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Solar power water pump studies for small-scale irrigationWilliamson, Erin. January 2006 (has links)
No description available.
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Estimated plant water use and crop coefficients for drip-irrigated hybrid polarsGochis, David J. 23 January 1998 (has links)
Estimations of plant water use can provide great assistance to growers, irrigators,
engineers and water resource planners. This is especially true concerning the introduction
of a new crop into irrigated agriculture. Growing hybrid poplar trees for wood chip stock
and veneer production under agronomic practices is currently being explored as an
alternative to traditional forestry practices. To this author's knowledge, no water use
estimates or crop coefficients, the ratio of a specified crop evapotranspiration to a
reference crop evapotranspiration, have been verified for hybrid poplars grown under drip
irrigation.
Four years of weekly, neutron probe measured, soil water data were analyzed to
determine averaged daily, monthly and seasonal plant water use, or crop
evapotranspiration. The plantation studied was located near Boardman, Oregon on the
arid Columbia River Plateau of North-Central Oregon. Water was applied by periodic
applications via drip irrigation. Irrigation application data, weekly recorded rainfall and
changes in soil water content permitted the construction of a soil water balance model to
calculate weekly hybrid poplar water use. Drainage was estimated by calculating a
potential soil water flux from the lower soil profile. Sites with significant estimated
potential drainage were removed from the analysis so that all sites used in the development
coefficients were calculated using reference evapotranspiration estimates obtained from a
nearby AGRIMET weather station. Mean crop coefficients were estimated using a 2nd
order polynomial with 95% confidence intervals. Plant water use estimates and crop
curves are presented for one, two and three year old hybrid poplars.
Numerical simulation of irrigation practices was attempted using weekly soil water content and soil physical characterization data. Parameter optimization and numerical simulations were attempted using the HYDRUS-2D Soil Water and Solute Transport model. Parameter optimization and numerical simulations were largely unsuccessful due to lack of adequate soil physical and root zone system representation and dimensional differences between drip irrigation processes and the model design used in this study. / Graduation date: 1998
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Solar power water pump studies for small-scale irrigationWilliamson, Erin. January 2006 (has links)
Irrigation is a well established procedure on many farms in western Canada and is practiced on various levels around the world. It allows diversification of crops, while increasing crop yields. However, typical irrigation systems consume a great amount of conventional energy through the use of electric motors and generators powered by fuel. / The overall objective of this research was to determine the feasibility of using photovoltaic (PV) modules to power a water pump for a small-scale drip irrigation system in Montreal (Quebec, Canada). The study involved field observations, as well as computer simulations of global solar radiation and PV electrical output. / Field observations involved a summer and winter installation of two amorphous silicon 42 W PV modules, directly connected to a 12 V surface water pump. The parameters monitored were voltage, current, back-of-panel temperature, pressure, and flow. These observed parameters were used to determine PV electrical output and volume of water pumped. Site latitude, elevation, and panel tilt were applied to the solar radiation and PV electrical output models, along with the following meteorological data: daily average, maximum, and minimum temperatures, and global solar radiation. / Daily solar radiation prediction showed a linear correlation of 0.69 with the observed daily values, over the years 2000 to 2005. The correlation coefficient was improved to 0.91, when 7 day moving averages of both the observed and predicted solar radiation data were used. PV electrical output and volume of water pumped were monitored between August 2005 and May 2006. Both the power and water output observations were less than expected. However, the predicted daily PV electrical output ranged from 1.0 MJ d-1 in the summer to approximately 0.6 MJ d-1 in the winter. As expected, an increase in power caused an increase in the volume of water pumped.
