O objetivo deste trabalho foi avaliar as alterações químicas de solos tratados com água residuária de café (ARC). O experimento foi conduzido em colunas de PVC, onde foram avaliadas quatro doses de ARC (0; 174; 522 e 870 t ha-1), em dois Argissolos Amarelos subdivididos em quatro camadas, para dois períodos de incubação (30 e 60 dias). O delineamento experimental foi o inteiramente casualizado, em arranjo fatorial, e as variáveis analisadas foram cálcio, magnésio, potássio, sódio, pH e condutividade elétrica do extrato da pasta saturada. As doses de ARC alteraram as propriedades químicas dos solos nos dois períodos de incubação estudados, aumentando os teores de Ca++, Na+ e, principalmente, K+ nos dois solos. A dose de aplicação de 174 t ha-1 de ARC elevou a concentração de K+ no solo para a faixa ideal, de acordo com as exigências nutricionais da cultura. A camada superficial apresentou maior concentração de K+, Na+, Ca++ e, consequentemente, maior CEes. | The objective of the present study was to evaluate chemical changes of soils treated with coffee fruit washing and pulping wastewater (CWW). The experiment was carried out in PVC columns, where it was applied four doses of CWW (0, 174, 522, and 870 t ha-1) in two Yellow Argisoil split into four layers in two incubation periods (30 and 60 days). The experimental design was completely randomized in a factorial arrangement, and it was analyzed calcium, magnesium, potassium, sodium, pH and electric conductivity of the saturated paste extract. The CWW doses affected chemical soil properties in both incubation periods evaluated increasing Ca++, Na+ and mainly K+ in both soils. The CWW dose of 174 t ha-1 increased K+ concentration in soil to the recommended level according to nutrition necessity of the crop. The surface layer presented higher concentration of K+, Na+, Ca++ and, consequently, higher ECes.

O objetivo deste trabalho foi avaliar a relação entre o consumo de água pelas plantas de cana-de-açúcar e plantas daninhas e a absorção de herbicidas. O trabalho foi desenvolvido em dois experimentos: no primeiro, mediu-se o consumo de água através da pesagem diária das espécies de plantas daninhas Digitaria horizontalis, Panicum maximum, Ipomoea grandifolia, Ipomoea hederifolia, Brachiaria decumbens, assim como para os cultivares de cana-deaçúcar PO8862, SP80 3280 e RB83 5486; e, no segundo, foram determinadas as concentrações do amicarbazone, imazapic, tebuthiuron e hexazinone no xilema dos três cultivares de cana-deaçúcar e de I. grandifolia por meio da bomba de Schollander e de cromatografia e espectrometria de massas (LC-MS). A taxa de transpiração e, consequentemente, a taxa de consumo de água mostraram-se determinantes da taxa de absorção de herbicidas pelas plantas de diferentes espécies de plantas daninhas e cultivares de cana-de-açúcar. As concentrações de herbicidas na seiva do xilema foram variáveis em função da espécie e do herbicida em contato com o sistema radicular, indicando que a facilidade de absorção pelas raízes pode ser determinante para eficácia e/ou seletividade de herbicidas. | The objective of this work was to evaluate the relationship between water consumption by sugarcane plants and weeds and herbicide absorption. Two experiments were carried out. In the first, water consumption was measured by daily weighing the weed species Digitaria horizontalis, Panicum maximum, Ipomoea grandifolia, Ipomoea hederifolia, Brachiaria decumbens, as well as the sugarcane cultivars PO8862, SP80 3280, and RB83 5486. In the second experiment, the concentrations of amicarbazone, imazapic, tebuthiuron and hexazinone in the xylem of the three sugarcane cultivars and I. grandifolia were measured using the Schollander pump and chromatography and mass spectrometry (LC MS). The transpiration rate and, consequently, the water consumption rate were determinants of the rate of herbicide absorption by the different weed species and sugarcane cultivars. The herbicide concentrations in the xylem sap varied according to the species and herbicide in contact with the root system, indicating that easy absorption by the roots can be crucial to the effectiveness and/or selectivity of herbicides.

