrogênio por volatilização após a aplicação dos dejetos com diferentes pHs. O trabalho foi conduzido em dois experimentos. O primeiro foi conduzido na safra 2015/2016 em sistema de plantio direto com a cultura da soja. No dia da semeadura foram aplicados os tratamentos compostos por três doses de dejeto líquido de suínos (48; 96 e 144 m3 ha-1), mais os tratamentos adicionais, que foram a testemunha (sem adubação) e um tratamento com adubação mineral (300 kg ha-1 do formulado NPK 04-20-10). Foram analisados a produtividade de grãos, hastes verdes, alturas de plantas e massa de cem grãos. O segundo trabalho foi conduzido em casa de vegetação durante o período de outubro a dezembro de 2017. Foi avaliada a volatilização da amônia em função dos pHs ajustados do dejeto líquido de suínos, sendo 3,0; 4,0; 5,0; 6,0 e 7,4 (natural do dejeto). Além disso, foram avaliados dois tratamento adicionais: dejeto natural + gesso agrícola e a testemunha (sem aplicação de dejeto). Para captação da amônia volatilizada foram utilizados coletores do tipo Sale, com câmara semiaberta livre estática. Foram analisados o fluxo de volatilização; volatilização acumulada e porcentagem de perda de amônia. A adubação mineral da cultura da soja pode ser substituída pela adubação com dejeto líquido de suínos, principalmente em solos de fertilidade alta. A adubação com 48 m³ ha-1 de dejeto líquido de suínos foi capaz de suprir a necessidade nutricional da cultura da soja conforme a produtividade obtida. A aplicação do dejeto líquido de suínos com pH natural (7,4) proporcionou altas perdas de amônia, em torno de 46 %. Com a acidificação dos dejetos ajustando-se o pH em torno de 3 a 5 houve e redução para 5 % de perda de nitrogênio por volatilização.
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Pessotto, Patrícia Pretto. "DEJETOS LÍQUIDOS DE SUÍNOS: ESCOAMENTO SUPERFICIAL, ALTERAÇÕES NOS ATRIBUTOS QUÍMICOS E FÍSICOS DO SOLO E PRODUTIVIDADE DO FEIJÃO." Universidade Federal de Santa Maria, 2016. http://repositorio.ufsm.br/handle/1/4949.
Abstract:
Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe use of pig slurry as a source of nutrients for crops is a common practice in regions of pig production, however there is a growing concern about the risk of environmental contamination of soil and water as the continuous and excessive use of such waste. The purpose of this study was to evaluate losses of water, sediment and nutrients (N, P and Cu) through surface runoff and changes in chemical and physical attributes of a Red Oxisol under no-tillage system with continuous application of increasing doses of liquid pig manure (DLS) during the bean crop cycle. The study was conducted in an experimental area of the Federal University of Santa Maria campus Frederico Westphalen- RS, on a Red Oxisol, with a history of six years with DLS application. The treatments were: mineral fertilizer (NPK), organic fertilizer, consisting of DLS in doses of 25, 50, 75 and 100 m3 ha-1 and control without fertilization (0). Were evaluated surface runoff, loss of nutrients, chemical and physical properties of soil, productivity and crop yield components. The drained solution by natural rainfall was collected in gutters of 0.25 m2 installed in each plot, from October 2014 to January 2015. A sample of the drained volume was collected for measurement of sediment and concentrations of N, P and Cu present in the solution. Soil samples were collected for the determination of chemical parameters (N, P, K, Ca, Mg, Cu, Zn, MO, soil acidity indicators and total organic carbon) and physical parameters (aggregation, porosity and bulk density). The largest losses of soil, water and nutrients were observed from the beginning of sowing to the flowering of the culture, showing that little ground cover of the bean canopy is a determining factor for the runoff. Doses from 50 m3 h-1 DLS applied to the soil, associated with the application time, resulted in an increase of TOC content and enhance aggregation, porosity and density in the surface layer. The mineral fertilization of bean crops can be replaced by doses of DLS from 25 m3 ha-1, with no losses in maize productivity in an Red Oxisol clayey after six years of applying DLS.
A utilização de dejeto líquido de suínos como fonte de nutrientes para as culturas agrícolas é uma prática comum em regiões produtoras de suínos, entretanto há uma crescente preocupação quanto ao risco de contaminação ambiental do solo e água quanto à utilização contínua e excessiva desses resíduos. O objetivo deste estudo foi avaliar perdas de água, sedimentos e nutrientes (N, P e Cu) por escoamento superficial e alterações nos atributos químicos e físicos de um Latossolo Vermelho sob sistema plantio direto com aplicação contínua de doses crescentes dejetos líquido de suínos (DLS) durante o ciclo da cultura do feijão. O estudo foi desenvolvido em uma área experimental da Universidade Federal de Santa Maria, campus de Frederico Westphalen - RS, sobre um Latossolo Vermelho, com histórico de seis anos com aplicação DLS. Os tratamentos avaliados foram: adubação mineral (NPK), adubação orgânica, constituída de DLS nas doses de 25, 50, 75 e 100 m3 ha-1 e testemunha sem adubação (0). Foram avaliados o escoamento superficial, perda de nutrientes, atributos químicos e físicos do solo e produtividade e componentes de rendimento da cultura. A solução escoada por chuva natural foi coletada em calhas de 0,25 m2 instaladas em cada parcela de outubro de 2014 a janeiro de 2015. Uma amostra do volume escoado foi coletada para quantificação dos sedimentos e teores de N, P e Cu presentes na solução. Foram coletadas amostras de solo para a determinação dos atributos químicos (N, P, K, Ca, Mg, Cu, Zn, MO, indicadores de acidez do solo e carbono orgânico total) e físicos (agregação, porosidade e densidade do solo). As maiores perdas de solo, água e nutrientes foram observadas no início da semeadura até o florescimento da cultura, evidenciando que a pouca cobertura do solo pelo dossel vegetativo do feijão é um fator determinante para o escoamento superficial. As doses a partir de 50 m3 ha-1 de DLS aplicados ao solo, associados ao tempo de aplicação, implicaram em aumento dos teores de COT e, melhoram a agregação, porosidade e densidade do solo na camada superficial. A adubação mineral na cultura do feijão pode ser substituída por doses de DLS a partir de 25 m3 ha-1, sem que haja prejuízos na produtividade da cultura do milho em um Latossolo Vermelho de textura argilosa após seis anos de aplicação de DLS.
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Carneiro, Leocir José. "Compostagem de resíduos agroindustriais: revolvimento, inoculação e condições ambientais." Universidade Estadual do Oeste do Parana, 2012. http://tede.unioeste.br:8080/tede/handle/tede/397.
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Previous issue date: 2012-02-21This trial aimed at testing the turning, cover courtyard and inoculation with a Commercial Biological Product (CBP) at the composite period and the produced compost quality using agro-industrial residues. The experiment was carried out at the Experimental Center of Agricultural Engineering (NEEA), at Western Paraná State University (UNIOESTE). The following wastes were used during the composting process from the activities developed by the Agricultural Cooperative Consolata - COPACOL: hatchery waste, flotation sludge, ash and remaining coal from boiler, solid fraction of swine manure, solid fraction of waste from trucks washing and waste from cleaning and pre-cleaning of cereals. Twelve treatments were performed and composed of three combinations of shift plowing frequencies with these conditions: uncovered and covered courtyard without and with CBP inoculation. The windrows were piled with 300 kg of weight each, so that each one could have the same composition. The pile temperature was daily monitored. The parameters as reduced mass, volume, total and volatile solids were weekly monitored. Electrical conductivity, pH, carbon and nitrogen were measured at the beginning, 28, 56 days and at the end of the process. The contents of P, K, Mg, Ca, Na, Zn, Cu, Mn and Fe were determined at the beginning and end of the composite process. The electrical conductivity, pH, carbon and nitrogen were measured at the beginning, at 28, 56 days and at the end of the process. The levels of P, K, Mg, Ca, Na, Zn, Cu, Mn and Fe were determined at the beginning and end of the composite process. The coverage at composite courtyard showed significant effect on volume and nitrogen decreases (p<0.05) and increases electrical conductivity, contents of Na, Mg, K and composite time (p <0.05). The use of frequent turnings at the beginning of the process allowed greater volume reduction and composting reduced the time within 20 days (p <0.05). However, there were greater losses of N, C, and consequently the C / N ratio. The frequency of shift plowing was twice a week on the first month (F2), so it was more effective in keeping nitrogen in the pile. The CBP use was not significant for any of the variables (p> 0.05) and pH, concentration of P, Ca, and micronutrients were not affected by any of the variables.
