Made available in DSpace on 2014-06-11T19:29:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-08Bitstream added on 2014-06-13T18:59:25Z : No. of bitstreams: 1 santos_eb_me_ilha.pdf: 2249660 bytes, checksum: 0671e80475fb96ecddd11946fe401103 (MD5) / O biossólido é um composto passível de utilização agronômica, sendo fonte de nutrientes para as culturas e condicionador de solo. Neste sentido, desenvolveu-se um trabalho que teve por escopo estudar a influência da reaplicação de doses de biossólido na recuperação de atributos físicos e químicos do solo e no desenvolvimento da cultura do eucalipto e da braquiária, num Latossolo Vermelho degradado. O estudo foi realizado cinco meses após a reaplicação do biossólido, numa área em recuperação cultivada há seis anos com eucalipto e braquiária. O delineamento experimental foi em blocos casualizados com seis tratamentos e quatro repetições, sendo: Solo cultivado com eucalipto e braquiária sem adição de insumos; Solo cultivado com eucalipto e braquiária com adubação mineral; Solo cultivado com eucalipto e braquiária com reaplicação de 4,64 Mg ha-1 (base seca) de biossólido; Solo cultivado com eucalipto e braquiária com reaplicação de 9,28 Mg ha-1 (base seca) de biossólido; Solo exposto (sem qualquer cultivo ou adubação); Solo com vegetação natural de Cerrado. Estudou-se nas camadas do solo de 0,00- 0,05; 0,05-0,10; 0,10-0,20 e de 0,20-0,40 m, os atributos físicos: macroporosidade; microporosidade; porosidade total e a densidade do solo. Para os atributos químicos nas mesmas camadas os teores de: P, MO, pH, K, Ca, Mg, H+Al, SB, CTC e V%. Já para a cultura do eucalipto estudou-se a altura média de plantas e o diâmetro a altura do Peito (DAP) e na braquiária a massa fresca e seca. Verificou-se que a replicação do biossólido está recuperando o solo tanto em relação aos atributos físicos como químicos, sobretudo nas camadas mais superficiais, e que a maior dose influencia no desenvolvimento do eucalipto. Não foi constatada diferença significativa entre médias dos tratamentos para recuperação do solo da matéria... / The sludge is a compound capable of agricultural use, a source of nutrients for crops and soil conditioner. In this sense, has developed a work which objective on studying the influence of reapplication of biosolids in the recovery of physical and chemical properties of soil and the development of culture of eucalyptus and grass in a degraded Oxisol. The work was conducted five months after the biosolids re-application in a recovery area cultivated for six years under eucalyptus and pasture. The experimental design was randomized blocks with six treatments and four replications, with: Solo under eucalyptus and pasture with no added inputs, soil under eucalyptus and pasture with mineral fertilization, soil under eucalyptus and pasture with reapplication of 4.64 Mg ha-1 (on dry basis) of sludge, soil under eucalyptus and pasture with reapplication of 9.28 Mg ha-1 (on dry basis) of sludge, soil exposed (without any cultivation or fertilization), soil with Savannah vegetation. Was studied in soil layers of 0.00-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.40 m, the physical attributes: macroporosity, microporosity; porosity and soil bulk density. For the chemical in the same layers of levels: P, organic matter, pH, K, Ca,Mg, H+Al, SB, CEC and V%. As for the cultivation of eucalyptus studied the average plant height and diameter at breast height (DBH) and the grass fresh and dry. It was found that replication of the sludge is regaining ground in relation to both physical and chemical properties, especially in the surface layers, and the highest dose influences the plantations development. There was no significant difference between treatment means for soil recovery of fresh and dry grass, after reapplication of biosolids

Made available in DSpace on 2014-06-11T19:29:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-06-27Bitstream added on 2014-06-13T21:00:06Z : No. of bitstreams: 1 lima_cgr_me_ilha.pdf: 1824427 bytes, checksum: 2c8f6de8a9b1cf06bd3d4c3b5302f56f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O milho é um dos cereais mais cultivados e consumidos no mundo. Para silagem é a forrageira de melhor qualidade, muito utilizada na alimentação bovina. Por apresentar sistema radicular com alto potencial de desenvolvimento, os atributos físicos do solo são de extrema importância à sua produtividade, uma vez que, em condições adversas, podem dificultar a penetração das raízes e, conseqüentemente, limitar o adequado aproveitamento dos nutrientes e da água disponível. No ano agrícola de 2005, na Fazenda Bonança (Agropecuária Dahma), município de Pereira Barreto (SP), Brasil (20o40’12’’ latitude S; 51o01’50’’ longitude W), foram analisadas a produtividade de forragem do milho safrinha outonal (MSF), no sistema plantio direto irrigado, as densidades da partícula (DP) e do solo (DS), as porosidades totais determinada (PT) e calculada (PTc), os teores de areia (AR), silte (SI) e de argila (AR) de um Latossolo Vermelho Distrófico (Acrustox Háplico) local, nas profundidades 1 (0-0,10 m), 2 (0,10-0,20 m) e 3 (0,20-0,30 m). O objetivo foi estudar a variabilidade e as correlações lineares e espaciais entre os atributos da planta e do solo, visando selecionar um indicador da qualidade física do solo de boa representatividade para a produtividade da forragem. Foi instalada a malha geoestatística para a coleta dos dados do solo e da planta, contendo 125 pontos amostrais, numa área de 2500 m2 e declive homogêneo de 0,025 m/m. No geral, os atributos estudados, além de não terem revelado distribuição aleatória, apresentaram variabilidade entre média e baixa. Seguiram padrões espaciais claramente definidos, com alcances da dependência espacial entre 6,8 e 46,8 metros. Assim, o maior alcance que poderá assegurar extrema semelhança em magnitude para qualquer atributo estudado, e que poderá alimentar os pacotes... / Corn is one of cereals most cropped and consumed in the world. At silage is the best green crop, very employed in the bovine nutrition. Once it has roots with high growth capability, the soil physical attributes are very important to his productivity, so that, in adverse conditions, they can inhibit the roots penetration, and thus restrict the suitable absorption of plant nutrients and available water. The forage productivity of autumnal corn (FP) in no-tillage and irrigated, and the particle (PD) and bulk (BD) densities, the determined (TPd) and computed (TPc) total porosities, the contents of sand (SA), silt (SI), and clay (CL) soil attributes, in depths 1 (0-0,10 m), 2 (0,10-0,20 m), and 3 (0,20-0,30 m), in a Haplic Acrustox of Bonança Farm (Dahma Agricultural Company) in Pereira Barreto County, Sao Paulo State, Brazil (20o40’12’’ latitude S; 51o01’50’’ longitude W), were analyzed in the agricultural year of 2005. The purpose was to study the variability and linear spatial correlations among the attributes (plant and soil), aiming to select an index of soil physical quality with good capacity to represent the forage productivity. A grid geostatistical to collect soil and plant data was installed, with one hundred and twenty five sample points, in a area of 2500 m2, with homogeneous slope steepness of 0.025 m/m. Yonder not changed randomly, the studied attributes showed median to low variability, with excellent spatial performances, and ranges between 6.8 and 46.8 meters. Therefore, the farthermost range at to guarantee high similitude in size, at every-one soil researched attribute, and however it will be used in the computational software of precision agriculture, must be of 46.8 meters. The FP will be estimated through equation of multiple linear regression, from the TPd1 and TPd2 attributes. The Core Method must determine the TP advantageous. Although the ...(Complete abstract click electronic access below)

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-05-19T19:21:27Z No. of bitstreams: 2 Dissertação - Tatiane de Silveira Garcia - 2015.pdf: 4358862 bytes, checksum: b6b8705226b2e440381f50b05edf1087 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-05-20T13:49:32Z (GMT) No. of bitstreams: 2 Dissertação - Tatiane de Silveira Garcia - 2015.pdf: 4358862 bytes, checksum: b6b8705226b2e440381f50b05edf1087 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-05-20T13:49:32Z (GMT). No. of bitstreams: 2 Dissertação - Tatiane de Silveira Garcia - 2015.pdf: 4358862 bytes, checksum: b6b8705226b2e440381f50b05edf1087 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-03-13 / The soils are important natural elements of the landscape composition. However, it is one of the most degraded resources by society due to the type of occupation, use and management. In this sense, the intensive cultivation of the soil changes its physical, chemical and biological properties, which impacts directly on their productivity. Thus, determine the physical and chemical quality of the soil, through physical and chemical characteristics, its important in the deployment of appropriate use and management; this contributes not only to productivity, but also in the preservation of many natural qualities of the soil, achieved over its evolution. So, its rational to use geography knowledge, soil science or other sciences as management tools for use/occupation and management mainly on local and regional, respecting the areas of environmental conservation interest and the necessary conditions for the life of flora and terrestrial fauna populations. In addition, the study of land use evolution wa done by using methodological bases, developed by IBGE and presented in the technical manual of land use, 2006. The present work proposed, alsol, to evaluate the relationship between soil use and management with its physical characteristics such as texture, density, porosity, air space, water retention and movement in the soil and chemical characteristics such as pH, organic matter and nutrients, based on “Methods of Soil Analysis