The state of Rio Grande do Sul (RS) grown in crop 2013/2014, 1,120,112 ha of rice, making up 46.18% of the cultivated area in Brazil, accounting for 66.21% of national production. The Fronteira Oeste of RS cultivated an area of 333,695 ha and 85.7% of this water pumping stations are used, making the cost of irrigation represents 10.74% of the total cost of production of cereal, one of the most expressive. The efficiency of energy use in the process of irrigation of rice fields linked to this agronomic aspects (definition of cultivars and suitable choice of the area) and engineering (pump of choice with adequate affieciency, adjusted net power engine with the need, compatible coupling with installed capacity, pipe sizing, positioning the pump-motor assembly and use of special parts). The lack of parameters that can define the quality of the design of pumping stations creates uncertainty regarding the proper use of energy in the process. Performance indices are indicators that can be used to establish the quality of pumping stations, with regard to aspects sizing. This work aimed to propose performance indexes and ranks them in order to generate referrals, to be used for evaluation of water pumping stations in irrigated rice fields. We evaluated 160 pumping stations, located on the Western Border of RS, under normal working conditions. For each of them were determined appropriate piping, through total cost minimization analysis (fixed more operational) for a period of 10 years of operation, and checked the possible power savings from the same exchange. Similarly been proposed replacement of equipment (pumps and motors) seeking, among commercially available, those with higher operating efficiency for the working conditions of each season. Were proposed nine performance indices and applied situations initially found in the field and those optimized by the replacement of pipes, pumps and motors. The variability found allowed them to be categorized and then was proposed performance index rating as "excellent", "very good", "good", "bad" and "very bad". / O Estado do Rio Grande do Sul (RS) cultivou, na safra 2013/2014, 1.120.112 ha de arroz irrigado, perfazendo 46,18% da área cultivada com o cereal no Brasil, contribuindo com 66,21% da produção nacional. A região da Fronteira Oeste do RS cultivou uma área de 333.695 ha e, em 85,7% desta são utilizadas estações de bombeamento de água, fazendo com que o custo da irrigação represente 10,74% do custo total de produção deste cereal, sendo um dos mais expressivos. A eficiência do uso de energia no processo de irrigação das lavouras de arroz esta atrelada a aspectos agronômicos (definição das cultivares e escolha adequada da área) e de engenharia (escolha de bomba com rendimento adequado, motor com potência útil ajustada à necessidade, acoplamento compatível com a potência instalada, dimensionamento de tubulação, posicionamento do conjunto bomba-motor e uso de peças especiais). A falta de parâmetros que possam definir a qualidade do dimensionamento das estações de bombeamento gera insegurança em relação ao bom uso da energia no processo. Índices de desempenho são indicadores que podem ser usados para estabelecer a qualidade das estações de bombeamento, no que se refere aos aspectos de dimensionamento. Este trabalho teve como objetivo propor índices de desempenho e classificá-los de forma a gerar referências, a serem usadas para avaliação de estações de bombeamento de água em lavouras de arroz irrigado. Foram avaliadas 160 estações de bombeamento, localizadas na Fronteira Oeste do RS, em condições normais de trabalho. Para cada uma delas foram determinadas as tubulações adequadas, através de análise de minimização de custo total (fixo mais operacional) para um período de 10 anos de operação, e verificada a possível economia de energia gerada pela troca das mesmas. Da mesma forma foram propostas substituição de equipamentos (bombas e motores) buscando, entre os disponíveis comercialmente, aqueles de melhor rendimento operacional para as condições de trabalho de cada estação. Foram propostos nove índices de desempenho e aplicados as situações inicialmente encontradas em campo e aquelas otimizadas pela substituição de tubulações, bombas e motores. A variabilidade encontrada permitiu que os mesmos fossem categorizados e então proposta uma classificação de índices de desempenho como excelente , muito bom , bom , ruim e muito ruim .