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Drip fertigation : effects on water movement, soil characteristics and root distributionPijl, Isabelle 12 1900 (has links)
Thesis (MScAgric)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: The application of water and nutrients via a drip irrigation system influences the water
distribution in the soil, soil characteristics and root distribution beneath the dripper. To
determine the water distribution pattern beneath a dripper in sandy soil, EnviroSCAN
(Sentek) capacitance probes were installed directly below the dripper and at distances of
20, 40 and 60 cm from the dripper. The continuous monitoring of the soil water content
(SWC) beneath the dripper provided a good indication of how the water applied through
the dripper is distributed in the soil. In this study a semi-impermeable layer in the soil
was detected through observing water accumulation patterns in the SWC. Water
accumulated above the layer and SWC values increased to far above the upper level of
easily available soil water (EAWupper),while the lower soil layers remained drier. The
measurements also show that the horizontal water movement is restricted to 20 cm from
the dripper. Specific parameters, such as the lower level of easily available soil water
(EAWlower),can be used to determine optimal irrigation management. Together with the
water distribution study, the root distribution beneath a dripper was also investigated. A
high concentration of roots in the area beneath the dripper was found, which
corresponds with the area wetted by irrigation.
In another study, three irrigationlfertigation methods where investigated to ascertain the
influence on soil characteristics and root distribution. These were: micro irrigation (MI)
(micro-spinner irrigation with broadcast granular fertilization), conventional drip
fertigation (CDF) (daily drip irrigation with daily or weekly fertigation with a
unbalanced nutrient solution, containing macronutrients only) and daily drip fertigation (DDF) (daily fertigation of a balanced nutrient solution, containing macro- and
micronutrients). The study was conducted in two locations, viz. in the Western Cape
Province, on sandy soil, and in the Eastern Cape Province, on silt loam soil.
Micro Irrigation: A wide and even root distribution in the entire wetted volume was
found on the sandy and silt loam soil. On the sandy soil, the soil pH(KC1)directly
beneath the spinner was significantly lower than the pH(KC1)at positions further away
from the spinner.
Conventional Drip Fertigation: Root studies on sandy soil indicate a poor root
development beneath the dripper, with a high concentration of roots in the area between
the drippers. The poor root development directly beneath the dipper may be due to
oxygen deficiency and/or acidification beneath the dripper. The soil pH(KC1)values
show a significant lower pH(KC1)value directly beneath the dripper than further away. In
comparison to the sandy soil, the roots developed well beneath a dripper in a silt loam
soil. It appears as if soil acidity and/or oxygen deficiency was not a problem on this soil
type. The rest of the root system was also well developed. This may be due to this
soil's higher water holding capacity which creates a bigger wetted zone.
Daily Drip Fertigation: In the sandy soil it seems that the roots developed in a
continuous column beneath the dripper line, with little root development further than
20 cm from the dripper line. Where over-irrigation occurred, it caused a poor root
development directly beneath the dripper. The root density in this treatment was much
higher than in the other two treatments. The use of a balanced nutrient solution and
pulse irrigation may be reasons for the better root development. In a silt loam soil a very high concentration of roots was found beneath the dripper and the rest of the root
system was also well developed. As with the CDF treatment, it appears as if oxygen
deficiency was not a problem on this soil type. / AFRIKAANSE OPSOMMING: Die toediening van water en voedingstowwe deur 'n drip-besproeiings stelsel beïnvloed
die waterverspreiding in die grond sowel as die grondeienskappe en wortelverspreiding
onder die dripper. Die waterverspreiding onder 'n dripper in 'n sandgrond is bepaal
deur EnviroSCAN kapasitansie meetpenne direk onder die dripper en 20, 40 en 60 cm
van 'n dripper af te installeer. Die aaneenlopende monitering van die grondwaterinhoud
het 'n goeie indikasie van waterverspreiding in die grond gegee. Die horisontale
waterbeweging is grootliks beperk tot 'n 20 cm radius vanaf die dripper en die
waterbeweging was hoofsaaklik in 'n vertikale rigting. Die teenwoordigheid van 'n
semi-deurlaatbare grondlaag in die grondprofiel is opgemerk deur water-akkumulasie in
die profiel waar te neem. Wortelverspreiding onder die dripper is ook ondersoek en 'n
hoë konsentrasie wortels is in die benatte sone gevind.