Manual”, published by EMBRAPA, in 1997. In areas cultivated with sugar cane and pasture, comparing them to areas under native vegetation, on an Oxisoil of Ituiutaba municipality(MG). The analysis of variance indicated no significant difference in hydraulic conductivity values and on other indicators of water movement in the soil. The degradation detected in the use and soil management should be more due to the level of technology used in soil management than in respect to types of use. It is suggested , as future work , to assess these characteristics in areas with longer use, especially with sugar. cane / Os solos são importantes elementos naturais na composição das paisagens. No entanto, é um dos recursos muito degradado pela sociedade devido ao tipo de ocupação, uso e manejo utilizados. Neste sentido, o cultivo intensivo do solo altera suas propriedades físicas, químicas e biológicas, o que influencia diretamente em sua produtividade. Assim, determinar a qualidade física e química do solo, por meio de características físicas e químicas, é de fundamental importância na implantação de usos e manejos mais apropriados; isto contribui não somente para aumentar a produtividade, mas, também, para a preservação das inúmeras qualidades naturais do solo, alcançadas ao longo de sua evolução. Por isso, é recomendável utilizar conhecimentos de Geografia, Pedologia ou outras ciências como instrumentos de gerenciamento do uso/ocupação e manejo, principalmente no âmbito local e regional, respeitando-se as áreas de interesse de preservação ambiental e as condições necessárias para a vida das populações da flora e da fauna terrestre. Além da evolução do uso da terra, utilizando-se bases metodológicas elaboradas pelo IBGE e apresentadas no Manual técnico de uso da terra, de 2006, no presente trabalho foi proposto, ainda, avaliar a relação do uso e manejo do solo através de suas características físicas, como textura, densidade, porosidade, espaço de aeração, retenção e movimento de água no solo e de características químicas como pH, matéria orgânica e nutrientes, com base no Manual de Métodos de Análise de Solo, publicado pela EMBRAPA, em 1997, em áreas cultivadas com cana-de-açúcar e sob pastagem, comparando-as com áreas sob vegetação natural, num Latossolo Vermelho Distrófico do município de Ituiutaba (MG). As áreas sob pastagem apresentaram uma maior densidade do solo, indicando compactação pelo pisoteio bovino. A análise da variância não detectou diferença significativa na condutividade hidráulica saturada e nos outros valores que medem o movimento de água no solo. A degradação detectada no uso e manejo do solo, deve-se mais ao grau de tecnologia utilizada no manejo do solo do que aos tipos de uso. Sugere-se, como trabalhos futuros, avaliar tais características em áreas com maior tempo de utilização, principalmente, com cana-de-açúcar.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nesse trabalho foi estudada uma seqüência de amostras de solos de acordo com os perfis; , com o objetivo de identificar através de análise difratométrica, óxidos de ferro, a partir do concentrado magnético induzido das amostras dos solos coletados em terras nas proximidades de Amajarí, Boa Vista, Bonfim e Alto Alegre em Roraima, visando fornecer subsídios para futuros projetos de uso do solo relacionados às áreas em que esses perfis estão localizados. Em uma primeira etapa as amostras foram coletadas em horizontes superficiais e subsuperficiais sendo definidos em 0,0 a 0,10 m; 0,60 a 1,00 m e 0,80 a 1,00 m e levadas ao laboratório de Manejo de Solos no Centro de Ciências Agrárias, onde procedemos ao tratamento e posterior afinamento das amostras de areia total (TFSA), e a separação do concentrado magnético. Na segunda etapa, as amostras tratadas foram levadas ao Laboratório de Propriedades Magnéticas no campus do Paricarana, onde foram feitas análises mineralógica utilizando a técnica de Difração de Raios-X / In this work was studied a soil sequence sample according to the profiles; and P_5, aiming to identify through analysis diffractogram, iron oxides, from the concentrated samples of induced magnetic soils collected on land near Amajarí, Boa Vista, Bonfim and Alto Alegre, Roraima, to provide data for future projects related to land use areas in which these profiles are located. In a first step the samples were collected in surface and subsurface horizons were defined in 0.0 to 0.10 m: 0.60 to 1.00 m and 0.80 to 1.00 I brought to the laboratory of Soil Management Center of Agricultural Sciences, where he proceeded to treatment and subsequent thinning of the sand samples total (TFSA), and the separation of the magnetic concentrate. In the second step, the treated samples were brought to the Laboratory of Magnetic Properties on the campus of Paricarana where mineralogical analysis was performed using the technique of X-ray diffraction

