Knowing the concentrations of the nutrient elements in soils is important due to their toxic effect on humans and the environment. The aims of this study were to assess the effects of water quality, depths and distances of lateral installation on soil chemical properties during turfgrass cultivation. A field experiment was conducted using a Split Split Plot design based on the Randomized complete Block (RCB) with two treatments (well’s and wastewater), and eight sub-treatments (45 and 60 cm distance of the laterals and 15, 20, 25, and 30 cm depths of laterals) in three replicates on a sandy-loam soil, in Shahrekord, Iran. Soil samples were collected from 0-30 and 30-60 cm depth for measuring nitrate (NO3-), electrical conductivity (EC), and pH at the end of the experiment. During the experiment, fecal coliform (FC) were also measured at the soil surface. Results indicated that by increasing lateral distance, NO3- level increased in both layers. With installing laterals in deeper levels, NO3- concentration decreased at the beginning, then increased in the first layer, whereas in the second layer NO3- concentration decreased. In addition, installing laterals in deeper depth, caused an increase in soil EC in the top layer, but a decrease in the lower layer. However, the results showed that there was no significant effect of experimental factors on soil pH. The results also show that with increasing laterals depth, Fc level decreased at the soil surface.

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.

Improving water efficiency is and will continue to be a top concern to meet the world food production demands for a growing population. By having a clear understanding of water efficiencies, communities will be able to address these concerns from an economic standpoint and use more productive methods to grow food and limit water consumption. This study examines the water efficiencies of three irrigation methods over a single growing season in southeastern Oklahoma. Two crops, tomatoes and cucumbers, were grown using drip irrigation, a self-wicking container, and a non-circulating hydroponics barrel. Results at the end of the season showed the drip irrigation method had the highest water efficiency in terms of yield of product over water applied for both crops. The drip irrigation method also had the lowest associated set up costs and second lowest time requirements after the hydroponics method. These results were found to be consistent with other studies that compared drip irrigation to other irrigation methods and showed drip to have the highest water efficiencies.

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No description available.

Master of Science / Department of Agronomy / Scott A. Staggenborg / In recent years, subsurface drip irrigation (SDI) acres have increased substantially. The use of SDI on corn (Zea Mays L.) in the Great Plains has increased due to increased land costs, reduced irrigation water availability, and higher commodity prices. Applying phosphorus (P) fertilizer through a SDI system becomes a major advantage, but further investigation of the interaction between water and fertilizer is needed. Sub-surface drip irrigation systems can be used to better improve the application efficiencies of fertilizers, applying in wet soil-root zones can lead to better uptake of soil applied materials. The objectives of this study were to determine how corn responds to P fertilizer applied via SDI and to create methodologies to simulate fertilizer and irrigation water compatibility tests for use in SDI systems. A plot sized SDI system was installed near Manhattan, KS to evaluate P treatments. Eight separate P fertilizers were applied via SDI mid-season at a rate of 34 kg P2O5 ha-1 and split-plots were created with 2x2 starter band at planting. Nitrogen was a non-limiting factor, with 180 kg N ha-1 applied as urea. Both starter fertilizer and injected fertilizer affected corn grain yield as indicated by the starter by treatment interaction. Split applying starter fertilizer at planting increased yield. A secondary laboratory study was conducted to evaluate the water and fertilizer interactions. A filtration system was used to simulate field conditions and each fertilizer/water mix was filtered through a 400 mesh filter paper to evaluate fertilizer precipitant formation. Sixteen common fertilizers were analyzed with different rates of Avail. Differences were observed between fertilizer treatments, visually and quantitatively. A secondary P soil movement field study was performed to quantify P concentrations around the SDI emitter. Soils were sampled in a 30.5 cm by 30.5 cm square adjacent to the emitter on a control treatment and a fertilized treatment, in both years of the study. Visual and quantitative differences were observed between the two treatments in both years of the study. When P fertilizers were added to the SDI system, higher P concentrations were found very close to the emitter orifice. Control treatments exhibited lower P concentrations around the emitter than fertilized treatments.