Esta pesquisa objetivou testar o turno de revolvimento, cobertura do pátio e inoculação com Produto Comercial Biológico (PCB) no tempo de compostagem e qualidade do composto produzido, utilizando resíduos agroindustriais. O experimento foi conduzido no Núcleo Experimental de Engenharia Agrícola (NEEA) da Universidade Estadual do Oeste do Paraná (UNIOESTE). Os resíduos utilizados no processo de compostagem, oriundos das atividades desenvolvidas pela Cooperativa Agrícola Consolata COPACOL foram: resíduo de incubatório, lodo de flotador, cinza e carvão remanescente da caldeira, fração sólida de dejeto de suíno, fração sólida do resíduo da lavagem de caminhões e resíduos da limpeza e pré-limpeza de grãos. Foram implantados doze tratamentos, compostos pelas combinações de três frequências de revolvimento, com as condições: sem e com cobertura do pátio; sem e com inoculação do PCB. As leiras foram montadas com 300 kg de massa fresca cada, com composição igual. A temperatura da leira foi monitorada diariamente. As variáveis redução de massa, volume, sólidos totais e voláteis foram monitoradas semanalmente. A condutividade elétrica, pH, carbono e nitrogênio foram mensurados no início, aos 28, 56 dias e ao final do processo. Os teores de P, K, Mg, Ca, Na, Zn, Cu, Mn e Fe foram determinados no início e final do processo de compostagem. A cobertura no pátio de compostagem teve efeito significativo nas reduções de volume e nitrogênio (p<0,05), além de aumentar a condutividade elétrica, os teores de Na, Mg, K e o tempo de compostagem (p<0,05). Os frequentes revolvimentos no início do processo possibilitaram maior redução de volume e reduziram o tempo de compostagem em até 20 dias (p<0,05). Entretanto, causaram maiores perdas de N, C e consequentemente da relação C/N. A frequência de revolvimento de duas vezes por semana no primeiro mês (F2) mostrou-se mais eficiente na manutenção de nitrogênio na pilha. O uso do PCB não foi significativo para quaisquer das variáveis analisadas (p>0,05). O pH, teores de P, Ca e micronutrientes não foram influenciados pelas variáveis.
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Beasley, Jeffrey S. "Nitrogen Regime Influence on Nutrient and Sediment Surface Runoff During Vegetative Establishment of Bermudagrass." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/31900.
Abstract:
Bermudagrass (Cynodon dactylon (L.) Pers.) is a popular turfgrass used throughout the Southeast. Bermudagrass is established primarily as sprigs on large acreage sites. Currently, the industry standard practice (ISP) of fertilization during
bermudagrass sprig establishment is 48.8 kg N ha-1 wk-1. This fertilizer rate can be excessive on morphologically immature sprigs in the initial weeks of establishment, thus making the possibility of offsite surface runoff N events more likely. Two experiments were conducted in 2000 and 2001 where sprigs were established at 2, 4, 6, 8, and 10 weeks prior to applying simulated rainfall (WPRS) following N fertilization rates of the ISP or a lower initial N (LIN) rate of 12.2 kg N ha-1 wk-1 the first four weeks and then
48.8 kg N ha-1 wk-1 until full establishment. At the tenth week all treatments were subjected to rainfall simulation at 63.5 mm hr-1. Once surface runoff was induced, rainfall continued for thirty minutes during which time runoff samples were taken every five minutes and analyzed for sediment losses, N concentrations in the nitrate and ammonium forms, and phosphorus losses as dissolved reactive P (DRP). Experimental results indicate an ability to curb N losses through surface runoff during the initial weeks of sprig establishment following the LIN with only modest delays in sprig establishment.
Sprigs established for the same time period, under the ISP or LIN, were very similar in
growth, release of surface runoff, and sediment losses during runoff events.Master of Science
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Soracco, Kelly L. "Seasonal differences in nutrient intake, supplement use, and eating behaviors of high school wrestlers." Virtual Press, 1999. http://liblink.bsu.edu/uhtbin/catkey/1154780.
Abstract:
The purpose of this study was to examine weight loss methods and to determine if seasonal differences existed in energy and nutrient intakes, supplement use and eating behaviors of high school wrestlers. Weight loss history, food and activity records, supplement use and knowledge and bulimic behavior data were collected from twenty wrestlers during the 1998-99 wrestling season and from eleven wrestlers 3 months post wrestling season.This study found that wrestlers practiced extreme weight control behaviors including fasting, food and fluid restriction resulting in inadequate nutrient intakes. No significant seasonal differences were found in energy balance, nutrient intake or supplement use for this study group. There was a significant difference in bulimic behavior post season as compared to peak season, though no wrestler approached the cutoff score for clinical diagnosis of bulimia nervosa.Given the negative effects of extreme weight loss practices and inadequate nutrient intake on performance, nutrition education remains crucial for high school wrestlers. Further research using instruments to measure restrictive behaviors (as was practiced by subjects in this study) would be beneficial. Additionally future studies are needed to continually assess this population of athletes to gauge if changes in extreme behaviors are occurring.Department of Family and Consumer Sciences
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Santos, Ana Carolina Nascimento. "Análie do custo da erosão do solo na microbacia hidrográfica do Ceveiro." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/11/11143/tde-06102014-155551/.
Abstract:
A erosão acelerada do solo constitui um processo importante de degradação dos solos e da água e no entanto as consequências econômicas dessas perdas são ainda pouco conhecidas. Este estudo objetivou analisar o emprego de um SIG na estimativa do valor monetário da perda de solo nas áreas de produção de cana-de-açúcar e pastagem na Microbacia Hidrográfica do Ceveiro (MHC). Para a realização da modelagem da erosão laminar foi utilizado a Equação Universal de Perdas de Solo (USLE) e para a estimativa do custo o método Custo de Reposição dos Nutrientes (CRN). A estimativa de perda de solo por erosão da MHC mostrou que 38,5% da área da microbacia apresenta perda de solo entre 0 e 10 Mg.ha-1.ano-1; 20% na classe de 20 e 50 Mg.ha-1.ano-1; 25% na classe de 50 e 100 Mg.ha-1.ano-1. Em 91% das áreas de cana-de-açúcar a perda de solo estimada é maior que a perda tolerável. O CRN estimado médio para as áreas de cana-de-açúcar foi R$ 285,64 .ha-1.ano-1 e de e R$27,21 .ha-1.ano-1 para as áreas de pastagem. Quando analisadas separadamente a cultura da cana-de-açúcar e a pastagem, o valor médio do CRN é de R$ 285,64. ha-1.ano-1 e R$ 27,21. ha-1.ano-1 respectivamente. Além disso, para ambas as culturas o nitrogênio é o nutriente com maior participação na composição do CRN estimado e efetivo, sendo responsável por aproximadamente 82% para as áreas de cana-de-açúcar. A aplicação do Custo de Reposição de Nutrientes por Sistema de Informação Geográfica forneceu indicadores que permitem a análise comparativa quanto ao custo de reposição de nutrientes perdidos por erosão.Accelerated soil erosion is an important process of land and water degradation; however the economics consequences of these losses are still little known. This pourpose of this study was to analyze the use of a GIS to estimate the monetary value in the areas of sugarcane and pasture cultivation in the Ceveiro Watershed. Average annual soil loss rates had been estimated using the Universal Soil Loss Equation (USLE), and the monetary costs had been estimated using the Replacement Cost of Nutrients Method. The estimated soil loss by erosion of MHC showed that 38.5 % of the area of the watershed presents soil loss between 0 and 10 Mg ha - 1.year - 1; 20 % in the class of 20 and 50 Mg ha - 1.year - 1 ; 25 % in class 50 and 100 Mg. ha -1.year -1. In 91% of the areas of sugarcane the soil loss estimated is greater than the tolerable loss. The CRN estimated average for the areas of sugarcane was R$ 285.64 year - 1 .ha - 1 and R$ 27.21 year -1 ha - 1 for pasture areas. When analyzed separately, the culture of sugarcane and pasture, the average value of the RCN is R$ 285.64. ha -1 year-1 and R$ 27.21 . ha -1 .year-1 respectively. Moreover, for both crops nitrogen is the nutrient with the highest participation in the composition of Estimate and Effective RCN, accounting for approximately 82 % to the areas of sugarcane. The application of the method of economic valuation of natural resources for Replacement Cost provides indicators that allow comparative analysis regarding the cost of replacing nutrients lost through erosion.
