97 research outputs found

    Energy balance in irrigated wheat in the Cerrados Region of central Brazil.

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    To evaluate the water requirements for Irrigated wheat, a mlcrometeorological study was conducted during the dry seasons of 1982 and 1983 at the Cerrados Agricultural Research Center, Brasilia-DF, BraziL The crop was Irrigated when the soU water potential at 5 cm reached-60 to -7OJIkg. Bowen ratio measurements were made on an hourly basls during the entire crop season, Total amount of water evapotranspired during the crop cycle and the energy balance terms varied year to year due to regional advection; ln 1982,a Iess advective year, the total amount of water evapotranspired was 345 mm, with approximately 80% of the net radlation dlsslpated as latent heat, 13% as a sensible heat and 7% as soU heat after the crop obtalned a Leaf Area lndex (LAI) of 1.5. ln 1983, when advection was greater than 1982, total water evapotranspired Increased to 385mm. The partitloning of energy was similar to 1982 during periods of title or no advecnon, However, during periods of Intense advection, latent heat was greater. In net radlation partitioning. Although regional advection Increased the water used by the crop, Irrigation scheduling based on so√≠l tensiometers was considered adequate and eflicient due to the low values of the Bowen ratio obtalned. Um estudo n√ļcrometeorol√≥gico para avaliar a demanda h√≠drica do trigo Irrigado foi conduzido nasesta√ß√Ķes secas de 1982 e 1983 no Centro de Pesquisa Agricola dos Cerrados, Brasilia-DF, Brasil A cultura foi Irrigada quando o potencial de √°gua no solo a 5 cm atinriu -60 a -70 JIkg. Durante todo o ciclo da cultura medidas da raz√£o de Bowen foram feitas numa base hor√°ria. A quantidade total de √°gua evapotranspirada durante todo ciclo da cultura e o balan√ßo energ√©tico variaram entre os anos devido √† advec√ß√£o regional; em 1982, um ano menos advectivo, a quantidade total de √°gua evapotranspirada foi de 345 mm, sendo 80% da radia√ß√£o l√≠quida dissipada como calor latente, 13% como calor sens√≠vel e 7% como calor do solo ap√≥s a cultura ter atingido um √ćndice de √Ārea Foliar (IAF) de 1.5. Em 1983, quando a advec√ß√£o foi maior que em 1982, a quantidade total de √°gua evapotranspirada aumentou para 385 mm. A parti√ß√£o de energia foi similar √† 1982 durante periodos de pouca ou nenhuma advec√ß√£o. Entretanto durante periodos de Intensa advec√ß√£o, o calor latente representou a maior parte da radia√ß√£o l√≠quida. Apesar da advec√ß√£o regional aumentar o consumo de √°gua da cultura, programa√ß√£o da irriga√ß√£o baseada em tensiometros foi considerada adequada e eficiente devido aos baixos valores da raz√£o de Bowen obtidos.N¬ļ especial

    Bioeletricidade no setor sucroalcooleiro paulista: participação no mercado de carbono, perspectivas e sustentabilidade.

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    Energy balance in irrigated wheat in the Cerrados Region of central Brazil.

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    Um estudo micrometeorol√≥gico para avaliar a demanda h√≠drica do trigo irrigado foi conduzido nas estac√Ķes secas de 1982 e 1983 no Centro de Pesquisa Agr√≠cola dos Cerrados, Brasilia-DF, Brasil. A cultura foi irrigada quando o potencial de √°gua no solo a 5 cm atingiu -60 a -70 J/kg.Durante todo o ciclo da cultura medidas da raz√£o de Bowen foram feitas numa base horaria. A quantidade total de √°gua evapotranspirada durante todo ciclo da cultura e o balanco energ√©tico variaram entre os anos devido a advec√ß√£o regional; em 1982, um ano menos advectivo, a quantidade total de √°gua evapotranspirada foi de 345 mm, sendo 80% da radia√ß√£o liquida dissipada como calor latente, 13% como calor sens√≠vel e 7% como calor do solo apos a cultura ter atingido um √ćndice de √Ārea Foliar (IAF) de 1.5. Em 1983, quando a advec√ß√£o foi maior que em 1982, a quantidade total de √°gua evapotranspirada aumentou para 385mm. A parti√ß√£o de energia foi similar a 1982 durante per√≠odos de pouca ou nenhuma advec√ß√£o. Entretanto durante per√≠odos de intensa advec√ß√£o, o calor latente representou a maior parte da radia√ß√£o liquida. Apesar da advec√ß√£o regional aumentar o consumo de √°gua da cultura, programa√ß√£o da irriga√ß√£o baseada em tensi√īmetro foi considerada adequada e eficiente devido aos baixos valores da raz√£o de Bowen obtidos

    Expansion of sunflower crop production in Brazil: a survey of future trends.

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    Sunflower cropped area in Brazil has been showing potential possibilities to be increased in a short period of time for biofuel production. Planning the activities is one of the requirements for the success of future cropped area expansion. This requires a previous survey that identifies future trends in the transformation and rearrangement of the sunflower agro-industry sector and also identifies technological needs that may affect this process. With the objectives of identify future trends and technological needs, a value production chain was built and a questionary was applied to agents of all the sectors participating at the V National Brazilian Symposium of Sunflower and at the XVII Sunflower National Research Meeting Network. The results pointed out a strong tendency for area expansion in the next two to five years (75%); being as a secondary follow-up crop (83%) specially after soybean and top be used for biofuel (77%). The main research needs were linked with disease control, crop zoning and varietal improvement for disease resistance and high oleic oil content. Also considering the vision of and concerns regarding the future expansion and transformation of the sunflower productive complex, it is believed that the expansion is a consolidated trend, requiring a strategic sector planning associated with an economic and technological police for its success within the Brazilian agribusiness

    Medida de condutividade elétrica do solo adaptada a uma plantadeira.