In 'n verdere studie is drie besproeiings/sproeibemestings behandelings gebruik om die
invloed van besproeiing/sproeibemesting op grondeienskappe en wortelverspreiding te
ondersoek. Die drie behandelings was: mikro-besproeiing (mikro-besproeiing met
korrelbemesting), konvensionele-drip-sproeibemesting (daaglikse drip-besproeiing met
daaglikse of weeklikse sproeibemesting van 'n ongebalanseerde, voedingsoplossing wat
alleenlik uit makro-elemente bestaan) en daaglikse-drip-sproeibemesting (daaglikse
drip-besproeiing met daaglikse sproeibemesting van 'n gebalanseerde
voedingsoplossing wat mikro- en makro-elemente bevat). Die studie is in twee areas
gedoen, een in die Wes-Kaap, op 'n sandgrond, en die ander in die Oos-Kaap, op 'n
slik-leemgrond. Mikro-besproeiing: Die wortelverspreidings studies op die sand- en slik-leemgrond wys
op 'n wye en eweredige wortelontwikkeling in die totale benatte volume. Op die sand
grond is gevind dat die grond pR(KCl)direk onder die sproeiertjie betekenisvol laer was
as die pR(KCl)waardes verder weg van die sproeiertjie.
Konvensionele-drip-sproeibemesting: Die wortelverspreiding in die sandgrond wys op
geringe wortelontwikkeling direk onder die dripper met die hoogste konsentrasie
wortels tussen die drippers. Grondversuring en/of suurstoftekorte onder die dripper kan
die oorsaak wees van die swak wortelontwikkeling direk onder die dripper. Die grond
pR(KCl)direk onder die dripper was betekenisvol laer as die pR(KCl)verder weg van die
dripper. In vergelyking met die sandgrond, het die wortels in die slik-leemgrond goed
ontwikkelonder die dripper. Dit wil voorkom of versuring en suurstoftekorte onder die
dripper nie 'n probleem was in die slik-leemgrond nie. Die res van die wortelstelsel
was ook goed ontwikkel. Dit mag wees weens die grond se hoë waterhoudingsvermoë
wat 'n groot benatte area tot gevolg het.
Daaglikse-drip-sproeibemesting: In die sand grond wil dit voorkom asof die wortels in
'n aaneenlopende kolom onder die dripperlyn ontwikkel met weinig wortelontwikkeling
verder as 20 cm van die dripperlyn. Waar oorbesproeiing 'n probleem was, was daar
weinig wortelontwikkeling in 'n klein area direk onder die dripper. Die wortel-digtheid
in die behandeling was baie hoër as in die ander behandelings. Die gebruik van 'n
gebalanseerde voedingsoplossing en puls-besproeiing mag dalk redes wees vir die beter
wortelontwikkeling. In die slik-leemgrond is 'n hoë konsentrasie wortels onder die
dripper gevind en die res van die wortelstelsel was ook goed ontwikkel. Soos in die konvensionele-drip-sproeibemesting behandeling wil dit voorkom of suurstoftekort en
versuring onder die dripper nie 'n probleem was in die grond nie.
