Dissertations / Theses on the topic 'Drip irrigation system'

Drip irrigation design is a multi-step routine that has to be carried out in a step by step fashion with each step covering a part of the design process. An expert system has been developed with a set of external programs to accomplish the drip system design. The expertise used in the present expert system knowledge base was induced from engineering handbooks and articles as well as personal consultations. The expert system has been developed in such a way that a variety of cases can be handled. In addition, to simulate the human expert, a new drip irrigation design evaluation factor has been introduced (Design Success Indicator, DSI) in order to estimate the system response on field depending on the confidence of data being used. The results are very promising with respect to the expertise used. However many parts of the knowledge-base have to be fine-tuned in order to reach a highly performing expert system.

A newly installed subsurface drip system was compared to a conventional furrow-irrigated cotton production system in the Marana Valley in 2000. Regular measurements included soil moisture, flower tagging, general plant growth and development measurements, and lint yield. Results indicate that an increase in lint yield of approximately 250 lbs. lint/acre was obtained under the drip irrigation system. Approximately 1/3 less irrigation water was used under the drip irrigation system. Pounds of lint produced per acre-inch of water applied provide the most dramatic results. In the furrow-irrigated system approximately 25 lbs. of lint was produced per inch of water applied while the drip system ranged from 70-80.

Purpose - The thesis investigates effects of automatic variation of the deficit irrigation level with the growth stage of drip irrigated maize on grain yield and crop Water Use Efficiency (WUE). It further examines the impact of water-efficient irrigation controllers on the solar Photovoltaic energy level requirements for water pumping systems. Methodology - A Wireless Sensor and Actuator Network was deployed to monitor field conditions and actuate irrigation valves according to whether the level of moisture was within the set points. A Control Treatment (CT) field was fully irrigated using constant moisture threshold levels, while an Experimental Treatment (ExT) field had the highest level of deficit irrigation at the early and later growth stages. Full irrigation was applied at the middle growth stage. Irrigation depths and grain yields were measured, while WUE and the solar energy required by the water pumping system were calculated. Findings - The findings show that 880 mm and 560 mm of water were applied to CT and ExT fields, respectively. This represents a 36% water saving and a corresponding water pumping energy saving of 36% in the ExT field. The grain yields were 0.752 kg/m2 and 0.812 kg/m2 for CT and ExT fields, respectively. This shows that, despite applying a lower amount of water, the ExT improved the grain yield by 7.4%. Furthermore, the results show an increase in WUE from 0.86 kg/m3 for the CT field to 1.45 kg/m3 for the ExT field, representing a 69% improvement. Research limitations/implications - This study focused on the maize production under Malawi's weather conditions. However, the concept would easily be replicated in other crops and in other parts of the world with two modifications: firstly, sensor calibration must be done on-site; and secondly, the specific crop coefficient pattern must be used to develop the irrigation scheduling strategy.

This study was conducted to investigate the effects of four drip irrigation treatments on five fruiting characteristics of cotton (Gossypium hirsutum L.) using periodic observations to gauge the relative impact of these effects over time. The fruiting characteristics measured were: (1) number of flowers, (2) percent boll set, (3) number of bolls, (4) weight boll-1, and (5) seedcotton production. The irrigation treatments included four levels that in total season applied irrigation equaled 60, 68, 76, and 83 cm of water. Periodic observations included three, 3-week-intervals from the onset of flowering (26 June) to cutout (29 August). Results indicate that irrigation treatments had a significant effect on all characters measured, only in the later stages of development (later in the season) with higher amounts of irrigation applied producing higher levels of each character measured. Significant differences were found among periods of observation for all characters measured.

A intrusão de raiz e partículas de solo em gotejadores instalados na subsuperfície do solo, conduz à redução da uniformidade de emissão de água e compromete as condições ideais de operação e a vida útil do sistema de irrigação. Estes fatos motivaram a realização desta pesquisa, sendo propostos protótipos de emissores, cujas características físicas e funcionais impeçam a entrada de raízes e partículas de solo por sucção dentro dos mesmos, e possibilite a vazão de projeto. Desenvolveram-se quatro modelos de emissores sendo: modelo A que utiliza êmbolo; modelo B constituído por uma membrana com módulo de Young (MY) de 1000 kPa; modelo C constituído por uma membrana com MY de 1000 kPa e protetor da membrana; e, sistema protetor (tubo) do emissor (modelo D) no qual se utilizou um gotejador comercial para controlar a vazão. Uma vez que o modelo A não apresentou desempenho satisfatório, estudos posteriores com o mesmo foram interrompidos. Em fase de campo instalaram-se os modelos B, C, D, e um gotejador comercial, modelo E. Os emissores foram avaliados em laboratório em relação ao coeficiente de variação de fabricação (CVF), coeficiente de uniformidade de emissão da água (CUE) e à curva vazão versus pressão; e, instalados em vasos com cana-de-açúcar e sem cultura, para avaliação periódica quanto à capacidade em obstar a entrada de raiz e partículas de solo, sendo analisados a vazão relativa (QR), o coeficiente de variação da vazão relativa (CVQR), CUE e distúrbio de vazão (DQ). Para o emissor modelo C desenvolveram-se Equações que descrevem o comportamento da membrana que o compõe. Os resultados obtidos com a Equação de estimativa da pressão mínima foram próximos dos dados medidos em laboratório. Os emissores B e C apresentaram altos valores de CVF e CVQR, e baixos valores de CUE. Após o terceiro período de avaliação, notou-se redução na QR do modelo E, devido a entupimento por raiz. Dos emissores construídos em laboratório, o modelo C apresentou melhor desempenho quanto à variação dos dados de vazão na linha lateral, ao longo do tempo, tendo valores agrupados entre primeiro e terceiro quartil. Após 3 meses (modelo E) e 18 meses (modelos D) de funcionamento em campo, houve presença de solo e raiz, enquanto os modelos B e C apresentaram os melhores resultados quanto ao impedimento da entrada de raiz e solo dentro do emissor, sendo este último indicado para estudos mais detalhados em relação à membrana a ser utilizada. O emissor que utiliza membrana e protetor foi adequado para evitar entrada de raiz e solo dentro do mesmo, sendo necessário estudos a respeito da membrana e de um sistema para controlar a vazão. Com as Equações propostas para o modelo C serão possíveis futuros estudos que busquem aperfeiçoar o protótipo, podendo ser utilizadas para estimativa da pressão mínima de funcionamento, variação do diâmetro da membrana, e vazão do emissor.
Roots and soil particles intrusion in drippers installed in the subsurface soil leads to reduction of the water emission uniformity, and compromise the ideal conditions of operation and the lifetime of irrigation system. These facts motivated this research, being proposed prototypes of emitters whose physical and functional characteristics prevent the entry of roots and soil particles by suction into them, and allow the design flow. Four emitters models were developed: (i) A model that uses piston; (ii) B model composed by a membrane with Youngs modulus (YM) of 1000 kPa; (iii) C model composed by a membrane with YM of 1000 kPa plus a membrane protector;(iv) protector (tube) emitter system (D model) in which was used a commercial dripper to flow control. The A model study was stopped since it did not present a good performance. In the field stage models B, C, D and a commercial dripper E were installed. In the laboratory stage, emitters were evaluated in relation to the manufacturing coefficient of variation (CVF), the emission uniformity coefficient of water (EUC) and the flow rate versus pressure curve. After that, the emitters were installed in pots with and without sugar cane for periodic evaluation considering the potential to prevent the entry of roots and soil particles into the emitter. Relative flow (QR), variation coefficient of relative flow (CVQR), EUC and flow disturbance (DQ) were analyzed. Equations that describe the behavior of C model emitters membrane were developed. The results obtained with the Equation to estimating the minimum pressure were close to the measured data in laboratory. B and C emitter´s model showed the higher values of CVF and CVQR, and the lower values of EUC. After third evaluation period, reduction in QR for E model was observed due to clogging by root. Among the emitters built in the laboratory, C model showed better performance in relation to variation of data flow in lateral line, with values grouped between the first and third quartile. After 3 months (E model) and 18 months (D model) of operation in the field, the presence of soil and roots was observed, while B and C models showed the best results to avoid the entry of root and soil into the emitter. C model was recommended for detailed studies in relation to the membrane which can be used. The emitter that uses membrane plus protector was suitable to prevent entry of root and soil into them needing to studies about it membrane and a system which its possible to control the flow rate. The Equations proposed for C model can be used in: studies to improve the prototype; estimation of the minimum operation pressure; changing in the membrane diameter; and, to estimate the emitter flow. Keywords: Drip irrigation; Subsurface irrigation; Root intrusion; Technological Innovation; Prototype of emitters