Os movimentos de massa fazem parte da dinâmica da paisagem e se destacam como um dos principais processos geomorfológicos responsáveis pela evolução do relevo. Estes são condicionados por uma relação complexa de fatores naturais: geomorfológicos, geológicos e geotécnicos e hidrológicos. Tais tipos de movimentos de massa ficaram registrados em 17 e 18 de março de 1967 nas encostas da escarpa da Serra do Mar no município de Caraguatatuba, quando ocorreram de modo generalizado, causando um grande impacto ambiental, culminando em 120 mortes e 400 casas destruídas, mais concentrados em uma área de aproximadamente 180km2 em torno do município. Sendo assim, o objetivo deste trabalho é investigar algumas propriedades físicas do solo a fim de analisar a influência destas na distribuição e na deflagração dos escorregamentos translacionais rasos. As amostras de solo foram coletadas em três pontos, em diferentes profundidades (lateral, superior e interior) de três cicatrizes de escorregamentos rasos de 1967. As seguintes propriedades foram analisadas: distribuição granulométrica, limites de Atterberg, porosidade, densidade, curvas de retenção de água e resistência ao cisalhamento. As amostras apresentaram valores altos para as frações de areia, cerca de 80%, com uma composição granulométrica variável, destacando a existência de areias siltosas e pouco argilosas e siltes pouco argilosos, com os horizontes de solos mais profundos formados predominantemente por materiais siltosos e/ou arenosos, enquanto os horizontes superficiais apresentaram-se mais argilosos. Ainda que com baixos índices de atividade e por muitas vezes inatividades, não apresentaram significativa variabilidade quanto aos índices físicos onde os corpos de prova não atingiram a saturação total, alcançando uma média percentual de 70% de umidade e valores para densidade e índices de vazios muito próximos, de 2,55 g/cm3 e 1,151 g/cm3, respectivamente quanto aos parâmetros de resistência. Os ângulos de atrito foram menores para os horizontes superficiais (29,1º e 25,8º) em detrimento das camadas subjacentes, 1,75m e 2,00m, (31,9º e 36,8º). É importante ressaltar que boa parte dos estudos já desenvolvidos sobre a temática Serra do Mar Paulista focam o mapeamento destes processos na paisagem e o papel dos parâmetros topográficos, sobretudo da declividade, na distribuição dos mesmos. Entretanto, são escassas as informações sobre a tipologia e as propriedades dos solos, em escala de detalhe que possam efetivamente influenciar a estabilidade das encostas da Serra do Mar. Espera-se, portanto, que este estudo possa subsidiar em melhor entendimento dos mecanismos de ruptura dos escorregamentos rasos neste compartimento geomorfológico. / Mass movements are part of the landscape dynamics and stand out as major geomorphological processes responsible for the evolution of relief. These are determined by a complex of natural factors: geomorphological, geological and geotechnical and hydrological. These types of mass movements were recorded on 17 and 18 March 1967 on the slopes of the escarpment of the Serra do Mar in the city of Caraguatatuba, when there were so widespread, causing a major environmental impact, resulting in 120 deaths and 400 homes destroyed more concentrated in an area of approximately 180km2 around the county. Therefore, the objective of this work is to investigate some physical properties of the soil in order to analyze their influence on the distribution and outbreak of shallow translational landsliding. Soil samples were collected at three points at different depths (side, top and interior) of three shallow landslide scars from 1967. The following properties were analyzed: size distribution, Atterberg limits, porosity, density, water retention curves and shear strength. The samples had high values for the sand fractions, about 80%, with a variable grain size composition, highlighting the existence of silty sands and silts and clay little bit clay, with deeper soil horizons formed predominantly silty materials and / or sandy, while the surface horizons were more clay. Even with low levels of activity and often outages, showed no significant variation between the physical indexes where the samples have not reached full saturation, reaching an average percentage of 70% moisture content and density values for indices and very empty next, at 2.55 g/cm3 and 1.151 g/cm3, respectively for the parameters of resistance. The friction angles were smaller in surface horizons (29.1 º and 25.8 º) over the underlying layers, 1.75 m and 2.00 m (31.9 º and 36.8 º). Importantly, many of the studies already undertaken on the subject Serra do Mar Paulista focus on the mapping of these processes in the landscape and the role of topographic parameters, especially the slope in their distribution. However, there is little information about the types and properties of soils in detail scale that can effectively influence the stability of the slopes of the Serra do Mar. It is hoped, therefore, that this study may support better understanding of failure mechanisms of shallow landslides in geomorphological compartment.

