Spatial variability of infiltration and its relationship to some physical properties

Water infiltration into soil is one of the basic factors for estimating irrigation intensity according to the plants' requirements; this is aimed at avoiding problems of surface run-off and degradation. The purpose of the present investigation was to determine the spatial variation of infiltration and its relationship to some physical properties of soil by means of geostatistical techniques in Typic Plinthaquult soils having average texture and flat relief. A 113 point mesh was designned, having a regular distance of 10 m between points, samples being taken from 0 to 0.20 meters depth. Sand, silt and clay content, bulk density, macroporosity, microporosity and total porosity were determined. Infiltration tests were carried out in the field by means of a 15 cm diameter ring. Descriptive statistics and geostatistics were used for analysing the data. Infiltration, silt and microporosity data did not fit a normal distribution curve. Infiltration had high variability, having an average 36.03 mm h(-1). Total porosity was 56.73%, this being the only property that did not show spatial dependency. The smallest ranges were observed for bulk density, macroporosity and microporosity, having values of less than 40 m. The smallest degrees of spatial dependence were observed for infiltration, silt and clay, evidence also being shown of the influence of silt and clay on infiltration rate. Contour maps were constructed; fitting them to the semivariogram models, together with studying the correlations, led to establishing relationships between the properties.

Densidade do solo e infiltração de água como indicadores da qualidade física de um Latossolo Vermelho distrófico em recuperação

A necessidade cada vez maior de alimentos, espaço e condições para sobrevivência faz com que as interferências antrópicas no ambiente sejam cada vez maiores. Solos intensivamente cultivados e de forma inadequada são degradados, assim como a construção de obras civis no meio rural sem atender à legislação pertinente tudo isso tem ocasionado problemas ao meio. Várias técnicas têm sido utilizadas para recuperar esses solos, sendo a principal delas a adição de MO. Contudo, informações sobre tempo para recuperação do solo, influência dos tipos de material orgânico e indicadores das alterações ainda são escassas. Este trabalho objetivou avaliar a recuperação das propriedades de um Latossolo Vermelho distrófico, de onde foi retirado material usado na terraplanagem e nas fundações da usina hidrelétrica de Ilha Solteira-SP, utilizando-se como indicadores de qualidade física a densidade do solo e a taxa de infiltração de água. A pesquisa foi feita em uma área onde se retirou uma camada de solo de 8,60 m. O delineamento experimental foi em blocos casualizados, com cinco repetições e cinco tratamentos: testemunha (solo exposto sem técnicas de recuperação); espécie arbórea gonçalo-alves (Astronium fraxinifolium Schott); gonçalo-alves + feijão-de-porco (Canavalia ensiformis); gonçalo-alves + nabo forrageiro (Raphanus sativus); e gonçalo-alves + gramínea (Brachiaria decumbens) + lodo de esgoto (60 Mg ha-1). A densidade do solo foi avaliada antes e 356 dias após a implantação dos tratamentos, e a infiltração de água no solo foi determinada 188 dias depois da instalação dos tratamentos. Concluiu-se que ocorrem melhorias na qualidade do solo quando efetuado o seu preparo e a adição de lodo de esgoto e adubos verdes. A densidade do solo e a infiltração de água do solo são bons indicadores na avaliação dessas melhorias. As diferentes fontes de MO adicionadas ao solo e a ação do preparo deste interagem de maneira semelhante na recuperação da sua qualidade, porém a combinação lodo de esgoto mais braquiária proporciona maior altura de planta da espécie gonçalo-alves.

Amitriptyline aggravates the fibrosis process in a rat model of infravesical obstruction

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dinâmica da regeneração do subsolo de áreas degradadas dentro do bioma Cerrado

The objective of this research was to evaluate the physical and chemical conditions of revegetated subsoil in degraded areas in a Cerrado biome and to verify which plants promote better conditions for soil recovery. The research was conducted in the remaining area of the hydroelectrical plant site at Ilha Solteira (SP). The experimental design was a completely randomized with five treatments and three replications. The treatments consisted of: natural regeneration area, brachiaria area, Pinus sp. area, exposed soil area and Cerrado grassland (used as control). The following soil characteristics were appraised: porosity; density, stability of aggregates, infiltration rate, temperature, exchangeable cations, organic matter, pH and potential acidity. The results show that Pinus is not a good species to recover the chemical attributes of the subsoil. The revegetated areas need to be improved in their physical attributes to allow a better development of the vegetation. Brachiaria and the natural regeneration were the most promising treatments, presenting results similar to natural Cerrado.

Influência da aplicação de vinhaça na capacidade de Infiltração de um solo de textura franco arenosa

The objective of this study was to analyze effects in different depth in soil water infiltration and to verify the Horton and Kostiakov-Lewis models adequacy in infiltration rate estimate. The treatments were five doses of vinasse (0, 200, 250, 300 and 350 m3?ha1?. The vinasse application reduced the soil erosion risk increasing the possibility of runoff. The Horton model had the best adjustment on the observed data, and the Kostiakov-Lewis model overestimated the infiltration rate values.