The main objective was to set up models of the soil-plant-atmosphere system for the growing of Grape Leaves with drip irrigation in the Binh Thuan Province, Vietnam. The computer software tool CoupModel was used in this modelling process. The focus of the model was the systems soil hydraulics and the water balance between its components. When running several 21 years simulations it could be seen that slight variations in soil texture inputs resulted in relatively big output changes. For example, by either using the soil texture laboratory results or the soil water retention inputs gained from tensiometers and moisture meters in the field, gave an annual irrigation amount difference of 100 mm. However, it can be questioned if the models reached the goal of simulating an  efficient irrigation schedule  due to the soil evaporation output being high throughout the year.  For further research, longer time series of field measurements together with more knowledge about the plant would be preferable in order to validate and improve the model.
MÂlet med denna studie var att uppr‰tta modeller ˆver mark-v‰xt-atmosf‰r-systemet i programmet CoupModel. Modellerna skulle anpassas fˆr odlingen av vinblad med hj‰lp av droppbevattning i Binh Thuan-provinsen i Vietnam. Fokus i denna studie var vattenflˆden och vattenbalansen mellan systemets komponenter. Efter att ha kˆrt flera 21 Âr lÂnga simuleringar var det tydligt att sm variationer i indata resulterade i relativt stora skillnader i utdata. Om till exempel  v‰rden  angÂende jordartens struktur  erhÂllna  frÂn laboratoriet anv‰ndes ist‰llet fˆr f‰ltm‰tningar frÂn tensiometrar och fuktm‰tare blev det en Ârlig bevattningsskillnad p 100 mm. Det kan ifrÂgas‰ttas huruvida mÂlet att simulera en vatteneffektiv bevattning blev nÂtt d jordavdunstningen var hˆg Âret runt. Fˆr vidare studier skulle l‰ngre tidsserier av f‰ltm‰tningar tillsammans med mer kunskap om plantan vara nyttigt fˆr att kunna validera och fˆrb‰ttra modellen.

Celem pracy było określenie potrzeb wodnych sosny zwyczajnej (Pinus sylvestris L.) uprawianej w cyklu dwuletnim z nasion, z odkrytym systemem korzeniowym, z zastosowaniem podcinania korzeni w pierwszym i drugim roku uprawy, nawadnianej kroplowo w warunkach melioracji próchnicą nakładową

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Brazil, has been feeling from a lack of technical guidance and ecological awareness in the exploitation of forest resources to meet the furniture industry, which has caused irreparable harm to species of great ecological value. The African mahogany source countries of the west coast of the African continent is one such tree species being used in commercial plantations, due to its high commercial value, the quality of the wood, its high yield potential and good adaptation to Brazilian climatic conditions. However, little is known about its water and a nutritional need which hinders adequate technical recommendation for this crop in the Cerrado region whose water deficit and the low fertility soils are very characteristic. Thus this study had the objective: evaluate plant growth in the first two years cultivation, irrigation and drip irrigation under different managements and topdressing. The research consisted of field experiments with plants of African Mahogany (Khaya ivorensis) spaced 5 x 5 m, experimental design was a randomized complete block design (RBD) with three blocks in split plots. For drip irrigated treatments were used 1, 2 and 3 emitters per plant with flow rates of 2 L.h-1, 4 L.h- 1 and 8 L.h-1, and irrigated treatments, microsprinkler, using 1 emitter for every 2 plants with different flow rates: 20, 30, 35, 40, 50, 58, 70 and 90 L.h-1, and no irrigation. For the following plots of fertilization doses were used 83.5 e 42.0; 167.0 e 83.5; 250.0 e 125.0; 333.5 e 167.0; 416.6 e 208.5 g.plant-1 of NH4SO4 and KCl, installments bimonthly in 5 applications from 4th to 12th month of planting.
O Brasil vem sentindo com a falta de direcionamento técnico e de conscientização ecológica na exploração dos recursos florestais para atender a indústria moveleira, o que tem acarretado prejuízos irreparáveis a espécies de grande valor ecológico. O mogno africano de origem de países da costa oeste do continente Africano é uma dessas espécies arbóreas que está sendo utilizada em plantios comerciais, devido ao seu grande valor comercial, da qualidade da madeira, do seu alto potencial produtivo e a boa adaptação às condições edafoclimáticas brasileira. Porém, pouco se sabe sobre suas necessidades hídricas e nutricionais, o que dificulta uma recomendação técnica adequada para essa cultura na região do cerrado, cujo déficit hídrico e os solos com baixa fertilidade são bem característicos. Assim este estudo teve o objetivo: avaliar o crescimento de plantas, nos dois primeiros anos cultivo, irrigadas por gotejamento e microaspersão em diferentes métodos de irrigação e adubação de cobertura; A pesquisa constituiu de experimentos a campo com plantas espaçadas em 5 x 5 m, com delineamento experimental em blocos casualizados, com três blocos, em parcelas subdividas. Para os tratamentos irrigados por gotejamento foram utilizados 1, 2 e 3 gotejadores por planta com vazões de 2 L.h-1, 4 L.h-1 e 8 L.h-1, e os tratamentos irrigados por microaspersão, utilizando 1 emissor para cada 2 plantas, com diferentes vazões: 20, 30, 35, 40, 50, 58, 70 e 90 L.h-1, além de uma testemunha sem irrigação. Para as subparcelas de adubação foram utilizados as doses de: 83,5 e 42,0; 167,0 e 83,5; 250,0 e 125,0; 333,5 e 167,0; 416,6 e 208,5 g.planta-1 de sulfato de amônio e cloreto de potássio, parcelado em 5 aplicações bimestrais do 4º ao 12º mês do plantio. As variáveis analisadas foram: altura de planta, diâmetro no colo e diâmetro na altura do peito (DAP) e altura de fuste. Concluiu-se que as plantas de mogno respondem a irrigação e que de uma maneira geral, as plantas irrigadas por microaspersão apresentaram melhor crescimento que as plantas irrigadas por gotejamento, e que o mogno nos dois primeiros anos, não respondeu a adubação de cobertura.