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Distribuição de água e fertilizante no solo em coqueiral microirrigado / Water distribution and fertilizer in microirrigatiom coconut tree landCamboim Neto, Luís de França January 1995 (has links)
CAMBOIM NETO, Luís de França. Distribuição de água e fertilizante no solo em coqueiral microirrigado. 1995. 80 f. Dissertação (Mestrado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 1995. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-24T18:24:30Z
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Previous issue date: 1995 / A field study was conducted at the seacoast of Itarema, Ceará, Brazil, to evaluate water and fertilizer distribution in the soil of a coconut plantation. The potassium ion was used as a tracer to determine uniformity of distribution of water and fertilizer by the irrigation system and predict water and fertilizer distribution within the soil profile. Analysis of the efectiveness of the system in satisfying the water and fertilizer needs of the crop was also done. Samples of the solution water plus fertilizer were collected at the exit of the fertilizer tank and at 64 different places (emitters) on the lateral lines, representing the most and the least favorable hydraulic conditions within the system. Soil samples, to trace the limits of the wet bulbs, were collected at points covering a section of the wet volume, one meter on both sides and 1.40 m of depth from the surface of the soil, at 0.20 m increments. In conclusion, it was found that there were misconceptions in the original project concerning discharge, time of application and positioning of the emitters in relation to each coconut plant. The management of the system was also found to be inadequate, with a great number of emitters displaced from the ideal location and in lack of use of the fertilizer injection equipment. Although good water distribution indexes were found (above 85% for CUC and PE) for the system, the water distribution in the soil was found to be poor, as indicated by the wet bulb graphs. As the fertilizer distribution follows, approximately, the same patterns for the water distribution, it is valid to predict that fertilizer distribution within the soil of the area would have also been poor, if the fertilizer injection device had been used. A relatively high average annual rainfall on the area tends to reduce the adverse effects of the misconceptions and bad management of the irrigation system, although the actual productivity of the plantation is far from predicted. / Estudos de campo foram realizados na região costeira do Estado do Ceará (Itarema) objetivando avaliar a distribuição de água e fertilizante no solo, aplicados por fertirrigação em microirrigação. Utilizou-se o íon potássio, como traçador, para se determinar a uniformidade de distribuição da água e fertilizante na rede de irrigação e no solo (formação do bulbo úmido) e a conseqüente capacidade do equipamento em satisfazer às necessidades hídricas e nutricionais da cultura de coqueiro explorada na área. As amostras da solução foram coletadas na saída do tanque de fertilizante e em 64 pontos das linhas laterais com ramificações, nas duas unidades operacionais selecionadas. A unidade operacional I situava-se próxima ao cabeçal de controle (condição hidráulica mais favorável) enquanto a unidade operacional II ficava na posição mais distante da área (condição hidráulica menos favorável). As amostras de solo para determinação do bulbo úmido foram coletadas até a distância de 1,0 m para ambos os lados do emissor e até 1,40 m de profundidade, com incrementos de 20 cm, tanto no sentido vertical como horizontal. O projeto de irrigação original apresenta falhas de concepção (como vazão, tempo de aplicação e posicionamento inadequado dos emissores), com reflexos negativos na distribuição da água no solo e no desempenho da cultura. O manejo do sistema também não tem sido efetuado de maneira adequada (com emissores deslocados de posição e não uso do equipamento injetor do fertilizantes), agravando ainda mais as falhas iniciais do projeto e prejudicando a cultura. Os bons índices de distribuição da água obtidos para o sistema (Coeficiente de Uniformidade de Christiansen – CUC médio de 94,07% na unidade I e 92,74% na unidade II e Pattern Efficience - P.E médio de 89,81% na unidade I e 88,62% na unidade II) não refletem, necessariamente, boa distribuição de água no solo da área como ficou patente no caso em estudo. A distribuição de fertilizante no sistema e no solo,acompanha, aproximadamente, a distribuição de água, sendo, portanto, válido afirmar que a má distribuição da água no solo seria também acompanhada por uma má distribuição de fertilizantes, se o sistema estivesse sendo rotineiramente usado para fertirrigação. A pluviosidade relativamente elevada (1.107,88 mm/ ano) na área em que foi realizado o trabalho tende a amenizar os efeitos negativos mencionados nos itens anteriores.
