As condições físicas do solo têm efeitos diretos e indiretos na produtividade e na qualidade ambiental. Solos bem agregados, com um manejo adequado, são capazes de manter um balanço de ar e água assim como promover a ciclagem de nutrientes e propiciar o desenvolvimento de raízes. O objetivo desse trabalho foi avaliar o uso do modelo de Dexter índice S, para o mapeamento da qualidade física do solo em uma escala de microbacia hidrográfica (MB) e avaliar o desempenho do modelo indireto de Arya e Paris e programa Qualisolo para a obtenção do índice S. O experimento foi dividido em três etapas: 1) Medida do índice S em uma base de dados de solos contendo 111 amostras e avaliação da sua dependência com a densidade do solo. Em todas as amostras obteve-se o índice S de duas formas: i) a partir da curva de retenção (CR) experimental (SCRexperimental) e ii) por meio da granulometria detalhada, usando o modelo de Arya e Paris com o programa Qualisolo (SCRqualisolo); 2) Estudo do índice S em uma escala de microbacia hidrográfica (MB), 15 parcelas na MB do Ribeirão Canchim, São Carlos, SP, compreendendo classes de solos e coberturas mais comumente encontradas nessa região. 3) Ampliação do estudo do índice S na microbacia, realizando medidas de granulometria, densidade (s), resistência à penetração (RP) e a obtenção do índice SCRqualisolo em mais trinta pontos da MB. Na comparação entre os métodos para o cálculo do índice S verificou-se que SCRexperimental apresentou uma maior variabilidade entre seus pontos, demonstrando ser mais sensível as variações de , textura ou estrutura. Apesar do modelo de Arya e Paris receber uma forte influência da textura do solo, sua determinação integrado ao programa Qualisolo, demonstrou ser uma opção rápida para obter a curva de retenção e o índice S. Com relação ao estudo do índice S na MB, as áreas de pastagem apresentaram os maiores valores de RP, s e relativa e os menores valores de índice S, sendo classificadas como solos de qualidade física pobre. Os valores de S apresentaram a mesma tendência dos parâmetros do solo que estão associados com a qualidade física, que são s e RP, porosidade, curva de retenção e a avaliação qualitativa e quantitativa das imagens de microtomografia que estão associadas com a macroporosidade. Apesar de ser possível uma classificação visual do solo em relação a sua qualidade física, o índice S é possibilita uma avaliação quantitativa e objetiva do estado de degradação física do solo, uma vez que possui uma boa correlação com os demais parâmetros que indicam a qualidade do solo, como observado / The soil physical conditions have direct and indirect effects on plant productivity and environmental quality. Well aggregated soils with appropriate management are able to maintain a good balance between air and water, promote nutrient cycling and good development of roots. The objective of this work was to evaluate the use of the S index of Dexter, for mapping the soil physical quality in a watershed and evaluate the performance of the indirect model of Arya and Paris and the Qualisolo software to estimate the S index. The study was divided into three parts: Measurement of the S index in a database containing 111 soils and the evaluation of their dependence with the soil bulk density (s). For all samples the S index was determined by: i) using the experimental soil water retention curve (SRCexperimental) and ii) using the Arya and Paris model and the Qualisolo software (SRCqualisolo) on measured particle size distribution data; 2) The study of the S index in 15 points of the Ribeirão Canchim watershed, São Carlos, SP, covering the most abundant soil classes and the most commonly used crops in this region; 3) Extension of the S index study to other 30 points where only the SCRqualisolo was determined from measured particle size distribution and compared with measured s and penetration resistance (PR). When comparing the two methods for determining S it was verified that SRCexperimental presented a greater variability among points, showing to be more sensitive to variations in s, texture and structure. Although the significant influence of soil texture on the Arya and Paris model,,the estimation of SCRqualisolo from particle size distribution is very simple and faster than SCRqualisolo and it is an interesting alternative. The areas under pasture presented the lowest S index and the highest s and were classified as low physical quality areas. The S values follow the same trends of the soil parameters associated with soil quality, which are s, PR, porosity, the soil water retention curves and the qualitative and quantitative parameters of the microtomographic images. The S index allows a quantitative and objective measure and expresses the state of physical degradation of soil, since it showed a good correlation with other parameters associated with soil physical quality

