Viticulture in Baja California (Mexico), located in a semi-arid region, is limited by the availability of water. Treated wastewater (TWW), however, could be used to irrigate some crops. Therefore, the objective of this study was to assess the effect of irrigating grapevines with TWW on the microbiological and chemical quality of grapes in the Guadalupe Valley. Five-year-old Tempranillo grapevines were irrigated with 10 or 20 L week-1 of TWW from the El Sauzal wastewater treatment plant; for the control treatment, water from the Guadalupe Valley aquifer was used. The analysis showed that TWW satisfied all the parameters of the norms NOM-001-SEMARNAT-1996 and NOM-003-SEMARNAT-1997 for restricted and non-restricted irrigation, as well as for direct and indirect contact during the study. No significant differences (p>0.05) were observed in pH, titratable acidity, the concentration of soluble solids (sugar) or yeast assimilable nitrogen in the grapes, regardless of the type of water used for irrigation. The concentrations of the Ca, Mg, Na and K ions were not affected by the irrigation treatments (p> 0.05). This study shows that TWW from the El Sauzal treatment plant did not cause short-term negative impacts on the quality of grapes for vinification, and that treated water could be used to irrigate this crop. | La viticultura está limitada en Baja California por la disponibilidad del agua debido a que es una zona semidesértica, peto las aguas residuales tratadas (ART) se podrían utilizar pata regar algunos cultivos. Por tanto, el objetivo de este estudio fue evaluar el impacto del riego de la vid con ART sobre la calidad microbiológica y química de las uvas en el Valle de Guadalupe, México. Entre 10 a 20 L semana-1 de ART de la planta de tratamiento de El Sauzal fueron aplicados a vides Tempranillo de 5 años de edad y para los testigos se usó agua del acuífero Valle de Guadalupe. El análisis mostró que las ART de la planta de tratamiento cumplieron con todos los parámetros de las normas NOM-001-SEMARNAT-1996 y NOM-003-SEMARNAT-1997 para el riego restringido y no restringido, así como para el contacto directo e indirecto durante el estudio. No se observaron diferencias significativas (p>0.05) en pH, acidez titulable, concentración de sólidos solubles (azúcar) y nitrógeno asimilable por las levaduras de las uvas, independientemente del tipo de agua aplicada como riego. Las concentraciones de los iones de Ca, Mg, Na y K no fueron afectadas por los tratamientos de riego (p> 0.05). Este estudio muestra que el ART de la planta de tratamiento de El Sauzal no tuvo un impacto negativo a corto plazo sobre la calidad de la uva para vinificación y el agua tratada podría usarse para regar este cultivo.

Este trabalho teve como objetivo avaliar a influência de fertilizantes na qualidade da água no entorno do lago de Sobradinho. O estudo foi realizado em 26 pontos de coleta, avaliando-se fósforo total, amônio, nitrito e potássio; fontes de fertilizantes. A maioria das amostras analisadas atendeu à legislação brasileira e somente dois pontos no município de Casa Nova excederam o limite de fósforo total, caracterizando um ambiente aquático contaminado e sujeito a processo de eutrofização.

La evaluación de la disponibilidad de agua en una cuenca realizada únicamente mediante la obtención del volumen disponible no es suficiente para el establecimiento de los criterios administrativos que puedan llevar a resolver la condición de sobreexplotación del recurso. El uso de indicadores tales como la disponibilidad relativa permite generar medidas de sensibilidad en los balances proyectados, a fin de evaluar tendencias e identificar sus causas. Aquí se presenta un ejercicio realizado con estos criterios para la cuenca del río San Pedro en la Región Hidrológica 11 de México, en el cual es posible identificar las variaciones de la condición de las subcuencas que la componen en un balance hidrológico de agua superficial realizado por mes, y proyectado a 10 y 20 años. | Assessing the availability of water in a basin solely by obtaining the volume available is not sufficient to establish management criteria to aid in solving overexploitation. The use of indicators such as relative availability makes it possible to generate sensitivity measurements for projected balances, in order to assess trends and identify causes. This work describes an exercise using these criteria for the San Pedro River Basin in Hydrologic Region 11 in Mexico, in which it was possible to identify changes in the conditions of the sub-basins, including the monthly surface water balance and 10 and 20 year projections.