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Caracterização hidráulica do microaspersor Eden Twister em posição normal e invertidaSoares, Cristiana Araujo [UNESP] 29 July 2013 (has links) (PDF)
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000725700.pdf: 1375913 bytes, checksum: 3015b6dfede897f877793647442680d5 (MD5) / Devido ao limitado número de informações fornecidas nos catálogos dos fabricantes e pouca realização de pesquisas com microaspersores de fabricantes brasileiros, este trabalho teve por objetivo avaliar o desempenho hidráulico do microaspersor Twister, fabricado pela empresa Eden Irrigação, para os seis diâmetros de bocais e em duas posições de instalação, visando-se gerar informações que possam contribuir para o dimensionamento de sistemas e manejo de áreas irrigadas com este microaspersor. Com essa finalidade, foram realizados testes em bancada de ensaios no Laboratório de Hidráulica e Irrigação da FCAV/UNESP - Jaboticabal - SP. Foram determinadas as equações características (relação vazão x pressão), os coeficientes de variação de fabricação (CVF), as perdas de carga provenientes da inserção do microtubo e conector, os raios de alcance e os padrões de molhamento, e as uniformidades de distribuição de água, utilizando os coeficientes de uniformidade de Christiansen (CUC) e de distribuição (CUD). O microaspersor foi caracterizado como de fluxo turbulento e o CVF variou de excelente a baixo. Somente o diâmetro de cobertura do microaspersor com bocal de 1,0 mm de diâmetro em posição normal está de acordo como os dados informados pelo fabricante; os demais apresentaram valores inferiores aos citados no catálogo. As maiores intensidades de aplicação de água ocorreram a 0,25 m do emissor para os ensaios em posição de instalação normal e abaixo dos emissores testados em posição invertida, decrescendo com o aumento da distância. Em relação à uniformidade de aplicação, o microaspersor Twister com 0,83; 1,0 e 1,1 mm de diâmetro de bocal foram classificados como bons, nas duas posições de instalação / Due to the limited amount of information provided in catalogs of manufacturers and conducting research with little microsprinklers Brazilian manufacturers, this study aimed to evaluate the hydraulic performance of the emitter Twister, manufactured by Eden Irrigation, for the six nozzle diameters and in two installation positions, aiming to generate information that can contribute to the design of systems and management of irrigated areas with this emitter. For this purpose, tests were performed on test bench at the Laboratory of Hydraulics and Irrigation FCAV / UNESP - Jaboticabal – SP, Brazil. They were determined characteristic equations (pressure x flow relation), the manufacture of variation coefficient (CVF), the head losses resulting from the insertion of the microtube and connector, the wetted ray and patterns of wetness, and the uniformity of water distribution, using the Christiansen uniformity coefficient (CUC) and distribution (CUD). The emitter was characterized as turbulent flow and CVF ranged from excellent too low. Only the diameter of coverage of the emitter with 1.0 mm nozzle diameter in normal position is in accord with the data reported by the manufacturer; the rest were lower than those cited in the catalog. The higher intensities water application occurred at 0.25 m from the emitter to the tests in normal installation position and below the emitters tested in an inverted position, decreasing with increasing distance. In relation to the uniformity of application, the emitter Twister with 0.83, 1.0 and 1.1 mm diameter of nozzle were rated as good in both installation positions
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Dimensionamento da linha lateral utilizando dois espaçamentos entre gotejadores /Ludwig, Rafael, 1986. January 2012 (has links)
Orientador: João Carlos Cury Saad / Banca: Rodrigo Máximo Sanches Roman / Banca: Edson Eiji Matsura / Resumo: O bom desenvolvimento e a produtividade das culturas estão associados à disponibilidade de água em níveis ideais, que pode ocorrer de forma natural pelas chuvas ou por meio de irrigações. Nestes casos, a escolha do sistema de irrigação deve levar em consideração a sua eficiência, destacando-se a irrigação por gotejamento que é realizada diretamente na região radicular, em baixas vazões e alta frequência, mantendo o teor de água no solo em nível adequado. O uso de gotejadores não autocompensantes é significativo em cultivo protegido, áreas com hortaliças e em pomares, desde que o plantio seja em nível, uma vez que seu custo é menor. Entretanto, dada à ausência de mecanismos de autocompensação, as linhas laterais com gotejadores convencionais apresentam menor comprimento, o que implica em maior número de linhas de derivação. Desta forma, é oportuno avaliar procedimentos e técnicas que possam definir o comprimento máximo da linha lateral sem prejudicar a uniformidade de distribuição de água. Acredita-se que a utilização de dois espaçamentos em trechos distintos, e não um único como normalmente é realizado, seria uma alternativa para a obtenção de maiores comprimentos de linha lateral e, consequentemente, a redução nos custos de implantação. Isto também é alcançado com a utilização de maiores variações de vazão, podendo-se empregar um Δq de 30% que mesmo assim a uniformidade de emissão permanece acima de 80%, conforme preconizado por Wu (1997). As questões fundamentais são: a definição dos dois espaçamentos e a determinação do local de troca de espaçamento. Assim, foram desenvolvidos dois modelos matemáticos, um com programação não linear e outro de simulação elaborado com a linguagem de programação Pascal. Os resultados levaram ao entendimento de que a utilização da... