Os manejos de plantas invasoras em lavouras cafeeiras podem promover alterações estruturais que comprometem a capacidade do solo em infiltrar, distribuir, transmitir e reter água, em função da distribuição dos poros por tamanho. Nesse contexto, o objetivo deste estudo foi verificar a influência da adoção de diferentes manejos de plantas invasoras no sistema poroso e na capacidade de retenção de água em um Latossolo Vermelho distroférrico (LVdf), nas entrelinhas de uma lavoura cafeeira, em relação ao solo sob mata nativa. A área de estudo localiza-se na Fazenda Experimental da Epamig, em São Sebastião do Paraíso, região sul de Minas Gerais. O experimento foi instalado no ano de 1977 em blocos casualizados (DBC), com três repetições. Os seguintes manejos de plantas invasoras foram utilizados nas entrelinhas dos cafeeiros: sem capina (SCAP); capina manual (CAPM); herbicida de pósemergência (HPOS); roçadora (ROÇA); enxada rotativa (ENRT); grade (GRAD); e herbicida de pré-emergência (HPRE). Em dezembro de 2007, amostras de solo com estrutura indeformada foram coletadas aleatoriamente no centro das entrelinhas dos cafeeiros sob os diferentes manejos, nas profundidades de 0-3 cm, 10-13 cm e 25-28 cm, totalizando 315 amostras. Em uma mata nativa (MATA) sob LVdf, adjacente à área de estudo, foram coletadas 15 amostras adicionais por profundidade, as quais serviram de referência para os atributos avaliados. A partir da curva de retenção de água no solo, foi obtida a distribuição de poros por tamanho (macroporosidade: poros com diâmetro > 50 µm e microporosidade: poros com diâmetro < 50 µm), e o volume total de poros foi calculado pela equação [VTP = 1-(densidade do solo/ densidade de partículas)]. As principais alterações, tanto na curva de retenção de água como na distribuição de poros por tamanho, ocorreram na profundidade de 0-3 cm. Os extremos foram para o LVdf sob MATA e o solo sob lavoura cafeeira manejado com a GRAD e HPRE. Os demais sistemas de manejo proporcionaram ao LVdf valores intermediários das variáveis avaliadas.<br>The weed management systems applied in coffee plantations can promote changes in soil structure that compromise the capacity of the soil to infiltrate, distribute, transmit and retain water, in function of pore-size distribution. The aim of this study was to verify the effect of applying different techniques of weed management on the pore system and water retention capacity in a Latosol (Oxisol) in the inter-rows of a coffee plantation. The area of study is located at the Epamig Experimental Farm (Latitude 20º55'00" S and Longitude 47º07'10" W) in São Sebastião do Paraíso, southern Minas Gerais. The weed managements evaluated were: without hoe (SCAP), manual hoe (CAPM), post-emergence herbicide (HPOS); mower (ROÇA), rotary tiller (ENRT), coffee tandem disk harrow (GRAD) and pre-emergence herbicide (HPRE). Undisturbed soil samples were collected randomly in the inter-rows of the coffee plants under different weed managements at 0-3, 10-13 and 25-28 cm depths, totaling 315 samples. In a native forest (MATA) adjacent to the LVdf in the study area, 15 additional samples were collected per depth, as reference for the attributes. Soil water retention curve, pore size distribution (macroporosity: pores with effective diameter greater than 50 mm and microporosity: pores with effective diameter smaller than 50 mm) and volumetric total porosity (VTP) were also assessed. The main alteration in soil structure was observed in soil water retention curve and pore size distribution at 0-3 cm depth. The extreme behaviors for all the physical-hydric attributes assessed were for the LVdf under MATA and the soil under coffee with GRAD and HPRE. The other management systems presented intermediate behavior for all the attributes. The use of the soil with coffee plants decreases volumetric total porosity and macroporosity at 0-3 and 10-13 cm depths, compared to native forest. There was no effect of the different weed management systems on volumetric total porosity, macro-porosity and micro-porosity at 25-28 cm depth of LVdf in relation to the soil under native forest.