The hydraulics of IDEal drip irrigation system components were analyzed under controlled laboratory conditions and the results can be applied to the design of IDEal systems. The hydraulic loss coefficient for the lateral-submain connector valves was determined based on laboratory measurements. It was found that the hydraulic loss due to friction in the lay-flat laterals can be accurately estimated with standard friction loss equations using a smaller effective diameter based on the wall thickness and inlet pressure head. The equivalent length barb loss, expressed as an equivalent length of lateral, was calculated for button emitters, as well as for micro-tubes inserted to lengths of 5 and 10 cm. It was concluded that the barb loss is essentially constant over the micro-tube insertion range of 5-10 cm. The head-discharge relationship and coefficient of manufacturer's variation of pre-punched lateral holes (without emitters), button emitters, and micro-tubes were characterized. Finally, several IDEal drip irrigation systems in the Central Rift Valley of Ethiopia were evaluated in the field. Recommendations were given for future research and improvements in the manufacturing, installation, operation, and maintenance of IDEal drip irrigation equipment.

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The main economic activities developed at Turuçu-RS (Brazil) are the dairy cattle breeding, cultivation of temperate climate fruit, tobacco and red-hot chili pepper. Among the fruits, strawberry is a relevant crop which is providing worthy investment return for the farmers, generating income, employment, social inclusion and therefore rising quality of life of the farmers. Drip irrigation is one of the adopted technologies by the rural producers in the strawberry crop system. The irrigation water quality has an important role in this system due the potential to cause emitters clogging, reducing the equipment life time and irrigation uniformity. The effect of the water quality may very depending on factors as the kind of water source, local climate and the irrigation management employed by the farmer. This work intended to characterize the irrigation water sources in relation to their origin and to assess the spatial and temporal variability of the water quality utilized in the strawberry crop in 15 rural properties affiliated to the Association of Strawberry Producers of Turuçu-RS. Water samples were collected monthly at water supply for ten months. The water quality was evaluated in terms of its physical (suspended solids, dissolved solids and turbidity), chemical (pH, total iron, dissolved oxygen, electrical conductivity and hardness) and microbiological parameters (total and fecal coliform bacteria). These parameters were evaluated in relation to the hazard to cause damages to the drip irrigation systems and to their spatial and temporal distribution by means of box plot graphs. To characterize the irrigation water sources relating to their origin was employed a typology for grouping the sources based on the CONAMA (National Council for the Environment) Resolution 303/2002. In this manner, six sources were classified as Group 1, five as Group 2, three as Group 3 and one as Group 4. It was verified that the rural producers had no technical advice about reservoir construction or water withdrawal location. The spatial and temporal variability of the water quality analyzed presented different magnitude for the parameters. The dissolved solid concentration presented the greatest among physical parameters, and dissolved oxygen, followed by electrical conductivity among the chemical. In relation to the clogging hazard, the suspended solid concentration was the physical parameter that presented the greatest percentage of samples classified as of moderate and severe risk, while turbidity was classified as adequate for most samples. For the chemical parameters, total iron levels presented the greatest percentage of samples classified as of moderate and severe risk. For dissolved oxygen, the percentage of samples classified as inadequate was over 50% in six properties, and it was classified as adequate over 50% in six properties. For the pH parameter the clogging hazard was found low in ten water sources while electrical conductivity and hardness presented low risk for all samples. It was not detected the presence of total and fecal coliform bacteria in four and five water samples, respectively, along the studied period.
No município de Turuçu-RS as principais atividades econômicas desenvolvidas são a pecuária leiteira, a produção de frutíferas de clima temperado, de fumo e de pimenta vermelha. Dentre as frutíferas, destaca-se o morangueiro que tem propiciado aos produtores rurais, boa rentabilidade constituindo-se em instrumento de geração de renda e emprego, inclusão social e assim incrementando o padrão de qualidade de vida destes produtores. A irrigação localizada por gotejamento foi um dos incrementos tecnológicos adotados na produção do morangueiro. Neste sistema, a qualidade da água utilizada assume papel importante podendo afetar seu funcionamento causando obstrução de emissores diminuindo sua vida útil e comprometendo a uniformidade da irrigação. Baseado nisto, este trabalho teve como objetivo caracterizar as fontes de captação de água usada para irrigação quanto a sua origem e avaliar a variabilidade espacial e temporal da qualidade da água usada na produção de morangos em 15 propriedades, pertencentes à Associação dos Produtores de Morango do Município de Turuçu-RS. Para tal, foram coletadas, mensalmente, amostras de água das fontes de captação em cada uma das propriedades, durante um período de 10 meses, determinando suas características físicas (sólidos suspensos, sólidos dissolvidos e turbidez), químicas (pH, ferro total, oxigênio dissolvido, condutividade elétrica e dureza), e microbiológicas (coliformes totais e fecais). Estas características foram avaliadas quanto ao potencial de causar danos ao sistema de irrigação por gotejamento e quanto a sua distribuição espacial e temporal ao longo do período utilizando gráficos em caixa. Na caracterização das fontes de captação de água foram usadas as definições da Resolução CONAMA 303/2002 para identificar características semelhantes quanto a origem das fontes de captação resultando em seis fontes caracterizadas como Tipo 1, cinco como Tipo 2, três como Tipo 3 e uma como Tipo 4. A variabilidade espacial e temporal da qualidade da água apresentou magnitudes diferentes quanto aos parâmetros, sendo a concentração de sólidos dissolvidos a maior dentre os físicos e o oxigênio dissolvido, seguido pela condutividade elétrica dentre os químicos. Quanto ao potencial de risco a causar entupimento dos gotejadores, a concentração de sólidos em suspensão apresentou o maior percentual das amostras classificadas como moderado e severo, dentre os parâmetros físicos, sendo a turbidez da água classificada como adequada em onze fontes de captação. Dentre os parâmetros químicos, a concentração de ferro apresentou o maior percentual de amostras com potencial de risco moderado e severo, o oxigênio dissolvido apresentou seis propriedades com mais de 50% das amostras de água classificadas inadequadas e em outras seis mais de 50% das amostras classificadas adequadas. O pH da água de irrigação apresentou baixo potencial de risco, em dez fontes de captação, enquanto que, a condutividade elétrica e a dureza total apresentaram potencial de risco baixo em todas as amostras. Não foi detectada a presença de coliformes totais em quatro amostras de água analisadas e de coliformes fecais em cinco, ao longo do período estudado.