The site-specific management of alfalfa has not been well-evaluated, despite the economic importance of this crop. The objectives of this work were to i) characterize the effects of soil moisture deficits on alfalfa and alfalfa yield components and ii) evaluate the use of canopy reflectance patterns in measuring treatment-induced differences in alfalfa yield. A randomized complete block design with five replicates of subsurface drip irrigation (SDI) and rainfed treatments of alfalfa was established at the University of Kentucky Animal Research Center in 2003. Potassium, as KCl, was broadcast on split-plots on 1 October 2004 at 0, 112, 336, and 448 kg K2O ha-1. In the drought year of 2005, five harvests (H1 - H5) were taken from each split-plot and from four locations within each SDI and rainfed plot. One day prior to each harvest, canopy reflectance was recorded in each plot. Alfalfa yield, yield components, and leaf area index (LAI) were determined. In 2005, dry matter yields in two harvests and for the seasonal total were increased (Pandlt;0.05) by SDI, but SDI did not affect crown density. Herbage yield was strongly associated with yield components but yields were most accurately estimated from LAI. Canopy reflectance within blue (450 nm), red (660 nm) and NIR bands were related to LAI, yield components, and yield of alfalfa and exhibited low variance (cv andlt; 15%) within narrow ( 0.125 Mg ha-1) yield ranges. Red-based Normalized Difference Vegetation Indices (NDVIs) and Wide Dynamic Range Vegetation Indices (WDRVIs) were better than blue-based VIs for the estimation of LAI, yield components, and yield. Decreasing the influence of NIR reflectance in VIs by use of a scalar (0.1, 0.05, or 0.01) expanded the range of WDRVI-alfalfa yield functions. These results indicate that VIs may be used to estimate LAI and dry matter yield of alfalfa within VI-specific boundaries.

Com o propósito de avaliar o potencial de intrusão radicular e os efeitos da ocorrência de vácuo nas linhas de irrigação em diversos modelos de gotejadores, quando utilizados em irrigação subsuperficial, foram conduzidos três experimentos em condição de ambiente protegido. Dois experimentos foram conduzidos em vasos: um com a cultura da cana-de-açúcar; e o outro com o objetivo específico de avaliar a possibilidade de estabelecimento da cultura do feijão como padrão de ensaio para experimentos de suscetibilidade de gotejadores à intrusão radicular. Para esses dois experimentos, os tratamentos consistiram de 14 modelos de gotejadores de diferentes marcas comerciais, dos quais 7 do tipo não-compensante e 7 do tipo autocompensante de pressão; os modelos foram instalados em duas profundidades, 0,15 m e 0,30 m do nível da superfície (P15 e P30, respectivamente), e conduzidos em solo sob três condições de enraizamento: a)Úmido, no qual a irrigação era iniciada quando o potencial de água no solo atingia -30 kPa, medido através de tensiômetro, b) Seco, quando o potencial matricial da água no solo atingia -80 kPa e c) Sem cultivo (SC), no qual os vasos foram mantidos sem plantas, sendo utilizados para comparação das vazões determinadas nos vasos com culturas, tanto do experimento com cana-de-açúcar como com feijão, possibilitando, assim, isolar o efeito de outros fatores causadores de variação de vazão dos gotejadores que não a intrusão de raízes. O terceiro, conduzido nos mesmos vasos do feijão após finalizado o experimento inicial, simulou o efeito de 5 níveis de vácuo na vazão dos gotejadores, em função do sucção de partículas do solo. Os níveis de sucção avaliados foram -13, -20, -26, -53 e -80 kPa. Com o propósito de avaliar a capacidade de recuperação da vazão de gotejadores afetados pela sucção de partículas, foi efetuada uma leitura de vazão após 3 irrigações, de 1 hora cada. As leituras de vazão foram realizadas com freqüência mensal, por um período de 90 dias para o feijão, e de 270 dias para a cana-de-açúcar. No experimento com a cana-de-açúcar, os resultados obtidos mostraram diferenças marcantes no comportamento do gotejadores do tipo nãocompensante de pressão daqueles do tipo autocompensante e, dentro de cada tipo, diferenças estatisticamente significativas quanto à suscetibilidade à intrusão de raízes. Quanto ao efeito da intrusão e enterrio, os modelos autocompensantes apresentaram maior magnitude de variação da vazão em