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    Risk assessment of water contamination by agrochemical in watershed.

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    Intensive agricultural systems are based on the heavy use of pesticides and fertilizers. This fact offer a high contamination risk of the natural resources, even when adequate technical of storage, application and disposal are used. Brasil used in 1993 61,845t of active ingredients of pesticides (insecticide, fungicide and herbicide) and 11,424,635 t of fertilizers (phosphorus, nitrogen and potassium), being the application rates variable as a function of region and crop plants. The use was very high, for example, in corn, cotton, orange, potato, soybean, sugar-cane and tomato in the east region of Rio Parana basin. The risk of agrochemical contamination of the natural resource varies according to the environment and product properties, therefore it is necessary to improve the knowledge about environment/product relation in order to permit a space-temporal management on application of these products, to reduce the risks. In our country, because its large surface area (8,500,000 km2) the data of environmental properties are poorly detailed and are not continuous in time and space. We have access to good information about properties of the used products, but few information is available about the quantity, the site and the method of their application. This work was done with all these things in mind and with the objective of the establishment of a method which permits a first approximation to identify areas with high risk of water contamination by agrochemical. We decided only use data which are available to everyone, in order to facilitate the method acceptance. The basic idea was that the water is the main agrochemical transport medium after its application in the crop field, and the environmental properties involved in the water moving (here considerated only in liquid state) are soil type, terrain slope and precipitation rate. An algorithm was built, based upon logical relationship matrixes, which permits to establish the water runoff and infiltration potential by crossing information of soil and terrain slope. This crossing was done by geographic information of soil and terrain slope. This crossing was done by geographic information system IDRISI, using like example the data of the Corrego Espraiado watershed, Ribeirao Preto county, Sao Paulo, Brasil. Maps were generated with the localization of the areas with high, medium and low water runoff and infiltration (one is opposite of the other) potentials. The areas were quantified, resulting that from the total 4,463ha of the watershed, 1,779ha had high (low) runoff (infiltration) potential. Maps which permits the identification of the areas which have greater risk of water contamination in the watershed has been generated. These maps can be made on monthly, seasonal (dry, normal and rainy seasons) or annual basis, for the main products used in any other watershed that has similar data availability

    Um referencial de self coaching para apoiar processos de mentorias.

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    Em 2019 ocorreu o primeiro ciclo do TechStart Agro Digital, tendo sido a experi√™ncia de seu planejamento e execu√ß√£o a base para que se identificasse e aplicasse para o ciclo de 2020/2021 algumas adapta√ß√Ķes metodol√≥gicas, de forma a contemplar maior aproxima√ß√£o entre as startups aceleradas e os mentores t√©cnicos do programa, que s√£o empregados, analistas e pesquisadores da Empresa Brasileira de Pesquisa Agropecu√°ria (Embrapa). Uma maior defini√ß√£o a respeito da carga hor√°ria de dedica√ß√£o ao programa, incluindo-se a carga hor√°ria dedicada exclusivamente √† realiza√ß√£o de sess√Ķes de mentoria, sob lideran√ßa do mentor, bem como uma melhor prepara√ß√£o dos mentores para que fosse poss√≠vel a defini√ß√£o antecipada de quais ferramentas adicionais de tecnologia, produto ou mercado, seriam agregados durante o processo de acelera√ß√£o. O material apresentado neste documento foi desenvolvido como parte do processo de prepara√ß√£o dos mentores da Embrapa para que atuem em programas de acelera√ß√£o de startups no segundo ciclo do TechStart AgroDigital (TSAD), realizado em 2020 e 2021. Essa parte do processo, corresponde a um treinamento para ampliar autoconhecimento e melhorar os relacionamentos interpessoais. O processo completo, desenvolvido no contexto do projeto Solu√ß√Ķes Tecnol√≥gicas para Acelera√ß√£o de Neg√≥cios em Agricultura Digital - StarAgro (C√≥digo do projeto no IDEARE: 30.21.90.010.00.00), liderado pela Embrapa Agricultura Digital, tamb√©m foi aplicado a outro programa de inova√ß√£o da Embrapa, o SoilsPlay da Embrapa Solos, em 2021. Devido √† relativa aceita√ß√£o do treinamento realizado e √† sua aplicabilidade no dia a dia, decidiu-se public√°-lo n√£o apenas como apostila de curso, mas em uma linguagem que permita a utiliza√ß√£o de partes do material em outros treinamentos ou mesmo como um self coaching pelo seu leitor. Embora o material proposto tenha sido desenvolvido para atendimento √†s particularidades do Programa TechStart AgroDigital, acredita-se que pequenas modifica√ß√Ķes sejam poss√≠veis aos interessados em aplic√°-los a outros contextos de inova√ß√£o, com outros grupos de mentores e l√≠deres de iniciativas correlatas da Empresa
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