307 resultados para soil water levels
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Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This study was undertaken in a 1566 ha drainage basin situated in an area with cuesta relief in the state of São Paulo, Brazil. The objectives were: 1) to map the maximum potential soil water retention capacity, and 2) to simulate the depth of surface runoff in each geographical position of the area based on a typical rainfall event. The database required for the development of this research was generated in the environment of the geographical information system ArcInfo v.10.1. Undeformed soil samples were collected at 69 points. The ordinary kriging method was used in the interpolation of the values of soil density and maximum potential soil water retention capacity. The spherical model allowed for better adjustment of the semivariograms corresponding to the two soil attributes for the depth of 0 to 20 cm, while the Gaussian model enabled a better fit of the spatial behavior of the two variables for the depth of 20 to 40 cm. The simulation of the spatial distribution revealed a gradual increase in the depth of surface runoff for the rainfall event taken as example (25 mm) from the reverse to the peripheral depression of the cuesta (from west to east). There is a positive aspect observed in the gradient, since the sites of highest declivity, especially those at the front of the cuesta, are closer to the western boundary of the watershed where the lowest depths of runoff occur. This behavior, in conjunction with certain values of erodibility and depending on the land use and cover, can help mitigate the soil erosion processes in these areas.
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Expansion of agricultural practice, cattle raising and forestry, in a disorderly way and no limits of land use, generates the degradation of natural resources such as soil, water and vegetation. That fact brings consequences, impacts the environment and the rural landscape. This study aimed to identify and quantify the land use in nine watersheds included in the watershed of Faxinal creek, located in western Botucatu, São Paulo State, Brazil, at 22º 51’ 35” and 22º 57’ 02” – Latitude S and 48º 39’ 42” and 48º 38’ 01” – Longitude W. The basin was subdivided into 9 subunits, being eight from second and one from third-order branch. The diagnosis of the subunits was carried out with geospatial technologies, in order to gather data on the use and occupation of the soil. Based on the obtained results, was concluded that the sub watersheds are occupied by the sum of areas of Citrus, horticulture, coffee plantation and small other occupations (25,81%), followed by reforestation (24,80%), as an isolated occupation element, has occupied the largest area.
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The experiment was conducted in the experimental field of the University of GoiásUEG, UNU Ipameri - GO with the objective of evaluating the effect of different doses of vinasse on the vegetative development of degraded pasture and soil physical properties in two seasons. The pasture used in the experiment was in a state of degradation, and had eight years of formation. The experimental design was randomized blocks consisted of eight treatments and four blocks, totaling 32 experimental units. We evaluated the following soil physical properties: density the soil, particle density, total porosity, infiltration velocity, soil water. We also evaluated the following parameters of vegetative development of grassland: green and dry mass of shoots, effective depth of the root system, the grass height. The results were submitted to analysis of variance at 5% significance level and after we performed regression testing. The vinasse promoted significant effect on all parameters related to vegetative development of both grazing during the rainy season as in the dry. In this case, a model that best fit the dataset vegetative pasture was quadratic. It appeared that the vinasse different doses did not cause changes in the physical properties of the soil.
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Pós-graduação em Geociências e Meio Ambiente - IGCE