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Knowledge of the physical and hydraulic properties of the soil and its spatial dependence is important because it allows you to perform the zoning of the area in plots that receive differentiated management. This work was divided into three chapters whose general objective is to measure the hydraulic conductivity and water retention curve in soil by different methods and by using the Kriging, draw maps of soil physical attributes of the Irrigation Perimeter Baixo AcaraÃ. To obtain the water retention in soil curve method was used filter paper compared to the traditional method in five different soils Perimeter. To measure the hydraulic conductivity were used capacitive sensors to replace the tensiometer in the instantaneous profile installed method on a Argissolo Vermelho Amarelo eutrÃfico , as well as the calibration of these sensors in the field and laboratory. The maps were obtained by kriging of soil properties: sand, silt, clay, soil and particle density, porosity and saturated hydraulic conductivity. To obtain this last the tension infiltrometer and the constant load permeameter were used. / O conhecimento dos atributos fÃsico-hÃdricos do solo e de sua dependÃncia espacial à importante, pois permite realizar o zoneamento da Ãrea em glebas que receberÃo prÃticas de manejo diferenciadas. Este trabalho foi dividido em trÃs capÃtulos cujo objetivo geral à medir a condutividade hidrÃulica e a curva de retenÃÃo de Ãgua no solo por diferentes mÃtodos e, utilizando a Krigagem, elaborar mapas de atributos fÃsicos dos solos do PerÃmetro Irrigado Baixo AcaraÃ. Para obtenÃÃo da curva de retenÃÃo de Ãgua no solo foi utilizado o mÃtodo do papel filtro em comparaÃÃo ao mÃtodo tradicional em cinco diferentes solos do PerÃmetro. Para medida da condutividade hidrÃulica foram utilizados sensores capacitivos em substituiÃÃo aos tensiÃmetro no mÃtodo do perfil instantÃneo instalado em um Argissolo Vermelho Amarelo eutrÃfico, como tambÃm a calibraÃÃo desses sensores em campo e laboratÃrio. Os mapas obtidos atravÃs da Krigagem foram dos atributos do solo: areia, silte, argila, densidade do solo e partÃculas, porosidade e condutividade hidrÃulica saturada. Para obtenÃÃo deste ultimo foram utilizados o infiltrÃmetro de tensÃo e o permeÃmetro de carga constante.

My deepest respect and appreciation are extended to Dr. L. Gray Wilson for providing the opportunity to conduct this research, for his advice and assistance during the course of the research, and for his review of and suggestions for improving this manuscript. I would also like to thank Michael Osborn for his assistance. This research was funded by the City of Tucson. The assistance and direction provided by Mt. Bruce Johnson and Mt. Joe Babcock at Tucson Water are gratefully acknowledged. My thanks are also extended to Dr. Daniel D. Evans, Dr. L.G. Wilson, and Dr. Stanley N. Davis for serving on my thesis committee. Bruce Smith's assistance is gratefully acknowledged. Bruce spent two long days with 110-degree temperatures In a parking lot describing the lithology of sediment samples collected during the drilling phase of this research. He also determined the moisture content and particle size distribution on samples collected from the borehole. The assistance of Ralph Marra and Steve Brooks is also gratefully acknowledged. Ralph waded through city and county bureaucracies to determine zoning at each dry-well site. Steve assisted with collecting dry-well settling chamber sediment samples.