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Regnault, Timothy Robert Hume, of Western Sydney Hawkesbury University, Faculty of Agriculture and Horticulture, and School of Agriculture and Rural Development. "Orchestrated partitioning of maternal nutrients during ovine pregnancy." THESIS_FAH_ARD_Regnault_T.xml, 1997. http://handle.uws.edu.au:8081/1959.7/15.
Abstract:
Ovine placental lactogen (oPL) is postulated to be involved in the repartitioning of maternal nutrients during pregnancy, through its effect on insulin metabolism. Ovine pancreatic insulin responses to exogenous glucose are depressed during pregnancy and this depression becomes more pronounced as gestation advances. In addition, under the hormonal environment of rising oPL and growth hormone (oGH) concentrations, maternal whole body glucose irreversible loss (GIL) increases. The percentage of GIL accounted for by uterine glucose uptake also increases with advancing gestation and increasing litter size. Regression analysis of oPL concentration with glucose uterine uptake as a percentage of GIL, accounts for 39% of variation. Maternal oPL concentrations which increase with gestational age, were significantly greater in multiple bearing ewes and ewes subjected to reduced metabolisable energy (ME) intakes. It is postulated that through actions on pancreatic sensitivity, oPL plays a major role as a homeorhetic control during pregnancy. Elevated oPL concentrations were strongly associated with continually depressed pancreatic insulin secretory ability. The reduction in pancreatic sensitivity to glucose was not as a result of elevation in GH or non-esterified fatty acid (NEFA) concentrations. Muscle insulin receptor number and affinity were found to increase with increasing litter size, suggesting that pregnancy associated insulin resistance occurs predominantly in adipose tissue. During ovine pregnancy there is a specific stimulation of maternal gluconeogenesis. As gestation advances, an increasingly greater proportion of this glucose is partitioned to the gravid uterus. The development of insulin resistance, together with the suppression of pancreatic activity, ensures the preferential uptake of glucose by non-insulin dependent tissues over insulin dependent tissues. These activities favour uterine glucose uptake, decrease adipose glucose uptake, and also promote adipose mobilisation and hepatic gluconeogenesis, so as to meet the increasing energy requirement of pregnancy. It is postulated that through these effects on insulin secretion and associated adipose tissue mobilisation factors, oPL plays a major role in homeorhesis during pregnancy.Doctor of Philosophy (PhD)
29
Acharya, Govind Prasad. "The development of interventions to minimise soil and nutrients losses in the bari land of the middle hills and Western Development Region of Nepal." Thesis, Bangor University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273686.
30
Prazeres, Stella da Silva. "Respostas biomÃtricas e fisiolÃgicas de duas cultivares de feijÃo-de-corda sob irrigaÃÃo com Ãgua salina e potÃssio no solo." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=9452.
Abstract:
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoA intensidade do estresse causado pela salinidade nas culturas irà depender principalmente, do nÃvel de tolerÃncia da espÃcie vegetal e das formas de manejo utilizadas. O feijÃo-de-corda à uma cultura de importÃncia econÃmica, no entanto apresenta sensibilidade ao estresse salino. Dessa forma, objetivou-se avaliar as respostas biomÃtricas, fisiolÃgicas e produtivas de duas cultivares de feijÃo-de-corda, submetidas à irrigaÃÃo com Ãguas salinas e doses de potÃssio. O experimento foi conduzido em ambiente protegido na Ãrea experimental do Setor de Agrometeorologia da Universidade Federal do CearÃ. Foram utilizadas sementes de duas cultivares de feijÃo-de-corda (CE790 e CE104), as quais foram submetidas a nÃveis crescentes de salinidade, utilizando Ãgua de irrigaÃÃo com condutividade elÃtrica (CEa) de 0,8; 2,2; 3,6 e 5,0 dS m-1 e doses crescentes de potÃssio, utilizando 0,5, 1,0 2,0 e 4,0 g vaso-1 de Cloreto de PotÃssio. ApÃs coleta os dados foram submetidos a anÃlises estatÃsticas. O aumento da salinidade na Ãgua de irrigaÃÃo nÃo prejudicou o crescimento radicular das cultivares, por outro lado, a Ãrea foliar reduziu linearmente a cada incremento salino. A cultivar CE104 apresentou maior inibiÃÃo à acumulaÃÃo de Na+ com adiÃÃo de potÃssio. A salinidade afetou as trocas gasosas, das plantas de feijÃo-de-corda. Com a aplicaÃÃo de potÃssio houve uma menor perda hÃdrica e maior lixiviaÃÃo de Na+ nas plantas de feijÃo-de-corda sob estresse.
The strength of the stress caused by salinity in crops will depend largely on the level of tolerance of plant species and ways to employed manegement The cowpea is an of economic importance crop, however has sensitivity to salinity. This way, objective was to assess the responses biometric, physiological na production of two cultivars of cowpea, subject to irrigation with saline water and doses of potassium. The Experiment was carried in a protected environment at the experimental area the Sector of Agrometeorology, Federal University of CearÃ. The seeds used were two cultivars of cowpea (CE790 and CE104), which were subject to increasing salinity levels, used irrigation water with eletric conductivity (Eca) of 0,8; 2,2; 3,6 and 5,0 dS m-1 and increasing doses of potassium using 0,5; 1,0; 2,0 and 4,0 g pot-1 of potassium chloride. After collect the data was submitted to statistical analysis. The increase in the salinity in irrigation water did not impair to root growth of cultivars, however, the leaf Ãrea linearly reduced to each increase saline. The cultivar CE104 had highest inhibition to accumulation of Na+ with the addition of potassium. Gas exchanges been affected the effect of the salinity. As potassium application there was less water loss and higher leach of Na+ in cowpea plants under stress.
31
Grainger, Tess Nahanni. "Winners and losers in a changing climate : causes and consequences of long-term nutrient enrichment in a boreal forest understory." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43628.
Abstract:
Nitrogen levels are predicted to rise dramatically in the coming decades as a result of increased deposition from the burning of fossil fuels and the large-scale conversion of nitrogen into a useable form for agriculture. Plant communities react strongly to increases in soil nitrogen, particularly in northern ecosystems where nitrogen levels are naturally very low. An experiment in northern Canada that began in 1990 has been investigating the effects of long-term nutrient enrichment (fertilizer addition) and release from herbivory (fencing). After 22 years of treatment, plant community composition has been substantially altered in fertilized plots, whereas exclusion of herbivores has had almost no detectable effects. I used this experiment to address two questions about the causes and consequences of long-term nitrogen enrichment in the boreal forest.
In the first data chapter I focused on four understory species that had different levels of success in fertilized plots to investigate why some species are more successful than others under nutrient enrichment. I hypothesized that successful species would be taller, have higher specific leaf area, spurt earlier in the growing season and be more morphologically plastic than their less successful counterparts. I demonstrated that each of the two species that came to dominate fertilized plots has a different combination of traits and responses that likely gave them a competitive advantage; Mertensia paniculata has the highest specific leaf area of the four species, and E. angustifolium is tallest and exhibits morphological plasticity when fertilized by increasing biomass allocation to leaf tissue.
In the second data chapter I assessed how increasing nitrogen levels has affected investment in sexual reproduction in four herbaceous understory species. Whereas plants in northern ecosystems reproduce mainly through clonal growth, rapidly changing environmental conditions and warmer temperatures will likely result in increased benefits of sexual reproduction. Fertilization increased the probability of flowering for Achillea millefolium and resulted in a higher allocation of biomass to flower parts for E. angustifolium but did not affect investment in reproduction for Festuca altaica or M. paniculata. Increased investment in sexual reproduction could give a competitive advantage to the former two species in the future.
32
Meneses, Bruno Miguel do Carmo Santana. "Influência de um fogo florestal na qualidade da água da Ribeira de São Domingos localizada na Região Oeste de Portugal." Master's thesis, ISA, 2013. http://hdl.handle.net/10400.5/6489.