Little is known of the interactions between groundwater and surface water on deeply weathered landscapes of low relief in the Great Lakes Region of Africa (GLRA). The role of groundwater in sustaining surface-water levels during periods of absent rainfall is disputed and groundwater is commonly excluded from estimations of surface-water balances. Triangulated piezometers installed beside lake gauging stations on Lake Victoria and Lake Kyoga in Uganda provide the first evidence of the dynamic interaction between groundwater and surface water in the GLRA. Stable isotope ratios (2H:1H, 18O:16O) support piezometric evidence that groundwater primarily discharges to lakes but show further that mixing of groundwater and lake water has occurred at one site on Lake Victoria (Jinja). Layered-aquifer heterogeneity, wherein fluvial-lacustrine sands overlie saprolite, gives rise to both rapid and slow groundwater fluxes to lakes which is evident from the recession of borehole hydrographs following recharge events. Darcy throughflow calculations suggest that direct contributions from groundwater to Lake Victoria comprise <1% of the total inflows to the lake. Groundwater/surface-water interactions are strongly influenced by changing drainage base (lake) levels that are controlled, in part, by regional climate variability and dam releases from Lake Victoria (Jinja).

Tertiary treatment of biological wastewater exposes treating agent(s) to competition and predation by large populations of microflora but mainly by microfauna residing in the wastewater; this effectively reduces their efficiency. Therefore, protection against competition is vital. It is assumed, yet without experimental proof, that immobilization in a polymer matrix, such as beads, will provide a physical barrier between the treating agents and the microbiologically-hostile wastewater environment. Our objectives were to: (1) Demonstrate that the internal population of wastewater treating agents within the bead is not reduced upon expose to wastewater; (2) Determine the kind of protection that immobilization provide (3) Quantify how much tertiary treatment is performed. In the present study we use as a model the microalgae-bacteria co-immobilized system for tertiary wastewater treatment as a model, proposal by the environmental microbiology group of CIBNOR. All of this has been done using wastewater from the municipal treatment plant of La Paz, B.C.S., Mexico. When placed in wastewater, populations of C. sorokiniana in the beads increased over time. Joint immobilization with A. brasilense further increased the population size of the microalgae and mitigated the decline of A. brasilense populations over time. Evaluation of bacterial population of jointly-immobilized beads, using FISH, revealed that exterior populations was made of unidentified bacteria where the inside population was composed solely of A. brasilense Immobilization in alginate beads provides a separation barrier between wastewater treating agents and the micro- and macro-organisms inhabiting wastewater, which allows uninterrupted tertiary wastewater treatment. The microalgae-bacteria system show to be efficient in the removal of ammonia and phosphates from wastewater, although there are no difference with the treatments with just microalgae. It was show an increase in the concentration of nitrates in all treatments except the control, this increase could be related to nitrification process carry out by wastewater indigenous bacteria. It’s recommended more studies aimed to improve the system efficacy for nutrient removal. | El tratamiento biológico terciario de aguas residuales expone a los agentes de biorremediación a la depredación y competencia por la microflora y principalmente microfauna presentes en el agua residual, lo cual reduce su eficiencia. Por lo que la protección contra la competencia es vital. Sin embargo se ha asumido, todavía sin pruebas experimentales, que la inmovilización en matrices de polímeros, por ejemplo esferas de alginato, brinda una barrera física entre los microorganismos inmovilizados y la comunidad microbiológica hostil presente en el agua residual. El objetivo de este trabajo fue: (1) demostrar que la cantidad de los microorganismos utilizados no se ve afectada por la exposición a agua residual; (2) determinar el tipo de protección que ofrece la inmovilización de microorganismo en esferas de alginato; (3) Analizar la eliminación de nutrientres del sistema microalga-bacteria en agua residual doméstica. En el presente trabajo se utilizó como modelo de estudio el sistema microalga-bacteria (Chlorella sorokiniana-Azospirillum brasilense) co-inmovilizado para el tratamiento terciario de aguas residuales, propuesto por el grupo de microbiología ambiental del CIBNOR. Todos los experimentos fueron llevados a cabo con agua residual doméstica proveniente de la planta de tratamiento de La Paz, B.C.S., México El crecimiento de la microalga no se vio disminuido por la exposición al agua residual sino se registró un crecimiento mayor al reportado anteriormente para medio residual sintético. La co-inmovilización también mostro tener efectos positivos en la microalga estimulando su crecimiento. Por medio de microscopia de fluorescencia e Hibridación Fluorescente in Situ (FISH) se logró determinar la ubicación de A. brasilense y de las demás bacterias en la esfera de alginato, logrando establecerse que las bacterias que no son A. brasilense quedan detenidas en la superficie de la esfera, mientras que en el interior solo se encuentra A. brasilense y C. sorokiniana. El sistema microalga-bacteria mostró ser eficiente en la eliminación de amonio y fosfato del agua residual, aunque no hubo una diferencia evidente comparado con el tratamiento de solo microalga. Se registro un aumento en la concentración de nitratos, lo cual pudiera atribuirse a procesos de nitrificación llevados a cabo por bacterias presentes en el agua residual. Se recomienda realizar más estudios encaminados a mejorar la eficiencia del sistema para la eliminación de nutrientes en agua residual real