Este trabalho teve, como objetivo, quantificar o rendimento, as características quantitativas e qualitativas de interesse econômico do meloeiro, analisando também a distribuição espacial da água e de íons fertilizantes (nitrato e potássio) no sistema radicular da planta, em dois tipos de solo: Latossolo Vermelho Amarelo (franco-arenoso) e Argissolo Vermelho (argiloso), submetidos aos efeitos do "mulching", em condições de gotejamento superficial e subsuperficial (0,20 e 0,40 m de profundidade). O ensaio foi conduzido na área experimental do Departamento de Engenharia Rural da Escola Superior de Agricultura "Luiz de Queiroz" – ESALQ/USP, em uma área protegida de 330 m2 (22,0 m x 15 m), localizada no município de Piracicaba, SP. Os experimentos foram conduzidos no delineamento em blocos casualizados, com 4 blocos cada, com o arranjo dos tratamentos em fatorial 2 x 3 (6 tratamentos), com a combinação das variáveis "mulching" plástico e profundidade de gotejamento, totalizando 24 parcelas experimentais em cada solo. O monitoramento da umidade foi realizado com tensiômetros de punção e a concentração de nitrato, potássio, pH e condutividade elétrica através de extratores de solução do solo, instalados nas profundidades de 0,15, 0,30 e 0,50 m da superfície do solo, e nas distâncias do gotejador de 0,10, 0,20, 0,30 e 0,40 m. Foram coletadas, ainda, amostras de solo nas profundidades de 0,04, 0,08 e 0,12 m e nas mesmas distâncias do emissor, para o mesmo monitoramento. Foram realizadas análises de pH e de condutividade elétrica do solo nas mesmas posições. O uso do "mulching" incrementou a altura da planta, o diâmetro de colo, a massa média de fruto, a produção por planta, o diâmetro longitudinal e a espessura de polpa, nos solos franco-arenoso e argiloso, além do diâmetro transversal, da relação de formato do fruto, dos sólidos solúveis totais e do pH, no solo argiloso. A profundidade de gotejo a 0,20 m da superfície do solo proporcionou maiores valores médios de massa do fruto e de produção por planta, no solo arenoso, e influenciou o pH do fruto, no solo argiloso. Não foi possível observar efeito dos tratamentos na distribuição de nitrato nos solos franco-arenoso e argiloso, devido a sua complexa dinâmica no solo. A profundidade de gotejo a 0,20 m da superfície do solo e sem "mulching" disponibilizou mais íons potássio à zona de absorção das raízes do meloeiro no solo franco-arenoso, dos 47 DAT aos 63 DAT, período que compreendeu desde o início do florescimento até a fase inicial de frutificação da cultura. Para o solo argiloso, o efeito do "mulching" foi mais evidente na distribuição de íons potássio ao redor da zona radicular do que na profundidade de gotejo. Em ambos os solos, nas caixas sem "mulching", o tratamento com gotejo à 0,20 m da superfície apresentou maior produtividade da água, quando comparado aos demais tratamentos que utilizaram gotejo à superfície e a 0,40 m.
This work aims to quantify melon yield, quantitative and qualitative aspects, as well to observe water and ions distribution (nitrate and potassium) in the root zone for two soils: Yellow Red Latossol (Sandy loam soil) and Red Argissol (Clay soil), under plastic mulching and subsurface drip irrigation (0.20 m and 0.40 m from the soil surface). Melon cycle occurred between november, 2005 until january, 2006. The research site was a greenhouse (330 m2) located at the University of São Paulo (ESALQ/USP), Piracicaba, Sao Paulo, Brazil. The experimental design was four randomized complete blocks. The treatments were comprised of 24 experimental units for each soil. Soil moisture evaluated by tensiometric batteries, and the nitrate, potassium, pH and EC values by soil solution based on extractors of ceramic capsules disposal at depths of 0.10 m, 0.30 m, and 0.50 m and horizontal distances of 0.10 m, 0.20 m, 0.30 m and 0.40 from the plant, and by soil sampling as shallow depths of 0.04 m, 0.08 m, and 0.12 m at the same horizontal distances from the plant. The plastic mulching increased the height plant, stem diameter, plant production, longitudinal diameter and pulp thickness of the fruit for the sandy loam and clay soil, and transversal diameter, format of the fruit, soluble solids levels and pH of the fruit for the clay soil. The subsurface drip irrigation at 0.20 m from the surface soil provided larger fruit average mass and plant production to sandy loam soil and make influence in pH of the fruit to clay soil. It was not possible to find treatments effects for the nitrate distribution at sandy loam and clay soils due the complex nitrate dynamics in the soil. The subsurface drip irrigation at 0.20 m and without plastic mulching made available more potassium concentration at the melon root absorption zone for the sandy loam soil, from 47 and 63 days after planting, when the blooming started until to frutification period. To clay soil the mulching effect was more evident at the potassium distribution than the subsurface drip irrigation. For both soils, without mulching, subsurface drip irrigation at 0.20 m showed larger water productivity compared to 0.40 m and surface drip irrigation treatments.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Surface drip irrigation is widespread for the melon crop. To improve the efficiency of this system subsurface drip irrigation and plastic mulching can be used. These management practices can influence soil moisture, and growth and development of plants and hence fruit yeld and quality of melon. Root system can give good information for the design of the irrigation system, because it is closely related to the volume of soil used by the roots to absorb water and nutrients arising from irrigation. This study aimed to evaluate the influence of the position of emitters and plastic mulching on soil moisture, the final growth of roots and yield and fruit quality of drip irrigated melon plants. The experiment was conducted during the spring/summer of 2008 growing season at the Experimental area of the crop science Department of the University of Évora Portugal. Treatments consisted of surface drip irrigation (with and without plastic mulching) and subsurface drip irrigation (without plastic mulching). Soil moisture was monitored using a portable TDR probe and Watermark tensiometers. Leaf area, dry weight and number of leaves per plant were measured. Harvested fruits were separated into commercial and non-commercial and soluble solids content and the lenght and wieth of fruits were measured. Root growth was quantified in terms of root intensity, measured by a minirhizotron (non-destructive method) and root density (destructive method) measured by manual collection of soil samples over roots with an auger. Results indicated no significant differences among treatments for commercial yeld and for fruit quality parameters and vegetative growth of melon. The yeld of unmarketable fruits was significantly higher with surface drip irrigation without plastic mulching in relation to surface drip irrigation with plastic mulching and subsurface drip irrigation. The root length intensity varied significantly between treatments. Under cover of plastic, the increased intensity of roots tended to expand horizontally into the soil, while burying the emitters provided greater root depth in the soil profile, ie between 0.20 and 0.33 m .
A irrigação por gotejo localizado superficial é amplamente difundida na cultura do meloeiro. Para melhorar ainda mais a eficiência desse sistema é possível utilizar a irrigação em subsuperfície e a cobertura do solo nas linhas de cultivo por filme plástico, técnica conhecida como mulching. Essas opções de manejo podem influenciar na condição de umidade do solo e no crescimento e desenvolvimento das plantas e consequentemente na produtividade e qualidade dos frutos do meloeiro. Quanto ao sistema radicular, poderá representar uma informação viável para o dimensionamento do sistema de irrigação, por estar intimamente relacionado com o volume de solo explorado pelas raízes para absorção da água e nutrientes advindos da irrigação. Neste trabalho objetivou-se verificar a influência da posição dos gotejadores e da cobertura do solo por plástico na umidade do solo, no crescimento final de raízes e na produtividade e qualidade dos frutos do meloeiro irrigado por gotejo localizado. Para tal, cultivou-se o meloeiro na primavera/verão na área experimental do Departamento de Fitotecnia da Universidade de Évora Portugal. Os tratamentos constaram da irrigação por gotejo localizado superficial, com e sem cobertura do solo nas linhas de cultivo pelo plástico, e gotejo subsuperficial sem a cobertura do solo. A umidade do solo foi monitorada por meio de uma sonda TDR portátil e por tensiometros do tipo watermark. Foram coletados dados de área foliar, massa seca e número de folhas por planta. A colheita de frutos foi realizada para quantificar sua produtividade comercial e não comercial, seu teor de sólidos solúveis totais e diâmetro longitudinal e transversal. O crescimento radicular foi quantificado em termos de intensidade radicular, medida pelo minirhizotron, como método não destrutivo e densidade radicular, método destrutivo realizado por coletas manuais de amostras de solo mais raízes com um trado. Os resultados não indicaram diferenças significativas entre os tratamentos para a produtividade comercial e para os parâmetros relativos à qualidade dos frutos e crescimento vegetativo do meloeiro. A produção de frutos não comerciais foi significativamente maior no tratamento com irrigação superficial sem a cobertura do solo em relação à irrigação subsuperficial e a superficial com a cobertura do solo nas linhas de cultivo por filme plástico. A intensidade radicular variou significativamente entre os tratamentos. Sob a cobertura por filme plástico, além da maior intensidade radicular, as raízes tenderam a expansão horizontal no solo, enquanto que o enterrio dos gotejadores proporcionou maior crescimento radicular em profundidade no perfil do solo, ou seja, entre 0,20 e 0,33 m.