Abstract:
Mestrado em Engenharia do Ambiente - Instituto Superior de AgronomiaForest fires are responsible for several environmental problems, especially for polluting watercourses. In this dissertation we intend to evaluate the changes occurring in the physical and chemical constitution of water of São Domingos stream (crossing the municipalities of Lourinhã and Peniche, Portugal), in particular pH and nutrient content variation, related to surface runoff from the burnt area of the Cezaredas plateau, where a forest fire occurred at July 19th, 2012. Thus, water samples were collected in three points strategically chosen along this stream (one upstream of the burnt area and two downstream, one of the last being located immediately after the burnt area) from which the pH, the electrical conductivity and the concentrations of N, P, K, Na, Ca and Mg were assessed. The data obtained in the analysis of the samples collected downstream of the burnt area show an input of nutrients in the stream water and an evidence that nutrient transportation occurs in a higher degree during the first episodes of rainfall which are also responsible for generating surface runoff. This is due to the greater availability of nutrients in these areas and the reduced soil protection, a factor that facilitates surface runoff.
33
Regnault, Timothy Robert Hume. "Orchestrated partitioning of maternal nutrients during ovine pregnancy." Thesis, View thesis View thesis, 1997. http://handle.uws.edu.au:8081/1959.7/15.
Abstract:
Ovine placental lactogen (oPL) is postulated to be involved in the repartitioning of maternal nutrients during pregnancy, through its effect on insulin metabolism. Ovine pancreatic insulin responses to exogenous glucose are depressed during pregnancy and this depression becomes more pronounced as gestation advances. In addition, under the hormonal environment of rising oPL and growth hormone (oGH) concentrations, maternal whole body glucose irreversible loss (GIL) increases. The percentage of GIL accounted for by uterine glucose uptake also increases with advancing gestation and increasing litter size. Regression analysis of oPL concentration with glucose uterine uptake as a percentage of GIL, accounts for 39% of variation. Maternal oPL concentrations which increase with gestational age, were significantly greater in multiple bearing ewes and ewes subjected to reduced metabolisable energy (ME) intakes. It is postulated that through actions on pancreatic sensitivity, oPL plays a major role as a homeorhetic control during pregnancy. Elevated oPL concentrations were strongly associated with continually depressed pancreatic insulin secretory ability. The reduction in pancreatic sensitivity to glucose was not as a result of elevation in GH or non-esterified fatty acid (NEFA) concentrations. Muscle insulin receptor number and affinity were found to increase with increasing litter size, suggesting that pregnancy associated insulin resistance occurs predominantly in adipose tissue. During ovine pregnancy there is a specific stimulation of maternal gluconeogenesis. As gestation advances, an increasingly greater proportion of this glucose is partitioned to the gravid uterus. The development of insulin resistance, together with the suppression of pancreatic activity, ensures the preferential uptake of glucose by non-insulin dependent tissues over insulin dependent tissues. These activities favour uterine glucose uptake, decrease adipose glucose uptake, and also promote adipose mobilisation and hepatic gluconeogenesis, so as to meet the increasing energy requirement of pregnancy. It is postulated that through these effects on insulin secretion and associated adipose tissue mobilisation factors, oPL plays a major role in homeorhesis during pregnancy.
34
Nilsson, Bengt. "Extraction of logging residues for bioenergy : effects of operational methods on fuel quality and biomass losses in the forest." Doctoral thesis, Linnéuniversitetet, Institutionen för skog och träteknik (SOT), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-58307.
Abstract:
Wood products play a key role in the transformation to a more sustainable society based on renewable bio-based resources, together with the positive effects on climate mitigation by replacing fossil fuels. However, to increase the use of forest fuel in practice it is important to understand the effects of handling and storage on its quality and removal of nutrients from the forest. This thesis addresses these effects with special focus on a comparative evaluation of the traditional dried-stacked with “new” and to some extent more controversial fresh-stacked methods for extraction of logging residues from Norway spruce (Picea abies (L.) Karst). The results indicate that a normal extraction of logging residues will leave at least 20% of logging residues at the clear-felled area, in accordance with Swedish Forest Agency recommendations. However, the results also indicate that the ambition of the dried-stacked method to leave the majority of the needles well spread over the clear-felled area does not meet these recommendations. In fact, the harvesting operation is more important than the extraction method, with respect to how much logging residues (nutrients) being left in the forest. The results also show that the quality of fuel yielded by the two handling methods differs only to minor extent, indicating that other factors have stronger effects, where “dried-stacked” and “fresh-stacked” logging residues from different clear-felling areas is often similar. Generally, logging residues stored over summer (regardless method), seem to provide sufficiently dry forest fuel, with a needle content of about 5–10%. There is a clear correlation between drying and effective loss of needles from twigs, but the loss does not necessarily mean that the needles will remain in the forest. However, needle color (green or brown) is not a strong indicator for a reduction in needle content. Acceptance of the fresh-stacked method would provide opportunities for the development of new technologies, more efficient use of machinery throughout the whole year, reduced costs, shorter lead times and increased amounts of logging residues extracted from each clear-felled area. This is mainly because it would enable extraction at optimal times from a logistical, financial and/or forestry perspectives. Written in English with summary and conclusion in Swedish.Skogen och dess produkter har en nyckelroll i omställningen till ett framtida hållbart samhälle eftersom användande av träråvara har en positiv effekt på klimatet, t.ex. genom träbyggande eller att fossila bränslen ersätts med bioenergi. Men för att kunna ta tillvara mer skogsbränsle i form av grenar och toppar (grot) från bestånd dominerade av gran (Picea abies (L.) Karst) är det viktigt att förstå hur hanteringen påverkar såväl bränslekvalitet som bortförsel av näringsämnen från skogen. Denna avhandling belyser hanteringens effekter på bränslekvalitet och näringsförluster genom att jämföra den traditionella metoden (skotning av torkad grot, ”brunrisskotning”), med den ”nya” och till viss del ifrågasatta skotningen av färsk grot (”grönrisskotning”). Resultatet visar att ett normalt grot-uttag kommer att lämna minst 20 % av groten kvar på hygget, helt i linje med Skogsstyrelsens rekommendationer. Däremot uppfylls inte rekommendationerna med avseende på att lämna merparten av barren väl spridda på hygget, detta trots att det är ambitionen med den traditionella hyggestorkningen av grot. Hur mycket grot (och således näringsämne) som lämnas kvar på hygget påverkas i själva verket mer av hur avverkningen utförs, än när groten skotas ihop. Resultatet visar också en skillnad i bränslekvalitet mellan de båda beskrivna hanteringsmetoderna. Denna skillnad är dock så liten att andra faktorer sannolikt påverkar mer än hanteringsmetoden. Hyggestorkad grot från ett enskilt hygge i södra Sverige, kan i verkligheten ofta vara ganska likt färskskotad grot från ett annat hygge. Grot som har lagrats över sommaren kan alltså förväntas ha torkat tillräckligt, samt ha en barrandel på ca 5–10 % oavsett hanteringsmetod. Det verkar också finnas ett klart samband mellan torkning och att barren släpper från kvisten, men det betyder inte nödvändigtvis att barren blir kvar i skogen. Hur som helst, barrens färg (gröna eller bruna) är inte en rättvisande indikator på avbarrning. Om skotning av färsk grot accepteras ger det möjligheter för utveckling av ny teknik, effektivare användning av maskinresurser över hela året, minskade kostnader, kortare ledtider, samt möjligt ökat grot-uttag från enskilda hyggen. Detta beror främst på att det skulle vara möjligt att utföra grot-uttaget när det passar bäst ur ett logistiskt, ekonomiskt och/eller skogligt perspektiv. Skriven på engelska, men med sammanfattning och slutsatser på svenska
Tidigare handledare har också varit:
Thomas Thörnqvist, Professor, Linnéuniversitetet
Dick Dandberg, Professor, Linnéuniversitetet
Åsa Blom, Docent, Linnéuniversitetet
Sammanläggningsavhandlingen består av totalt fyra Paper:
Paper I
Nilsson, B., Blom, Å., Thörnqvist, T. 2013. The influence of two different handling methods on the moisture content and composition of logging residues. Biomass and Bioenergy, 52, 34–42.