Doutoramento em Engenharia dos Biossistemas - Instituto Superior de Agronomia | Climatic, hydrologic and soil characteristics were determined for the watersheds of São Domingos and Ribeira Seca, Santiago’s island, Cape Verde. In the following, pedo-transfer functions (PTFs) for the agricultural soils of Santiago’s island were developed and applied for modelling. Several models of irrigation and water balance – WINISAREG, SIMDualKc, MIRRIG and Temez – were combined in terms of application to enable a detailed study of water management in agriculture focusing the study area. The evaluation of net irrigation requirements (NIR) was performed for the nine main crops practiced in the area. NIR were related with estimated water availability. An analysis of irrigation water demand to cope with severe and extreme droughts was performed considering various levels of satisfaction of crop water requirements. Several strategies/scenarios of irrigation were simulated for each of the nine selected crops comparing the field observed irrigation management practices with various improved ones. Attention was paid to yields through comparing the observed crop yields with the estimated potential (maximum) crop yield. This estimation was performed using the Stewart model combined with the Agro-Ecological Zones model. Information and data gathered through the field evaluation of micro-irrigation systems were used to develop improved solutions through the model MIRRIG. Using observed and simulated data on crop yields and irrigation and production costs an economic analysis was performed focusing water productivity and economic water productivity of the considered crops subject to alternative water management strategies. This allowed to assess different deficit irrigation schedules and their economic impacts in terms of farmers revenue and the associated risk relative to droughts. Results have shown that the adoption of the deficit irrigation together with improved micro-irrigation systems can lead to minimizing non-beneficial water uses in irrigation and to consequent water savings. Results also enabled a more realistic perception of the levels of production in relation to restrictions on water availability, particularly aiming at coping with water scarcity and drought.

Water retention in soil is used in many agronomic and environmental applications, but its direct measurement is time-consuming and expensive. Therefore, pedotransfer functions (PTFs) are alternatives to obtain this information faster and more economically. The objectives of this study were to generate and validate PTFs to estimate the water content at potentials of -33 kPa (field capacity) and -1500 kPa (permanent wilting point) for different soil classes from the central-south portion of Rio Grande do Sul State. The physical and chemical analyses database from soil surveys of the Celulose Riograndense Corp were used. The database is composed of particle size distribution (coarse and fine sand, silt and clay), soil organic matter, and water content data at the above mentioned potentials, besides other information concerning the behavior of the soil classes at field conditions. Firstly, the data were stratified by soil classes and depths, and then 70% of the data were separated for PTF generation and 30% for validation. PTFs were generated for each specific soil class and also general PTFs which were not stratified by soil class, by means of stepwise multiple regression. In most situations, PTFs for a specific soil class showed a better fit than the general PTFs. Proper adjustment of the data showed that the water retention values at potentials of -33 kPa and -1500 kPa can be estimated for the soils from the central-south portion of Rio Grande do Sul State that do not have such analyses through the use of PTFs.<br>A retenção de água no solo é utilizada em diversas aplicações agronômicas e ambientais, porém sua medição direta consome tempo e dinheiro. Por isso, funções de pedotransferência (FPTs) são alternativas para a obtenção dessas informações de forma mais rápida e econômica. Neste trabalho, objetivou-se gerar e validar FPTs, para estimar o conteúdo de água nos potenciais de -33 kPa (capacidade de campo) e -1500 kPa (ponto de murcha permanente) para diferentes classes de solos na porção centro-sul do Rio Grande do Sul. Utilizou-se o banco de dados de análises físicas e químicas dos levantamentos de solos da empresa Celulose Riograndense, que é composto por dados de textura (areia grossa e fina, silte e argila), matéria orgânica do solo e dados de conteúdo de água nos potenciais supracitados, entre outras informações sobre o comportamento das classes de solo em condições de campo. Primeiramente, os dados foram estratificados por classes de solos e profundidades e, posteriormente, 70% dos dados foram separados para geração das FPTs e 30% para validação. Geraram-se FPTs específicas para cada classe de solo e também FPTs gerais, sem estratificação por classe de solos, por meio de regressão múltipla stepwise. Na maioria das situações, as FPTs específicas por classe de solo apresentaram melhor ajuste do que as FPTs gerais. Na maioria dos casos, o ajuste adequado dos dados demonstrou que os valores de retenção de água nos potenciais de -33 kPa e -1500 kPa podem ser estimados por meio de FPTs para os solos da porção centro-sul do Rio Grande do Sul que não possuem tais análises.