Neste trabalho, discutem-se os valores da declividade da curva de retenção de água no seu ponto de inflexão de acordo com a variável independente utilizada na construção da curva.

In places like the Valencian Region, where the climate is arid, the flow rate of the rivers is irregular, and irrigation is essential if agrarian returns are to increase, the way water was distributed among irrigators often gave rise to clashes between them. This paper begins with an analysis of the mechanisms that were used in the irrigated areas of Valencia, during the feudal era, to prevent these kinds of conflicts from getting out of hand. It then focuses on the disputes that arose between farmers and millers. Contrary to what is usually claimed, there is no decisive evidence to show that the millers were a permanent cause of such troubles, which only reached a dangerous level of intensity in certain places at certain times

FAPESPA - Fundação Amazônia de Amparo a Estudos e Pesquisas | O capítulo I apresenta os aspectos que envolveram a pesquisa, como: definição da capacidade de carga recreacional, a importância dos estudos de qualidade das águas costeiras utilizadas para lazer, a opinião e percepção dos usuários de praia acerca da qualidade do meio ambiente e da infraestrutura e serviços disponíveis, bem como a importância destes estudos para planos de ordenamento do espaço costeiro. Alguns processos meteooceanográficos e a influência das atividades antrópicas no litoral amazônico foram também abordados. O capítulo II descreve sobre os usos recreacionais das praias de Ajuruteua, Atalaia e Princesa durante o mês de julho de 2009, mostrando os principais padrões da dinâmica recreacional das mesmas. Neste capítulo foram abordados e discutidos os tipos de usos recreacionais, o período de maior frequência de usuários e a capacidade de carga recreacional por zona estudada (zona subtidal, zona de intermarés e zona de bares e restaurantes). O capítulo III descreve as condições da qualidade da água utilizada para as atividades recreativas, a capacidade de carga recreacional e os padrões de usos espaciais nas três praias estudadas, comparando o mês de julho dos anos de 2009 e 2010. O capítulo IV descreve a percepção e a opinião dos usuários destas praias, acerca dos aspectos oceanográficos, paisagísticos e de saneamento; dos serviços e infraestrutura disponíveis; assim como do perfil social dos frequentadores. Este artigo está em fase de preparação e será submetido à revista Ocean and Coastal Management. O capítulo V aborda as conclusões gerais da dissertação de forma integradora. Em anexo está o artigo publicado no JCR, no formato original.

