Under the European system of agri-environmental indicators, the Council of the European Union recognized the need for comparable data on agricultural activities, especially with regard to farm management practices and use of agricultural inputs, including the use of irrigation water, having been enshrined this principle in the Regulation (EC) 1166/2008. To meet this legal requirement, established a partnership between the INE and ISA / CENTROP to develop the MECAR - Methodology for Estimating Irrigation Water in Portugal. After the comparative approach of different methodologies, it was considered that the use of estimation models based on water balance would be the best approach to achieve these objectives. The methodology was based on soil water balance, which is done by the mathematical model ISAREG (Teixeira and Pereira, 1992 and Teixeira, 1994), which is based on the procedure of the FAO (Doorenbos and Pruit, 1977 and Doorenbos and Kassam, 1979) determining the water requirements of crops, which apply correction factors for loss of efficiency that stem from the characteristics of irrigation systems used and the conditions of irrigation, particularly in their management of their respective owners. The validation of results produced by MECAR, to prove that the volumes obtained by simulation were located close to the actual values, it was considered satisfactory. However, it is recommended that a second validation be performed, comparing the annual simulated data recorded by the irrigation farmers associations and individual farmers for the same period. The application of MECAR to actual data from IE 2007 is an operational test of this solution is adequate as it allowed to obtain reliable information and consistent with the requirements of the regulation.

Under the European system of agri-environmental indicators, the Council of the European Union recognized the need for comparable data on agricultural activities, especially with regard to farm management practices and use of agricultural inputs, including the use of irrigation water, having been enshrined this principle in the Regulation (EC) 1166/2008. To meet this legal requirement, established a partnership between the INE and ISA / CENTROP to develop the MECAR - Methodology for Estimating Irrigation Water in Portugal. After the comparative approach of different methodologies, it was considered that the use of estimation models based on water balance would be the best approach to achieve these objectives. The methodology was based on soil water balance, which is done by the mathematical model ISAREG (Teixeira and Pereira, 1992 and Teixeira, 1994), which is based on the procedure of the FAO (Doorenbos and Pruit, 1977 and Doorenbos and Kassam, 1979) determining the water requirements of crops, which apply correction factors for loss of efficiency that stem from the characteristics of irrigation systems used and the conditions of irrigation, particularly in their management of their respective owners. The validation of results produced by MECAR, to prove that the volumes obtained by simulation were located close to the actual values, it was considered satisfactory. However, it is recommended that a second validation be performed, comparing the annual simulated data recorded by the irrigation farmers associations and individual farmers for the same period. The application of MECAR to actual data from IE 2007 is an operational test of this solution is adequate as it allowed to obtain reliable information and consistent with the requirements of the regulation.

Sistemas de irrigação demandam quantidades significativas de energia elétrica, o que aumenta consideravelmente o custo de produção. Simularam-se o gasto com energia elétrica e as lâminas de irrigação, para um perímetro irrigado hipotético na região do Jaíba, MG, para as culturas: abacaxi, banana, goiaba, limão, mamão, manga, maracujá, melão, pinha e uva. A partir de dados das necessidades hídricas das culturas, calcularam-se as lâminas de irrigação mensal e para cada um dos lotes, simularam-se as alturas manométricas, as demandas hidráulicas e elétricas e o consumo de energia, para diferentes combinações de culturas nos lotes e, para as combinações, simulou-se o uso do inversor de frequência com restrição do número de horas de funcionamento diário em função da época do ano visando maximizar o índice de carregamento dos motores e o rendimento do conjunto motobomba. Concluiu-se que o uso do inversor de frequência e o gerenciamento do número de horas de disponibilidade da irrigação no sistema de fornecimento de água para irrigação no perímetro estudado, garantiram economia de energia elétrica, que variou em torno de 7% a 62% para as combinações estudadas.<br>Irrigation systems demand significative electrical energy quantities, that increase considerably the production costs. The electric energy expenditure and the irrigation depth for one hypothetical irrigated perimeter on Jaíba region - MG, Brazil were simulated for the: pineapple, banana, guava, lemon, papaya, mango, passion fruit, cantaloupe, pine cone and grape crops. From the monthly irrigation depth calculated for a hypothetical area the pressure head, the electrical and hydraulic demands and the electrical energy consumption for different crop combination were simulated. The frequency inverter use and the daily restriction to the availability of the number of hours of irrigation were simulated for each combination, in order to maximize the motor´s load and the motor pump set performance. It is concluded that the frequency inverter use and the management of the availability of the number of hours of irrigation secure energy savings that varies around 7 to 62% for the studied combinations.

RESUMEN El agua es un compuesto que gracias a sus propiedades ha posibilitado la vida, ha conformado el paisaje y ha moldeado las civilizaciones en la faz de la tierra. No todas las regiones poseen la misma disponibilidad y su escasez relativa; junto con el cambio climático está generando conflictos entre pueblos y actividades económicas y medioambientales, pero siendo un conflicto global, se debe enfrentar en la esfera local, para lo cual se deben fortalecer las capacidades locales en todos aquellos ámbitos en que el agua participa. | ABSTRACT Thanks to the properties of water life is possible; it has shaped the landscape and molded the civilizations on the face of the earth. Not all regions have adequate availability of water; its relative scarcity together with climate change is generating conflicts between nations and between economic activity and environmental concerns. Although this is a global conflict, it must be faced in local spheres, thus it is necessary to strengthen local capacities in all areas in which water is a factor.