relação aos gotejadores não-compensantes, em todos os experimentos conduzidos. Nos modelos mais susceptíveis, observou-se maior nível de intrusão na condição de enraizamento úmido, embora esse comportamento não tenha sido estatisticamente significante na análise efetuada para a leitura de vazão efetuada no final do experimento, aos 270dias. Tanto para a cana como para o fe ijão, não foi observada diferença significativa no nível de intrusão de raízes em relação à profundidade de instalação dos gotejadores. Os resultados obtidos com a cultura do feijão indicam sua inadequabilidade para testes rápidos de suscetibilidade de gotejadores à intrusão de raízes. Evidenciou-se que as estratégias de barreira física devem ser definidas visando não apenas à prevenção da ocorrência da intrusão mas também, depois de efetivada a intrusão, a minimização da possibilidade de a raiz intrusa penetrar no interior da linha lateral de gotejadores, o que ampliaria o efeito da intrusão na malha hidráulica da parcela de irrigação; pequenas adequações em parâmetros da arquitetura ou no processo de montagem dos tubos gotejadores poderiam reduzir essa possibilidade. / In order to evaluate the potential of root intrusion and vacuum damage (flow disturbance) in subsurface drip irrigation (SDI), fourteen emitters were tested on three experiments under controlled environment (greenhouse and vase conditions). The first one was based on sugar-cane crop and the second one based on bean crop, aiming to establish this temporary crop (bean) as a reference plant in a future root intrusion standard test applied to SDI. Among the selected emitters from different manufactures, seven of them were no compensating drippers and the others pressure compensating drippers. The drippers were installed in two different depths: 0.15m and 0.30m from soil surface (P15 and P30) and conducted under three watering conditions: 1. Moist : irrigation started when the water potential in soil reached -30 kPa (tensiometer) 2. Dry, irrigation started when the water potential in soil reached -80 kPa, and 3. No crop / Moist (NOC) where the vases were kept without any crop (Control) with the same irrigation level of condition 1, being possible to isolate other factors than root intrusion, which could disturbed emitters flow rate. The third experiment was conducted after finalizing the experiment with the bean crop (same vases), simulating 5 levels of vacuum in the hydraulic network (condition reached just after closing parcel valves in the field), trying to measure the flow rate variation of emitters, related to particles suctioned from soil. The suction levels evaluated were -13, -20, -26, -53 and -80 kPa for a short time and flow rate was measured just after 3 hours of irrigation, in order to stimulate the self-cleaning processes of emitters before measuring the vacuum-disturbed flow rate. An electromagnetic flow meter was used during all experiment, in order to measure the individual flow rate of buried emitters in vases; flow rate readings were taken every month in the bean crop (90 days cycle) and in the sugar cane crop (270 days cycle). For the sugar-cane experiment, the root intrusion results showed remarkable differences between no compensating and pressure compensating drippers (statistically significant). The self-compensating models showed a larger flow rate variation, compared to the no compensating emitters. It was visually observed for some susceptible emitters a greater level of root intrusion under high soil moistur e content, although this behavior has not been statistically significant at the end of the sugar cane experiment (270th day). There were no significantly differences in root intrusion (either for sugar-cane or bean crops) related to the installation depth of emitters (15 and 30 cm). The obtained results do not recommend the use of a temporary crop (bean) as a reference plant for a standard test related to root intrusion, because it takes at least 6 month to detected significant root intrusion in SDI. The strategy of developing emitters physical barriers against root intrusion, should focus not only in the prevention of entering but also in the minimization of damage related to the intruded root inside the emitter, because in some circumstances it is possible to keep flow rate close to nominal rate even with roots inside the drippers.