O herbicida sistémico imazapyr foi usado no controle da taboa (Typha subulata Crespo & Peres-Moreau f.) em drenos de irrigação, como alternativa ao controle mecânico. O resíduo do princípio ativo do herbicida na água foi analisado por cromatografia líquida de alta performance (HPLC). A curv a de di ss ip ação de imazapyr mostrou que o herbicida pode ser usado para o contro le de taboa em drenos de irr iga ção, sem causar danos a culturas vizinhas, desde que a água seja usada, no mínimo, depois de 1,6 a 3,7 dias da aplicação das doses de 500 a 1500 g ha-1, respectivamente.

En el presente trabajo se presenta un método de identificación de áreas críticas para sistemas de agua y saneamiento, aplicado a la ciudad de Salta mediante la utilización de Sistemas de Información Geográfica (SIG). El método consistió en primer lugar en la confección de tres mapas base mediante la utilización de datos de NBI, reclamos y nitratos, los cuales fueron probados como criterios de evaluación. Posteriormente, estos mapas fueron mezclados, utilizando dos combinaciones de capas, mediante software específico. Como resultado de este proceso se obtuvieron mapas de áreas críticas, considerados pasos iniciales de un análisis de sustentabilidad más profundo del sistema de agua y saneamiento local. La información necesaria para la confección de los mapas se obtuvo de datos entregados por la empresa prestataria del servicio (CoSAySA), el Ente Regulador de los Servicios Públicos (ENRESP), el Instituto Nacional de Estadísticas y Censos (INDEC) y la Dirección de General de Estadísticas de la provincia de Salta. Los resultados obtenidos mostraron que la metodología es sensible para detectar áreas críticas y mostrar información del sistema zonificada por niveles de criticidad. Otros criterios de evaluación podrían ser probados en etapas posteriores para analizar la sensibilidad de los mismos en la identificación de áreas críticas a nivel local. | In this article we categorize the water and sanitation management system of the city of Salta (Argentina) in homogeneous areas by using Geographic Information Systems (GIS). Three criteria were used to distinguish between different areas: (1) the index of Unsatisfied Basic Needs (NBI); (2) the number of complaints received by the water company in different neighborhoods; and (3) the level of nitrates in water samples obtained in all active groundwater wells. These criteria were mapped and the resulting maps were combined using two different arrangements of layers with specific GIS software. The combined maps can be used to spot areas where there are actual or potential problems in the water and sanitation management system (critical areas). The identification of critical areas is important to assess the overall sustainability of this system and to devise more efficient action plans. Information used to build the maps was obtained from the local water company, the government’s regulatory body, and national or provincial statistics offices. The methodology used was appropriate to classify the city in different areas according to the indicators studied, and to spot areas that could be critical in terms of water and sanitation services. Future research will include maps obtained with other criteria (such as service coverage and water quality) and complementary field research to confirm or refute the findings obtained with GIS techniques. | Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES)

In order to evaluate the growth and accumulation of nutrients in watermelon 'Quetzal' grown under different levels of salinity of irrigation water, was developed in the period november/2007 to January 2008, an experiment at the Experimental Farm "Rafael Fernandes", University Federal Rural do Semi-arid (UFERSA) Mossoró-RN. The experiment was a randomized blocks design with four replications. The treatments were arranged in split plots with the plots represented by the salinity levels of irrigation water: 0.60, 1.69, 2.36, 3.46 and 3.98 dS m-1, and the subplots consist of samplings of plants: 12, 22, 32, 42 and 52 days after transplanting, DAT. In achieving the levels of salinity were mixed natural waters and / or saline in order to obtain approximate composition of natural waters in the region. Plant growth, expressed by the accumulation of dry matter and accumulation of macronutrients by watermelon over the age of the plants decreased with increasing water salinity. The largest increases of dry matter and macronutrients occurred after fruit set, which took place from 42 DAT. The period of greatest demand for phosphorus, potassium and calcium was 42-52 DAT, and nitrogen, and magnesium was 32-42 DAT. The order of extracted nutrients was K> N> Ca> Mg> P.