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 79-81).
This thesis presents a design and cost optimization for solar-powered, drip irrigation systems. Historical irradiance data and crop consumption data are considered and modelled during these design steps. A cost optimization is utilized in order to determine low-cost, optimum configuration that meets the required water consumption rate of a given crop. In this case, Jalgaon, India is used as an example to determine the configuration and cost per acre for solar-powered, drip irrigation systems for sunflowers, tomatoes, and barley. These configurations consisted of five 310 Watt solar panels coupled with a 5m³ water buffer, three 295 Watt solar panels coupled with a 5m³ water buffer, and three 320 Watt solar panels coupled with a 4m³ water buffer, respectively. These systems are projected to cost $4,600, $3,870, and $3,750, respectively. The results of this study show the value of a system optimization of solar-powered, drip irrigation systems.
by David Doan.
S.B.

Els sistemes de reg per degoteig es consideren com un mètode apropiat per a la reutilització d’aigües regenerades, ja que disminueixen els riscos sanitaris. No obstant això, el problema més important en l’aplicació dels efluents en els sistemes de reg localitzat és l’obturació dels filtres i degoters, el que disminueix la uniformitat de distribució del aigua. L’objectiu principal d’aquesta tesi doctoral va ser comparar el comportament hidràulic d’un sistema de reg per degoteig superficial (DI) i un d’enterrat (SDI) aplicant un efluent terciari amb tres freqüències de rentat dels laterals (sense rentat, un rentat al final de cada temporada de reg i un rentat mensual) amb dos tipus d’emissors (autocompensant i no autocompensant). Altres objectius han estat investigar la influència de la qualitat de l’efluent en el procés de filtració i calcular la pèrdua de càrrega i la durada dels cicles de filtració en el filtre de sorra mitjançant l’anàlisi dimensional. Els resultats van demostrar que la durada del cicle de filtració va dependre principalment de la qualitat de l’efluent aplicat i del diàmetre efectiu de la sorra utilitzada. També es va constatar que l’eficàcia del procés de filtració va ser deguda al diàmetre efectiu de la sorra del filtre i que quan menor va ser el diàmetre efectiu de la sorra utilitzada, més eficaç va ser la filtració. L’anàlisi dimensional va ajudar a desenvolupar un model matemàtic per a descriure la pèrdua de càrrega en el filtre amb un alt coeficient de determinació ajustat i una bona distribució del residus. A més, es va trobar que el cabal del lateral va dependre significativament del tipus de degoter, sistema de reg, la temporada de reg i la freqüència de neteja. En el sistema de DI, el cabal de l’emissor no autocompensant es va incrementar significativament durant l’experiment a causa d’un desgast de l’emissor i es va disminuir significativament en el sistema de SDI degut a l’obturació del degoters. El cabal del degoter autocompensant va augmentar durant l’experiment en els sistemes de DI i SDI. També es va observar que la causa principal de l’obturació de l’emissor en el sistema de DI va ser el desenvolupament de biofilm, mentre que en el SDI es va correspondre a una combinació de factors biològics i físics. Finalment, es va trobar que rentar els laterals una sola vegada al final de cada temporada de reg va ser la millor opció de maneig per assolir la major eficiència de distribució de l’aigua després de 1620 h de reg, tant en DI com SDI.
Los sistemas de riego por goteo se consideran como un método apropiado para la reutilización de aguas regeneradas, ya que disminuyen los riesgos sanitarios. Sin embargo, el problema más importante en la aplicación de los efluentes en sistemas de riego localizado es la obturación tanto de filtros como de goteros, lo que disminuye la uniformidad de distribución del agua. El objetivo principal de esta tesis doctoral es comparar el comportamiento de un sistema de riego por goteo superficial (DI) y otro enterrado (SDI) aplicando un efluente terciario con tres frecuencias de lavado de los laterales (sin lavado, un lavado al final de cada temporada de riego y otro mensual) con dos tipos de emisores (autocompensante y no autocompensante). Otros objetivos fueron investigar la influencia de la calidad del efluente en el proceso de filtración y calcular la pérdida de carga y la duración de los ciclos de filtración en filtro de arena mediante el análisis dimensional. Los resultados demostraron que la duración del ciclo de filtración dependió principalmente de la calidad del efluente aplicado y del diámetro efectivo de la arena utilizada. También se constató que la eficacia del proceso de filtración fue debida al diámetro efectivo de la arena del filtro, pues cuanto menor era el diámetro efectivo de la arena utilizada, más eficaz fue la filtración. El análisis dimensional ayudó a desarrollar un modelo matemático para describir la pérdida de carga en el filtro con un alto coeficiente de determinación ajustado y una buena distribución de los residuos. Además, se encontró que el caudal del lateral dependió significativamente del tipo del gotero, sistema de riego, temporada de riego y la frecuencia del lavado. En el sistema de DI, el caudal del emisor no autocompensante se incrementó significativamente durante el experimento debido a un deterioro del gotero y se disminuyó significativamente por culpa de la elevada porcentaje de los emisores obturados. El caudal del gotero autocompensante aumentó durante el experimento en los sistemas de DI y SDI. También se observó que la causa principal de la obturación del emisor en el sistema de DI fue el desarrollo de un biofilm, mientras que el de SDI se correspondió a una combinación de factores biológicos y físicos. Sin embargo, se encontró que lavar los laterales una sola vez al final de cada temporada de riego fue la mejor opción de manejo para lograr la mayor eficiencia de distribución del agua después de 1620 h de riego tanto en el sistema de riego por goteo superficial como en el enterrado.
Microirrigation is considered as an appropriate method for reclaimed wastewater reuse because it diminishes the health risks. However, the most important problem when applying reclaimed effluents in microirrigation systems is emitter and filter clogging, which lead to low system distribution uniformity. The main target of this PhD dissertation is to compare the performance of a surface (DI) and a subsurface (SDI) drip irrigation systems when applying a tertiary treated effluent under three flushing frequency (no flushing, seasonal flushing and monthly flushing) using two emitter types (pressure and non-pressure compensating). In addition, the study aimed to investigate the influence of effluent quality on the sand filtration process. Another purpose was to compute head loss across the sand media filter and time between backwashing in a sand filter media through dimensional analysis. The results revealed that sand filtration cycle duration depended mainly on the applied effluent quality and sand filter effective diameter. It was also found that the effectiveness of filtration process was significantly due to sand effective diameter, being the smaller the effective diameter the more effective the filtration process. The dimensional analysis helped to develop a mathematical model to calculate head loss across sand filter with a high adjusted coefficient of determination and a good distribution of residuals. Besides, it was found that lateral flow rates depended significantly on emitter type, irrigation system, irrigation season and flushing frequency. In DI system, lateral flow of the non-pressure compensating emitter was significantly increased throughout the experimental time due to emitter failure and significantly decreased in SDI one due to the elevated percentage of clogged emitters. The pressure compensating emitter lateral flow was increased during the experiment for DI and SDI systems. The study, as well, showed that emitter clogging in DI system was primarily due to biological factors and in the SDI one was due to a combination of biological and physical factors. However, it was found that the seasonal flushing frequency was the best management practice for achieving the highest system distribution uniformity after 1620 h of irrigation for both DI and SDI systems.