Paper II
Nilsson, B., Nilsson, D., Thörnqvist, T. 2015. Distributions and losses of logging residues at clear-felled areas during extraction for bioenergy: Comparing dried- and fresh-stacked method. Forests, 6, 4212–4227.
Paper III
Nilsson, D., Nilsson, B., Thörnqvist, T., Bergh, J. 2016. Amount of nutrients extracted and left behind at the clear-felled area using the fresh- and dried-stacked method of logging residue extraction. Submitted to Scandinavian Journal of Forest Research (2016-11-01).
Paper IV
Nilsson, B., Lerman, P. 2016. Experimental study of relations between defoliation, moisture content and color change in logging residues. Department of Forestry and Wood Technology, Linnaeus University, Växjö, Sweden. Manuscript.
35
Challinor, Paul Francis. "An evaluation of pumice, unloaded clinoptilolite and nutrient-loaded clinoptilolite zeolites, as plant growth substrates in the intensive production of long season glasshouse crops." Thesis, University of Plymouth, 2003. http://hdl.handle.net/10026.1/2625.
Abstract:
Annual losses of nitrogen from existing glasshouse crop production substrate systems could be as high as 600 kg ha 1, using an average of 30% drainwater containing a nitrate-nitrogen concentration of 200 mg 1". The use of nutrient recirculation systems such as nutrient film technique (NFT) helped to reduce nutrient losses to the environment but the commercial area of NFT has decreasedd ue to high initial capital costs, concernso ver diseaset ransmissionw ithin the system and an absence of recent research and development. Most substrate systems rely on the provision of liquid nutrient feeds at every watering. This study examines clinoptilolite which is able to selectively store, supply and exchange cations with plant roots. The use of the naturally-occurring volcanic aluminosilicates pumice and clinoptilolite zeolite in the intensive production of edible and ornamental protected crops, tomatoes, sweet peppers and standard carnations was studied. Pumice from Sicily, Italy and clinoptilolite (84-87%) from Beli Plast, Bulgaria were used in the experiments. The management of the pumice and unloaded clinoptilolite systems involved provision of all the plant growth nutrients via a drip irrigation system. In comparison, the nutrient-loaded clinoptilolites were examined using only water in the irrigation cycles which allowed relatively unimpeded cation exchange to take place between the clinoptilolite and the surrounding solution, thus providing nutrients for plant roots. The total cation exchange capacity of clinoptilolite was measured as 132.0-158.3 meq 100g'', compared with 1.8 meq 100g-' for pumice. Unloaded clinoptilolite irrigated with nutrient-balanced liquid feeds gave yields and quality equivalent to those of tomatoes, peppers and standard carnations grown on rockwool, pumice and peat / peat alternatives. For the first nine months of an eighteen month experiment, the yield and quality of standard carnation flowers from high nutrient-loaded clinoptilolite matched those from pumice receiving liquid feeds at every watering. Thereafter, lower concentrations of available nitrogen and, to a lesser extent phosphorus, limited production by up to 25%. Drainwater nutrient concentrations were, however, extremely low and reduced the potential pollution risk to the surrounding environment. Drainwater nitrate-nitrogen concentrations of below 10 mg 1'' were measured, compared with 100-300 mg 1.1 for pumice. Drainwater potassium concentrations were also comparatively low at < 20 mg 1'' for clinoptilolite and 200 mg 1" for pumice. Phosphorus concentrationsi n the drainwater did not exceed1 2 mg 1.1c, omparedw ith a maximum of 70 mg 1'1 in drainwater from pumice. The inclusion of phosphate rock (apatite) in with the clinoptilolite provided a source of phosphorus available to plants and the dissolution of apatite was regulated by the rate of absorption of phosphorus and calcium by plants. In all the experiments, clinoptilolite adsorbed ammonium-nitrogen and potassium, releasing calcium and sodium. However, concentrations of sodium released into the root zone were not harmful to plant growth. The average nitrate-nitrogen concentration of new, fully-expanded carnation leaves was 51.7% lower than the target levels. The nutrient loading of nitrogen and phosphorus regulated the overall yield of the crops evaluated in the experiments. The use of nutrient-loaded clinoptilolite to produce commercial crops and reduce environmental pollution by regulating the concentration of nutrients in the drainwater over long periods of time is further explored in the study.
36
Ferreira, Raquel Sofia e. Vasconcelos. "Wildfire effects on soil nutrients stocks and exports by overland flow." Doctoral thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/16825.
Abstract:
Doutoramento em Ciências e Engenharia do AmbienteO objetivo deste trabalho foi realizar uma avaliação de perdas de nutrientes após incêndio por escorrência superficial, à escala de microparcela e à escala de encosta (embora de forma limitada) numa área recentemente queimada da região Mediterrânica, fornecendo estimativas das exportações de catiões, azoto e fósforo, num enquadramento paisagístico como este propenso ao fogo. Representa um importante complemento para o até agora modesto número de estudos sobre as perdas de nutrientes pós-fogo por escorrência superficial, realizado na região Mediterrânica, para antecipar os impactos dos incêndios recorrentes na produtividade do solo. Este trabalho é parte do projeto FIRECNUTS (PTDC/AGR-CFL/104559/2008) - efeitos de um incêndio nas reservas de nutrientes, dinâmica e exportações – e lida com estas lacunas de pesquisa, estudando a exportação de nutrientes selecionados (catiões, azoto e fósforo) numa área florestal recentemente queimada, no centro-norte de Portugal (Sever do Vouga). Os objetivos específicos foram comparar as exportações de catiões, assim como de azoto e fósforo nas formas totais e solúveis, principalmente à escala de micro-parcela: (i) para duas das espécies de árvores mais propensas ao fogo, i.e. eucalipto e pinheiro; (ii) para duas das geologias mais comuns na área, i.e. granito e xisto; (iii) para diferentes orientações do declive, i.e. face a norte e face a sul; (iv) com tempo-desde-incêndio durante os meses iniciais após incêndio e durante um período de monitorização mais extenso. As exportações de nutrientes foram particularmente acentuadas nos três meses após o fogo. No entanto, após este período inicial, foram observados também picos nas concentrações de nutrientes, em associação a eventos de precipitação intensa, com diferenças na variação de cada nutriente, e com o declínio das exportações de fósforo a seguir um padrão mais linear com o tempo desde o incêndio. Os resultados deste estudo enfatizaram a importância de uma camada protetora do solo (ou seja, com as agulhas das árvores queimadas de pinheiro) para minimizar a exportação de nutrientes pósfogo. A geologia também foi identificada como uma variável importante na avaliação de riscos de erosão pós-incêndio e na definição de medidas de conservação do solo. A orientação do declive não foi uma variável decisiva neste estudo. Estes resultados mostram também que as escalas de tempo mais amplas são úteis para obter mais conhecimento sobre o ciclo hidrológico dos nutrientes e os complexos processos que ocorrem nas áreas de floresta queimada.
The aim of this work was to perform an evaluation of post-fire nutrient losses by overland flow at micro-plot scale, and at slope scale (although on a limited basis) in a recently burnt Mediterranean area, providing estimates of the range of base cations, nitrogen and phosphorus exports in a fire-prone landscape. It represents an important add-on to the up to now modest number of studies on post-fire nutrient losses by overland flow conducted in the Mediterranean region, for anticipating the impacts of recurrent fires on soil productivity. This work is part of the FIRECNUTS project (PTDC/AGR-CFL/104559/2008) - WildFIRE effects on topsoil Carbon and NUTrient Stocks, dynamics and exports – and addresses these research gaps by studying the export of selected nutrients (base cations, nitrogen and phosphorus) in a recently burnt forest area in northcentral Portugal (Sever do Vouga).The specific objectives were to compare base cations exports together with nitrogen and phosphorus exports in the total and soluble forms by overland flow mainly at the micro-plot scale: (i) for the two predominant and fire-prone forest types in north-central Portugal, i.e. eucalypt and pine plantations; (ii) for the two prevailing parent materials in the region, i.e. granite and schist; (iii) for two different slope aspects, i.e. a slope facing north and a slope facing south; (iv) with time-since-fire during the initial months of the window-ofdisturbance and for an extended monitoring period. In parallel, nitrogen and phosphorus stocks in the topsoil were also compared. Nutrient exports were particularly pronounced in the three months after fire. However, after this initial period, peaks in nutrients concentrations were also observed in association to intense rainfall events, with differences in the variation of each nutrient, with phosphorus exports decline following a more straightforward pattern with time since fire. The results of this study emphasized the importance of a protective soil layer (i.e. of scorched pine needle) for minimizing post-fire nutrient export. Parent material was also found to be an important variable when assessing post-fire erosion risks and defining soil conservation measures. Slope aspect was not a decisive variable in his study. These results also show that broader time scales are useful to gain insight into the hydrological and nutrient cycle complex processes in burnt forest areas.