Thesis (M.Sc. Agriculture (Soil Science)) -- University of Limpopo, 2021 / Woody plant encroachment results in the degradation of grasslands. It is defined here as the increase in density, cover and biomass of woody plants into formerly open grasslands, reducing grassland productivity. Globally, many arid and semi-arid savanna grasslands are affected by this land cover transformation which changes the vegetation structure by altering the ratio of woody plants relative to grass species and influences soil hydrology. In the existing literature there is limited information on the effects of woody plant encroachment on soil physical and hydrological properties, especially in savanna grasslands. This study quantified and compared the soil physical and hydrological properties in the topsoil and subsoil of open and woody plant encroached grassland sites located on two contrasting soil forms, namely Bainsvlei and Rensburg. To achieve this objective, the two soils were sampled at various depth intervals from dug soil profiles at both sites at Towoomba Research Station in Bela Bela, Limpopo Province, South Africa. Soil physical properties including bulk density, porosity and aggregate stability as well as hydrological properties (water retention and hydraulic conductivity) were determined from collected samples. Compared to open grassland, soil bulk density was 11% and 10% greater in the topsoil and subsoil, while porosity was respectively 6% and 9% lower in the topsoil and subsoil of woody plant encroached grassland for Rensburg soils. In Bainsvlei soil, there was a minimal increase and decrease in the soil bulk density and porosity, respectively. Soil aggregate stability increased by 38% in the subsoil of woody plant encroached grasslands in Rensburg soil, due to increasing clay content with depth. In Bainsvlei soil, the soil aggregate stability was 9% and 13% lower in the topsoil and subsoil of the woody plant encroached grasslands compared to open grassland. Furthermore, the results revealed that in both soils, there was lower soil water retention and hydraulic conductivity in the topsoil and subsoil layers of woody plant encroached grassland than in open grasslands. There were no significant differences observed for soil hydraulic conductivity in the Bainsvlei and Rensburg topsoil. The subsoil hydraulic conductivity decreased by 24% in Bainsvlei and 44% in Rensburg soils in the woody plant encroached grassland. The soil water retention (SWR) decreased with an increase in woody plants. Specifically, there was 25% and 42% decrease in SWR with woody plant encroachment in the topsoil and subsoil of Bainsvlei soil, respectively. The same trend was observed in the Rensburg soils with 50% and 19% decrease in SWR in the topsoil and subsoil, respectively. Overall, the results revealed that soil type and depth influenced soil physical and hydrological properties in the studied woody plant encroached savanna grassland. As such, interventions aimed at controlling woody plant encroachment need to factor in soil type and depth in the development of management practices tailored to improve the soil hydrology of savanna grasslands

Orientador: Paulo Torres Fenner / Banca: Cláudio Angeli Sansígolo / Banca: Sérgio Hugo Benez / Banca: Jorge Roberto Malinovski / Banca: Fernando Seixas / Resumo: Foram avaliados os efeitos causados ao solo pelo tráfego de máquinas florestais de corte e baldeio de madeira, com ênfase à compactação, em floresta de Eucalyptus grandis Hill ex Maiden, de 91 meses de idade, através do comportamento de parâmetros físicos e mecânicos de um Latossolo Vermelho Amarelo, com 480 g.kg-1 de areia total e 430 g.kg-1 de argila. Os tratamentos avaliados foram o trânsito anterior ao experimento, a fase de corte e processamento de madeira, efetuada por colhedora (harvester) sobre esteiras e a fase de extração, por trator transportador autocarregável (forwarder) com rodado de pneus, considerando-se as condições de presença ou ausência de cobertura de galhada. Os parâmetros físicos empregados na avaliação foram: densidade do solo, porosidade total, macroporosidade, microporosidade, água disponível no solo, taxa de infiltração de água, temperatura do solo e estabilidade de agregados a seco. Os parâmetros mecânicos avaliados foram resistência do solo à penetração e ao cisalhamento, densidade máxima do solo, teor de água crítico para compactação e grau de compactação. Também foram avaliadas a área de contato rodado-solo e a pressão de rodados sobre o solo. Adotou-se o delineamento inteiramente casualizado, sendo os resultados obtidos submetidos à análise de variância pelo Statistical Analysis System (SAS), com aplicação do teste Tukey a 5% e 10% de significância. Comparativamente, a densidade do solo, a resistência mecânica ao cisalhamento e a pressão de rodados sobre o solo foram maiores após o tráfego do trator transportador em relação ao conferido pela colhedora de madeira. Os parâmetros porosidade total, macroporosidade, microporosidade, água disponível e estabilidade de agregados a seco foram maiores na fase de corte de madeira do que na fase de baldeio... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: A study of soil compaction was carried out on a Red-Yellow Latosol with 43% of clay and 48% of sand, according to some soil physical and mechanical parameters in a harvester of a 91-month-old Eucalyptus grandis Hill ex-Maiden forest. The aim was to evaluate the influence caused by the traffic of a 100 kWa-tracked harvester followed by a 190 kWa-wheeled-forwarder, over and without slash, in comparison to the soil conditions before the harvesting operations. The physical parameters used were soil dry bulk density, total porosity, air-filled porosity, micro porosity, soil water availability and infiltration rate, temperature and soil mean aggregate sizes. The mechanical parameters were soil penetrometer resistance, shear strength, Proctor test and machine ground pressure. A randomized-block trial with 15 replicates was used, applying Statistical Analysis System (SAS) and Tukey test at 5% and 10% significance levels. Results showed that wheeled-forwarder increased soil dry bulk density, soil shear strength and soil machine pressure in relation to the tracked-harvester. Thus, the parameters total porosity, air-filled porosity, micro porosity, soil water availability and soil mean aggregate sizes were higher on harvesting than on wood hauling. The wheeled-forwarder operating without slash produced a higher soil dry bulk density, temperature and soil compaction degree. Also, this work condition decreased total porosity and air-filled porosity in relation to the same operation accomplished over slash. Micro porosity, water availability, soil infiltration rate, soil penetrometer resistance and the maximum soil dry bulk density were not affected by both machines working on both slash conditions. All the soil mechanized operations evaluated were rated higher than 2 MPa on soil penetrometer resistance parameter, looked like a soil limit to allow the root growing... (Complete abstract, click eletronic address below) / Doutor

Reducing groundwater withdrawals from the Mississippi River Valley Alluvial Aquifer is imperative to sustain future irrigated cropping systems in the mid-southern USA. This research was conducted to determine the impacts of cover crops and irrigation sensor thresholds on corn (Zea mays L.) and soybean (Glycine max L.) production, water productivity, irrigation water use efficiency, and soil physical properties in the Mississippi Delta. The cover crop treatments included cereal rye (Secale cereale L.), hairy vetch (Vicia villosa R.), wheat (Triticum aestivum L.)-radish (Raphanus sativus L.)-turnip (Brassica rapa L.) mix, and no cover crop. The irrigation thresholds included -40 kPa, -90 kPa, and no irrigation. In 2020, cover crops and irrigation thresholds showed minimal impacts on most of the measured parameters but showed improvements as the study progressed. After two years, it was determined that long-term evaluations are needed to make a recommendation to producers in the mid-southern USA.

