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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Controle de tráfego agrícola e seus efeitos nos atributos do solo e na cultura da cana-de-açúcar / Controlled traffic farming and its effects on soil attributes and culture of sugarcane

Souza, Gustavo Soares de 07 December 2012 (has links)
Orientadores: Zigomar Menezes de Souza, Reginaldo Barboza da Silva / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-20T23:31:38Z (GMT). No. of bitstreams: 1 Souza_GustavoSoaresde_D.pdf: 2647640 bytes, checksum: 16829b5386093b4e4869edac0f73f3e9 (MD5) Previous issue date: 2012 / Resumo: O sistema de produção da cana crua, sem queima da palha e com frequente uso da mecanização agrícola promove o tráfego intenso sobre o solo, resultando na sua compactação. O sistema de manejo com controle de tráfego agrícola representa uma alternativa viável para o setor agrícola, pois separa as zonas de tráfego e não tráfego, concentrando a passagem de pneus em linhas permanentes, diminuindo a influência da compactação sobre a cultura. O objetivo deste trabalho foi comparar os sistemas de manejo com e sem controle de tráfego agrícola em relação à qualidade física de um Latossolo Vermelho, indicada por meio da análise de atributos físicos e mecânicos do solo, e seu efeito na cana-de-açúcar colhida mecanicamente e sem queima. A pesquisa foi desenvolvida em lavoura comercial com os manejos: ausência de controle de tráfego (T); controle de tráfego com ajuste da bitola do trator e transbordos para 3,0 m (CT1); e controle de tráfego com ajuste da bitola e piloto automático. Os atributos do solo avaliados foram: densidade, porosidade, resistência à penetração, conteúdo de água, estabilidade de agregados, teor de carbono e curva de retenção de água do solo. O solo foi amostrado nas linhas de plantio e do rodado e no canteiro, nas camadas 0,00-0,10; 0,10-0,20 e 0,20-0,30 m. A qualidade física do solo foi avaliada por meio do intervalo hídrico ótimo. A estrutura do solo foi avaliada por meio de análise de imagens digitalizadas de monólitos de solo, quantificando a forma e tamanho dos poros. Foram coletadas amostras indeformadas para análise da capacidade de suporte de carga do solo. A cana foi colhida mecanicamente e a produtividade medida por meio de balança específica para transbordo. Amostras de colmo foram coletadas em cada parcela para determinação das variáveis tecnológicas. As raízes foram coletadas em monólitos, separadas do solo por peneiramento. Densidade, porosidade e resistência do solo a penetração demonstraram diferenças entre os sistemas de manejo, com melhores condições físicas nos manejos com controle de tráfego na linha da soqueira e no canteiro. Os índices de agregação e o teor de carbono do solo não diferiram entre os manejos. Foram observadas alterações na retenção de água do solo entre tratamentos. O intervalo hídrico ótimo foi maior no canteiro e linha de plantio nos manejos com controle de tráfego. Predomínio de poros arredondados e complexos indicaram maior porosidade e menor compactação no manejo com controle de tráfego na linha de plantio. A testemunha apresentou maior pressão de pre- consolidação na linha de plantio, enquanto o manejo com controle de tráfego apresentou maior capacidade de suporte de carga na linha do rodado. Os manejos com controle de tráfego apresentaram maior produtividade e rendimento de açúcar. As variáveis tecnológicas não diferiram entre os manejos. O manejo com controle de