Este trabalho teve como objetivos avaliar a relação entre a condutividade elétrica e os teores de Na+ na lâmina de água e na solução de solos com diferentes níveis de sais, sob o cultivo de arroz irrigado. Foram selecionados solos para o cultivo de arroz com percentagens de sódio trocável de 5,6%; 9,0%; 21,2% e 32,7%. Previamente à entrada de água nas parcelas, foram instalados coletores de solução do solo nas profundidades de 5, 10, 20 e 40cm. Após o alagamento, foram realizadas coletas semanais, até 91 dias após o início da irrigação, da solução do solo e da lâmina de água, para a análise da condutividade elétrica e dos teores de Na+ e K+. Os valores dos atributos da lâmina de água correlacionaram-se positiva e signifi cativamente aos valores da solução do solo, em cada profundidade. A melhor correlação média foi obtida para a condutividade elétrica, portanto, sua estimação na solução do solo pode ser obtida a partir da análise da lâmina de água, com o uso de condutivímetros portáteis. | This study aimed to investigate the relationship between electrical conductivity and Na+, and K+ in the water table and in the solution of soils with different levels of salinity under fl ooded rice. For rice cultivation, soils with exchangeable sodium percentages of 5.6% 9.0% 21.2% and 32.7% were selected. Prior to fl ooding, soil solution collectors were installed at depths of 5, 10, 20 and 40cm. After fl ooding, soil solution and water layer samples were collected weekly until 91 days after onset of irrigation, for the analysis of electrical conductivity and Na+. The content of these attributes in the water table were related to the values at each depth, and there was a signifi cant positive association for all attributes at all depths. The highest average correlation was obtained for the electrical conductivity, so its estimation in the soil solution can be obtained easily through the water table, using a portable conductivity meter.

Contiene los resultados de la evaluación de los parámetros físicos, químicos y microbiológicos relacionados con la calidad del agua en el ámbito de la cuenca del río Chao, que involucra a el río Chorobal, río Huamanzaña (aguas arriba se llama Huaraday) correspondientes a la época de transición de estiaje en el año 2013.

Evalúa la calidad de los cuerpos naturales de agua superficial en el ámbito de la cuenca del río Rímac, como base para promover la implementación de la estrategia orientada a la recuperación y protección de la calidad de los recursos hídricos. Contiene los resultados de la evaluación de los parámetros físicos, químicos y microbiológicos relacionados con la calidad del agua en el ámbito de la cuenca del río Rímac, que involucra la Quebrada Huaycoloro, Collque, Leoncocha y Antaranra, río Chinchan, río Blanco, río Aruri, río Mayo, río Santa Eulalia y las lagunas Ticticocha y Canchis correspondientes a la época de transición de avenida en el año 2013.

Evalúa el estado de la calidad de los cuerpos naturales de agua superficial en el ámbito de la cuenca del río San Juan, en base a los resultados de los análisis de muestras de agua y las mediciones de los parámetros realizados en campo, en noviembre de 2013.