The rice culture for Rio Grande do Sul economy is of great relevance. Annually, around one million of hectares are planted. As it is a culture irrigated by a continuum flood, the supply of the high hydric demand is done in 70% of the area through pumping station, representing a significant portion of the production costs. Associate with this fact, there is a necessity in reducing water and energy consumption, object of several official and private actions undertaken in the latest years with the object of preserving the sources, reducing costs and contouring conflicts in the water access. The objective of this work was to find an easily and quickly way of planning, trying to help the extensions of the pumping station to rice irrigation. Real known data were used related to the ground-plant-climate system of the Central Depression rice culture region, doing a calculation based in the simplified hydric balance adapted to the rice farming system. Instantaneous hydric demands were calculated for the initial flood and for the maintenance of the flood until the end of the irrigation cicle. To reduce either outflows or installed powers was adopted a division of the total areas established in the simulation (between 10 and 190 ha), and after was done a temporal stagger of the sowing and the irrigation process. A reduction of 64% in the outflow of the initial flow was attained and 63% in the installed electrical powers of the pumping station, when compared to the simultaneous flow process of the farming total areas. When it was used the regression analysis, were got equations for outflows adjustment and required power in operation of total areas for estimations in the intervals of the adopted areas in the work. The resource makes possible the previous planning of farmings relating to the instantaneous demand for initial flow and support supply, as well as in relation to the electrical powers, observing pumping stations in installations in parallel (two or more pump motor system) sets. Another possible application refers to the procedures of elaborating Basin Administrative Committees and corresponding processes of warranting right of water use, in order to offer basic and trustful information to establish maximum cultivable areas because of the minimum availabilities established regionally to the activity. / É incontestável a relevância da cultura do arroz para a economia do Rio Grande do Sul. São plantados anualmente em torno de um milhão de hectares, os quais são irrigados por inundação contínua, exigindo elevada demanda hídrica. O suprimento hídrico do cultivo é atendida em 70% da área através de sistemas de recalque (bombeamento), representando uma parcela apreciável do custo de produção e compreendendo, entre custos diretos e indiretos, 27% do custo total. Evidencia-se assim a necessidade de redução no consumo de água e energia, objeto de várias ações oficiais e privadas empreendidas nos últimos anos com vistas a preservar os mananciais, reduzir custos e contornar conflitos no acesso à água. O foco do presente trabalho voltou-se para a busca de uma ferramenta de planejamento de fácil e ágil aplicação, visando subsidiar os dimensionamentos de sistemas de recalque para a irrigação do arroz. Partiu-se de dados reais típicos relativos ao sistema solo-planta-clima da Região Orizícola da Depressão Central, estabelecendo-se um procedimento de cálculo baseado no balanço hídrico simplificado adaptado ao sistema lavoura de arroz . Foram calculadas as demandas hídricas instantâneas para as fases de inundação inicial e para a manutenção da inundação até o final do ciclo de irrigação. Objetivando a redução tanto das vazões quanto das potências instaladas, foi adotado um fracionamento das áreas totais estabelecidas na simulação (entre 10 e 190ha, em incrementos de 20ha), com conseqüente escalonamento temporal do processo de irrigação. Atingiu-se dessa forma uma redução de até 64% na vazão de inundação inicial e de até 63% na potência instalada elétrica dos sistemas de recalque, quando comparados a processo de inundação simultânea das áreas totais das lavouras. Aplicando análise de regressão foram ajustadas equações que permitem estimar vazões e potências requeridas em função de áreas totais de lavoura no intervalo de áreas da simulação. Este recurso possibilita o planejamento de lavouras no tocante às vazões mínimas requeridas para inundação inicial e para o suprimento de manutenção, bem como em relação ao pré-dimensionamento das potências elétricas mínimas correspondentes, contemplando sistemas de recalque na modalidade de instalações em paralelo (dois ou mais conjuntos motor-bomba). Foram igualmente calculados os módulos de irrigação (vazões específicas expressas em l.s-1.ha-1) para as fases de inundação inicial e de manutenção. Os resultados obtidos permitem aplicações no planejamento regional (alocação de recursos hídricos), no planejamento de formação de lavouras, na estimativa de volumes totais de demanda, em prédimensionamentos de estações de bombeamento, em ações de re-engenharia de instalações existentes e no processo de outorga de direito de uso da água.