The Southeastern Lower Coastal Plain wet pine flats include thousands of acres of jurisdictional wetlands that are economically, socially, and environmentally important. These highly productive forests have been intensively managed as pine plantations for the past few decades. More recently, harvesting and site preparation practices have become a concern among natural resource managers because intensive forestry practices may alter soil physical properties and site hydrology. These alterations could decrease seedling survival, growth, and future site productivity. However, the effects of soil disturbance on long-term site productivity and the effects of amelioration techniques on site hydrology are uncertain. The overall objectives of this study were (1) to characterize disturbed forest soil morphology and physical properties, (2) to assess their impact on the processes that control site hydrology and site productivity, (3) to determine effects of harvesting and site preparation on site hydrology, specifically on the overall hydrological balance and on spatial and temporal patterns of surface water storage. The study site is located in an intensively managed loblolly pine (Pinus taeda L.) plantation in the lower coastal plain of South Carolina. This study was established in winter 1991, and dry- and wet-weather harvesting treatments were installed in summer 1993 and winter 1994, respectively. Bedding and mole channel/bedding treatments were installed in both dry- and wet-harvested plots in fall 1995. Soil profiles were described for a recently disturbed, deeply-rutted area, and 2-year-old deeply-rutted and churned areas, bedded and undisturbed areas. Intact soil core samples and composite loose soil samples were collected from each morphological section for soil physical characterizations. Automated weather station and wells were used to collect continuous climatic and surface water level data since 1996. Surface water levels were monitored monthly on a 20 x 20 m grid of 1-m wells since 1992. Total groundwater heads were determined from differential piezometer measurements at high and low elevation places in each treatment plot. Soil profile descriptions and soil physical property measurements indicated that significant amounts of organic debris were incorporated into the surface horizons, and subsurface soil horizons showed significant soil structural changes and increased redoximorphic features caused by soil disturbance. The disturbed soil layers in recently created traffic ruts consisted of exposed and severely disturbed subsurface soils, but this layer was naturally ameliorated 2 years after the disturbance. Bedding site preparation had little amelioration effects on the physical properties of surface soil horizons because the surface horizons already had some incorporation of organic debris. Overall, the main consequence of bedding in a disturbed wet site was to increase the aerated soil volume. The bedding appeared to have little effect on disturbed subsurface horizons. Groundwater head in the study site was constantly higher than -25 cm during the study period, which caused groundwater inflow when the surface water level was low. Frequent fluctuation of the surface water level and constant water supply from the groundwater probably explain the high productivity of the study site. Results of the annual water balance showed that surface soil water storage changes were very small, and annual precipitation and potential evapotranspiration were approximately equal. Silvicultural practices and minor topography on the study site had significant effects on the water balance because they influenced surface water level. Surface water hydraulic gradient evaluation and multivariate cluster analysis indicated that micro-site hydrology and water flow patterns were significantly altered by wet-weather harvesting and bedding site preparation, but overall site hydrology was not altered. Evaluation of predicted surface water level indicated that micro-topography and precipitation patterns had significant influences on surface water levels during the site establishment period. These results revealed that the hydrologic components of wetland delineation are complex in the wet pine flatwoods. / Ph. D.

Made available in DSpace on 2016-12-23T14:37:30Z (GMT). No. of bitstreams: 1 Lucas Contarato Pilon.pdf: 1648966 bytes, checksum: cac40ef638ed16eaccc0afa53f321565 (MD5) Previous issue date: 2013-02-28 / Diante da necessidade de obter informações sobre o cultivo de cafeeiros arborizados, o objetivo do trabalho é avaliar a relação dos atributos químicos, físicos e os componentes da matéria orgânica do solo sob cultivo de café consorciado com diferentes espécies arbóreas, comparativamente ao café cultivado a pleno sol, tendo como referência uma área sob floresta. O trabalho foi conduzido em sistemas de produção de café, numa propriedade familiar, município de Nova Venécia - ES. O solo da área é um ARGISSOLO AMARELO Distrocoeso típico, cultivado com café conilon consorciado com árvores, nos seguintes sistemas de uso e manejo: 1) café sem consórcio (pleno sol), 2) café consorciado com nim (Azadirachta indica), 3) café consorciado com cedro australiano (Cedrela fissilis) e 4) café consorciado com teca (Tectona grandis). Foi utilizado um solo de área florestal, como referência. A amostragem do solo foi realizada nas seguintes profundidades: 0,0 0,05; 0,05 0,10; 0,10 0,20; e 0,20 0,40 m, avaliando-se atributos químicos (pH, P, K, Ca, Mg, Al, H+Al, N, C total, C ext em água, C biomassa microbiana e emissão de CO2) e