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Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mexican Journal of Economics & Finance / Revista Mexicana de Economia y Finanzas is the property of Instituto Mexicano de Ejecutivos de Finanzas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, we analyze extensive segmented and standardized agricultural fields in the marginally productive terrain of the Pampa de Guereque in the Jequetepeque Valley on the north coast of Peru. Although portions of the associated canal system were constructed continuously from late Formative to Chimú times, the segmented fields date to the late Chimú–Inka period and were only partially finished, apparently never fully used, and ultimately abandoned. We provide description of field plots and irrigation canals and discuss the implications of state-level construction and labor management of the fields, as well as the probable reasons for their abandonment. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objetivou-se, com este trabalho avaliar o uso de diferentes lâminas de irrigação e adubação na maximização da produtividade e na eficiência do uso da água pelo amendoim cultivado em argiloso de Tabuleiro Costeiro do Alagoas. O experimento foi conduzido no período de 20/03/ 2017 a 18/07/2017, em Campo Experimental do Centro de Ciências Agrárias, localizado no município de Rio Largo, AL, altitude de 9° 27’ S, longitude de 35° 27’ W e uma altitude média de 127 m acima do nível do mar. O delineamento experimental foi inteiramente ao acaso, no esquema fatorial 4x2 (quatro lâminas de irrigação e duas adubações, com quatro repetições, em que os tratamentos foram: laminas de irrigação de 50, 75, 100, 125% da Etc. Foram avaliados os seguintes componentes de produção: área foliar (AF), número de folhas (NF), massa seca da raiz (MSR), massa seca da parte aérea (MSPA), número de grãos (NG), peso de grãos por planta (PGP), peso de grãos de amendoim em vagem (PGV) e a eficiência do uso de água (EUA). A máxima eficiência do uso da água pela cultura do amendoim obtidas foram 6,86 kg ha‑1 mm‑1 para adubação orgânica e 5,36 kg ha-1 mm‑1 para adubação mineral, obtidas com lâmina de 75% da Etc, respectivamente.

Este estudio se desarrolló en el distrito 9 (sub cuenca del lago de Apanás-Asturias) Jinotega, comprendido por las comunidades de: Tomatoya, Las Lomas, El Limón, Saraguasca, Las Cureñas, Las Joyas, Las Pilas y Chagüite Grande, las que se seleccionaron mediante la priorización de territorio. Se analizaron 100 familias, cuya información general de referencia fue obtenida de los datos facilitados por La Cuculmeca y ENEL, los cuales son actores de desarrollo con mayor nivel de presencia en las comunidades. Esta población ya ha sido previamente estudiada y se tenían disponibles los datos de su ubicación.Delos datos más relevantes obtenidos en el estudio, se destaca que las principales fuentes de obtención de agua es la fuente potable (49%), respecto a la calidad del agua, los entrevistados expresan que es buena (55%) y muy buena (33%). La administración del agua la realizan los CAPS (68%), el manejo del agua residual proveniente del lavado de equipos de aplicación de agroquímicos, nos encontramos que un 60 % escurre libremente, en cuanto al manejo de aguas grises, el 55% no realiza manejo alguno de estas aguas. Es importante destacar que estos resultados se obtuvieron mediante encuestas, entrevistas, grupos focales y planes de finca y patio.

Although cassava is recognized for its high tolerance to drought, irrigation is showing satisfactory results. However, few studies have been carried out to determine the effects of soil cover, irrigation and the combination of both on crop development. The objective of this study was to determine the influence of irrigation and plastic soil cover on the agronomic performance of sweet cassava. The planting was done in beds, in the double row system with the stem cutings implanted vertically, with 0.60 m between rows and 0.80 m between plants. The following treatments were applied: naked non-irrigated bedding, bedding covered with non-irrigated black polyethylene plastic, naked bedding with irrigation and bedding covered with irrigated black polyethylene plastic. Irrigation was performed by conventional sprinkling, based on the daily soil water balance at the effective depth of the cassava root system in the different stages of crop development. The characters evaluated were: shoot weight, root yield, starch percentage in the roots and time for cooking. The expression of the characters shoot weight, root yield and starch percentage in the roots was significantly influenced by irrigation management and soil cover. The individual use of irrigation and plastic soil cover technologies led to increases in root yield of 55% and 13%, respectively, and when used together, root yield increased by 89%. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Se estudia un agroecosistema de la subcuenca del río San Miguel en el estado de Sonora con el objetivo de identificar sus subsistemas productivos y la problemática relacionada con el manejo de agua. Se presentan, como resultados preliminares, la caracterización del agroecosistema que produce forrajes para el subsistema pecuario y la jerarquización de problemas, con apoyo del Marco de Evaluación de Sistemas de Manejo Incorporando Indicadores de Sustentabilidad y métodos de Evaluación Rural Participativa. Asimismo, se identifican conflictos derivados de la confluencia de dos tipos de instituciones de manejo de agua locales: una tradicional autogestiva y otra impuesta por el gobierno.

Objetivou-se estudar o desempenho agronômico do pimentão cv. Ikeda, irrigado com diferentes qualidades de água, sob dois métodos de manejos de irrigação: reflectometria no domínio da frequência e tensiometria, sob ambiente protegido. O delineamento estatístico utilizado foi o inteiramente casualizado, em esquema de parcelas subdivididas, constituído de três qualidades de água nas parcelas, e dois manejos de irrigação nas subparcelas. Foram avaliadas a produtividade total; produtividade comercial; eficiência do uso da água; massa média dos frutos; comprimento; diâmetro; relação comprimento/diâmetro; teor de sólidos solúveis; acidez titulável e pH. Os resultados obtidos permitem concluir que a produtividade e qualidade físicas dos frutos de pimentão não foram afetadas pela qualidade da água de irrigação, enquanto a menor demanda hídrica quantificada pela tensiometria influenciou significativamente apenas nos pH dos frutos.

