Efeito da calagem e sulfato de am��nio no algod��o. I - Transporte de c��tions e ��nions no solo

Applying lime on the soil surface in soils managed under no-tillage has caused an excess of basic cations in the most superficial layers of the soil profile. On the other hand, subsoil acidity is considered a constraint to the development of deep plant roots. The objective of this study was to evaluate Ca 2+, Mg 2+, NO 3- and SO 4 2- leaching in the soil profile as affected by liming and top dressing nitrogen fertilization in cotton, grown with straw cover on the soil surface. Cotton plants (Gossypium hirsutum) were grown for 60 days in PVC columns filled with a Distroferric Red Latosol (sand loam Rhodic Oxisol) with liming applied over the straw on the soil surface, incorporated liming 0-20 cm deep, or without liming. Nitrogen was applied at rates of 0, 50, 100 and 150 kg ha -1 as ammonium sulfate. The PVC columns were set up in layers of 0-5, 5-10, 10-20, 20-30 and 30-30 cm, totaling 15.71 dm 3. The ammonium sulfate application caused intense leaching of SO 4 2- in the soil, irrespective of the lime application method. Liming increased the concentration of NO 3 in the 0-20 cm soil layer, whereas the correction of the soil acidity did not affect the NO 3- concentration in the 30-50 cm soil layer. The influence of ammonium sulfate on Ca 2+ leaching below 20 cm was only observed in the soil with incorporated lime. Nitrogen application resulted in extensive Mg 2+ leaching from the soil, regardless of the lime application method. In the soil layer below 30 cm, SO 4 2- presented a higher correlation than NO 3- in the formation of ionic pairs with Ca 2+ and Mg 2+.

Morfo-anatomia do eixo vegetativo aéreo de Achyrocline alata (Kunth) DC. (Asteraceae)

Achyrocline alata occurs in a dense and low vegetation in Mato Grosso do Sul State, Brazil and it has been studied under physical-chemical and yield aspects, being scarce anatomical data. The present work has as objective the study of the aerial vegetative axis. Stem is cylindrical and hairy, having five wings, which are arisen from their leaves. The blade shows the presence of uniseriate epidermis, which is covered by the cuticle of variable thickness; and non-glandular and glandular trichomes. The non-glandular trichomes are uniseriate and multicellular and have their apex cell in whip form, while the glandular trichomes are multicellular, uniseriate or biseriate. The mesophyll is dorsiventral with uni-stratified palisade parenchyma in most of the cases and lacunal parenchyma formed by three to four layers of irregular cells. Only one collateral vascular bundle occurs in the midvein. Stem in transversal section is covered by epidermis with trichomes similar to leaves; the cortex is constituted by a discontinuous area of angular collenchyma, which is followed by chlorophyll parenchyma. Vascular cylinder that is delimited by pericycle shows vascular bundles of collateral type. In the secondary structure, the periderm is originated from epidermal and subepidermal tissues. In vascular region, the fascicular cambium differs into secondary xylem and phloem, while interfascicular cambium produces sclerenchymatous tissue.

Enxertia e ��gua de irriga����o carbonatada no transporte de 15N e na produ����o do tomateiro

The effects of CO2 application through irrigation water, and of grafting in transport of 15N and in the tomato production, were studied. These treatments were arranged in a 2 x 2 factorial scheme (with and without CO2 in irrigation water and grafted and non-grafted tomato), in a completely randomized design, with four replications. The injection of CO2 into the water began at 34 days after transplant of seedlings (DAT) and continued for all irrigations. The application of the sulfate of ammonium with abundance in atoms of 15N of 3.13% in plants destined to analysis was done at 45 DAT when the plants were in the middle of fructification. After 14 days of fertilizer (15N) application the plants were harvested, washed, dried and sent for analysis of 15N in plant tissue. The results demonstrated that CO2 and the grafting did not alter the transport of 15N in the plant. The production of commercial fruits was larger when CO2 was applied in water.

Vulnerabilidade �� eros��o do solo da Regi��o do Alto Rio Pardo, Pardinho, SP

This study aimed at the elaboration of a database with information and a map of erosion vulnerability for ecological zoning for the upper Pardo River, Botucatu, SP, by using the Geographical Information System - SPRING. The map of erosion vulnerability was made from spectrally homogeneous regions, producing a grid of zone averages, which was then subdivided, resulting in a vulnerability map to erosion. The results allowed us to conclude that digital imaging produced valuable information for mapping of soil use and database formation. The GIS - SPRING was efficient at identifying soil and vulnerability erosion classes and 95% of the basin presents a moderately stable vulnerability degree, through the presence of medium young soils in gently waring reliefs and covered by 49.27% of pasture and 29.88% crops.

El impuesto sobre circulaci��n de mercader��as y servicios de transporte (ICMS) como instrumento econ��mico para la gesti��n ambiental: el caso de Brasil

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El desarrollo sostenible en Am��rica Latina y el Caribe: tendencias, avances y desaf��os en materia de consumo y producci��n sostenibles, miner��a, transporte, productos qu��micos y gesti��n de residuos. Informe para la decimoctava sesi��n de la Comisi��n para el Desarrollo Sostenible de las Naciones Unidas

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Concentraci��n en los servicios de l��neas regulares: causas del proceso y sus efectos sobre el funcionamiento de los puertos y de los servicios de transporte mar��timo de las regiones en desarrollo

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Bibliograf��a sobre transporte en Chile

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Biocombustibles l��quidos para transporte en Am��rica Latina y el Caribe

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Los cambios en los sistemas integrados de transporte masivo en las principales ciudades de Am��rica Latina

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Pol��ticas de movilidad urbana e infraestructura urbana de transporte

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El potencial de servicios multimodales en el corredor de transporte Asunci��n - Montevideo

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Ecoeficiencia y desarrollo de infraestructura urbana sostenible en Asia y Am��rica Latina: estrategias y medidas para el desarrollo de infraestructura de transporte urbano basada en principios de ecoeficiencia. An��lisis aplicado al ��rea Metropolitana de La Serena y Coquimbo

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Metodolog��a de evaluaci��n de pol��ticas p��blicas de vivienda y transporte urbano bajos en carbono. Innovaci��n ambiental de servicios urbanos y de infraestructura: hacia una econom��a baja en carbono

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Institucionalidad y transporte p��blico urbano: Santiago de Chile y Medell��n, Colombia. Innovaci��n ambiental de servicios urbanos y de infraestructura: Hacia una econom��a baja en carbono

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