This study set out to investigate the processes that lead to emitter fouling in wastewater reuse systems. The susceptibilities of several emitter designs to clogging were compared and the role of phytoplankton in the clogging process and in the development of algal mats was investigated. Emitter design was found to be an important factor controlling the degree of clogging. Those designs that operated most efficiently used a long-path narrow labyrinth to control emitter output and encourage turbulent flow. Simpler designs that controlled flow by small sponge inserts or by stitched tubing were found to be unsuitable for use with treated wastewaters. The most common cause of clogging was found to be sand particles in the size range 360 urn to 1080 urn, trapped within the narrow channels of emitters. The sand contaminated the entire irrigation system from the potable water supply in July 1987, before a screen filter was installed in the water supply line. Emitter clogging under these circumstances was a problem, to varying degrees, for all emitter designs and for all water qualities. Emitters supplied with WSP effluent generally clogged to a greater degree than those supplied with potable water and the principal cause of clogging was shown to be sand particles. However, no statistically significant difference was recorded in the discharge characteristics of the most efficient emitter design between different water qualities. Thorough cleaning of the irrigation laterals in 1987 and replacement of emitters in 1988 failed to eradicate the sand contamination problem. Examination of clogged emitters by electron microscopy showed that organic material encased the sand particles in clogged emitters from laterals supplied with WSP effluent, thereby sealing the water channel. This mass was shown to be comprised of dead microalgae and invertebrate animals such as Daphnia spp. on which bacteria developed. Microalgae did not multiply in the dark environment of the emitter interiors. External algal mats were detected on less than 5 percent all emitters supplied with WSP effluent and were absent on all emitters supplied with potable water. Emitter C, which was the design that presented the largest wetted surface to sunlight, developed the greatest number of mats and covering these emitters with black polythene prevented mat development. The mats were shown to comprise of predominantly filamentous cyanobacteria (Oscil/atoria spp. and Lyngbya spp.) and filamentous green algae (Microcystis spp.). Although these organisms were also detected on the walls of the maturation pond, they were not detected in grab samples of pond effluent which contained predominantly planktonic algal genera such as Euglena spp. and Chlorella spp. Short decaying filaments of Oscillatoria spp. were, however, detected within the irrigation laterals and on the surfaces of sand particles within clogged emitters and no degree of filtration would guarantee their complete removal from the pond effluent. It was hypothesised that their development on the outer surfaces of emitters was a result of colonization of a well-illuminated, wet and nutrient-rich environment and that the source of the inoculum was as likely to be the soil as to be the maturation pond. Studies of greenhouse irrigation systems in the UK revealed that algal mats were a consequence of applying inorganic nutrients to the crop in the irrigation water: their development can be prevented in greenhouses by chlorination of the water supply. It was concluded that clogging results from a combination of physical, chemical and biological factors. Sand particles can be efficiently removed from the water supply by incorporating a simple screen filter, with a mesh size of at least 120, that allows microalgae to pass through the system to the soil. Clogging by sand particles was exacerbated by chemical precipitation of calcium carbonate and by the development of a organic material over the surface of the sand particles in emitters supplied with pond effluent. Biological growth alone was not shown to cause emitter clogging. It was also shown that the development of algal mats over the outer surface of emitters supplied with pond effluent were not a result of an accumulation of pond algae at this point but represented an opportunistic colonization of a well illuminated nutrient-rich environment by microorganisms from the atmosphere and/or soil. Algal mats had no adverse effect on the operation of emitters in WSP reuse irrigation.

Agriculture accounts for 50% of India's gross national product and irrigated agriculture for two thirds of the nation's crop output. The energization of agricultural pumpsets is one of the main goals of India's rural electrification program but the economics of these long power line extensions for small power loads are often unfavourable. Other options for satisfying India's need for remote irrigation water supply systems include the use of photovoltaic (PV) pumps. In this study an attempt was made to determine suitable applications for PV pumping systems in the irrigation sector. Drip irrigation was considered the most appropriate method of irrigation for use with a PV pump. Grapes were considered a suitable crop due high water savings under drip irrigation, the perennial nature of the crop, and high economic returns. Insolation, evapotranspiration, and effective precipitation were determined for a number of stations across India. This information was used to calculate irrigation water requirements for grapes and size a suitable PV pumpset. The cost of irrigating with a PV pump was compared to costs for other remote water pumping options and the net present worth of all costs and benefits for grape cultivation were calculated from both an economic and financial perspective. PV pumping systems did not prove to be the least cost option for irrigation due to the exceptionally low cost of diesel pumpsets in India. In spite of this, the net present worth of grape cultivation with a PV drip irrigation system was found tc be positive as was the incremental benefit of PV drip irrigation over surface irrigation with a diesel pump.

In der Wintersaison 2005-2006 wurde ein Split-Split Plot-Design Feldversuch mit drei Wiederholungen für jede Behandlung von Kartoffeln, als Indikatorpflanze, unter den ariden Bedingungen der Kharga Oasis in der Westlichen Wüste von Ägypten durchgeführt. Drei Bewässerungslevel (100 %, 80 %, und 60 % of ETc) mit Tröpfchenbewässerung, zwei Mulchvarianten (Zuckerrübenabfall ohne und mit 24 ton ha-1) und 4 Kompostraten (0, 12, 24, und 36 ton ha-1) wurden getestet. Generell und als Ergebnis einer Regressionsanalyse der Versuchsvarianten ohne Kompost war die beste Variante die Tröpfchenbewässerung bei 80% ETc unabhängig ob gemulcht oder nicht gemulcht wurde. Andererseits die Variante mit 36 t Kompost und mit 24 t Mulch ergab die besten Ergebnisse bei 60% of ETc sowohl beim Ertrag und den Ertragskomponenten, bei den hydrophysikalischen Eigenschaften, bei der Bodenwasserretention, beim Wasserverbrauch, bei den Pflanzenkoeffizienten, der Wassernutzungseffizienz, der Düngernutzungseffizienz sowie beim Nettogewinn. Wird die Rate der Kompostgabe aber auf 24 ton ha-1 reduziert, die höchsten Nettogewinne bei der lokalen Vermarktung als auch signifikant beim Kartoffelexport werden erreicht.
Under the arid condition of Kharga Oasis in the Western Desert of Egypt, split-split plot design field experiment with three replications for each treatment using potato as an indicator plant was carried out during the winter season 2005-2006. Three irrigation levels of water regime (100 %, 80 %, and 60 % of ETc) using drip irrigation system, two treatments of soil covering (sugar cane wastes at the rate of 0 and 24 ton /ha) and compost rates (0, 12, 24, and 36 ton ha-1) were tested. In general and as a result of the triple interaction among the studied treatments, using drip irrigation either with soil mulching or not, 80 % of ETc as a water regime was the best. On the other hand, reducing drip irrigation water level at 60% of ETc in mulched soil that was treated with 36 ton ha-1 of compost recorded the highest values yield and yield components, soil hydrophysical properties, soil water retention, water consumption, crop coefficients, water economy water use efficiency, fertilizer use efficiency, net profit. But reducing the compost rate to 24 ton ha-1 attained the highest net profit for local potato consumption and achieved the best significant net profit for exportation.