37
Walker, Beau Jensen. "The Interaction of Aeolian and Fluvial Processes in Dry Washes on the Colorado Plateau, USA." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5597.
Abstract:
In the past decade there has been a call for integrated studies that examine the interaction of fluvial and aeolian processes (Belnap et al., 2011; Bullard and Livingstone, 2002). In this study, we examined the role of land-use, weather, and soil type on the flux of aeolian material into dry washes on the Colorado Plateau in central Utah, USA, and western Colorado, USA. Our goal was to quantify the impact of individual deposition and erosion events by correlating weather and land-use data with a combination of measurement methods including dust collection via dust traps, GPS surveying, and close-range photogrammetry. Our data suggest that there is an interaction between these processes and that seasonality and land-use play a large role in determining the strength of this interaction. Particularly, high land-use and dry, windy conditions were most conducive to the surface movement of sediment and subsequent removal of that sediment by fluvial processes.
38
Andrews, Aaron A. "Phosphorus loss with surface runoff as affected by bioenergy-based residue and nutrient management systems for an Iowa loam soil." [Ames, Iowa : Iowa State University], 2010. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1475914.
39
SLOAN, MELISSA ANN. "Designing and Pilot Testing a Database to Properly Track Nutrient Consumption in Overweight, Postpartum Women and Infants Enrolled in a Dietary Intervention Study." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1218512743.
40
Peccatiello, Kathy Louise. "The effect of a comprehensive weight reduction program on blood variables, body composition, and nutrient intake in obese black women." Thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/43889.
Abstract:
The effect of comprehensive weight reduction program on selected
blood parameters, body composition, and nutrient intake was investigated
in 56 obese black women, 22 to 51 years old. Subjects attended
nutrition and behavior modification classes once per week for 3 months.
Twenty subjects participated in a low impact aerobics programs 3 times
per week for 3 months. A 3.8 kg average weight loss was observed. A
2.6% significant reduction in body fat (BF) was observed in the exercise
group. Total cholesterol (TC) and low-density lipoprotein-cholesterol
(LDL-C) fell significantly from 198 to 175 mg/dL, and 130
to 109 mg/dL, respectively, in the exercise group. High density lipo-protein2-cholesterol (HDL2-C) was lowered significantly from 24 to
17 mg/dL in the non-exercise group. Triglycerides, HDL-C, TC/HDL-C
ration, glucose, thyroxin, and insulin values were not significantly altered. Significant reductions in protein, fat, and cholesterol intake were reported. A comprehensive weight loss treatment promoted gradual weight loss, changes in body composition and food intake patterns, and significantly altered some blood lipid levels in obese black females.Master of Science
41
Pellegrini, André. "Sistemas de cultivo da cultura do fumo com ênfase às práticas de manejo e conservação do solo." Universidade Federal de Santa Maria, 2006. http://repositorio.ufsm.br/handle/1/5513.
Abstract:
Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorSoil management systems with minimum tillage and mulch are predominant in agriculture of Southern of Brazil. No-tillage for tobacco crop is not common and restricted to isolated places and only for some farmers that, through empiric tests and adaptation of equipments, search for soil preservation and increased yield. The objective of this work was study the main soil management systems for tobacco crop and possibilities of changing the traditional system of tobacco cropping, with emphasis on practices of soil management and conservation to maintain the levels of yield and decrease the environmental impacts. Six treatments, in a completely randomized blocks design with three replicates, were installed: PC conventional till; CMP - minimum tillage rest; CMA - minimum tillage oat; PDcC no-tillage with camalhão; PDcCC no-tillage with consolidated camalhão; PDsC no-tillage without camalhão. The experiment was installed in a watershed, located in Agudo-RS city, in the agricultural year of 2004, in a Leptosol. The maim physical parameters were soil moisture, measured with a time domain reflectometer (TDR), in the depths of 0-0,06, 0,06-0,12 and 0,12-0,18 m, and soil temperature in the depth of 0,05 m, measured with datalogger and termopars, both during 87 days in the growth cycle; total porosity, macroporosity, microporosity, bulk density and soil water retention curve (CRA), determined in the depths of 0-0,06, 0,06-0,12, 0,12-0,18 and 0,18-0,24 m, 30 days after transplantion (DAT) and on 135 DAT, except for CRA, in the depths of 0-0,06 and 0,06-0,12 m; water and soil loss by runoff, determined for eight rain events, in two blocks, with on area of 1.2 m2 of collection; potassium and phosphorus, soluble and total were determined for seven rain events; the root system, the distribution in the cultural profile, nutrients availability in the exploration area, dry mass for soil volume and maximum depth of roots were determined; mechanical resistance of soil was determined with a manual penetrometer to verify the depth of the root impediment; measures of the plants included the leaf area, determination of plant height, number of leaves and yield for hectare. The conservation managements reduced soil and water losses, providing smaller amplitude in the daily temperature variation, larges soil moisture, but the yield was smaller than PDsC. This result for the PDsC was directly influenced by the shallower roots depth, which was a consequence of several factors, such as: presence of impediment layer; absence of ridge; nutrients in the surface and favorable initial conditions of soil temperature and moisture. However, there was great interaction among factors, turning complex the explanation of the results obtained; therefore, factors such as nutrients in the surface favored the losses of P and K soluble, decreasing their availability to plants; the impediment layer reduced the volume of soil explored by the roots and the ability for water storage, whereas the management systems PDcCC and PDsC were outside the upper or lower limit of water availability, in the layer of 0 to 0,06 m, for about 15 days.
Sistemas de manejos do solo com o mínimo de revolvimento e com palha em superfície predominam na maioria dos cultivos agrícolas, no Sul do Brasil. A utilização do plantio direto na cultura do fumo está sendo iniciada, mas restrita a locais isolados e a alguns agricultores, que, via testes empíricos e adaptação de equipamentos, buscam preservar o solo e aumentar a produtividade. O objetivo deste trabalho foi estudar os principais sistemas de manejo do solo para a cultura do fumo e as possibilidades de mudança no sistema tradicional de cultivo de fumo, com ênfase às práticas de manejo e conservação do solo, mantendo os níveis de produtividade e diminuindo os impactos ambientais. O delineamento experimental foi blocos ao acaso com três repetições e seis tratamentos, sendo eles: PC - preparo convencional; CMP - cultivo mínimo pousio; CMA - cultivo mínimo aveia; PDcC - plantio direto com camalhão; PDcCC - plantio direto com camalhão consolidado; PDsC - plantio direto sem camalhão. O experimento foi implantado em uma microbacia hidrográfica, localizada no município de Agudo-RS, no ano agrícola de 2004, sobre em um Neossolo litólico eutrófico típico. Os principais avaliadores físicos foram umidade volumétrica do solo, medida com reflectômetro de domínio de tempo (TDR), nas profundidades de 0-0,06, 0,06-0,12 e 0,12-0,18 m, e temperatura do solo na profundidade de 0,05 m medida com datalogger e termopares, ambas durante 87 dias no período de crescimento; porosidade total, macroporosidade, microporosidade, densidade do solo e curva de retenção de água (CRA), realizadas nas profundidades de 0-0,06, 0,06-0,12, 0,12-0,18 e 0,18-0,24 m aos 30 dias após transplante (DAT) e aos 135 DAT, exceto CRA, nas profundidades de 0-0,06 e 0,06-0,12 m; perda de água e solo pelo escoamento superficial, determinados em oito chuvas, em dois blocos, com uma área de coleta de 1,2 m2; fósforo e potássio solúvel e total, em sete chuvas; no sistema radicular foram determinados a distribuição no perfil cultural, disponibilidade de nutrientes na região de exploração, massa seca por volume de solo e profundidade máxima das raízes; a resistência mecânica do solo determinada com um penetrômetro manual para diagnosticar a profundidade de impedimento radicular; medidas avaliadoras das plantas foram área foliar, comprimento de caule, número de folhas e produtividade por hectare. Os preparos conservacionistas reduziram as perdas de solo e água e proporcionaram uma menor amplitude na temperatura diária, maior umidade do solo, mas a produtividade no PDsC ficou aquém dos preparos convencionais. Esse resultado no PDsC foi diretamente influenciado pelo menor aprofundamento das raízes, sendo esse conseqüência de vários fatores como presença de camada de impedimento, não possuir camalhão, posicionamento mais superficial da adubação de base e condições iniciais favoráveis de temperatura e umidade do solo. Contudo, houve grande interação de fatores, tornando complexa a explicação do resultado obtido, pois fatores como a adubação superficial favoreceu as perdas de P e K solúvel, diminuindo a disponibilidade; a camada de impedimento diminuiu o volume de solo explorado pelas raízes e a capacidade de armazenamento de água, sendo que os manejos PDcCC e PDsC ficaram em torno de 15 dias fora da faixa de disponibilidade de água, na camada de 0 a 0,06 m.