A diagnostic research was done to assess the relationship between the affectation of soils by salts and soil use, sample depth, saturated pasta percentage (H), and irrigation water quality. Samples of water and soil were collected from twelve farms in the Paraguaná Peninsula, north of Falcón state, Venezuela. Soil samples were taken under three soil use conditions: under native vegetation (VN), under cultivation (C) and fallow (D). Each of those samples were taken at three different depths: 0-20, 20-40 and 40-60 cm. Using data from the soil electrical conductivity of a saturation extract at 25 °C (ECe) the effects of soil use and sample depth were analized by placing in a table of double entrance the number of samples with ECe ≥ 2 dS m-1 in each combination of these categorical variables, finding that soils under cultivation (C) had the highest number of samples with ECe ≥ 2 dS m m-1. The effect of the saturation percentage (H) was evaluated through a correlation between H and the ECe, obtaining low correlation (r=0.426 P= 0.0000). Ayers and Westcot (1985) and Villafañe (2011) procedures for assessing the effect of salts of irrigation water on soils (irrigation water quality) were used. Results indicated strong restrictions that may limit irrigation water utilization due the effect of NaCl of irrigation water on soil. Nevertheless, the sampled soils showed lower values of the ECe and sodium adsorption ratio which may be due to the sandy texture in most of sampled soils. | Se realizó una investigación diagnóstica en doce unidades de producción de la península de Paraguaná, estado Falcon, Venezuela, con el objetivo de relacionar la afectación de los suelos por sales con la condición de uso del suelo, la profundidad de muestreo, el porcentaje de humedad de la pasta (%H) y la calidad del agua de riego. Se colectaron muestras de agua y de suelo en tres condiciones de uso: vegetación nativa (VN), cultivo (C) y en descanso (D), a 20, 40 y 60 cm de profundidad. Con los datos de conductividad eléctrica del extracto de la pasta del suelo a 25 °C (CEe) se analizó el efecto de la condición de uso y la profundidad de muestreo, colocando en un cuadro de doble entrada el número de muestras con valores de salinidad igual o superior a 2 dS m-1 en cada combinación de estas variables categóricas, encontrando en los suelos bajo cultivo el mayor número de muestras con salinidad igual o superior al valor preestablecido. El efecto del %H sobre la CEe se evaluó en un análisis de correlación, obteniéndose un valor bajo (r = 0,426 P = 0,0000). El efecto de la calidad del agua sobre la afectación de los suelos por sales se llevó a cabo con dos calificaciones predictivas: Ayers y Westcot (1985) y Villafañe (2011). Las aguas de riego califican con restricciones fuertes por salinidad. Las predicciones fueron acertadas, aunque los suelos mostraron valores de CEe y relación de adsorción de sodio, inferiores a los esperados; quizás por la textura, en su mayoría arenosa.

"Por el valor económico de su producción, el nogal pecanero (Carya Illinoensis K) es una especia frutícola de gran importancia para México. Su cultivo se realiza en regiones de clima semidesértico donde el agua es el factor limitante de la producción, por lo que es necesario obtener la máxima eficiencia del uso de este recurso, que es función del sistema de riego y de las condiciones climáticas de la región. El estudio se realizó en el verano de 2008 en dos huertas de nogal pecanero del noreste de México: una de ellas ubicada en el Suroeste del Estado de Coahuila" | "For its production economical value, the pecan nut (Carya Illinoensis K) is an important fruit tree for Mexico. It is grown on arid regions were water availability is the limiting factor for its production, therefore, it is necessary to obtain the highest water use efficiency, which is a function of the irrigation method and the weather conditions of the region. So that the objective of this study was to evaluate the intrinsic water use efficiency of two orchards of pecan nut trees, with different methods of irrigation under different weather conditions. The study was done during the summer of 2008, in two orchards of pecan nut tress of Northeast Mexico. One of them located in the Southeast of Coahuila"