O solo fornece suporte e atua como reservatório de água para as plantas, promovendo condições fundamentais ao crescimento de raízes e à dinâmica da água e nutrientes. O conhecimento de suas propriedades hidráulicas, como a curva retenção da água, é de grande importância na descrição e predição dos processos de transporte da água e solutos. O objetivo deste trabalho foi determinar a curva de retenção pelo método tradicional dos funis e câmaras de pressão de ar com placa porosa, pelo método de campo utilizando tensiômetros e pelo método da evaporação da água em amostra de solo no laboratório munida de tensiômetro. O solo utilizado para estudo foi classificado como Nitossolo Vermelho eutrófico de textura argilosa, e estava sendo cultivado com café há mais de 10 anos. A comparação entre as curvas obtidas pelos três métodos indicou que o método da evaporação diferiu estatisticamente do método do funil e câmara e foi estatisticamente idêntico ao método do tensiômetro a campo. Por sua facilidade de execução, baixo custo e rapidez na determinação da curva de retenção até a tensão de aproximadamente 100 kPa, o método da evaporação aqui apresentado é uma boa opção de utilização. Com relação ao método do tensiômetro no campo, embora mais realístico, é muito trabalhoso. / Soil provides support and acts as a water reservoir to plants, promoting essential conditions to root growth and to water and nutrient dynamics. The understanding of its hydraulic properties, like the water retention curve, is of great importance for the description and prediction of the processes of water and solute transport. The objective of this study was to determine soil water retention curve through the traditional method using porous plate funnel and pressure chamber, through the field method using tensiometers and through the water evaporation in soil sample with tensiometer in the laboratory. The studied soil was classified as clayey Rhodic Hapludox, which had been cultivated with coffee for more than 10 years. The comparison of curves obtained through the three methods indicated that the evaporation method was statistically different from the method using funnel and chamber, and statistically equal to the method of tensiometers at field. For its easy execution, low cost and quickness to determine soil water retention curve until the tension of about 100 kPa, the evaportation method presented here is a feasible option. As for the method of tensiometers at field, although it is more realistic, it is very laborious.

Made available in DSpace on 2016-01-26T18:56:21Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 267052 bytes, checksum: b9f870d7db6c0449cc874e7dc779bf12 (MD5) Previous issue date: 2010-05-11 / The low water availability in the soil for agricultural crops is a limiting factor in agricultural productivity. In this context, the use of soil conditioners polymer s, in some systems may allow edaphic and make the supply chain more competitive. The work was based on assessing the increase in sugarcane production by using soil polymers conditioner during planting, the variety RB 867515. The study took place in the field and in two growing seasons. The test was first deployed in the field of experimental Unoeste in December 2007 to May 2009 in Ultisol, arranged in randomized blocks with four treatments (0, 4, 8 and 12g of polymer soil conditioner, per meter of row) and five blocks. The second test was carried out at Fazenda Ibiúna in Lucélia - SP in August 2008 to August 2009 in Alfissol, arranged in a randomized block design with four treatments (0, 1.4, 2.8 and 4.2g soil polymer conditioner, per meter of row) and five blocks. The polymer conditioner provided greater number of tillers per meter, allowed a larger vegetative growth leading to a greater amount of trash. There is a positive correlation between doses of the polymer with the TRS by area. / A baixa disponibilidade de água no solo, para as culturas agrícolas, é um fator limitante da produtividade. Neste contexto, o uso de polímeros condicionadores de solo, em alguns sistemas edáficos pode viabilizar e tornar a cadeia produtiva mais competitiva. O trabalho se fundamentou em avaliar o incremento na produção canavieira, utilizando polímeros hidroretentores, durante o plantio, na cultivar RB 867515. O estudo ocorreu à campo em dois anos agrícolas. O ensaio 1 foi implantado no campo experimental da Unoeste, em dezembro de 2007 a maio de 2009, em Argissolo Vermelho Distroférrico, no esquema blocos ao acaso com quatro tratamentos (0, 4, 8 e 12g de Polímero condicionador de solo, por metro de linha) e cinco blocos. O ensaio 2 foi implantado na Fazenda Ibiúna, em Lucélia SP, em agosto de 2008 a agosto de 2009, em Argissolo Vermelho Amarelo, no esquema de blocos ao acaso com quatro tratamentos (0, 1,4, 2,8 e 4,2g de Polímero condicionador de solo, por metro de linha) e cinco blocos. O polímero condicionador possibilitou maior numero de perfilhos por metro; permitiu um maior crescimento vegetativo levando a maior quantidade de palhiço. Existe uma correlação positiva entre as doses do polímero com o ATR por área.