42
Ferris, Conrad Peter Wesley. "Studies on the effects of ensiling grass with absorbent materials on nutrient loss during ensilage and on feed utilisation by dairy cows." Thesis, Queen's University Belfast, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334527.
43
Pugliesi, Adriane Cristine Vasconcelos. "Valoração economica pelo metodo custo de reposição do efeito da erosão em sistemas de produção agricola." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257010.
Abstract:
Orientador: Mara de Andrade Marinho WeillDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola
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Resumo: A erosão acelerada do solo constitui um processo importante de degradação da qualidade das terras agrícolas e do ambiente circundante. A avaliação dos efeitos da erosão em sistemas de produção agrícola, com ênfase nos aspectos econômicos da produção, representa uma valiosa ferramenta de análise para obtenção de subsídios ao planejamento do uso agrícola em bases sustentáveis. Este trabalho teve por objetivo valorar do ponto de vista econômico a erosão do solo agrícola a partir de diferentes sistemas de cultivo de milho em parcelas experimentais. A pesquisa foi desenvolvida no Campo Experimental da Faculdade de Engenharia Agrícola da UNICAMP (SP), na área correspondente às parcelas experimentais, conduzidas com diferentes sistemas de manejo em duas fases designadas por Ensaio Anterior (1990 a 1996) e Ensaio Atual (2003 a 2005). Foram avaliados dados de produtividade das culturas, de perdas de terra e de nutrientes por erosão e calculados os custos de reposição dos nutrientes. Para o Ensaio Anterior, os resultados em termos de produtividade de milho pipoca, indicam o melhor tratamento como tendo sido T1¿ Grade Aradora e o pior T8¿ Enxada Rotativa, sendo o rendimento do primeiro 54% superior em relação ao segundo. Para perda de terra, os resultados revelam que houve significância estatística entre tratamentos sendo que as perdas médias foram menores para os tratamentos conservacionistas, com destaque para o tratamento T4- Plantio Direto. As perdas de nutrientes também diferiram significativamente entre tratamentos, qualificando-as como um importante parâmetro na avaliação econômica do efeito da erosão sobre a qualidade do solo. Com relação ao custo reposição dos nutrientes, as parcelas sob tratamento convencional apresentaram, como esperado, os maiores custos em função das maiores perdas. Para o Ensaio Atual, na safra 2003/04, a produtividade média de grãos das parcelas manejadas sob sistema plantio direto foi de 9.053,33 kg ha-1, contra 8.062,03 kg ha-1 das parcelas sob sistema convencional e na safra 2004/05, os valores foram respectivamente de 8.440,00 kg ha-1 e 7.346,25 kg ha-1. Embora, não tenha sido caracterizada significância estatística entre tratamentos, produtividades superiores em 12% e em 15%, obtidas nas parcelas manejadas sob sistema plantio direto nas duas safras, representam um ganho significativo de receita para o produtor. Em termos absolutos, as perdas de terra por erosão e as perdas de nutrientes foram maiores para o plantio convencional (PC) em relação ao sistema plantio direto (SPD), mas não foi caracterizada significância estatística em função dos elevados coeficientes de variação. Em termos médios, os resultados do custo reposição indicam valores mais baixos nas duas safras para as parcelas sob SPD. A valoração econômica da degradação do solo pela erosão acelerada, utilizando o método de custo reposição dos nutrientes perdidos devido aos processos erosivos, demonstrou ser uma alternativa promissora para avaliação da sustentabilidade de sistemas agrícolas. Embora no presente trabalho apenas parte do custo de degradação por erosão tenha sido valorada, pôde-se observar uma tendência de superioridade em termos dos sistemas agrícolas mais conservacionistas em relação aos sistemas convencionais, no que refere ao controle da erosão e, por conseguinte, à diminuição dos custos de reposição de nutrientes. No presente trabalho, não foi possível comprovar a ocorrência de degradação temporal do solo por erosão, que poderia ser medida pela variação da produtividade da terra, tendo em vista se tratar de um solo resiliente, de baixa erodibilidade, cujo manejo com nutrientes por meio de adubação compensa os efeitos da erosão, mantendo a produtividade do sistema no período analisado
Abstract: Soil erosion is an important process of land and environment degradation. The evaluation of the erosion effects on agricultural production systems, with emphasis in economical aspects of production process, constitutes a valuable tool to acquire useful subsidies to the agricultural use planning in a sustainable basis. The main objective of this work was to apply an economic valuation method, as a manner of including part of the costs due to erosion in the agricultural production process. The study was conducted in the Experimental Area of the Agricultural Engineering College of UNICAMP (SP), in plots used with different management systems. The work was performed in two stages, referred by Previous Essay (1990 to 1996) and Present Essay (2003 to 2005). They were analyzed data of corn yield, soil and nutrients losses. In economic evaluation, the replacement cost approach was used. For Previous Essay (1990 to 1996), the obtained results showed that the biggest value of corn productivity occurred in T1- Heavy harrow treatment and the minor value in T8- Rotary tiller treatment. The yield of the first treatment was 54% larger than that of the second. In relation to soil losses, the differences between treatments were significant. The soil losses were smaller in conservationist treatments, especially in the T4- Direct drilling treatment. Soil nutrient losses were also significantly different between treatments, qualifying them as an important parameter for economic evaluation of the erosion effect on soil quality. The plots under conventional treatments presented the biggest nutrients replacement costs, probably due the major soil losses occurred in these plots. For Present Essay, in the first year (2003/04), the corn average yield from plots under Direct-drilling system was 9,053.33 kg ha-1, against 8,062.03 kg ha-1 obtained from plots under Heavy harrow system. In the second year (2004/05), the values were respectively of 8,440.00 kg ha-1 and 7,346.25 kg ha-1. Although significant differences between treatments were not characterized, gains of 12% and 15% on corn yields from plots under Direct-drilling system represent important increases of income to the producer. The soil and nutrients losses were larger in plots managed under conventional system (heavy harrow); however, significant differences were not characterized in this case, probably due to the high coefficients of variation. The nutrients replacement costs were smaller for the plots under Direct-drilling system. The valuation of soil degradation by erosion using the replacement cost approach is a promising alternative to the economic sustainability evaluation of agricultural systems. Even though in present work only part of the cost of soil degradation due to erosion had been studied, a tendency of advantage of the conservationist systems comparing with the conventional systems could be observed in relation to erosion control and, consequently, to diminishing of nutrients replacement costs. It was not possible to prove the occurrence of temporal soil degradation by erosion, once the soil of experimental plots is productive and has a low erodibility. In this case, the nutrient management with fertilizers is able to mask the erosion effects, maintaining crop productivity
Mestrado
Agua e Solo
Mestre em Engenharia Agrícola
44
Wasowska, Zuzanna. "The Fate of Nitrogen and Phosphorus from a SImulated Highway Cross-Section." Master's thesis, University of Central Florida, 2014. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/6380.
Abstract:
Nutrient pollution as a result of excessive fertilizer application is of major concern for Florida's water resources. Excess fertilizer can be lost either via surface runoff or by leaching through the soil mass eventually reaching water bodies and leading to eutrophication. The focus of this study is to analyze the effect of low rainfall intensities and overland flow from an adjacent roadway surface on the loss of nutrients from two different fertilizers. This study focuses on the fate of the nitrogen and phosphorus present in fertilizers utilized by the Florida Department of Transportation for the stabilization of highway embankments. This research was performed on a field-scale test bed and rainfall simulator located at the Stormwater Management Academy at the University of Central Florida.