tráfego apresentou maior massa seca, superfície e volume radicular. Os manejos com controle de tráfego proporcionaram compactação na linha do rodado e preservaram a qualidade física do solo na região da soqueira, resultando no maior desenvolvimento do sistema radicular, com aumento de 18% na produtividade e 20% no rendimento de açúcar / Abstract: The sugarcane production system without straw burning and with frequent use of agricultural mechanization promotes the excessive traffic on the soil, resulting in their compaction. The management with controlled traffic farming is a viable alternative for the agricultural sector, because it separates the areas of traffic and no-traffic, focusing on the passage of tires in permanent lines, reducing the influence of compaction on the crop. The objective this work was to compare the management systems with and without controlled traffic farming in relation to soil physical quality, indicated by the analysis of attributes physical and mechanical soil and its effects on sugarcane harvested mechanically and without burning. The research was developed in a commercial farm with the managements: non-controlled traffic (T); controlled traffic with adjustment of the tractor and trailer gauge to 3.0 m (CT1), and controlled traffic with adjustment of the gauges and autopilot (CT2). The soil attributes evaluated were: bulk density, porosity, penetration resistance, water content, aggregate stability, carbon content and soil water retention curve. Soil samples were collected in plant and wheel rows and in the seedbed, in the layers 0.00 to 0.10; 0.10 to 0.20 and 0.20 to 0.30 m. The soil physical quality was evaluated using the least limiting water range. The soil structure was evaluated by digitized images analysis of soil monoliths, quantifying shape and size of the pores. Undisturbed samples were collected for analysis of soil load carrying capacity. The sugarcane was mechanically harvested and the productivity was measured by weighing the sugarcane trailer. Sugarcane stalks were collected from each plot to determine the technological variables. The roots were collected in monoliths, separated from the soil by sieving. Bulk density, porosity and penetration resistance showed differences among management systems, with better physical conditions in the managements with controlled traffic in the plant row and seedbed. The aggregation indices and carbon content didn't differ between managements. There were changes in soil water retention curve between treatments. The least limiting water range was higher in the seedbed and plant row in the controlled traffic. Predominance of rounded and complexes pores showed higher porosity and lower compaction in the controlled traffic in the plant row. The management with non-controlled traffic had a higher soil preconsolidation pressure in the plant row, while the management of controlled traffic had a higher load carrying capacity in the wheel row. The management of controlled traffic had a higher cane productivity and sugar yield. The technological variables didn't differ between managements. The handling with controlled traffic had higher dry mass, surface and volume of roots. The management with controlled traffic promoted soil compaction in wheel row and preserved the soil physical quality in the plant row, resulting in greater root development, with 18% increase in productivity and 20% on yield of sugar / Doutorado / Engenharia de Água e Solo / Doutor em Engenharia Agrícola
72