Made available in DSpace on 2016-07-18T17:51:06Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 267052 bytes, checksum: b9f870d7db6c0449cc874e7dc779bf12 (MD5) Previous issue date: 2010-05-11 / The low water availability in the soil for agricultural crops is a limiting factor in agricultural productivity. In this context, the use of soil conditioners polymer s, in some systems may allow edaphic and make the supply chain more competitive. The work was based on assessing the increase in sugarcane production by using soil polymers conditioner during planting, the variety RB 867515. The study took place in the field and in two growing seasons. The test was first deployed in the field of experimental Unoeste in December 2007 to May 2009 in Ultisol, arranged in randomized blocks with four treatments (0, 4, 8 and 12g of polymer soil conditioner, per meter of row) and five blocks. The second test was carried out at Fazenda Ibiúna in Lucélia - SP in August 2008 to August 2009 in Alfissol, arranged in a randomized block design with four treatments (0, 1.4, 2.8 and 4.2g soil polymer conditioner, per meter of row) and five blocks. The polymer conditioner provided greater number of tillers per meter, allowed a larger vegetative growth leading to a greater amount of trash. There is a positive correlation between doses of the polymer with the TRS by area. / A baixa disponibilidade de água no solo, para as culturas agrícolas, é um fator limitante da produtividade. Neste contexto, o uso de polímeros condicionadores de solo, em alguns sistemas edáficos pode viabilizar e tornar a cadeia produtiva mais competitiva. O trabalho se fundamentou em avaliar o incremento na produção canavieira, utilizando polímeros hidroretentores, durante o plantio, na cultivar RB 867515. O estudo ocorreu à campo em dois anos agrícolas. O ensaio 1 foi implantado no campo experimental da Unoeste, em dezembro de 2007 a maio de 2009, em Argissolo Vermelho Distroférrico, no esquema blocos ao acaso com quatro tratamentos (0, 4, 8 e 12g de Polímero condicionador de solo, por metro de linha) e cinco blocos. O ensaio 2 foi implantado na Fazenda Ibiúna, em Lucélia SP, em agosto de 2008 a agosto de 2009, em Argissolo Vermelho Amarelo, no esquema de blocos ao acaso com quatro tratamentos (0, 1,4, 2,8 e 4,2g de Polímero condicionador de solo, por metro de linha) e cinco blocos. O polímero condicionador possibilitou maior numero de perfilhos por metro; permitiu um maior crescimento vegetativo levando a maior quantidade de palhiço. Existe uma correlação positiva entre as doses do polímero com o ATR por área.

No description available.

A laboratory test program was conducted to determine the moisture-suction relationships of geosynthetic clay liners (GCLs). Moisture-suction relationships were determined by combining suction data from pressure plate tests, contact filter paper tests, and relative humidity tests, then fitting water retention curves (WRCs) to the data. WRCs were determined for wetting processes and drying processes in terms of gravimetric moisture content and volumetric moisture content. The effects of GCL type, hydration solution, wet-dry cycles, and temperature on the moisture-suction relationships were analyzed. The three GCLs of the test program consisted of configurations of woven and nonwoven geotextiles reinforced with needlepunched fibers. A geofilm was adhesively bonded to the nonwoven side of one of the GCL products. The hydration solution tests involved hydrating GCLs with deionized water, tap water, 0.1 M CaCl2, or soil water from a landfill cover test plot for a 30-day conditioning period prior to testing. Cyclic wet-dry tests were conducted on the GCL specimens subjected to 20 wet-dry cycles from 50% to 0% gravimetric moisture content prior to testing. Temperature tests were conducted at 2°C, 20°C, and 40°C. GCL type affected moisture-suction relationships. The GCLs with an adhesively-bonded geofilm exhibited lower air-entry suction and higher residual suction than GCLs without a geofilm. The degree of needlepunched fiber pullout during hydration contributed to hysteresis between wetting WRCs and drying WRCs. Hysteresis was high for suction values below air-entry suction and was low for suction values greater than air-entry suction. Cation exchange reduced the water retention capacity for all three GCL types. The saturated gravimetric moisture contents were reduced from approximately 140% to 70% for wetting WRCs and 210% to 90% for drying WRCs for GCLs hydrated in deionized water compared to CaCl2 solution. Hysteresis of the nonwoven product decreased from 71%, to 62%, to 28% with respect to deionized water, tap water, and CaCl2 solution. Hysteresis of the woven product exposed to soil water was 24% and 0%, in terms of saturated gravimetric moisture content and saturated volumetric moisture content, respectively. The swell index, Atterberg Limits, mole fraction of bound sodium, and scanning electron microscopy images that were determined of bentonite from the conditioned GCLs indicated that changes in water retention capacity corresponded with cation exchange. Wet-dry cycles and temperature affected the moisture-suction behavior for GCLs. Wet-dry cycles reduced hysteresis and increased the swelling capacity of GCL specimens. Microscopy images indicated that wet-dry cycles caused weak orientation of the clay particles. Increasing temperature resulted in a small decrease in water retention capacity. Results of the test program provided a means for predicting unsaturated behavior for GCLs.