The loss of nutrients was measured from two soil and sod combinations typically found in Florida and used for highway stabilization –Pensacola Bahia on AASHTO A-2-4 soil and Argentine Bahia on AASHTO A-3 soil. Two different fertilizers were analyzed, an all-purpose, quick-release 10-10-10 (N-P-K) fertilizer previously used by FDOT, and the new slow-release 16-0-8 (N-P-K) fertilizer, both applied at a rate of 0.5 lb/1000 ft2 consistent with FDOT's practice. Each combination was analyzed under two rainfall intensities: 0.1 in/hr and 0.25 in/hr at a slope consistent with typical highway cross-sections found in Florida. Nutrient losses were measured by collection of runoff and/or baseflow that escaped the test bed. Additionally, from the soil samples collected throughout the testing period, the mass of the nutrients was compared to the mass balances values based on literature from a previous study on fertilizers performed at the Stormwater Management Academy.
The experimental findings of this study showed that there was a reduction in total nitrogen and total phosphorus on both A-2-4 soil and A-3 soil at the 0.25 in/hr intensity as a result of switching to the slow-release 16-0-8 (N-P-K) fertilizer. Results from the 0.1 in/hr rainfall intensity, which were available only for the A-2-4 soil, showed that at this intensity there was no apparent benefit to the switch in fertilizers. Furthermore, it was found that less total nitrogen and total phosphorus was lost from A-3 soil than A-2-4 soil at 0.25 in/hr when using 10-10-10 (N-P-K). At 0.1 in/hr, there was no apparent difference in total nitrogen lost. However, less total phosphorus was lost at this intensity.
The results of this study showed that there is an environmental benefit to applying slow-release fertilizers. This was more significant for the 0.25 in/hr intensity than the 0.1 in/hr intensity at which no apparent benefit was found. In addition, it was found that runoff was a greater source of nutrient loss than baseflow, although baseflow losses were substantial. Furthermore, it was found that total nitrogen tends to be lost via both pathways of runoff and baseflow while phosphorus has a lower tendency to leach through the soil but readily runs off the soil surface. It was also observed that because fresh sod tends to be heavily fertilized, applications of fertilizer could be reduced or avoided entirely after sod placement and applied as needed.M.S.Env.E.
Masters
Civil, Environmental and Construction Engineering
Engineering and Computer Science
Environmental Engineering
45
Sun, Huawei. "Theoretical and experimental study of a high rise hog building for improved utilization and environmental quality protection." Columbus, Ohio : Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1079066940.
Abstract:
Thesis (Ph. D.)--Ohio State University, 2004.Title from first page of PDF file. Document formatted into pages; contains xii, 200 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: Frederick C. Michel, Jr., Dept. of Food, Agricultural, and Biological Engineering. Includes bibliographical references (p. 173-181).
46
Delgado, Cristina. "Claims of Mistaken Identity: An Examination of U.S. Television Food Commercials and the Adult Obesity Issue." Master's thesis, University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2700.
Abstract:
Obesity is one of the major public health issues in the United States, often regarded as part of a global crisis. Companies invest billions of dollars each year towards television advertising campaigns aimed at convincing audiences how their ground-breaking discovery 'battles the bulge' or somehow offers an increased health benefit. This study examined how advertisers presented health-related claims, including health and nutrient-content claims, in U.S. adult-targeted television food commercials. The claims were compared to FTC, FDA, and USDA laws, regulations, and recommendations. A content analysis of food advertising was conducted of commercials from major and cable network programs broadcast during prime-time in the first quarter of 2009. The majority of claims match current regulations when compared to Federal references. The results show that Nutrient and Wellness claims were the most frequently cited. The type of benefit, Healthy Eating, emerged almost 3 times more than any other benefit type. This is also similar to those results which suggest advertisers' intentions were to promote overall wellness in their content delivery. As such, the Wellness Approach was identified and conceptualized, leading towards full development of a Wellness Effect theory. Implications and future research opportunities are discussed on both a theoretical and practical level.M.A.
Nicholson School of Communication
Sciences
Communication MA
47
Verbree, David Adrian Duiker Sjoerd W. "Sediment and nutrient losses in reduced tillage systems on dairy farms." 2008. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-3360/index.html.
48
Chen, Liang-Guu, and 陳亮谷. "Study of Fertilization on Nutrient Losses in Alpine Soils from Central Taiwan." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/33602158259609191754.
Abstract:
碩士國立中興大學
土壤學系
84
Abstract Fruits and vegetables were planted years at the area of Li-shang and Wu-ling in central Taiwan. The hidden danger of soil loss, fertilizer loss, water pollution and the connection of fertilizer loss and water pollution with soil fertilizer potential of nutrient retained became critical after great amounts of fertilizers were applied. The first objective of this study is to investigate the soil fertilizer potential index of nutrient retained of the soils from vegetable field in mountain and orchard in slopeland. Second, this study provide strategies for amelioration by assessing the potential of nutrient retained of soils applied with fertilizers. The potential index of available nutrient of four chosen soils - vegetable field soil in mountain (Wu-ling farm), orchard field soil in slopeland (Li-shang), vegetable field soil in lowland (Erh-ling series, Chang-hua Shi-hu) and forest soil (Li- shang) are 271, 45, 87 and 30%. In the first experiment, the soils mentioned above ( including gravel) were soaked in the distilled water added with 176 mg N L-1 of urea or 120 mg N L-1 of NH4NO3 by the ratio of 1:1 for 12 hr then leached out as the initiative leaching. Same steps were held in the 3rd, 10th, 24th, 45th and 73rd day as the 2nd, 3rd, 4th, 5th and 6th leaching. The results showed that vegetable field soil in mountain contained great amount of soluble N. The retained N and extracted N of cultivated soil reached to an equilibrium after four or five times of leaching within the application range of 600~700 mg N L-1 and the retained N in soil of forest is higher than that of vegetable field in mountain at the early applicationas well as extracted N from forest soil exceeded that from vegetable field soil in mountain after excess applications. The experiment was also treated under 3 different levels of temperature. The result showed that the percentage of nutrient loss decreased as the temperatures dropped. In the 3rd experiment, the 2 mm sieved soil from vegetable field in mountain was ready for the column leaching. Soils added with different fertilizers - urea (24 mg N L-1), peat, Bagasse manure and poultry manure were soaked in distilled water by water: soil = 2:1 for 12 hr﹐then leached out as the initiative leaching. Same steps were held in the 7th, 21st, 42nd, 70th and 105th day as the 2nd, 3rd, 4th, 5th and 6th leaching. Although urea mobilizes quickly yet no change of microorganism population was found during six times of incubation in 105 days. Though peat contains very low soluble salts, stable decomposing rate and the ability to absorb NO3- made it a better fertilizer even when it was leached. Besides, the populations of bacteria and actinomycetes was significant different after leaching and incubation. Soluble N, K, Ca, Mg and S in Bagasse manure were high. Much amount of nutrient was left because high levels of nutrient were contained in poultry manure including Cu and Zn. After times of application would lead to the accumulation of Cu and Zn. The results of these experiments came to the conclusion that vegetable field soil in mountain exhibited a high potential index of nutrient and a great amount of soluble N. But weak fertilizer holding capacity. Fertilizer loss and water pollution will be induced easily when if precipitate or irrigate. Applying materials of organic substances, such as peat, would create several advantaged , like decrease the amount of application of soluble N, minimize the cost, decrease the loss of N , enrich the fertility of soil and most important of all it will, keep the agriculture development sustainable.
49
Göbel, Leonie. "Nutrient Response Efficiencies, Leaching Losses and Soil-N Cycling in Temperate Grassland Agroforestry and Open Grassland Management Systems." Doctoral thesis, 2020. http://hdl.handle.net/21.11130/00-1735-0000-0005-13F5-1.
50
Formaglio, Greta. "The effect of reduced management intensity on soil nutrient dynamics in a large-scale oil palm plantation: soil nitrogen cycle, asymbiotic nitrogen fixation and nutrient leaching losses." Doctoral thesis, 2020. http://hdl.handle.net/21.11130/00-1735-0000-0005-1447-5.