4 pp.
Many growers in Arizona are switching from surface to drip irrigation. This change requires many changes in water management. One of the changes that growers are having the most difficulty with is the concept of applying gallons of water instead of inches. This paper helps growers make this conversion from inches to gallons and then back again. An accompanying EXCEL program, available on the web, will help growers determine run times and application amounts.

At present, agriculture is the human activity which requires more volume of water. Given the importance and scarcity of this resource, the efficient use of water has become a priority. On one hand, if possible, it is necessary to use irrigation systems such as microirrigation that use water more efficiently. On the other hand, treated wastewater reuse by agriculture helps to have the necessary water at the same time that it allows to release water of higher quality for other uses. In this sense, microirrigation is the safest system to apply reclaimed effluents. However, its main problem is emitter clogging, which can negatively affect crop yields and system maintenance. In order to avoid emitter clogging, the use of filters is compulsory. Those filters that work better with effluents are sand filters, although, due to their pressure requirements, concentrate most of the energy demand of drip irrigation systems. This thesis determines the effect of three types of sand filters with different drainage designs (arm collector, inserted domes and porous media), two media height (0.2 and 0.3 m) and two filtration velocities (30 and 60 m/h) in the quality of filtered water, the pressure loss in the filters, the energy consumption of the system and emitter clogging
En l’actualitat, l’agricultura és l’activitat humana que requereix més quantitat d’aigua. Davant la importància i escassetat d’aquest recurs, l’ús eficient de l’aigua s’ha convertit en una prioritat. D’una banda i si és possible, es fa necessària la utilització de sistemes de reg com el reg per degoteig que empren de forma més eficient l’aigua. D’altra banda, la reutilització d’aigües residuals tractades per l’ús agrícola ajuda a disposar de l’aigua necessària per a reg al mateix temps que permet alliberar aigües de major qualitat per a altres usos. En aquest sentit, el reg per degoteig és el sistema més segur per aplicar aigües regenerades. No obstant això, el seu principal problema és l’obturació dels degoters, que pot afectar negativament al rendiment dels cultius i al maneig de la instal·lació. Per intentar evitar les obturacions, resulta imprescindible instal·lar filtres. Els que millor funcionen amb aquest tipus d’aigües són els filtres de sorra, encara que, degut a la pressió que requereixen, concentren la major part de demanda d’energia dels sistemes de reg per degoteig. En la present tesi es determina l’efecte de tres tipus de filtres de sorra amb diferents dissenys de drenatge (de braços col·lectors, de crepines inserides i de medi porós), l’alçada del medi filtrant (0.2 i 0.3 m) i la velocitat de filtració (30 i 60 m/h) en la qualitat de l’aigua filtrada, la caiguda de pressió en els filtres, el consum energètic del sistema i l’obturació dels degoters

A agricultura irrigada, por se tratar do setor produtivo que mais demanda água, tem sofrido continuas pressões para garantir a produção de alimentos com uso eficiente da água. Diante disto, objetivou-se com este trabalho estudar: (i) o efeito de diferentes sistemas de irrigação localizada (microaspersão e gotejamento) sob diferentes configurações na produtividade da bananeira BRS Tropical; (ii) avaliar a distribuição de raízes das plantas irrigadas por esses sistemas; (iii) calcular a eficiência de aplicação de água desses sistemas na cultura da bananeira e (iv) definir o posicionamento de sensores de água no solo para monitoramento da irrigação sob os sistemas considerados. O experimento foi conduzido nos campos experimentais da Embrapa Mandioca e Fruticultura Tropical, no qual foram estudados diferentes sistemas de irrigação localizada na cultura da bananeira BRS Tropical. Verificou-se que não houve efeito das diferentes configurações dos sistemas de irrigação por microaspersão nas variáveis de produção da bananeira BRS Tropical, o mesmo ocorrendo com as plantas irrigadas por diferentes configurações de sistemas de gotejamento. Entretanto, a produtividade da bananeira foi maior quando irrigada por sistemas de microaspersão do que por sistemas de gotejamento. A profundidade efetiva das raízes da bananeira irrigada por microaspersão e gotejamento foram 0,5 e 0,3 m, respectivamente, com exceção dos sistemas com gotejadores distribuídos em faixa contínua e com quatro gotejadores por plantas, para os quais se registrou uma profundidade efetiva de 0,25m e 0,6m, respectivamente. Quanto à eficiência de aplicação de água, nos sistemas de microaspersão, para um mesmo volume de água aplicado, na medida em que a uniformidade de distribuição de água dos sistemas aumenta, diminui-se a percolação, aumenta-se a extração de água e a eficiência de aplicação de água torna-se mais elevada. Nos sistemas de gotejamento, o incremento no número de emissores na linha lateral promoveu o crescimento da área de distribuição de raízes no solo em relação a lateral da planta, aumentou as áreas de extração de água, reduziu as perdas por percolação e aumentou a eficiência de aplicação. Na definição do posicionamento de sensores no solo, para a microaspersão, verificou-se que os sensores podem ser localizados na região que compreende a distância do pseudocaule ao emissor de 0,1 m à 0,7 m, 0,1 m à 0,8 m e 0,4 m à 1 m, nos sistemas com um microaspersor de 32 L h-1 para quatro plantas, um microaspersor de 60L h-1 para quatro plantas e um microaspersor de 60L h-1 para duas plantas, respectivamente, sendo a profundidade de instalação limitada em 0,25 m. Nos sistemas de gotejamento, definiu-se que os locais ideais de instalação dos sensores nos sistemas que utilizam dois, quatro e cinco emissores de 4 L h-1 por planta, partindo-se do pseudocaule da bananeira na direção da fileira de planta, às regiões limitadas pelas distâncias horizontais e profundidades de 0,2 m e 0,4 m; 0,5 m e 0,35 m; 0,55 m e 0,35 m, respectivamente.
Irrigated agriculture is the part of the productive section that demands more water, as a consequence, it has been under continuous pressure in order to guarantee food production with efficient water use. This work had as objective, studies about: (i) effects of different trickle irrigation systems (sprayer and drip) configurations on yields of banana cv BRS Tropical; (ii) evaluation of root distribution of plants which were under these systems; (iii) application efficiency of these systems on banana crop and (iv) soil water sensor placement definition for irrigation scheduling of the evaluated systems. The experiment was carried out on the experimental fields of Embrapa Cassava & Tropical Fruits, where studies about different trickle irrigation systems on banana crop were accomplished. There was no effect of the different sprayer or drip irrigation systems configurations on the production variables of banana cv BRS Tropical, however yields of banana irrigated by sprayer were larger than those of banana irrigated by drip. The effective root depth of banana irrigated by sprayer and drip systems were 0.5 and 0.3 m, respectively, except for drip systems with drippers distributed as line source and systems with four drippers per plant. In those cases the effective root depths were 0.25 m and 0.6m, respectively. Concerning water application efficiency and the same volume of water applied for all sprayer systems, the larger the water distribution uniformity, the larger the root water extraction and the water application efficiency and the smaller the deep percolation. The increase of emitters on the lateral lines provided growth of root distribution area and root water extraction area around the plant, reduced deep percolation losses and increased water application efficiency. Concerning definition of sensor placement around plants for sprayer system, it was noticed that sensors may be placed in zones limited by distances between plant and emitter of 0.1 m to 0.7 m, 0.1 m to 0.8 m and 0.4 m to 1 m for systems of one 32 L h-1 sprayer for four plants, one 60 L h- 1 sprayer for four plants and one 60 L h-1 sprayer for two plants, respectively. In all cases, the depth for sensor installation was 0.25 m. In case of drip irrigation systems, the ideal zones for sensor placement for systems that use two, four and five 4 L h-1 emitters per plant were limited by horizontal distances and depths of 0,2 m and 0,4 m; 0,5 m and 0,35 m; 0,55 m and 0,35 m, respectively.