O aumento na utilização do sistema de gotejamento em grandes culturas como a cana-de-açúcar, visa minimizar perdas hídricas durante o processo de irrigação, principalmente em períodos de escassez hídrica ocorrida no país. Para atingir tal propósito, o dimensionamento correto desse sistema de irrigação é de fundamental importância, viabilizando o manejo adequado e uso de práticas para aplicação de fertilizantes (solutos), via água de irrigação (fertirrigação). Nesse sentido, são necessárias informações um pouco mais precisas sobre a dinâmica da água e dos solutos no solo, os quais estão relacionados com a distribuição desta solução em torno do emissor (gotejador). Assim sendo, o principal objetivo dessa pesquisa consistiu em avaliar o desempenho do modelo HYDRUS-2D nas simulações numéricas da formação do volume de solo molhado sob irrigação por gotejamento subsuperficial, em diferentes fases de desenvolvimento da cultura de cana-de-açúcar (perfilhamento, crescimento dos colmos e maturação), buscando-se comparar os resultados obtidos pelas simulações do modelo com aqueles obtidos em condições experimentais. Para tal, foram coletados dados de umidade volumétrica do solo e das concentrações de potássio no solo, pela Técnica da Reflectometria no Tempo (TDR), tornando possível a obtenção de dados em tempo real da distribuição da solução, como também, auxiliar na avaliação e performance do modelo matemático HYDRUS-2D. Assim sendo, a referida pesquisa foi dividida em duas etapas: Etapa 1) Coleta de dados das propriedades físico-hídricas do solo e da distribuição da água e do potássio mediante um arranjo experimental, distribuído em dois tratamentos, inteiramente casualizados, sendo três repetições e seis parcelas, dispostos da seguinte maneira, Tratamento 1 (T1): sem cultivo de cana-de-açúcar e com emissor de vazão de 4,0 L h-1, Tratamento 2 (T2): com cultivo de cana-de-açúcar, com emissor de vazão 4,0 L h-1 e na Etapa 2) Foi realizada a simulação numérica da distribuição da solução (água e potássio), pelo modelo HYDRUS-2D nos respectivos estágios de desenvolvimento do cultivo da cana-de-açúcar (citados anteriormente). O desempenho do modelo foi avaliado com base nos seguintes parâmetros estatísticos: Raiz do Erro Quadrático Médio (RMSE) e Erro Absoluto Médio (MAE). A partir dos resultados obtidos nos parâmetros estatísticos, os dados estimados pelo modelo HYDRUS-2D obtiveram uma boa concordância em relação aos dados observados do conteúdo de água e da concentração de potássio presente no perfil de solo. Diante disso, pôde-se concluir que o modelo HYDRUS-2D forneceu uma caracterização aceitável do volume de solo molhado nas diferentes fases de desenvolvimento da cana-de-açúcar e também sem a presença da cultura. / Drip irrigation systems are increasingly being used for such major crops as sugarcane to minimize water losses during irrigation. Saving water is becoming more and more important also in Brazil because of increasing water scarcity in the country. Proper design of a drip irrigation system is fundamental to implementation of optimal water and nutrient management practices, including possible application of fertilizers with the irrigation water (fertigation). This in turn requires reliable information about expected water and solute distributions in the soil profile around the emitters (drippers) during and after irrigation The main objective of this research was to use the HYDRUS-2D software package to estimate wetted soil volumes around the drippers during subsurface drip irrigation at different stages of sugarcane development (tillering, stalk growth, maturation), and to compare numerical results with experimental data. Field data collected for this purpose included soil moisture and potassium concentration distributions using Time Domain Reflectometry (TDR). Results made it possible to follow evolving solute concentration distributions around the drippers in real time, and to evaluate the performance of HYDRUS-2D. The research was divided into two steps: Step 1 involved collection of physical and hydraulic data of the soil, as well as of water and potassium distributions by means of a completely randomized experimental arrangement using two treatments, each with three replicates. Treatments 1 and 2 were for the scenarios without and with sugarcane cultivation, with both treatments having a flow emitter rate of 4.0 L h-1. Step 2 involved HYDRUS-2D simulations of the moisture and potassium concentration distributions around the drippers at different stages of sugarcane development. Model performance was evaluated using the following statistical parameters: Mean Squared Error Root (RMSE) and Mean Absolute Error (MAE). From the results obtained in the statistical parameters, HYDRUS-2D predictions obtained a good agreement with the observed data of water content and the potassium concentration in the soil profile. Therefore, it was concluded that HYDRUS-2D model provided an acceptable characterization of the wetted volume at different stages of development of sugarcane and also without the presence of culture.