físicos do solo (granulometria, densidade do solo e de partículas, porosidade total, macro e microporosidade, estabilidade de agregados, resistência do solo à penetração e umidade do solo). A avaliação do carbono solúvel (C ext) e do carbono da biomassa microbiana do solo (CBMS) foi realizada em duas épocas (março e setembro/2012) nas profundidades de 0,0 0,05 e 0,05 0,10 m; já a emissão de CO2 foi medida na mesma época que, na presença e ausência de serapilheira. Os resultados experimentais mostram que os sistemas de uso e manejo apresentam comportamento diferenciado para grande parte dos atributos estudados. O solo florestal apresenta maiores teores e estoques de carbono orgânico total e nitrogênio total, 19,8 e 1,99 Mg ha-1 respectivamente, além de maior teor de carbono na biomassa microbiana (518,8 μg g-1 solo em março e 364,8 μg g-1 solo em setembro). Os atributos dos solos sob cafeeiros consorciados, de maneira geral, não diferem do solo sob cafeeiro a pleno sol, exceção feita para os atributos Mg, N e o C ext, C-BMS, quociente microbiano (qMic) na duas épocas de coleta, os quais são superiores nos consórcios agroflorestais, e o quociente metabólico (qCO2) inferior, denotando maior estabilidade dos cafeeiros arborizados. O café a pleno sol mostra-se um agroecossitema mais perturbado com maior qCO2 (1,81 μg CO2 C-BMS-1 h-1 em março e 2,44 μg CO2 C-BMS-1 h-1 em setembro). A proteção do solo ocasionada pelo sombreamento das árvores e a deposição de serapilheira influencia principalmente os atributos biológicos estudados, favorecendo um maior equilíbrio nos cafeeiros arborizados. Com relação aos atributos físicos, o consórcio proporciona menor densidade do solo, maior porosidade total e macroporosidade do solo, diferindo do café a pleno sol. Os cafeeiros consorciados se diferem somente na agregação do solo. A resistência do solo à penetração é influenciada pela umidade do solo, com destaque para o café a pleno sol que apresenta valores mais baixos desse atributo, em função da irrigação, que eleva a umidade do solo. O estudo numa condição de Argissolo coeso, mostra que 5 anos de implantação de sistemas arborizados são suficiente para apresentar pequenas mudanças nos atributos estudados, no entanto para atributos de alta sensibilidade, como os biológicos, são suficientes para apresentar mudanças mais consistentes dos sistemas de uso e manejo / Faced with the need for information on the coffee agroforestry systems, the objective is to evaluate the relationship of the chemical, physical and components of soil organic matter under coffee intercropping with different tree species, compared to the full-sun coffee with an area under forest like reference. The research was conducted in coffee production systems, a family farm, in Nova Venécia city - ES. The soil is an YELLOW ULTISOL Distrocohesive typical, with shadow coffee plantation, the following different land use systems and management: 1) coffee full (full-sun), 2) coffee intercropped with neem (Azadirachta indica), 3) coffee intercropped with Australian cedar (Cedrela fissilis) and 4) coffee intercropped with Teca (Tectona grandis). It was used a soil of forest area, as a reference. Soil sampling was conducted in the following depths: 0.0-0.05, 0.05-0.10; 0.10-0.20, and 0.20-0.40 m, evaluating chemical soil attributes ( pH, P, K, Ca, Mg, Al, H + Al, total nitrogen (TN), total organic carbon (TOC), water-soluble carbon (WSC), soil microbial biomass carbon (SMBC) and soil CO2 emission and physical soil attributes (particle size, bulk density, total porosity, macroporosity, microporosity and soil resistance penetration), was collected and characterization of accumulated litter. The evaluation of soluble carbon (soluble C) and soil microbial biomass carbon (SMBC) was held twice a year (March and september/2012) at depths from 0.0-0.05 and 0.05-0, 10 m, the soil CO2 emission was measured at the same times, in the presence and absence of litter. The experimental results show that the use and management systems were characterized for most attributes researched. The forest soil has higher levels of stocks and TOC and TN, 19.8 and 1.99 Mg ha-1 respectively, and the higher SMBC (518.8 mg g-1 soil in March and 364, 8 mg g-1 soil in September). The soil under shadow coffee, in general, do not differ from full-sun coffee, except for the attributes Mg, N and soluble C, SMBC, microbial quotient (QMIC) at both harvests, which are higher in agroforestry systems, and attributes TOC/ soluble C and metabolic quotient (qCO2) lower values, indicating greater stability of shadow coffee systems. The full-sun coffee shows more disturbed agroecosystem with high qCO2 (1.81 μg CO2 CBMS-1 h-1in March and 2.44 μg CO2 CBMS-1 h-1 in September). The protection of soil caused by shading from trees and litterfall influences the biological attributes primarily, favoring a greater balance in shadow coffee. Relative to physical attributes, the intercropped provides a lower bulk density, higher total porosity and macroporosity, differing full-sun coffee. The shadow coffee up differs only in soil aggregation. The soil resistance penetration is influenced by soil moisture, especially for full-sun coffee which shows lower values of this attribute, depending on irrigation management, which increase soil moisture. The study provides a ULTISOL cohesive, shows that 5 years of systems implementation, are enough to present small changes in the attributes studied, however high sensitivity to attributes such as biological changes are sufficient to represent most consistent use and management systems