The objective of this study was to study the agronomic performance of chili cv. Ikeda, irrigated with different water qualities, under two methods of irrigation management: frequency reflectometry and tensiometry under protected environment. The statistical design used was completely randomized, in a subdivided plots scheme, consisting of three water qualities in the plots, and two irrigation managements in the subplots. The total productivity was evaluated; commercial productivity; efficiency of water use; average fruit mass; length; diameter; length/diameter ratio; soluble solids content; titratable acidity and pH. The results obtained allow us to conclude that the productivity and physical quality of the sweet pepper fruits were not affected by the quality of the irrigation water, while the lower water demand quantified by the tensiometry influenced only the pH of the fruits. [ABSTRACT FROM AUTHOR]

Copyright of Revista IRRIGA - Brazilian Journal of Irrigation & Drainage is the property of Revista IRRIGA (Brazilian Journal of Irrigation & Drainage) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The economic viability of an agricultural enterprise such as irrigation is influenced by the system's implementation and maintenance costs. These vary depending on the design water flow and water irrigated in crop cycle. So, the objective of this study was to verify the economic viability of the Jatropha plants irrigated by microsprinkler in the Goiás state. The experiment was conducted in the experimental area of the Federal University of Goiás (UFG), Goiânia-GO, Brazil. The experimental design was in a randomized block with four replicates. The treatments consisted of four irrigation levels, calculated on the basis of percentages of Class A tank (ECA) evaporation (0, 40, 80 and 120%). For the economic viability analysis, the productivity data of the no-irrigated treatment and the best irrigation treatment were used. Technical coefficients of jatropha cultivation were obtained for the region of Goiânia and the software AMAZONSAF-EMBRAPA was used for the calculation of economic indicators. The results showed that there was no economic viability of the production of jatropha, for no-irrigated and irrigated conditions in Goiás. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the efficiency of water use by the peanut crop subjected to different irrigation levels and forms of fertilization. The experiment was carried out in a greenhouse in the period from 20/03/2017 to 18/07/2017, in the perimental field of the Agrarian Sciences Center, located in the municipality of Rio Largo, AL. The experimental design was completely randomized in the factorial scheme 4 x 2, four irrigation depths (50, 75, 100, 125% of ETc) and two forms of fertilization (chemical and organic). The following variables were evaluated: number of Leaves (NF), Root dry mass (MSR), shoot dry mass (MSPA), number of grains (NG), grain yield per plant (PGP), POD grain weight (PGV) and water use efficiency (US). It was found that the organic fertilization, promotes an increase in the number of leaves and grains and that the maximum efficiency of water use by the peanut crop, corresponds to 0.79 g L-1 of water consumed by the crop, with the irrigation depth 62% of ETc, which indicates in high efficiency in the transformation of the water consumed in grains. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

La contaminación y la reducción del tamaño de los reservorios de agua tienen un impacto importante en la biodiversidad tropical. El Laguito de la Sede de Occidente, en Alajuela, Costa Rica, es un embalse artificial construido con fines recreativos, pero funciona actualmente como reservorio de agua de lluvia para prevenir las inundaciones que se presentan en las zonas bajas de la microcuenca. En los últimos años, se ha reducido su tamaño y ha perdido el espejo de agua y la capacidad del depósito es muy pequeña. Para evaluar el manejo del agua por parte de los vecinos, encuestamos los 92 hogares cercanos que descargan aguas residuales a El Laguito a través de un alcantarillado y una tubería. También tomamos muestras de agua en abril y setiembre de 2015 y julio de 2016 para el análisis fisicoquímico estándar. Los vecinos desperdician agua y el 80% de las casas descargan las aguas crudas sin tratar en el sistema. Un programa educativo mejoraría las prácticas en el área y beneficiaría al yacimiento y los organismos asociados.

ABSTRACT Knowledge of the terms (or processes) of the soil water balance equation or simply the components of the soil water balance over the cycle of an agricultural crop is essential for soil and water management. Thus, the aim of this study was to analyze these components in a Cambissolo Háplico (Haplocambids) growing muskmelon (Cucumis melo L.) under drip irrigation, with covered and uncovered soil, in the municipality of Baraúna, State of Rio Grande do Norte, Brazil (05º 04’ 48” S, 37º 37’ 00” W). Muskmelon, variety AF-646, was cultivated in a flat experimental area (20 × 50 m). The crop was spaced at 2.00 m between rows and 0.35 m between plants, in a total of ten 50-m-long plant rows. At points corresponding to ⅓ and ⅔ of each plant row, four tensiometers (at a distance of 0.1 m from each other) were set up at the depths of 0.1, 0.2, 0.3, and 0.4 m, adjacent to the irrigation line (0.1 m from the plant row), between two selected plants. Five random plant rows were mulched using dry leaves of banana (Musa sp.) along the drip line, forming a 0.5-m-wide strip, which covered an area of 25 m2 per of plant row with covered soil. In the other five rows, there was no covering. Thus, the experiment consisted of two treatments, with 10 replicates, in four phenological stages: initial (7-22 DAS - days after sowing), growing (22-40 DAS), fruiting (40-58 DAS) and maturation (58-70 DAS). Rainfall was measured with a rain gauge and water storage was estimated by the trapezoidal method, based on tensiometer readings and soil water retention curves. For soil water flux densities at 0.3 m, the tensiometers at the depths of 0.2, 0.3, and 0.4 m were considered; the tensiometer at 0.3 m was used to estimate soil water content from the soil water retention curve at this depth, and the other two to calculate the total potential gradient. Flux densities were calculated through use of the Darcy-Buckingham equation, with hydraulic conductivity determined by the instantaneous profile method. Crop actual evapotranspiration was calculated as the unknown of the soil water balance equation. The soil water balance method is effective in estimating the actual evapotranspiration of irrigated muskmelon; there was no significant effect of soil coverage on capillary rise, internal drainage, crop actual evapotranspiration, and muskmelon yield compared with the uncovered soil; the transport of water caused by evaporation in the uncovered soil was controlled by the break in capillarity at the soil-atmosphere interface, which caused similar water dynamics for both management practices applied.

