974 resultados para Soil erosion -- Queensland, Central
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Pós-graduação em Agronomia (Produção Vegetal) - FCAV
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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In recent years speleothem has been intensely studied due to its great potential of registering paleoclimate proxies but some considerably uncertaintiesregarding speleothem proxy interpretation still exist. In order to minimize these uncertainties, multi-proxy approach has been used. Here is presented the strontium isotope record from Bunker cave, northwest Germany. This cave was previously studied and has proved well record paleoclimate changes during Holocene for central Europe.87Sr/86Sr ratio is presented for rain water, A-horizon soil (water and leachate), C-horizon soil (water and leachate), host rock and host rock leachate, drip water and from a stalagmite (Bu4) previously dated covering the Holocene. Upper soil presented the higher values in contrast with host rock (lower values). Drip water and C-horizon presented intermediated ratios. Sr isotopesare used to track the source of 87Sr/86Sr in the Bunker system, resulting in a mixture between A-horizon soil, C-horizon soil and host rock. A decreasing trend in Bu4 indicates change in the Sr source in the system
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Pós-graduação em Geografia - FCT
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Agriculture provides food, fibre and energy, which have been the foundation for the development of all societies. Soil carbon plays an important role in providing essential ecosystem services. Historically, these have been viewed in terms of plant nutrient availability only, with agricultural management being driven to obtain maximum benefits of this soil function. However, recently, agricultural systems have been envisioned to provide a more complete set of ecosystem services, in a win-win situation, in addition to the products normally associated with agriculture. The expansion and growth of agricultural production in Brazil and Argentina brought about a significant loss of soil carbon stocks, and consequently the associated ecosystem services, such as flooding and erosion control, water filtration and storage. There are several examples of soil carbon management for multiple benefits in Brazil and Argentina, with new soil management techniques attempting to reverse this trend by increasing soil carbon (C) stocks. One example is zero tillage, which has the advantage of reducing CO2 emissions from the soil and thus preserving or augmenting C stocks. Crop rotations that include cover crops have been shown to sequester significant amounts of C, both in Brazilian subtropical regions as well as in the Argentinean Pampas. Associated benefits of zero tillage and cover crop rotations include flood and erosion control and improved water filtration and storage. Another positive example is the adoption of no-burning harvest in the vast sugarcane area in Brazil, which also contributes to reduced CO2 emissions, leaving crop residues on the soil surface and thus helping the conservation of essential plant nutrients and improving water storage.
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Pós-graduação em Engenharia Mecânica - FEG
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Pós-graduação em Geografia - FCT
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Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA
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Pós-graduação em Geociências e Meio Ambiente - IGCE
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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This manuscript aims proposing a methodology for correlating soil porosity to the respective geological units using geostatistical analysis techniques, including interpolation data by kriging. The site studied was in Lorena municipality, Paraíba do Sul Valley, southeastern Brazil. Specifically all studies were carried out within an area of 12 km2 located at Santa Edwirges farm. The database comprehended 41 soil samples taken at different geological and geomorphologic units at three different depths: surface, 50 cm and 100 cm depth. The geostatistical analyses results were correlated to a geological mapping specifically elaborated for the site. This mapping accounts for two different geological formations and a geological contact characterized by a shearing zone. The results indicate the existence of a significant relationship between the soil porosity and the respective geological units. The studies revealed that the residual soils from weathered granitic rocks tend to have higher porosities than the residual soils from weathered biotite gneiss rocks, while the soil porosity within the shearing zone is relatively un-sensitive to the respective geological formation. The spatial patterns observed were efficient to evaluate the relationship between the soil porosity, geology unit and the and geomorphology showing a good potential for correlating with others soil properties such as hydraulic conductivity, soil water retention curves and erosion potentials.