Land application of wastes has become increasingly popular, to promote nutrient recycling and environmental protection, with soil functioning as a partial barrier between wastes and groundwater. Dairy shed effluent (DSE), may contain a wide variety of pathogenic micro-organisms, including bacteria (e.g. Salmonella paratyphyi, Escherichia coli. and Campylobacter), protozoa and viruses. Groundwater pathogen contamination resulting from land-applied DSE is drawing more attention with the intensified development of the dairy farm industry in New Zealand. The purpose of this research was to investigate the fate and transport of bacterial indicator-faecal coliform (FC) from land-applied DSE under different irrigation practices via field lysimeter studies, using two water irrigation methods (flood and sprinkler) with contrasting application rates, through the 2005-2006 irrigation season. It was aimed at better understanding, quantifying and modelling of the processes that govern the removal of microbes in intact soil columns, bridging the gap between previous theoretical research and general farm practices, specifically for Templeton soil. This study involved different approaches (leaching experiments, infiltrometer measurements and a dye infiltration study) to understand the processes of transient water flow and bacterial transport; and to extrapolate the relationships between bacterial transport and soil properties (like soil structure, texture), and soil physical status (soil water potential ψ and volumetric water content θ). Factors controlling FC transport are discussed. A contaminant transport model, HYDRUS-1D, was applied to simulate microbial transport through soil on the basis of measured datasets. This study was carried out at Lincoln University’s Centre for Soil and Environmental Quality (CSEQ) lysimeter site. Six lysimeters were employed in two trials. Each trial involved application of DSE, followed by a water irrigation sequence applied in a flux-controlled method. The soil columns were taken from the site of the new Lincoln University Dairy Farm, Lincoln, Canterbury. The soil type is Templeton fine sandy loam (Udic-Ustochrept, coarse loamy, mixed, mesic). Vertical profiles (at four depths) of θ and ψ were measured during leaching experiments. The leaching experiments directly measured concentrations of chemical tracer (Br⁻ or Cl⁻) and FC in drainage. Results showed that bacteria could readily penetrate through 700 mm deep soil columns, when facilitated by water flow. In the first (summer) trial, FC in leachate as high as 1.4×10⁶ cfu 100 mL⁻¹ (similar to the DSE concentration), was detected in one lysimeter that had a higher clay content in the topsoil, immediately after DSE application, and before any water irrigation. This indicates that DSE flowed through preferential flow paths without significant treatment or reduction in concentrations. The highest post-irrigation concentration was 3.4×10³ cfu 100 mL⁻¹ under flood irrigation. Flood irrigation resulted in more bacteria and Br⁻ leaching than spray irrigation. In both trials (summer and autumn) results showed significant differences between irrigation treatments in lysimeters sharing similar drainage class (moderate or moderately rapid). Leaching bacterial concentration was positively correlated with both θ and ψ, and sometimes drainage rate. Greater bacterial leaching was found in the one lysimeter with rapid whole-column effective hydraulic conductivity, Keff, for both flood and spray treatments. Occasionally, the effect of Keff on water movement and bacterial transport overrode the effect of irrigation. The ‘seasonal condition’ of the soil (including variation in initial water content) also influenced bacterial leaching, with less risk of leaching in autumn than in summer. A tension infiltrometer experiment measured hydraulic conductivity of the lysimeters at zero and 40 mm suction. The results showed in most cases a significant correlation between the proportion of bacteria leached and the flow contribution of the macropores. The higher the Ksat, the greater the amount of drainage and bacterial leaching obtained. This research also found that this technique may exclude the activity of some continuous macropores (e.g., cracks) due to the difference of initial wetness which could substantially change the conductivity and result in more serious bacterial leaching in this Templeton soil. A dye infiltration study showed there was great variability in water flow patterns, and most of the flow reaching deeper than 50 cm resulted from macropores, mainly visible cracks. The transient water flow and transport of tracer (Br⁻) and FC were modelled using the HYDRUS-1D software package. The uniform flow van Genuchten model, and the dual-porosity model were used for water flow and the mobile-immobile (MIM) model was used for tracer and FC transport. The hydraulic and solute parameters were optimized during simulation, on the basis of measured datasets from the leaching experiments. There was evidence supporting the presence of macropores, based on the water flow in the post-DSE application stage. The optimised saturated water content (θs) decreased during the post-application process, which could be explained in terms of macropore flow enhanced by irrigation. Moreover, bacterial simulation showed discrepancies in all cases of uniform flow simulations at the very initial stage, indicating that non-equilibrium processes were dominant during those short periods, and suggesting that there were strong dynamic processes involving structure change and subsequently flow paths. It is recommended that management strategies to reduce FC contamination following application of DSE in these soils must aim to decrease preferential flow by adjusting irrigation schemes. Attention needs to be given to a) decreasing irrigation rates at the beginning of each irrigation; b) increasing the number of irrigations, by reducing at the same time the amount of water applied and the irrigation rate at each irrigation; c) applying spray irrigation rather than flood irrigation.