" El objetivo de este trabajo fue analizar los valores estadísticos básicos para determinar la correlación entre variables (pH, grasas y aceites (GA), nitrógeno total (NT), demanda bioquímica de oxigeno (DBO), fosforo total (PT), sólidos suspendidos totales (SST), temperatura (T) y demanda química de oxigeno (DQO)) de calidad del agua de una planta tratadora de aguas residuales de Gómez Palacio, Durango, utilizando la base de datos del año 2010 y el paquete estadístico computacional Statistical Analysis System (SAS 2001). Según los resultados, las ocho variables analizadas estadísticamente, el agua residual se encuentra dentro de los rangos de calidad que debe de existir en un efluente, que se emplea como agua de riego de cultivos, por lo tanto la planta tratadora de agua residual, está operando de manera correcta. Para determinar el modelo de predicción, se hicieron varias combinaciones hasta obtener la que mayor coeficiente de determinación presentó, siendo éste, el que consideró el pH como variable dependiente con un coeficiente de determinación de 0.90, siendo el NT la que más influyó en el modelo. Al analizar las correlaciones entre las diferentes variables se pudo observar que la mayor correlación fue la que obtuvo el nitrógeno total (NT) con relación a la demanda bioquímica de oxigeno (DBO)"

"La caña de azúcar es un cultivo que se establece mediante esquejes y puede mantenerse hasta por 20 años sin renovar las plantas madre, esta condición puede afectar la capacidad de asimilación de bióxido de carbono del ecosistema vegetal, la eficiencia intrínseca del uso del agua, la eficiencia cuántica y el rendimiento. Por lo v que los objetivos de esta investigación fueron: Analizar la dinámica de los flujos instantáneos de bióxido de carbono del ecosistema vegetal (NEE) y su relación con la tasa de evapotranspiración (ET), la tasa de absorción de la radiación fotosintéticamente activa (PAR) así como su relación con el rendimiento bajo condiciones de planta y de soca. Para esto, se instalo en una torre de 5 m de altura un sistema eddy covariance sobre el dosel de un cultivo de caña de azúcar en el rancho Santa Anita en el municipio de Xicotencatl, Tamaulipas, durante el otoño 2008 (planta) y otoño 2009 (soca), para medir los flujos de CO2, flujo de calor latente y la radiación fotosintéticamente activa absorbida por el dosel. Se observo que el cultivo de caña de azúcar tiene un alto potencial de asimilación de bióxido de carbono, tanto en planta como en soca, ya que la tasa instantánea de NEE fue mayor a la reportada en bosques y praderas de distintas especies pese que el estudio se realizo en otoño cuando el cultivo disminuye su actividad fisiológica. El NEE de las dos zafras fue muy sensible a los cambios en la tasa de ET y de absorción de la radiación PAR absorbida por el dosel. El intercambio neto de bióxido de carbono, la eficiencia intrínseca del uso del agua y de la radiación fotosintéticamente activa absorbida promedio diaria del ecosistema fue mayor en condiciones de planta que en condiciones de soca, de igual manera se comporto el rendimiento del cultivo." | "Sugarcane is a crop that is seeded by cuttings and can remain in the field up to 20 years without reseeding. This condition can affect the carbon dioxide net ecosystem exchange (NEE), the quantum and intrinsic water use efficiency and the crop yield. Therefore, the objectives of the study were: To analyze the dynamics of the NEE and its relation to the rate of evapotranspiration (ET), the rate of absorption of the photo VII synthetically active radiation (PAR) as well as its relation to yield for plant and first ratoon. The flux measurements of CO2, water vapor, PAR absorbed by the crop canopy were made by mounting the sensors of an eddy covariance system in a tower of 5 m tall (2 m above the crop canopy), in a sugarcane crop in the property Santa Anita, county of Xicontencatl, Tamaulipas, during the fall of 2008 (plant) and the fall of 2009 (first ratoon). The results of this study showed that the sugarcane crop has a high potential of CO2 assimilation, in plant as well as in the first ratoon, because the instantaneous rate of NEE was higher than that reported for forests and grasslands of different species, despite that the study was conducted in fall when the crop had a low rate of growth. NEE in plan as well as in first ratoon was very sensitive to the changes of the ET rate and the absorption of PAR by the crop canopy. NEE, the intrinsic water use efficiency and quantum yield efficiency was higher on the plan growing cycle than on the first ratoon, as well as the crop yield."