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The crop development and productivity are associated with the water supply at optimal levels, which can occur naturally by rain fed or irrigation. In these cases, the choice of the irrigation system must consider the efficiency, which is especially drip irrigation which is carried out directly in the root region, with low flow and high frequency while maintaining water content in the soil at the appropriate level. The use of no pressure compensating emitters is significant in greenhouse cultivation and fruit orchard with trees planted on level, since its cost is low. Though, given the absence of pressure compensation mechanisms, the lateral lines are shorter, which implies in a greater number of manifold lines. Thus, it is appropriate to evaluate procedures and techniques that can increase the lateral line length without affecting the water distribution uniformity. It is believed that the use of two spacing in lateral line different sections, not one, as usually is done, would be an alternative to achieving greater lateral line lengths and hence reduction in initial costs. This can also be achieved with the use of higher flow variations, by applying a pressure variation of 30% and maintaining the emission uniformity over 80%, as proposed by Wu (1997). The fundamental questions are: defining the two spacing values and to find the ideal location for the exchange. Two mathematical models were developed, one with non-linear... (Complete abstract click electronic access below) / Mestre
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Caracterização hidráulica do microaspersor Eden Twister em posição normal e invertida /Soares, Cristiana Araujo. January 2013 (has links)
Orientador: José Renato Zanini / Banca: Luiz Fabiano Palaretti / Banca: Antonio de Pádua Sousa / Resumo: Devido ao limitado número de informações fornecidas nos catálogos dos fabricantes e pouca realização de pesquisas com microaspersores de fabricantes brasileiros, este trabalho teve por objetivo avaliar o desempenho hidráulico do microaspersor Twister, fabricado pela empresa Eden Irrigação, para os seis diâmetros de bocais e em duas posições de instalação, visando-se gerar informações que possam contribuir para o dimensionamento de sistemas e manejo de áreas irrigadas com este microaspersor. Com essa finalidade, foram realizados testes em bancada de ensaios no Laboratório de Hidráulica e Irrigação da FCAV/UNESP - Jaboticabal - SP. Foram determinadas as equações características (relação vazão x pressão), os coeficientes de variação de fabricação (CVF), as perdas de carga provenientes da inserção do microtubo e conector, os raios de alcance e os padrões de molhamento, e as uniformidades de distribuição de água, utilizando os coeficientes de uniformidade de Christiansen (CUC) e de distribuição (CUD). O microaspersor foi caracterizado como de fluxo turbulento e o CVF variou de excelente a baixo. Somente o diâmetro de cobertura do microaspersor com bocal de 1,0 mm de diâmetro em posição normal está de acordo como os dados informados pelo fabricante; os demais apresentaram valores inferiores aos citados no catálogo. As maiores intensidades de aplicação de água ocorreram a 0,25 m do emissor para os ensaios em posição de instalação normal e abaixo dos emissores testados em posição invertida, decrescendo com o aumento da distância. Em relação à uniformidade de aplicação, o microaspersor Twister com 0,83; 1,0 e 1,1 mm de diâmetro de bocal foram classificados como bons, nas duas posições de instalação / Abstract: Due to the limited amount of information provided in catalogs of manufacturers and conducting research with little microsprinklers Brazilian manufacturers, this study aimed to evaluate the hydraulic performance of the emitter Twister, manufactured by Eden Irrigation, for the six nozzle diameters and in two installation positions, aiming to generate information that can contribute to the design of systems and management of irrigated areas with this emitter. For this purpose, tests were performed on test bench at the Laboratory of Hydraulics and Irrigation FCAV / UNESP - Jaboticabal - SP, Brazil. They were determined characteristic equations (pressure x flow relation), the manufacture of variation coefficient (CVF), the head losses resulting from the insertion of the microtube and connector, the wetted ray and patterns of wetness, and the uniformity of