碩士
義守大學
電子工程學系
102
Drip irrigation system is an important system to lead the traditional agriculture to the modern agriculture profound change. Currently, Taiwan''s agricultural policy is agricultural land regeneration, technology applied into agricultural, and let the operation scale becomes deeply and widely. Low-cost, simple and practical drip irrigation system must be strongly introduced to high-tech agricultural society to adopt into new agriculture model. In this thesis, MCU HT66F50, developed by Holtek Semiconductor INC., with fully functional human-machine interface, is been used as main controller to implement all smart irrigation functions. A set of transducer include: temperature, Moisture, light and water level sensors are been used for smart functioning. System automatically adjusts drip irrigation system output water and spray system working state by the sensed value of sensors. Thereby not affecting crop growth but maximize the use of water resources. Farmer can do farming everywhere. In addition to the water conservation, it also can achieve to improve crop quality, inhibit weed growth and increase crop yields, the most important thing is to save expensive labor cost, enhance market competitiveness.

碩士
國立中興大學
生物產業機電工程學系所
98
High quality agricultural products is the market trend, and the plant factory plays an important role. The most appropriate irrigation period for plants appeared in the just beginning of water scarcity. Too early irrigation often causes a waste of water. Variable rate irrigation control technology can achieve an ideal water irrigation based on precise timing and a small amount of water delivery for different physiological conditions and water requirements. The study is to test a commercial drip irrigation system base on a single emitter solenoid valve and partition area irrigation methods, cooperates with time control and flow control modes of measurement in each mode and the partition area of water flows. The results showed that retrofitting a solenoid valve with emitters will not affect the uniformity of drip irrigation system, its uniformity were higher than 95%, It can be supply different amount of water according to the plant in different needs by single emitter controlled. These results can be used as reference of drip irrigation system design.

Characteristics of emitters under low pressure are essential for designing drip irrigation systems. Low pressure data for drip emitters are not available from manufacturers. A laboratory test was conducted to evaluate the performance of five types of newly manufactured drip tapes, especially under a low pressure distribution system. The five drip products that were tested were (i) Toro Drip in PC (PCS 1810-18- 100), (ii) T-Tape (TT15-1245-0100), (iii) Mister_LS (MLD-HDT100), (iv) Mister_PS (MLD-1PC 25), and (v) Netafim (Techline CV 560 050). Drip tapes tested in this study have design discharge rates of 4.00 L/hr @ 206.84 Kpa (1.06 gph @ 30 psi), 1.02 L/hr @ 55.16 Kpa (0.27 gph @ 8 psi), 3.785 L/hr @ 172.37 Kpa (1.00 gph @ 25 psi), 3.785 L/hr @172.37 Kpa (1.00 gph @ 25 psi), and 0.984 L/hr @ 206.84 Kpa (0.26 gph @ 20psi), respectively. All of them, except T-Tape, were pressure compensating (PC) emitters; the T-Tape was non-pressure compensating (NPC). For all products, except Toro, the emitter spacing was 0.305 m (12 inches) and for Toro, it was 0.46 m (18 inches). Mister_PS (MLD-1PC 25) was the point source (PS) emitter and all others were line source emitters. Drip products were tested with 15 different operating pressures ranging from 5.97 KPa (0.87 psi) to 344.74 KPa (50.00 psi). From an evaluation of 60 emitters from each product, the Toro brand showed an average uniformity coefficient (UC) of 91.24 %, with a coefficient of variation (Cv) of 0.06, T-Tape drip products showed an average UC of 96.63 % with a Cv of 0.04, Mister_ LS showed an average UC of 93.12 % with a Cv of 0.08, Mister_PS showed an average UC of 96.33 % with a Cv of 0.04, and Netafim showed an average UC of 97.92 % with a Cv of 0.02. Flow rate vs. pressure head (Q-H) curves were also developed for each drip emitter tested. From emitter exponent values it was observed that all of the pressure compensating (PC) products behaved like NPC emitters at low pressures, although they behaved like PC emitters under normal operating pressures. From statistical analysis, it was determined that except for Netafim product, all other tested products were effective under low operating pressures as were under high operating or recommended pressures. Netafim product had no emission under low pressures. Using the measured average emission rate and developed Q-H curves, the distribution uniformities of all products except Netafim were calculated under low pressure ranges of 5.97 KPa (0.87 psi) to 23.88 KPa (3.50 psi ) for different lengths of laterals and under 0%, 1%, 2%

The objective of this study was to investigate the need for domestic wastewater to receive secondary treatment when being applied to the soil by subsurface drip irrigation (SDI). SDI uniformly distributes wastewater into the soil, which optimizes the soil’s chemical, physical, and biological capacity to remove waste constituents. Because of these advantages, many regulatory jurisdictions are allowing SDI at sites that previously were prohibited from using conventional trench-based soil application systems because of shallow soil restrictions. However, most of these regulatory agencies also require that the wastewater receives secondary treatment (dissolved organic carbon reduction) before the SDI system. At issue is whether the enhanced soil-based renovation provided by SDI should eliminate the necessity for secondary treatment before SDI.Two SDI systems were installed and monitored at two sites in Tennessee. These locations were residential developments served by a septic tank effluent pump (STEP) collection system, a recirculating media filter (fine gravel media), and SDI dispersal. At both locations, SDI plots were established to receive primary treated (septic tank effluent) and secondary treated (recirculating media filter effluent) wastewater. In close proximity to randomly selected SDI emitters, soil samples were extracted. Soil cores were analyzed to determine saturated hydraulic conductivity (Ksat), and pore water samples were analyzed for nitrate, total nitrogen, total carbon, and total phosphorus. Results indicate that the primary-treated sites had lower Ksat values, higher nitrate and higher total nitrogen levels than the secondary-treated side and the background soil. Interestingly, the primary treated side had less total carbon and the background phosphorus concentration was twice that of the primary and secondary treated sides. Primary effluent showed a decrease in concentration for all constituents with increased depth. Secondary treatment does result in a higher quality effluent but is not needed when applying effluent with a SDIS.