Los proyectos de sectorización de redes de agua potable, en proceso en diferentes ciudades mexicanas actualmente, consisten en dividir la red de la ciudad en varias subredes o sectores más pequeños con una o máximo dos entradas de agua por sector. Para diseñar los sectores se emplean modelos de redes de agua potable que revisan si la sectorización propuesta puede funcionar hidráulicamente de manera adecuada. Para los proyectos de sectorización en redes grandes se requieren, sin embargo, facilidades algorítmicas adicionales, como análisis de conectividad, zona de influencia y contribución de cada fuente sobre el consumo. En el presente artículo se discuten eficientes algoritmos de este tipo basados en la teoría de los grafos, implementados en un sistema de cómputo. | Water distribution network sectorization projects currently underway in many Mexican cities consist of dividing the city distribution network into smaller sub-networks, or sectors, with one or at most two water inlets per sector. To design the sectors, water distribution network models are used, which review whether the proposed sectorization can adequately function hydraulically. For large network sectorization projects, however, additional algorithmic capabilities are needed, such as connectivity analisys, zone of influence and the contribution of each source on consumption. This paper discusses efficient algorithms of this type based on graph theory, implemented in a computer system.

O presente trabalho teve como objetivo o desenvolvimento de métodos para determinação simultânea de trialometanos e agrotóxicos organoclorados e piretroides em água. Para proporcionar protocolos experimentais ambientalmente seguros, a cromatografia gasosa com detector por captura de elétrons foi associada a técnicas de preparo de amostra que não emprega solvente orgânico, ou que o volume deste é significativamente reduzido, como é o caso das técnicas de microextração em fase sólida e microextração em gota única, respectivamente. A microextração em fase sólida foi empregada no modo indireto (MEFS-HS), sendo avaliados os fatores adição de sal (Na2HPO4), temperatura e tempo de extração na sua otimização. A microextração em gota única foi empregada por imersão direta (MEGU-ID), sendo as variáveis experimentais solvente extrator, volume da microgota, tempo de contato da microgota com a solução aquosa, velocidade de agitação, adição de sal (NaCl) e volume de amostra avaliados a fim de maximizar o desempenho da técnica. Após a otimização das técnicas, a seletividade, linearidade, precisão intermediária, exatidão e limites de detecção e quantificação dos métodos foram determinados. Os dois métodos permitiram a análise simultânea de agrotóxicos organoclorados e piretroides em água, sendo que a MEFS-HS possibilitou também a análise de trialometanos (THM). Foram obtidos coeficientes de variação (CV) entre 3 e 21% e recuperações relativas entre 70 e 125%. Os protocolos desenvolvidos também apresentaram seletividade e linearidade adequadas, com coeficientes de correlação (r) maiores que 0,95. Os limites de detecção dos analitos de interesse encontram-se entre 0,003 e 3 μg L-1, sendo todos inferiores aos respectivos valores máximos permitidos (VMP) pela legislação nacional (Ministério da Saúde) e internacional (Organização Mundial da Saúde) para água potável. Amostras de água potável foram analisadas empregando os métodos propostos, não sendo detectado nenhum dos agrotóxicos. A partir da MEFS-HS foram detectados nas amostras analisadas os trialometanos clorofórmio, bromodiclorometano e dibromoclorometano em concentrações iguais a 4,4; 3,8 e 0,7 μg L-1, respectivamente. A soma da concentração de trialometanos foi menor do que 9 μg L-1 em todas as amostras analisadas, valor menor do que o VMP estabelecido pela Portaria 518 do Ministério da Saúde, de 25 de março de 2004, que é de 100 g L-1 para a soma dos quatro principais trialometanos. | This study aimed to develop methods for simultaneous determination of organochlorine pesticides, trihalomethanes and pyrethroids in water. In order to provide environmentally friendly experimental protocols, gas chromatography with electron capture detector was associated with sample preparation techniques, that uses no organic solvent, or that this volume is significantly reduced, as in solid phase microextraction and single drop microextraction, respectively. The solid phase microextraction was carried out in the headspace (HS-SPME), and