water distribution, using the Christiansen uniformity coefficient (CUC) and distribution (CUD). The emitter was characterized as turbulent flow and CVF ranged from excellent too low. Only the diameter of coverage of the emitter with 1.0 mm nozzle diameter in normal position is in accord with the data reported by the manufacturer; the rest were lower than those cited in the catalog. The higher intensities water application occurred at 0.25 m from the emitter to the tests in normal installation position and below the emitters tested in an inverted position, decreasing with increasing distance. In relation to the uniformity of application, the emitter Twister with 0.83, 1.0 and 1.1 mm diameter of nozzle were rated as good in both installation positions / Mestre
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Perda localizada de carga em conectores utilizados em microirrigação / Local head losses in the connectors used in microirrigationDanieli Bariviera Zitterell 25 March 2011 (has links)
As perdas localizadas de carga são elementos frequentemente negligenciados em dimensionamento de sistemas de irrigação, afetando a uniformidade de aplicação de água. Algumas peças acessórias não possuem equações que estimem estas perdas de forma simples e eficiente. Este trabalho foi desenvolvido com o objetivo de ajustar uma equação que estime a perda localizada de carga na passagem lateral em conectores. Foram testados 11 modelos de conectores em 12 diferentes diâmetros de tubos formando 15 conjuntos de tubo/conector. Os conectores foram caracterizados quanto aos diâmetros internos e dimensões. A perda localizada de carga foi obtida por diferença entre perda de carga distribuída no tubo mais conector e perda de carga no tubo. Os parâmetros responsáveis pela perda localizada de carga foram organizados em termos adimensionais utilizando o teorema de Buckingham. Um modelo matemático foi desenvolvido e apresentou um coeficiente de determinação de 93,31%. Elementos como diâmetro interno do conector e do tubo, comprimento do conector, velocidade de escoamento da água, número de Reynolds e número de Froude influenciaram na perda localizada de carga nos conectores. O modelo foi comparado com os dados observados e apresentou um desempenho classificado como ótimo, podendo ser empregado no cálculo da perda localizada de carga na passagem lateral em conectores. / Local losses are often neglected in design of irrigation systems affecting the uniformity of water application. Some accessories have no simple and efficient equations to estimate these losses. The main objective of this work was to develop an equation to estimate the local head loss in the lateral passage connectors. 11 models of connectors in 12 different diameters of pipes were tested forming 15 groups of pipe/connector. The connectors were characterized by its internal diameters and dimensions. The local head loss was determined by subtracting the head loss on the connector and pipe from the head loss on the pipe. The parameters affecting the local head loss were defined as dimensionless terms using Buckingham\'s theorem. A mathematical model was developed and presented a determination coefficient of 93.31%. Elements such as inner diameter of the connector and pipe length, connector, water flow velocity, Reynolds number and Froude number influenced the local head loss in the connectors. The model was compared with the observed data and presented a performance classified as excellent and can be used in calculating of the local head loss in the lateral passage connectors.
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Sequential cropping of vegetables using plastic mulch, trickle irrigation, and soil fumigationGayle, Lynn P. January 1982 (has links)
Successive cropping of two vegetable crops grown on the same site in one season utilizing trickle irrigation, plastic mulch, and soil fumigation was performed in two separate experiments. In 1980, cabbage (Brassicae olericea L. var capitata cv. Market Prize) was followed by tomato (Lycopersicon esculentum Mill cv. Pik Red). In 1981, cabbage was followed by broccoli (Brassicae oleracea L. var italica cv. Green Duke). Double cropping increased the annual productivity of the research plots both years and decreased production costs by 35% compared to conventional single cropping systems. Early spring planting of the first crop was essential for economic production of the second crop. Trickle irrigation increased yields of all crops grown and was the factor most responsible for yield response both years. Black plastic mulch increased yields of tomato and total yields in 1980 but cole crops showed no significant yield response to mulch either year. No difference in crop yield resulted from soil fumigation either year. Increased production costs have caused growers to seek improved methods to offset risks and costs involved. Trickle irrigation can reduce the risks involved in producing vegetables and is particularly suited to multiple cropping on plastic mulch. / Master of Science
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