Peer Reviewed | Postprint (published version)

No passado, não havia conscientização em minimizar o consumo de água em virtude de sua abundância e facilidade de obtenção. Entretanto, atualmente tem aumentado o interesse pelo uso racional da água e sua reutilização, especialmente em viveiros florestais. Porém, antes de sua reutilização, a água tem que ser devidamente tratada visando à erradicação de inóculo fitopatogênico a fim de minimizar os riscos de dispersão de patógenos e mitigar as perdas causadas por doenças. No presente trabalho, avaliou-se a eficiência do tratamento da água por ultrafiltração e pelo método físicoquímico convencional visando à erradicação de inóculo de Ralstonia solanacearum, Xanthomonas axonopodis, Botrytis cinerea e Cylindrocladium candelabrum, principais patógenos, comumente encontrados em viveiros florestais. A ultrafiltração permitiu erradicar acima de 99% de inóculo de R. solanacearum, X. axonopodis e B. cinerea e 100% de C. candelabrum. A baixa quantidade de inóculo remanescente dos três primeiros patógenos não induziu doenças nas mudas inoculadas. A floculação e filtração rápida em filtro de areia empregadas no método físíco-químico permitiram erradicação completa de inóculo de C. candelabrum, mas para os demais patógenos obteve-se a erradicação total somente após cloração da água filtrada com cloro residual a partir de 1,74 mg/L. Mudas de três clones de eucalipto irrigadas por 45 dias com água contendo cloro residual a 1,74 mg/L não apresentaram sintomas de fitotoxicidade. Ambos os métodos testados são práticos, viáveis e principalmente seguros visando à eliminação de inóculo de fitopatógenos da água de irrigação. | In the past, there was no preoccupation in minimizing water consumption which was probably due the belief of its abundance and easy access. Nowadays, the interest in water conservation and reuse has increased especially in forest nurseries. However, before water is reused it must be treated in order to minimize the risk of spread inocula of pathogens and to reduce losses caused by diseases. In this study, water treatment processes of ultrafiltration and conventional physical-chemical treatment were evaluated regarding the eradication inocula of Ralstonia solanacearum, Xanthomonas axonopodis, Botrytis cinerea and Cylindrocladium candelabrum, the most common nursery pathogens in Brazil. The ultrafiltration eradicated over 99% inocula of R. solanacearum, X. axonopodis and B. cinerea and 100% of inoculum of C. candelabrum. The treated water was tested for irrigation and yielded no infected eucalyptus rootted cuttings. Sand filtration used in the physical-chemical treatment system allowed complete eradication of C. candelabrum inoculum, but complete inoculum eradication of the other pathogens was only achieved after chlorination of the filtered water with residual chlorine from 1.74 mg/L. No symptoms of phytotoxicity were found on Eucalyptus rooted cuttings irrigated with water containing residual chlorine at 1.74 mg/L. Both methods tested are practical, viable and safe to eradicate phytopathogens inoculum from irrigation water. | Conselho Nacional de Desenvolvimento Científico e Tecnológico

Este trabalho objetivou realizar uma análise da eficiência do uso de água em um sistema de produção de cana-de-açúcar irrigada no Submédio do Vale do São Francisco, Brasil. Indicadores que consideram a resposta produtiva da cultura e o desempenho de aplicação de água no sistema de produção foram utilizados e calculados por meio de dados de biomassa seca acumulada, rendimento industrial e a partir dos valores de evapotranspiração de referência (ETo), evapotranspiração da cultura (ETc) e do volume de água que entrou no sistema de produção por precipitação e irrigação (P + I). Verificou-se que a maior eficiência do uso de água pela cultura ocorreu entre o sétimo e o oitavo meses produtivos em virtude do aumento da partição de biomassa para os colmos e do suprimento de radiação e, ainda, da redução da ETc em resposta ao tombamento das plantas. Os indicadores utilizados demonstraram que a demanda de água da cultura foi suprida adequadamente em relação à evapotranspiração máxima. A cana-de-açúcar apresentou uma eficiência de produção de 9,49 kg de colmos, 1,22 kg de açúcar e 875,23 mL de álcool por m3 de ETc e 5,36 kg de colmos, 0,69 kg de açúcar e 494,14 ml de álcool por m3 de P+I.<br>The objective of this work was to accomplish an analysis of the water use efficiency in a production system of irrigated sugarcane located in the Lower-Middle São Francisco river basin, Brazil. Indicators based on the crop yield and the water application performance in the production system were used. These indicators were calculated through accumulated dry biomass, industrial yield data and through the values of reference evapotranspiration, crop evapotranspiration and the water volume that entered in the system by rain and irrigation (P+I). It was verified that, the highest water use efficiency of crop occured between 7th and 8th month, due to increase in the stalk biomass partition and radiation supply, and due to reduction of ETc in response tumbling of the plants. The used indicators demonstrated that the water demand of crop was adequately in relation to maximum evapotranspiration of crop. The irrigated sugarcane presented a production efficiency of 9.49 kg of stalks, 1.22 kg of sugar and 875.23 mL of alcohol per m3 of ETc and of 5.36 kg of stalks, 0.69 kg of sugar and 494.14 mL of alcohol per m3 of P+I.