RESUMO Avaliou-se o efeito da irrigação e de fases de maturação dos frutos sobre o rendimento em massa de matéria seca e de óleo de sementes de pinhão-manso. O experimento foi conduzido na área experimental do departamento de Agricultura da Universidade Federal de Lavras - UFLA, em Lavras-MG, em uma lavoura de pinhão-manso irrigada por gotejamento, com três anos de idade. Frutos de pinhão-manso foram classificados em quatro fases de maturação, assim denominadas: F1 (frutos totalmente verdes e sementes brancas); F2 (20% de frutos verdes e o restante amarelos, marrons e secos); F3 (frutos amarelos com partes marrons, com início de deiscência e sementes pretas); e F4 (frutos marrons escuros, secos e deiscentes). As sementes foram extraídas para a determinação do teor de água, dimensões principais, volume, massa seca de mil sementes e teor de óleo. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 4 X 2 (4 fases de maturação dos frutos e duas formas de manejo de água – irrigado e sequeiro) e 3 repetições. A colheita de frutos na coloração marrom, em plantas irrigadas, proporcionou maior rendimento em massa seca e rendimento de óleo de sementes de pinhão-manso.

The objective of this experiment was to evaluate the effect of the application of irrigation and potassic fertilization levels on canopy growth of the Jatropha trees. The experimental design was in randomized blocks with subdivided plots and four replicates. The plots consisted of application of four irrigation levels (0, 40, 80, and 120% of the evaporation of the class A pan) and the four potassium fertilization levels in subplots (40, 80, 120 and 160 kg ha-1 of K2O). Twelve evaluation periods of the experiment were also considered for treatment during two agricultural years. Irrigation was by micro sprinkler system to each two days. The plant growth characteristics evaluated were: plant height, stem diameter, canopy projection area, and number of branches in the main branch. Irrigation and potassium levels significantly influenced the vegetative growth of jatropha plants. The best results were obtained with irrigation of 115% of ECA and 125 kg ha-1 of K2O levels. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Economía, Sociedad y Territorio is the property of El Colegio Mexiquense and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Quantifying soil evaporation is required on studies of soil water balance and applications aiming to improve water use efficiency by crops. The performance of a microlysimeter (ML) to measure soil evaporation under irrigation and non-irrigation was evaluated. The MLs were constructed using PVC tubes, with dimensions of 100 mm inner diameter, 150 mm depth and 2.5 mm wall thickness. Four MLs were uniformly distributed on the soil surface of two weighing lysimeters conducted under bare soil, previously installed at Iapar, in Londrina, PR, Brazil. The lysimeters had 1.4 m width, 1.9 m length and 1.3 m depth and were conducted with and without irrigation. Evaporation measurements by MLs (E ML) were compared with measurements by lysimeters (E L) during four different periods in the year. Differences between E ML and E L were small either for low or high atmospheric demand and also for either irrigated or non-irrigated conditions, which indicates that the ML tested here is suitable for measurement of soil evaporation.A quantificação da evaporação do solo é requerida em estudos de balanço hídrico de culturas e em aplicações que visam a aumentar a eficiência do uso da água pelos cultivos. O objetivo deste trabalho foi testar um modelo de microlisímetro (ML) para medir a evaporação do solo em condições irrigada e não irrigada. Os MLs foram construídos utilizando tubos de PVC rígido, medindo 100 mm de diâmetro interno, 150 mm de profundidade e 2,5 mm de espessura da parede. Quatro MLs foram assentados sobre a superfície de dois lisímetros de pesagem de alta precisão conduzidos com solo nu, previamente instalados no Iapar, em Londrina-PR. Os lisímetros tinham dimensões de 1,4 m de largura, 1,9 m de comprimento e 1,3 m de profundidade, e estavam sendo conduzidos com e sem irrigação. A evaporação medida nos MLs (E ML) foi comparada com a medida nos lisímetros (E L), durante quatro períodos do ano. As diferenças entre E ML e E L foram mínimas para condições de baixa e elevada demanda atmosférica, e também para condições de solo irrigado ou não irrigado, indicado que o modelo de ML testado neste trabalho é adequado para medir a evaporação do solo.