Caracterização fisiográfica e de alguns atributos físicos e químicos dos solos da microbacia Jardim Novo Horizonte, em Ilha Solteira, SP

Pós-graduação em Agronomia - FEIS

Compactação do solo causada pelo tráfego de máquinas na colheita de madeira de Eucalyptus grandis Hill ex Maiden

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo da degradação dos solos em áreas de pastagens no município de Porto Velho (RO)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Poço de infiltração para controle de enchentes na fonte: avaliação das condições de operação e manutenção

This study investigated the following aspects regarding a soakaway, i.e. an infiltration well: i) entrance filter device; ii) permeability of the geotextile; and iii) emptying time. The 3.6 m³ infiltration well drains a roof area of 241.8 m². The entrance device is made up of layers of sand, gravel and geotextile set on a metal structure. The concrete rings that form the lateral walls were covered with geotextile, and bricks were laid between the soil and concrete rings. The infiltration well remained in operation during the entire testing period, and specific events were simulated to measure the emptying time. Permeability and fine particle tests were carried out after eight months of operation. Samples of geotextile taken from the bottom, the walls and the entrance device presented average permeability reductions of approximately 50.7%, 7.7% and 21.2%, respectively. The sand in the entrance device retained around 34.8% of fine particles and the gravel retained 0.13% in the same period. The infiltration rate was approximately 34.7 mm/h. The R2 coefficient for measured and calculated times was 0.97.

Infiltração de água em um podzólico vermelho-escuro sob dois métodos de preparo, usando chuva simulada com duas intensidades

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization of Soil Surface Roughness Effects on Runoff and Soil Erosion Rates under Simulated Rainfall

This study aims at identifying the influence of soil surface roughness from small to large aggregates (random roughness) on runoff and soil loss and to investigate the interaction with soil surface seal formation. Bulk samples of a silty clay loam soil were sieved to four aggregate-size classes of 3 to 12, 12 to 20, 20 to 45, 45 to 100 mm, and packed in soil trays set at a 5% slope. Rainfall simulations using an oscillating nozzle simulator were conducted for 90 min at an average rainfall intensity of 50.2 mm h(-1). Soil surface roughness was measured using an instantaneous profile laser scanner and surface sealing was studied by macroscopic analysis of epoxy impregnated soil samples. The rainfall simulations revealed longer times to initiate runoff with increasing soil surface roughness. For random roughness levels up to 6 mm, a decrease in final runoff rate with increasing roughness was observed. This can be attributed to a decreased breakdown of the larger roughness elements on rougher surfaces, thus keeping infiltration rate high. For a random roughness larger than 6 mm, a greater final runoff rate was observed. This was caused by the creation of a thick depositional seal in the concentrated flow areas, thus lowering the infiltration rates. Analysis of impregnated soil sample blocks confirmed the formation of a structural surface seal on smooth surfaces, whereas thick depositional seals were visible in the depressional areas of rougher surfaces. Therefore, from our observations it can be learned that soil surface roughness as formed by the presence of different aggregate sizes reduces runoff but that its effect diminishes due to aggregate breakdown and the formation of thick depositional seals in the case of rough soil surfaces. Sediment concentration increased with increasing soil surface roughness, due to runoff concentration in flow paths. Nevertheless, final soil loss rates were comparable for all soil roughness categories, indicating that random roughness is only important in influencing runoff rates and the time to initiate runoff, but not in influencing sediment export through soil loss rates.

Mobilização do solo, velocidade de infiltração de água e taxa de cobertura do solo na grama esmeralda, sob manejos mecanizados

The excessive compaction of the soil observed in sod production systems, affects the physical attributes of the soil, which can influence the water infiltration into the soil and hence the rate of soil cover by turfgrasses and time of the sod production. To minimize the effects of soil compacting, some producers use soil preparation equipment that raises the soil on the surface but does not cause excessive roughness which may harm the quality of the sod. Thus, the aim of the present study was to evaluate the infiltration rate and soil cover rate due to different management mechanized in the zoysiagrass sod production. The experimental design had random plots and four replications. The treatments consisted of five mechanized managements of soil: witness (without the use of equipment); coulter blade disc harrow used once (1CB), coulter blade disc harrow used twice (2CB), surface chisel used once (1C), surface chisel and coulter blade disc harrow used once (1C + 1CB). The treatments with 2CB and 1C + 1CB provided greater basic water infiltration speed in the soil and higher rate of soil cover by the turfgrass. The rate of soil cover by turfgrass is positively correlated with water infiltration rate at 133 and 226 DAP, demonstrating the influence of managements used in zoysiagrass sod production and the increment in the infiltration rate of water. Soil preparation utilizing coulter blade disc harrow used twice or surface chisel and coulter blade disc harrow used once is recommended under the conditions this study was done.

Comportamento do carbono orgânico e de atributos químicos, físicos e microbiológicos de um solo arenoso em área de conversão pastagem - Eucalipto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cervical Lactobacillus and leukocyte infiltration in preterm premature rupture of membranes

Objectives: To evaluate the possible association between microorganisms present in the cervical secretions and amniotic fluid of pregnant women with preterm premature rupture of membranes (PPROM), and histologic chorioamnionitis. Methods: Thirty-seven pregnant women with PPROM and 21 healthy pregnant women were studied. Secretions from the cervical canal and amniotic fluid were collected to isolate microorganisms present in the genital tract. Cervical smears were Gram stained and evaluated microscopically. At delivery, chorioamniotic membranes were collected for histopathologic analysis. Results: Microscopic examination of the cervical secretion smears obtained from the PPROM group showed a low rate of Lactobacillus species, large numbers of leukocytes, and a wide diversity of microorganisms compared with the control group. The PPROM group presented an 80% rate of chorioamnionitis. Staphylococcus aureus isolation in cervical secretion was associated with intense inflammatory infiltrate in the membranes and might play a role in the pathogenesis of PPROM. Conclusions: the low colonization of cervical flora by Lactobacillus species associated with an intense leukocyte infiltrate detected in Gram-stained cervical smears can be considered a rapid method of detecting chorioamnionitis in pregnant women with PPROM. (C) 2003 International Federation of Gynecology and Obstetrics. Published by Elsevier B.V. Ireland Ltd. All rights reserved.

Annexin A1 protein attenuates cyclosporine-induced renal hemodynamics changes and macrophage infiltration in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)