Características agronômicas e bromatolôgicas do milho submetido a adubações com potássio na produção de silagem

The aim was to evaluate levels and forms of application of potassium on the agronomic and alimentary characteristics of corn used for silage. The experiment was carried out at UNIFENAS during the agricultural year of 2008/2009. Fertilization at planting and sowing was performed manually using 120kg ha-1 P2O5 and 30kg ha-1 N, the potassium being applied according to the treatments. The experimental design used was of randomized blocks in a 4 x 2 factorial arrangement with four replications, using four amounts (0; 60; 90 and 120 kg ha-1) and two formsof application of K (100% at planting and 50% at sowing+50% coverage). The interaction between the factors of amount and forms of application of the potassium was not significant (p>0.05) for the variables studied: the main effect of each factor was then investigated. There was no effect (p>0.05) for K levels on the percentage of drymatter (DM) and bedded plants, DM and grain productivity and grain participation in the mass. The highest grain yield was obtained when using K at planting (p<0.05). High doses of potassium did not produce changes in DM, percentage of bedded plants, DM production, grain yield or grain percentage of the plant. The different levels and forms of application of potassium do not alter the alimentary characteristics of corn silage.

Reestructuración del transporte público en la Ciudad de México

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Tránsito y transporte en la Ciudad de México: el sistema de ejes viales

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Liberalización del transporte urbano en Santiago de Chile

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Regulación y subvención del transporte colectivo urbano: los argumentos a favor y en contra

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Sistemas de manejo e efeito residual do potássio na produtividade e nutrição do feijão-caupi

Cowpea [Vigna unguiculata (L) Walp] have great social and economic importance for the Para State. It grows well in areas with low precipitation and two crop cycles can be obtained annually. This study aimed to assess the effect of the residual fertilization from a previous culture (Sorghum bicolor L. Moench) and crop systems on cowpea yield and macronutrient concentration on leaves of three cowpea cultivars (BRSMilênio, BRS-Urubuquara e BRS-Guariba). The study was conducted at the UFRA. The treatments were two crop systems (minimum tillage and conventional), four levels of potassium (50, 100, 200 e 300 kg de KCl ha-1 applied to a previous sorghum culture) and the three cowpea cultivars. Treatments were organized as a three (4 x 2 x 3) factor experiment on a randomized complete block design. The soil was a yellow latosol. In each experiment plot five plants were selected to determine shoot dry matter and foliar nutrient concentration. Grain yield was determined after harvesting all plants on the experiment plot. The residual KCl fertilization affected foliar nutrient content, but did not affect shoot dry mass or yield of grain. Yield was higher in the minimum tillage system. Highest yield (1590 kg ha-1) was recorded int the cv. 'Guariba' when 100 kg of KCl ha-1 had been used in the previous crop. The highest content of leaf N and K was found in cowpea under minimum tillage system. The amount of P and Mg were higher in the conventional system whereas the amount of Ca did not change.

Transporte marítimo

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Modelos matemáticos para problemas de dimensionamento de lotes com restrições de capacidade e custos de transporte

In this paper, capacitated lot sizing problems in which the classical lot sizing decisions are made considering the transportation costs of the manufactured products were studied. These costs are related to the necessary number of pallets or trucks to pack and/or transport the products from the factory to the warehouse. Three extensions of a mixed integer linear programming model from the literature are considered, representing general cases that are commonly found in companies. These models are tested and evaluated using an optimization package, and a Lagrangian heuristic was developed for one of the extensions proposed.

La política de los países de América Latina y el Caribe en materia de transporte marítimo regular y la Convención de las NU sobre un Código de Conducta de las Conferencias Marítimas = Latin American and Caribbean liner shipping policies and the UN Convention on a Code of Conduct for Liner Conferences

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La evolución de las redes de transporte terrestre en América Latina

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El significado para América Latina del estandar de las Naciones Unidas sobre el intercambio electrónico de datos para administración, comercio y transporte (UN

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El transporte eléctrico urbano en América Latina: una breve reseña de su pasado, presente y perspectivas

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Informe de la Reunión del Grupo Especial de Expertos sobre la Industria de Transporte Regular Internacional y la Competitividad del Comercio Exterior de los Países de América Latina y el Caribe

Contiene la organización de los trabajos y los informes de dos grupos de trabajo sobre transporte intermodal y multimodal y de transporte marítimo regular, cuya tarea fue analizar los problemas que la región experimentará ineludiblemente en el proceso de acomodación a las nuevas realidades impuestas sobre su comercio exterior por los cambios estructurales que están ocurriendo en el transporte.