factors such as, addition of salt (Na2HPO4), temperature and extraction time for optimization were evaluated. Single drop microextraction was used in direct immersion mode (MEGU-DI), and experimental variables such as organic solvent, volume of the microdrop, contact time of the microdrop with the aqueous solution, stirring rate, addition of salt (NaCl) and sample volume were evaluated to maximize the performance of the technique. After optimization the methods were validated through the following parameters: linearity, intermediate precision, accuracy and limits of detection and quantification. Both methods allow the simultaneous analysis of organochlorine pesticides and pyrethroids in water, and the HS-SPME also allowed the analysis of trihalomethanes (THM). Coefficients of variation (CV) between 3 and 21% and relative recoveries between 70 and 125% were obtained. The protocols developed also showed selectivity and linearity adequate, with correlation coefficients (r) greater than 0.95. The detection limits of all pesticides under study are between 0.003 μg L-1 and 3 μg L-1, being all below their respective maximum contaminant level (MCL) allowed by national (Ministério da Saúde) and international (World Health Organization) legislation for drinking water. Drinking water samples were analyzed using the proposed methods and any of the pesticides were detected. Using HS-SPME, the trihalomethanes chloroform, bromodichloromethane and dibromochloromethane at concentrations of 4.4, 3.8 and 0.7 μg L-1, respectively, were detected in water samples. The sum of the concentration of trihalomethanes was less than 9 μg L-1 in all samples, a value lower than the MCL established by Brazilian legislation (Portaria 518 of the Ministério da Saúde, March 25, 2004), which is 100 μg L-1 for the sum of the four main trihalomethanes.

The CAIBOX cruise was conducted from 25 July to 14 August 2009. Three consecutive transects (zonal, meridional, and transverse) formed a closed box to the west of the Strait of Gibraltar. This study aimed to analyze the thermohaline properties, volume transports, and water mass distributions (percentages) along the meridional section (30–41.5º N, 20º W). We identified the main geostrophic current (Azores Current) and its associated volume transport and interannual changes. Data from previous cruises (AZORES I, A16N, CLIVAR, OACES, and CHAOS) with similar tracks were employed to compare with the CAIBOX meridional section. All but one (CHAOS) were summer cruises. We estimated a mean transport for the Azores Current at 20º W of 9.3 ± 2.6 Sv. There appears to be an inverse relation between the position of this current and its associated transport, with relatively high (low) transports when the current is located roughly south (north) of 35º N. Regarding water masses, an increase of 14.4% was found for Mediterranean Water compared with the 1993, 1998, and 2003 cruises; however, Labrador Sea Water decreased its contribution and southward spreading between 1998 and 2009. Key words: Northeast Atlantic, Azores Current, water masses, multiparametric mixing analysis.  | Entre el 25 de julio y el 14 de agosto de 2009 se llevó a cabo la campaña CAIBOX, que constó de tres transectos consecutivos (zonal, occidental y transversal) conformando una caja cerrada al oeste del estrecho de Gibraltar. El objetivo principal del presente trabajo fue el estudio de las propiedades termohalinas, los transportes (en términos de volumen) y la distribución de las masas de agua (en porcentajes) a lo largo de la sección occidental (30–41.5º N, 20º W). Se identificó la corriente geostrófica principal (Corriente de las Azores), el transporte asociado a ella y sus cambios interanuales. Adicionalmente se consideraron los datos de cinco campañas anteriores (AZORES I, A16N, CLIVAR, OACES y CHAOS) con secciones similares a las de la campaña CAIBOX. Todas excepto una (CHAOS) fueron campañas estivales. El transporte medio para la Corriente de las Azores a 20º W se estimó en 9.3 ± 2.6 Sv. Parece existir cierta relación inversa entre la posición de dicha corriente y su transporte asociado, con transportes relativamente altos (bajos) cuando la corriente se sitúa al sur (norte) de 35º N. En cuanto a las masas de agua, se observa un incremento de 14.4% del Agua Mediterránea en comparación con las campañas de 1993, 1998 y 2003; sin embargo, el Agua de Labrador ha disminuido su contribución y su propagación hacia el sur entre 1998 y 2009.

