477 research outputs found

    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

    Página eletrônica: uma proposta de aperfeiçoamento.

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    Critérios utilizados no desenvolvimento do trabalho; Análise da homepage atual; Propostas para a nova homepage; Processos relacionados à homepage; Migração da versão atual para a nova homepage; Funcionalidades da homepage proposta; Tecnologias utilizadas na homepage proposta; Sites visitados.bitstream/item/59147/1/Doc-146.pd

    Themes and criteria selection for an agro-environmental diagnosis of sugar cane production chain.

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    The purpose of this study was to select themes and criteria to be used in agro-environmental diagnoses of the sugar cane (Sacharum spp.) chain for ethanol production. The selection of the themes and criteria was done after a literature research; interview with specialist, participation in meetings for ethanol production and the final union of all information. As a result the following themes and criteria were selected: 1) Land use (listed as theme) ? soil and climate, land use planning, competition for food production (listed as criteria); 2) Biodiversity - disturbance of flora and fauna, planning and management of biodiversity; 3) Quality of natural resources ? residue emissions for surface and ground waters, residue emissions to the atmosphere, recycling of residues, management and conservation of soil/plant system, yield planning and traceability of the product 4) Waste generation and recycling ? water, vinasse, bagasse, straw or cover residue, oil and filter cakes and toxic waste and 5) Energy ? energetic balance, integrated ethanol and biodiesel production, energetic planning and carbon market insertion

    Metodologia de detecção da adstringência em frutos de caqui para determinação do tempo de destanização.

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    Variabilidade em populações naturais de mangabeira do litoral de Pernambuco.

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    A mangabeira (Hancornia speciosa Gomes) apresenta os seus recursos genéticos extremamente ameaçados em Pernambuco e a conservação do germoplasma deve ser a principal estratégia para evitar a erosão genética na espécie. O presente trabalho teve como objetivo analisar a variabilidade de três populações com base nas características morfológicas das plantas. Foram estudadas as populações de Areias de Zé Chacon, Nazaré e Maracaípe, situadas, respectivamente, na Ilha de Itamaracá, Cabo de Santo Agostinho e Ipojuca, PE. Os remanescentes foram georreferenciados, avaliando-se 50 plantas adultas em cada população, levando-se em consideração as variáveis altura da planta; altura da ramificação principal; circunferência do caule; diâmetro médio (DMC), volume e índice de conformação (ICC) da copa. A partir dos valores obtidos foram realizadas análises de componentes principais para cada população e análise discriminante considerando as populações simultaneamente. Os dois primeiros componentes principais explicaram 80,52%, 75,00% e 71,87% de toda a variação disponível para as populações de Areias de Zé Chacon, Nazaré e Maracaípe, respectivamente. As dispersões dos genótipos em relação aos dois primeiros componentes principais, para cada população, demonstraram considerável variabilidade entre os genótipos. As variáveis que mais contribuíram para essa variabilidade foram DMC e ICC. Pela análise discriminante observou-se a formação de dois grupos contrastantes entre os genótipos das populações de Areias de Zé Chacon e Maracaípe. Os genótipos oriundos da população de Nazaré mostraram-se mais similares aos genótipos da população de Maracaípe que da população de Areias de Zé Chacon. Conclui-se que existe variabilidade genética entre os genótipos de mangabeira nativa para essas populações, podendo ser utilizados em programas de melhoramento e na formação de bancos de germoplasma
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