Effects of different levels of water deficit applied during rapeseed crop development were assessed in a trial with metallic pots in greenhouse at the Department of Agricultural Engineering of Kassel University, Witzenhausen, Germany. A randomized block design was used with one cultivar (Ability Summer Rape) and three levels of water deficit (0, 30, and 60% of evapotranspiration) in three treatments and 20 replicates. Irrigation management was carried out through daily water balance, where ET = I - D; ET: evapotranspiration; I: irrigation; and D: drainage. The following evaluations were carried out weekly: stem diameter (mm); plant height (cm); number of leaves; number of branches and number of pods. At the end of the experiment, assessed total green matter (g plant-1), total dry matter (g plant-1), grain yield (g plant-1), grain protein content (%) and grain oil content (%) were also assessed. Data were submitted to variance analysis and the effect of the treatments was assessed by regression analysis. Results showed significant differences between the treatments in all analysed variables except for plant height and grain protein content, by test F at 5% probability. Factor of response ky, indicator of crop sensitivity to water deficit, was lower than one for all assessed variables. Grain yield showed the highest sensitivity to water deficit.Os efeitos de diferentes níveis de déficit hídrico, aplicados durante o desenvolvimento da canola, foram avaliados por meio de um experimento conduzido em vasos de metal no interior de uma casa de vegetação, no Departamento de Engenharia Agrícola, da Universidade de Kassel, Alemanha. Foi utilizado um delineamento inteiramente casualizado, com a cultivar Ability (Summer Rape), e três níveis de déficit de água, 0%, 30%, 60% da evapotranspiração da cultura, totalizando três tratamentos com 20 repetições. O manejo da irrigação foi realizado por meio do balanço hídrico diário, em que ET = I - D, onde ET é evapotranspiração, I é irrigação, D é drenagem. Foram realizadas semanalmente as seguintes avaliações: diâmetro do caule (mm), altura da planta (cm), número de folhas, número de ramos e número de síliquas. No final do experimento, foram avaliadas a matéria verde total (g planta-1) e matéria seca total (g planta-1), produtividade de grãos (g planta-1), além do teor de proteína (%) e de óleo (%) dos grãos. Os dados foram submetidos à análise de variância, sendo o efeito dos tratamentos estudado por meio de análise de regressão. Os resultados mostraram diferenças significativas entre os tratamentos para as variáveis analisadas, exceto para a altura das plantas e teor de proteína dos grãos, pelo teste F a 5% de probabilidade. O fator de resposta ky, indicador da sensibilidade da cultura ao déficit hídrico, foi menor que um para todos os parâmetros estudados. A produtividade de grãos apresentou a maior sensibilidade ao déficit hídrico.

A irrigação é prática fundamental para o cultivo de crisântemo, porém seu manejo adequado tem sido negligenciado pelos produtores, resultando em prejuízos no crescimento vegetal e conseqüentes decréscimos na produtividade e na qualidade do produto final. Para melhorar a representatividade dos dados obtidos, o experimento foidesenvolvido na propriedade de um produtor tradicional, no Distrito de Holambra II, município de Paranapanema-SP (23º4’S e 49º00’W). O objetivo principal do trabalho foi identificar a tensão de água no substrato (potencial matricial) que resultasse em melhor crescimento e desenvolvimento do crisântemo em vaso, cultivar Puritan. Os tratamentos foram definidos por seis níveis de tensão de água no substrato: -2, -3, -4,- 6,-10 e -30 kPa. Conclui-se, que a melhor qualidade do crisântemo em vaso foi obtida nos potenciais de água no substrato de -2, -6 e -10 kPa e que a tensão de -30 kPa, embora tenha levado à redução na qualidade comercial do crisântemo, resultou em maior durabilidade póscolheita. Irrigation is an important practice in chrysanthemum growing, but water management has been neglected, resulting in quality losses and yield reduction. The experiment was conducted at the Steltenpool farm, in the Holambra II District of the city of Paranapanema (23º4’S and 49º00’W). The aim of this research was to identify the best substrate water tension that could assure quality and high yield for the chrysanthemum, Puritan cultivar. Treatments were composed of six levels of substrate water tension: -2, -3, -4, -6, -10 and -30 kPa.Results showed that -2, -6 and -10 kPa substrate water tension resulted in the highest number of pots with A1 quality, considered the highest level in the grower’s scale. Postharvest was also evaluated and plants irrigated when substrate water tension reached -30 kPa presented longer durability.

The Piracicaba, Capivari and Jundiaí River Basins (RB-PCJ) are located in the States of Minas Gerais and São Paulo, Brazil. By 2005, 5.8% of Brazil's General National Product-GNP was produced there. Such economic development has created a huge demand for water resources. The availability of water resources was assessed by running a dynamic systems simulation model to manage these resources in the RB-PCJ (WRM-PCJ), considering five 50-year simulations. WRM-PCJ was developed as a tool to aid the RB-PCJ Watershed Committee. The model computes water supply, demands, and contamination load from several consumers. When considering a Business-as-Usual scenario, by 2054, water demands will have increased up to 76%, 39% of the available water will come from wastewater reuse, and the contamination load will have increased by 91%. The Falkenmark Index started at 1403 m³ person-1 year-1 in 2004, ending at 734 m³ P-1 yr-1 in 2054; the Xu Sustainability Index started at 0.44 and ended at 0.20; and Keller's River Basin Development Phases started as Phase II, and ended at final Phase III, of Augmentation. The three criteria used to evaluate water resources showed that RB-PCJ is at a crucial management turning point. The WRM-PCJ performed well, and proved to be an excellent tool to assess water resources availability.As Bacias Hidrográficas dos Rios Piracicaba, Capivari e Jundiaí (BH-PCJ) estão localizadas, nos Estados de Minas Gerais e São Paulo, Brasil. Em 2005 produziu 5.8% do PIB brasileiro. Este desenvolvimento econômico demanda grandes volumes de água. Com o Modelo para a Gestão dos Recursos Hídricos das BH-PCJ (MRH-PCJ), desenvolvido em dinâmica de sistemas, cinco cenários para 50 anos foram simulados. O MRH-PCJ foi desenvolvido para ser uma ferramenta de gestão do Comitê de Bacia Hidrográfica. O modelo estima a oferta e demandas de água, e a carga contaminante dos diversos consumidores. No cenário Business as Usual, para 2054, as demandas de água incrementaram em 76%, 39% da água disponível terá origem em águas de reuso, e a carga contaminante incrementará 91%. O Índice de Falkenmark, que em 2004 era de 1403 m³ pessoa-1 ano-1, será 734 m³ P-1 ano-1 em 2054; o Índice de Sustentabilidade de Xu iniciou em 0.44 e chegou até 0.20; quando consideradas as Fases de Desenvolvimento das Bacias Hidrográficas, propostas por Keller, iniciou-se na Fase II, e terminou-se na Fase III, de Aumento. Os três critérios utilizados para avaliar os recursos hídricos mostraram que as BH-PCJ encontram-se num ponto de tomada de decisões importante. O MRH-PCJ mostrou-se uma excelente ferramenta para avaliar a disponibilidade de recursos hídricos.