As altas diluições aplicadas conforme os princípios da homeopatia ou da hormese são alternativas sustentáveis de baixo custo na agricultura, podendo ser usadas para melhorar a qualidade das águas. Foram conduzidos quatro experimentos no Laboratório de Homeopatia do Departamento de Fitotecnia da Universidade Federal de Viçosa. Objetivou-se investigar a alteração das propriedades físico-químicas de água em resposta à ação de altas diluições de Alumina e Calcarea carbonica no delineamento inteiramente casualizado com sete tratamentos (3 CH, 5 CH, 7 CH, 9 CH, 11 CH e 13CH e água destilada, como testemunha) e quatro repetições. As dinamizações foram preparadas em água destilada e aplicadas no procedimento duplo-cego . Cinquenta e seis frascos de vidro borossilicato com capacidade para 80 mL receberam 40 mL de água destilada, sendo 28 no primeiro experimento e 28 no segundo. Cinquenta e seis frascos de vidro borossilicato com capacidade para 80 mL receberam 40 mL de água ácida. Em 28 desses, foram aplicadas 10 gotas da Alumina, enquanto nos 28 restantes, 10 gotas da Calcarea carbonica. As variáveis avaliadas foram: potencial de hidrogênio, condutividade elétrica (em μS/cm) e oxigênio dissolvido (em mg/L), medidas imediatamente após a aplicação dos tratamentos (T1) e em intervalos de 24 horas até 72 horas após (T2, T3, T4). Os dados foram interpretados por meio de análise de variância, sendo utilizado o Programa SAEG. A testemunha foi comparada com os demais tratamentos pelo teste de Dunnett a 5% de probabilidade. A Alumina 3 CH na água destilada elevou o potencial de hidrogênio e a condutividade elétrica, a Alumina 7 CH reduziu o oxigênio dissolvido, a Calcarea carbonica 5 CH e a 7 CH elevaram o potencial de hidrogênio da água destilada, a 7 CH aumentou o oxigênio dissolvido e a 9 CH e 13 CH reduziram-no. No tratamento da acidez da água causada por alumínio, a Calcarea carbonica foi eficiente e a Alumina não. | The high dilutions applied according to the principles of homeopathy or hormesis are sustainable alternatives in agriculture low cost and can be used to improve water quality. Four experiments were conducted at the Laboratory of Homeopathy, Plant Science Department, Universidade Federal de Viçosa. The objective was to investigate the change of physicochemical properties of water in response to action of high dilutions of Alumina and Calcarea carbonica in a completely randomized design with seven treatments (3CH, 5CH, 7CH, 9CH, 11CH, 13CH and distilled water, as control) and four replications. The dynamizations were prepared in distilled water, and were applied in the procedure "double blind". Fifty-six bottles of borosilicate glass with a capacity of 80 mL received 40 mL of distilled water, and twenty-eight in the first experiment and twenty-eight in the second. Fifty-six bottles of borosilicate glass with a capacity of 80 mL received 40 mL of acidic water. In twenty-eight of these were applied 10 drops of Alumina in the remaining twenty-eight were applied 10 drops of Calcarea carbonica. The variables were: potential of hydrogen, electrical conductivity (in μS/cm) and dissolved oxygen (mg/L), measured immediately after treatment (T1) and every 24 hours until 72 hours after (T2, T3, T4). The data were interpreted by analysis of variance, using the program SAEG. The control was compared with other treatments by Dunnett test at 5% probability. Alumina 3 CH in distilled water increased the potential of hydrogen and electrical conductivity and Alumina 7 CH reduced the dissolved oxygen. The Calcarea carbonica 5 CH and 7 CH increased the potential of hydrogen from distilled water. The 7 CH increased dissolved oxygen, the 9 CH and 13 CH reduced it. In the treatment of water acidity caused by aluminum the calcarea carbonica showed efficiency and Alumina not been efficient.