The removal of vegetation and overburden changes the naturalwater purifying processes and thus decreases the groundwaterprotection in gravel pit areas. The sand and gravel depositsusedfor aggregate extraction in Sweden are also often valuablefor extraction of groundwater as a drinking water resource. TheSwedish legislation requires that gravel pits be restored afterthe cessation of extraction, the aim being to reestablishvegetation and to reinstate groundwater purifyingprocesses. The objective of this study was to improve our understandingof the processes governing groundwater protection andvegetation establishment so that these could be applied toimproving restoration methods for reestablishing naturalgroundwater protection. The focus was on the importance of soilphysical properties of the topsoil for vegetation establishmentand groundwater recharge. Actual field methods for restoration were reviewed.Conflicts between aggregate extraction and groundwaterinterests were common. In many cases the actual restorationcarried out differed from pre-planned specifications in permitdocumentation. Commonly available substrates that might be used forrestoration of gravel pits were investigated. The soils weredescribed as regards texture, organic content, porosity, waterretention and hydraulic conductivity. The way in which acombination of the water retention characteristic and theunsaturated conductivity influenced the behaviour of thesoil-plant-atmosphere system was demonstrated using aprocess-orientated simulation model. Plants with well-developedaboveground characteristics and shallow roots in particularexerted the highest requirements on the soil physicalproperties. Key words:groundwater protection, soil physicalproperties, CoupModel, unsaturated conductivity, waterretention, transpiration, soil evaporation

>Magister Scientiae - MSc / Aquifer vulnerability assessment is increasingly becoming a very significant basis in order to fulfil the water demands in South Africa. Knowledge of soil hydraulic properties that consists of the soil water retention and hydraulic conductivity functions is a prerequisite for predicting solution transport in soils. The overall objective of the study is to develop a database of hydraulic properties for collected undisturbed samples and to test selected models by making use of this database. Studies of the vadose zone are generally restricted to the top 1.2 meters; therefore this study aims at essentially improving the lack of measurements and modelling in the vadose zone. There exist several methods to determine hydraulic properties of soil that make use of hydraulic conductivity (K) determination in the vadose zone. The most accurate estimates of hydraulic conductivity are possible through direct measurements or measurements of the water retention curve. For this study, the drilling and sampling of five boreholes (maximum depth 20 m) proceeded during March and April 2005 at two typical sites in the Western Cape, namely the Berg river site (Riebeek West) and Ithemba site (Cape Flats). In total, 76 undisturbed core samples were collected from which the detailed borehole log descriptions were made. The determination of the soil water retention curves of the collected samples was based on laboratory techniques using Eijkelkamp drying and suction equipment (sand box and clay box). When modelling groundwater vulnerability, it is essential to look at the soil water retention curves with increased importance, as they provide graphical and mathematical confirmation of porosity, preferential flows, volumetric water content and unsaturated hydraulic conductivity. Therefore, a numerical model called RETC was used to determine soil hydraulic properties. The RETC model uses equations of Van Genuchten (Van Genuchten, 1980) and Brooks-Corey (Brooks and Corey, 1966) to determine parameters for soil water retention and the methods of Mualem (1976) and Burdine (1953) to determine unsaturated hydraulic conductivity functions. Saturated hydraulic conductivity values were estimated by using RETC soil database based on textural descriptions of collected samples. Using the soil hydraulic estimates obtained from RETC, sensitivity analyses were run with a one dimensional transport model, Macro 5.0 for two sites at iThemba and in the Berg river.