A vinhaça é um resíduo da produção de etanol e reutilizada nas áreas de cana-de-açúcar fornecendo nutrientes para cultura, principalmente potássio. Gerada na proporção de 10 a 13 litros para cada litro de etanol produzido, a vinhaça representa uma excelente alternativa aos fertilizantes químicos e apresenta desafios ambientais e técnicos para sua aplicação nos solos agrícolas. O manejo inadequado da aplicação de vinhaça pode acarretar, além dos problemas ambientais, pior qualidade da matéria prima para indústria. Esta pesquisa teve como objetivo estudar o efeito da aplicação de diferentes doses de vinhaça via gotejamento subsuperficial no desenvolvimento, na produtividade agrícola, nos parâmetros tecnológicos (oBrix, Pol, pureza, fibra, açúcar redutor, açúcar redutor toral, açúcar total recuperável e teor de cinzas), na produção de bioprodutos da cana-de-açúcar e nas alterações do pH e da condutividade elétrica da solução do solo, além da avaliação do sistema de irrigação por gotejamento subsuperficial. O experimento foi instalado na área experimental do Departamento de Engenharia de Biossistemas - USP/ESALQ, situada em Piracicaba-SP. Foi adotado o delineamento estatístico inteiramente casualizado com 6 tratamentos e 4 repetições, sendo o tratamento 1 sem irrigação e com adubação convencional junto ao plantio, tratamento 2 fertirrigado convencional, e os tratamentos de 3 a 6 fertirrigados com diferentes doses de vinhaça. O tratamento 4 recebeu a dose (DCETESB) calculada segundo os critérios da norma técnica P4.231/2005 da CETESB, e os tratamentos 3, 5 e 6 receberam, ½ DCETESB, 2xDCETESB e 3xDCETESB, respectivamente. Dois ciclos, cana-planta e primeira soca, foram avaliados. O acompanhamento do pH e da condutividade hidráulica do solo, o desenvolvimento vegetativo, a análise nutricional das folhas e o desempenho do sistema de irrigação foram avaliados no primeiro ciclo. A produção de biomassa, a produção de açúcar, a produção de etanol foram avaliados nos dois ciclos. Os resultados mostraram que houve um aumento dos valores de pH e CE no solo, diante do aumento do volume aplicado, mas evidenciou-se a necessidade de um maior intervalo de tempo para a percepção de suas diferenças. Os tratamentos 4, 5 e 6 apresentaram maiores valores de área foliar e altura de planta em relação ao tratamento 1, enquanto que os outros dados de biometria não apresentaram diferença entre os tratamentos. As análises foliares realizadas mostraram que não houve influência das doses de vinhaça no estado nutricional das plantas. Dentre os parâmetros tecnológicos avaliados o teor de cinzas no caldo foi influenciado pela aplicação de diferentes doses nas duas colheitas realizadas, já os outros parâmetros não foram influenciados. A produtividade de cana-de-açúcar apresentou diferença entre os tratamentos apenas na primeira colheita, sendo que aplicação de vinhaça resultou no aumento de produção. Esse aumento de produtividade ocorrido no primeiro ciclo resultou diretamente em um aumento do etanol de segunda geração (E2G), enquanto que a produção de açúcar, etanol de primeira geração (E1G) e etanol total (E1G+E2G) não apresentaram diferença significativa entre os tratamentos. / Vinasse is a by-product from ethanol production and reused in sugarcane fields providing nutrients to the plants, mainly potassium. Generated at a rate of 10-13 liters for every liter of ethanol, the vinasse represents an excellent alternative to chemical fertilizers and it also presents environmental and technical challenges for its applications on agricultural soils. Mismanagement of vinasse can cause environmental impacts and lower the quality of sugarcane production. This study had as aim to study the effect of application of different doses of vinasse by a subsurface drip irrigation system in sugarcane vegetative development, sugarcane yields, technological parameters, bio-products production, changes in pH and electrical conductivity (EC) of the soil, evaluation of potential to use of drip irrigation to apply vinasse. A completely randomized design with 6 treatments and 4 repetitions was conducted at experimental area of Bio systems Engineering Department of USP/ESALQ, placed in Piracicaba-SP. The treatment 1 was performed in dry land system with chemical fertilization at planting; treatment 2 was fertigated with chemical fertilizers (no vinasse); treatments from 3 to 6 received different levels of vinasse. Treatment 4 received the dose (DCETESB) calculated in according to criteria from technical standard P4.231/2005 of CETESB, and treatments 3, 5 and 6 received ½ DCETESB, 2xDCETESB and 3xDCETESB, respectively. Two cycles of sugarcane were evaluated, first year and firs ratoon. The monitoring of pH and EC of the soil, vegetative development, leaf nutrional analysis and drip irrigation performance were evaluated at first cycle. Biomass, sugar and ethanol production were evaluated at first and second cycles. The results showed that an increase of pH and EC occurred due to the vinasse application, however, was evident the need of a higher interval of time to see the differences. Treatments 4, 5 and 6 showed higher values of leaf area and plant height when compared to treatment 1, while the another biometric data did not show difference between the treatments. Leaf nutritional analysis showed that did not have effect of vinasse doses in nutritional status of the plants. Among technological parameters just as content was affected by the application of different doses of vinasse at two harvests, and the another parameters were not affected. Sugarcane yields showed difference between treatments just at first year when vinasse application resulted in production increasing. This increase caused an increase of second generation ethanol production (E2G), while the sugar, first generation ethanol (E1G) and total ethanol (E1G+E2G) did not show significance difference between treatments.