ABSTRACT With this study, the objective was to determine the most economic management of irrigation water applied at different levels in the culture of passion fruit grown in conventional system and in polyethylene bags. The experiment was conducted in the city of Remanso, state of Bahia, Brazil. The experimental set-up was a randomized block design in a factorial design 2 (conventional system, and polyethylene bags of 100 L) x 5 (irrigation levels: 100%, 80%, 60%, 40% and 20% an irrigation management at field capacity) with four replications and four plants per plot. The treatments began 30 days after transplanting the seedlings to the field, and the analyzed variables were: plant height, stem diameter, leaf area and number of tertiary branches, of flower buds and fruits per plant. The data were interpreted by means of analyses of variance (test F) and means were compared by Tukey test at 5% probability of error. It was found that the yellow passion fruit got greater agronomic performance when grown in polyethylene bags, with irrigation management at 80 % field capacity.

O objetivo deste trabalho foi quantificar o armazenamento, a disponibilidade e a extração de água no solo por plantas de milho irrigadas e submetidas a déficit hídrico terminal, cultivadas sob sistema de semeadura direta e preparo convencional. Foram realizados dois experimentos durante os anos agrícolas de 1999/00 e 2000/01, em área experimental do Departamento de Engenharia Rural da Universidade Federal de Santa Maria. Utilizou-se o delineamento experimental inteiramente casualizado, fatorial, com quatro repetições. Foram utilizados dois manejos da água de irrigação (fator A): irrigado e déficit hídrico terminal (plantas de milho foram submetidas a déficit hídrico terminal a partir dos 27 dias após a emergência); e dois sistemas de cultivo (fator B): semeadura direta e preparo convencional. Nas parcelas irrigadas, irrigações foram feitas para elevar o conteúdo de água no solo ao limite superior de disponibilidade de água às plantas, sempre que a evapotranspiração máxima acumulada da cultura do milho atingia 25 mm. O conteúdo de água no solo foi medido em três leituras semanais, para determinação da extração de água pelas plantas e disponibilidade de água às plantas de milho. Os resultados indicaram que a disponibilidade de água às plantas de milho foi similar nos sistemas semeadura direta e preparo convencional, em ambos os anos agrícolas avaliados. Plantas de milho cultivadas em preparo convencional extraíram maior quantidade de água, em ambos os anos, em relação à semeadura direta.The aim objective of this study was to quantify the soil water storage, plant-available water and extraction of soil water by corn plants under irrigation and terminal drought. Plants were cultivated under no-tillage and conventional tillage systems. Two experiments were conducted in the 1999/00 and 2000/01 growing season on an experimental field of the Agricultural Engineering Department of the Federal University of Santa Maria. Treatments consisted of a 2 x 2 factorial scheme, in a completely randomized design, with four replications. The tested treatments were: Factor A - irrigation management (irrigation and terminal drought, 27 days after emergence, when plants presented seven fully expanded leaves) and; Factor B - tillage system (no-tillage and conventional tillage). Irrigation water was applied to raise the soil water content to the maximum limit of plant-available water, always when the cumulative maximum crop evapotranspiration reached a value of 25 mm. Soil water content was measured three times a week to determine soil water extraction and water availability for corn plants. Results indicated a similar amount of water available to corn plants cultivated in both tillage systems during the two growing seasons. Conventionally cultivated maize plants extracted a higher amount of soil water than plants cultivated in no-tillage system.

O plantio de melão no período chuvoso tem sido um dos grandes desafios para os produtores da região do Nordeste brasileiro devido a problemas fitossanitários. Objetivou-se, neste trabalho, avaliar os efeitos de cobertura do solo e de lâminas de irrigação na produção e na qualidade do melão amarelo híbrido "Goldex", no período chuvoso. O experimento foi desenvolvido na Fazenda Santa Júlia Agrocomercial Exportadora de Frutos Tropicais Ltda, no município de Mossoró-RN, no período de abril a julho de 2003. O delineamento experimental utilizado foi o de blocos completos casualizados, com quatro repetições. Os tratamentos resultaram da combinação de cinco tipos de coberturas do solo (solo descoberto e coberturas do solo com plástico preto, prateado, amarelo e marrom) com três lâminas de irrigação (100%, 86% e 72% da lâmina padrão, esta equivalente a 238,4mm por ciclo). As características avaliadas foram número, massa média e produtividade de frutos comercializáveis (mercados interno e externo), refugos e totais, firmeza e espessura de polpa, relação de formato e teor de sólidos solúveis totais. Houve interação significativa entre os tipos de coberturas do solo e as lâminas de irrigação para a produtividade total. A maior produtividade de frutos comercializáveis e de conteúdo de sólidos solúveis totais foi registrada nas coberturas do solo com plástico. Os números de frutos comercializáveis, refugos e totais, bem como a produtividade de frutos comercializáveis e refugos, não foram afetados significativamente pelas lâminas de irrigação.Growing a melon crop during the rainfall period has been a great challenge for producers from the north eastern Brazil due to crop sanitary problems. This work was aimed at evaluating the effects of soil coverages and irrigation depth on yield and quality of yellow melon (hybrid Goldex) during the rainfall period. The experiment was carried out at Fazenda Santa Júlia Agro-Comercial Exportadora de Frutos Tropicais Ltda, Mossoró-RN, Northeastern Brazil, during the period of April to July 2003. The experimental design was a randomized complete blocks with four replications. The treatments were the combinations of five soil coverages (soil with no coverage and coverages with polyethylene films - black, silvery, yellow, and brown) with three irrigation depth (100%, 86% and 72% of the standard lamina, this equivalent to 238.44mm). The traits evaluated were number, mean weight and yield of marketable (internal and external markets), refuse and total fruits, pulp firmness and thickness, fruit shape index, and soluble solids content. Interaction between soil coverage types and irrigation depth was significant with regard to total fruit yield. The greatest marketable fruit yields and soluble solids contents were obtained with the use of polyethylene soil coverages. The numbers of marketable, refuse and total fruits, as well as the yields of marketable and refuse fruits were not significantly affected by the irrigation depth.

A determinação da quantidade de água necessária para as culturas é um dos principais fatores para o correto planejamento, dimensionamento e manejo de qualquer sistema de irrigação. O presente trabalho teve como objetivo, comparar medida da evapotranspiração da cultura (ETc) da cebola com estimativa obtida a partir da evapotranspiração de referência (ETo) determinada por diferentes métodos e Kc proposto na literatura. O experimento foi conduzido no campo experimental do Departamento de Tecnologia e Ciências Sociais da Universidade do Estado da Bahia - UNEB, em Juazeiro, no período de junho a setembro de 2011. As medidas da ETc foram obtidas em evapotranspirômetros e as estimativas, a partir de ETo determinada pelos métodos: Penman-Monteith (padrão FAO), Penman-Monteith modificado por Villa Nova et al. (2004), Hargreaves & Samani, Makkink e Jensen & Haise e Kc proposto por Marouelli et al. (2005), para a cultura da cebola. É fundamental a avaliação de métodos de estimativa da evapotranspiração de referência antes de sua aplicação, pois erros consideráveis podem ser cometidos na determinação da quantidade de água a ser aplicada a uma cultura, o que repercutirá certamente, na produtividade. Evapotranspiration crop onion Abstract: The determination of the amount of water needed for crops is a major factor for the correct planning, sizing and management of any irrigation system. This study aimed to compare measure of crop evapotranspiration (ETc) onion with estimates obtained from the reference evapotranspiration (ETo) determined by different methods and Kc proposed in the literature. The experiment was conducted in the experimental field of the Department of Technology and Social Sciences, University of the State of Bahia, in Juazeiro, from June to September 2011. The ETc measurements were obtained in evapotranspirometers and estimates, from ETo determined by the methods: Penman-Monteith (FAO standard), Penman-Monteith modified by Villa Nova et al. (2004), Hargreaves & Samani, Makkink and Jensen & Haise and Kc proposed by Marouelli et al. (2005), for the cultivation of onion. It is critical to evaluation of reference evapotranspiration estimation methods before their application because considerable mistakes can be made in determining the amount of water to be applied to a culture, which resonate certainly in productivity.

Copyright of Brazilian Journal of Applied Technology for Agricultural Science / Revista Brasileira de Tecnologia Aplicada nas Ciências Agrárias is the property of Brazilian Journal of Applied Technology for Agricultural Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

O objetivo deste trabalho foi avaliar o efeito de níveis de irrigação aplicados por gotejamento no perfil de umidade do solo na zona de concentração radicular do maracujazeiro-amarelo (Passiflora edulis Sims f. flavicarpa Deg). O experimento foi realizado no período de julho de 1999 a janeiro de 2000, no Campo Experimental da Fazenda Areão, em Piracicaba - SP (22º42'30"S e 47º38'00"W). Os níveis de irrigação, aplicados por um sistema de irrigação por gotejamento, foram: L1 = 0,25 L; L2 = 0,50 L; L3 = 0,75 L, e L4 = 1,00 L, em que L é a lâmina de água média medida em lisímetros. Os níveis de irrigação influenciaram nos perfis de distribuição temporal do potencial matricial, apresentando comportamento diferenciado na oscilação e na manutenção dos teores de água na zona radicular do maracujazeiro. A aplicação de volume de água entre 1.528 L planta-1 ano-1 (L2) e 2.117 L planta-1 ano-1 (L3) favoreceu perfis médios de umidade na zona radicular do maracujazeiro mais adequados, enquanto L1 e L4 tiveram valores de umidade abaixo e acima do valor referente à capacidade de campo, respectivamente. Valores de potencial matricial abaixo de -0,01445 MPa e acima de -0,00357 MPa afetam negativamente os parâmetros de produção do maracujazeiro-amarelo.The objective of this study was to evaluate the effect of irrigation levels in the moisture profile in the root zone concentration of yellow passion fruit (Passiflora edulis Sims f. flavicarpa Deg). The experiment was carried out in the Experimental Area at ESALQ/USP, Piracicaba, São Paulo State, Brazil (22º42'30"S e 47º38'00"W). The irrigation levels were: L1 = 0.25 L; L2 = 0.50 L; L3 = 0.75 L; L4 = 1.00 L, which, L is the average water depth measure in lysimeter. The irrigation levels influenced the temporal distribution profile of matrix potential, showed different behavior in the oscillation and maintenance of water content in root zone. The water volume applied between 1,528 L plant-1 year-1 (L2) and 2,117 L plant-1 year-1 (L3) conduced adequate moisture levels in the passion fruit root zone, while L1 and L4 presented medium values above and below of the field capacity, respectively. Matrix potential values below -0.01445 MPa and above -0.00357 MPa affect negativity the yield parameters.

Os efeitos de diferentes níveis de déficit hídrico, aplicados em dois estádios fenológicos da cultura da berinjela, foram avaliados por meio de um experimento conduzido em casa de vegetação, no Departamento de Engenharia, da Universidade Federal de Lavras, em Lavras - MG. Utilizou-se um delineamento experimental inteiramente casualizado em esquema fatorial 2 x 4, sendo duas fases fenológicas (pós-transplante/abertura da gema floral e formação de frutos/colheita) e quatro níveis de déficit hídrico (100; 80; 60 e 40% da evapotranspiração), totalizando oito tratamentos, com seis repetições. Avaliaram-se o diâmetro de caule, altura das plantas e número de folhas em diferentes épocas, produção e número de frutos. Os resultados mostraram que a produção e o número de frutos foram mais afetados pelo déficit hídrico quando esse ocorreu durante a fase de formação dos frutos e que a qualidade dos frutos foi mais afetada do que a produção total. Deficiências hídricas mais intensas provocaram redução nos valores da altura da planta, do diâmetro do caule e do número de folhas, independentemente da época em que foram aplicadas.The effects of different levels of water deficit, applied in two fenological phases of eggplant crop, were measured in an experiment conducted in a green house of the Department of Engineering - UFLA, in Lavras - MG, Brazil. A complete randomized experimental design was used in a factorial array of 2 x 4, being two phenological phases (after-transplanting/opening of the floral bud and fruits formation/harvest) and four levels of water deficit (100; 80; 60, and 40% of the evapotranspiration), in eight treatments with six replications. The stem diameter, height of the plants and number of leaves were evaluated in different times, production and number of fruits. The results showed that the production and the number of fruits were more affected by the water deficit when it occurred during the phase of formation of the fruits, and that, the quality of the fruit was more affected than the total production. The increase of the water deficit resulted in smaller values of the height of the plant, diameter of the stem and number of leaves, independently of the application time.

No interior de uma casa-de-vegetação, em Lavras, MG, conduziu-se um experimento, objetivando-se avaliar a demanda evaporativa do ar (ET) estimada pelos métodos do tanque Classe A e do atmômetro modificado da Soilcontrol, modelo JR 120, com a estimada pelo método de Penman-Monteith. Pelos resultados verifica-se que os métodos do tanque Classe A e do atmômetro modificado obtiveram boa correlação com o método de Penman-Monteith para períodos diários, com valores de "r" de 0,94 e 0,97, respectivamente, e ainda que os dois tipos de evaporímetros apresentaram, em média, valores maiores de ET em relação ao método de Penman-Monteith.An experiment was carried out under greenhouse conditions in Lavras, MG, aiming at evaluating the evaporative demand of the air (ET), estimated by of Class A pan and modified atmometer of Soilcontrol model JR 120 the methods, using the Penman-Monteith methodology. The results show that the methods of the Class A pan and the modified atmometer showed a good correlation with the method of Penman-Monteith for diary periods, showing "r" values of 0.94 and 0.97, respectively, and yet the two types of evaporimeters presented higher values of ET0 on the average when compared to Penman-Monteith method.

En las fábricas de azúcar si se logra un uso eficiente del agua de proceso, el mismo deber autosostenerse en cuanto a su consumo ya que estas fábricas tienen la característica especial de que la materia prima principal que procesan, la caña, consiste en aproximadamente 70% de agua. Los condensados recuperados constituyen la primera opción para recuperar agua de proceso y son destinados para la alimentación a calderas. Las cantidades de los diferentes tipos de condensados son dependientes de la configuración de evaporadores y del grado en que se presenten las extracciones de vapor en los mismos. En este artículo, se describen los aspectos fundamentales en cuanto al uso y manejo de agua en el proceso de fabricación de azúcar. También se presentan consideraciones importantes sobre los sistemas de tratamientos de residuales que en estas fábricas se generan. Se muestra como el área más importante en cuanto al manejo del agua en el proceso es el sistema de evaporación, en el mismo se produce vapor vegetal, que es utilizado en otros equipos tecnológicos del proceso y cuanto más eficiente energéticamente sea ésta área, mayor será el excedente producido. Se muestra a través de un balance de agua que el proceso tiene posibilidades de autosostenerse en cuanto a consumo de agua.

Indagar una fecha correcta o probable del establecimiento en Sudamérica occidental del sistema de manejo de agua -conocido en el Perú como puquio, y genéricamente llamado galería filtrante o qanat- es importante porque su supuesta existencia a mediados del primer milenio d.C. ha sido un elemento importante en la reconstrucción de ocupaciones humanas prehistóricas en la región Nazca. Cuando propusimos por primera vez que los puquios databan del periodo colonial, nuestra sugerencia no tuvo aceptación universal. Los estudiosos argumentaban, a partir de las fechas del método radiocarbónico, que los puquios de Nazca databan de más o menos un milenio antes de la llegada de los españoles. Los estudios de patrones de asentamiento también han sido usados para apoyar la conclusión de una invención temprana.

The determination of the amount of water needed for crops is a major factor for the correct planning, sizing and management of any irrigation system. This study aimed to compare measure of crop evapotranspiration (ETc) onion with estimates obtained from the reference evapotranspiration (ETo) determined by different methods and Kc proposed in the literature. The experiment was conducted in the experimental field of the Department of Technology and Social Sciences, University of the State of Bahia, in Juazeiro, from June to September 2011. The ETc measurements were obtained in evapotranspirometers and estimates, from ETo determined by the methods: Penman-Monteith (FAO standard), Penman- Monteith modified by Villa Nova et al. (2004), Hargreaves & Samani, Makkink and Jensen & Haise and Kc proposed by Marouelli et al. (2005), for the cultivation of onion. It is critical to evaluation of reference evapotranspiration estimation methods before their application because considerable mistakes can be made in determining the amount of water to be applied to a culture, which resonate certainly in productivity. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objetivou-se estudar, num solo aluvial, franco siltoso, no vale do Açu, no Rio Grande do Norte, o efeito do momento da última irrigação e da população de plantas sobre a altura das plantas e a produtividade do algodoeiro herbáceo (Gossypium hirsutum L.r. latifolium Hutch), cultivar Acala del cerro. Os tratamentos foram definidos pelos momentos da última irrigação aos 65, 80, 95 e 110 dias após a emergência e pela população com 30.000, 60.000, 90.000 e 120.000 plantas/ha. Usou-se o delineamento experimental em blocos ao acaso, com parcelas subdivididas, e quatro repetições. A altura das plantas aumentou com o retardamento da última irrigação e com o tamanho das populações. Houve efeito (P In an alluvial soil, silt loam, of Açu valley, in the state of Rio Grande do Norte, Brazil, a research was carried out to study the effect of time of the last irrigation and plant population on yield and plant height of the herbaceous cotton (Gossypium hirsutum L.r. latifolium Hutch) cultivar Acala del cerro. Treatments consisted of times of the last irrigation at 65, 80, 95 and 110 days after emergence and populations with 30,000, 60,000, 90,000 and 120,000 plants/ha. The experimental plan was a randomized complete blocks in a split-plot design, with four replications. Delaying time of last irrigation increased height and plant populations. A significant effect (P

En este trabajo se evaluó, la factibilidad de alternativas que favorecen el uso del agua y la energía en el proceso de obtención de alcohol. Se realizaron balances de masa yenergía con el fin de determinar los consumos de agua en la producción de alcohol yde esta forma proponer vías para el ahorro y correcta distribución de la misma, además, se aplicaron herramientas de integración para la identificación de una mejor distribución de la energía y con ello propiciar la reducción de los costos. Para la integración energética se utilizó el software ASPEN PLUS 11.1, donde se realizó la modelación y simulación de las etapas de dilución, pre- fermentación, fermentación y destilación del proceso de producción de alcohol técnico B y extrafino, además se evaluaron alternativas de intercambio de calor entre corrientes calientes yfrías con elASPEN PINCH y se identificaron los requerimientos de utilidades mínimos para el proceso. Se realizó la evaluación económica de las modificaciones propuestas, con el fin de determinar la factibilidad técnica y económica del ahorro de agua, energía y materias primas. Tambien se evaluó la factibilidad económica de la integración.

A irrigação é prática fundamental para o cultivo de crisântemo, porém seu manejo adequado tem sido negligenciado pelos produtores, resultando em prejuízos no crescimento vegetal e conseqüentes decréscimos na produtividade e na qualidade do produto final. Para melhorar a representatividade dos dados obtidos, o experimento foi desenvolvido na propriedade de um produtor tradicional, no Distrito de Holambra II, município de Paranapanema-SP (23°4’S e 49°00’W). O objetivo principal do trabalho foi identificar a tensão de água no substrato (potencial matricial) que resultasse em melhor crescimento e desenvolvimento do crisântemo em vaso, cultivar Puritan. Os tratamentos foram definidos por seis níveis de tensão de água no substrato: -2, -3, -4,- 6,-10 e -30 kPa. Conclui-se, que a melhor qualidade do crisântemo em vaso foi obtida nos potenciais de água no substrato de -2, -6 e -10 kPa e que a tensão de -30 kPa, embora tenha levado à redução na qualidade comercial do crisântemo, resultou em maior durabilidade pós- colheita.

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

sized classic Maya city in the extreme south of the Mexican state of Campeche. The project's research goal is to investigate the expansion and disintegration of hegemonic power in the Maya area, concentrating on the core area of the Maya lowlands and especially on Uxul's close relation to the powerful Kaan dynasty at Calakmul. New evidence strengthens the hypothesis that Uxul was under the control of Calakmul since the early 7th century. also, our data suggest that the downfall and abandonment of Uxul were closely related to the fateful defeats of Calakmul's rulers Yukno'm Yich'aak K'ahk' and Yukno'm took' K'awiil at the hands of Tikal in AD 695 and 736. When the central authority collapsed during the mid-8th century, the shrinking population of Uxul was not able to maintain the social cohesion to protect even the most vitally important of infrastructures: its water management system. [ABSTRACT FROM AUTHOR]