Atributos do solo e suas relações com resíduos vegetais e matéria orgânica em áreas cultivadas com cana-de-açúcar / Soil attributes and relations their with waste vegetable and organic matter in areas cultivation sugar cane

Araújo, Fernando Silva 22 August 2018 (has links)
Orientadores: Zigomar Menezes de Souza, Edson Eiji Matsura / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-22T04:49:55Z (GMT). No. of bitstreams: 1 Araujo_FernandoSilva_D.pdf: 5020372 bytes, checksum: af978a8271ef4c982fd82d0d223e486b (MD5) Previous issue date: 2012 / Resumo: É crescente a demanda global por fontes de energia renováveis, tais como o etanol, o qual no Brasil, possui como principal matriz energética a cultura da cana-de-açúcar. Neste contexto faz-se necessário a incorporação de novas tecnologias, como a mecanização da colheita, para o uso racional das áreas manejadas com cana-de-açúcar. O acúmulo superficial de resíduos vegetais da cana-de-açúcar na superfície do solo promove o enriquecimento das camadas superficiais com matéria orgânica bem como o incremento do intervalo hídrico ótimo, mitigando os efeitos da compactação do solo causados pelo tráfego de máquinas no sistema de cana colhida mecanicamente sem queima. Portanto, o objetivo deste trabalho foi estudar as alterações no comportamento físico e mecânico de um Latossolo Vermelho produzido pelo enriquecimento do conteúdo de matéria orgânica e, ainda, a capacidade dos resíduos vegetais acumulados na superfície do solo dissiparem cargas aplicadas sobre o mesmo, em áreas cultivadas com cana-de-açúcar colhidas com e sem queima. O projeto foi desenvolvido em três áreas cultivadas com cana-de-açúcar: 1- cana-de-açúcar sem queima e corte mecanizado, desde 1996 (com 16 anos de implantação do sistema de cana crua); 2- cana-de-açúcar sem queima e corte mecanizado, desde 2004 (com 8 anos de implantação do sistema de cana crua); 3- cana-de-açúcar com queima e corte manual, desde 1973 (cana queimada). Os atributos físicos avaliados foram: análise granulométrica, consistência do solo, densidade do solo, estabilidade de agregados, porosidade do solo e resistência do solo à penetração nas profundidades de 0,00-0,10 m, 0,10-0,20 m e 0,20-0,30 m. Determinou-se ainda o intervalo hídrico ótimo para desenvolvimento das plantas. Foram avaliadas as relações entre o teor de matéria orgânica e a compressibilidade do solo, as relações entre teor de matéria orgânica do solo e a umidade crítica para a compactação e as relações entre quantidade de resíduos vegetais na superfície e a densidade do solo obtida pelo teste Proctor. Os atributos de solo estudados apresentam estrutura de dependência espacial. O intervalo hídrico ótimo e ?p mostraram-se sensíveis as alterações ocorridas no solo em detrimento dos sistemas de manejo estudados. A área sob colheita manual da cultura da cana-de-açúcar apresentou menor valor de densidade crítica para o intervalo hídrico ótimo, sendo que a maior produtividade da cultura concentrou-se nas regiões de maior amplitude do intervalo hídrico ótimo e maior capacidade suporte de carga do solo / Abstract: An increasing global demand for renewable energy sources such as ethanol, which in Brazil, has as its primary energy matrix culture of sugar cane. In this context it is necessary to incorporate new technologies, mechanization of the harvest, for the rational use of managed areas with cane sugar. The accumulation of surface plant residues of sugar cane on the soil surface promotes the enrichment of the surface layers with organic matter as well as increasing the optimal water, mitigating the effects of soil compaction caused by machinery traffic on the system cane mechanically harvested without burning. Therefore, the aim of this work was to study the changes in physical and mechanical behavior of soil produced by enriching the content of organic matter, and also the ability of plant debris accumulated on the soil surface dissipate loads applied on it, in cultivated areas sugar cane harvested with and without burning. The project was developed in three areas cultivated with sugar cane: 1 - harvested with manual cutting and burning since 1973; 2 - mechanically harvested without burning since 2004 (8 years of implantation of sugarcane), 3 - mechanically harvested unburned since 1996 (16 years of implantation of sugarcane). The physical attributes were: particle size analysis, soil consistency, soil bulk density, and aggregate stability, soil porosity and soil resistance to penetration depths of 0.00 to 0.10 m, 0.10-0.20 me 0.20-0.30 m. It was determined the optimal water yet to identify the critical limits of soil density where resistance to penetration and aeration porosity are restrictive to plant development. We evaluated the relationship between the organic matter content and soil compressibility, the relationships between organic matter content and soil moisture critical for the compression and the relationship between the amount of crop residue on the surface and soil density obtained by the Proctor test. The soil attributes have studied the spatial dependence structure. The least limiting water range and ?p were sensitive to changes in the soil instead of studied treatments. The area under cultivation of manual harvesting cane sugar showed a lower value of the critical density for optimal water, and the greater crop concentrated in regions of higher altitude and lower load-bearing capacity / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola
73

Modelling, Simulation and Experimental Investigation of a Rammer Compactor Machine / Modellering, simulering och experimentell undersökning av en jordkompakteringsmaskin

Jönsson, Anders January 2001 (has links)
This licentiate thesis considers the modelling, simulation and experimental investigation of a rammer compactor machine. The purpose is to develop an efficient and verified method for simulation of rammer compactor machines to be used in the product development process. The experience gained through this work is also intended to be useful for studying other types of dynamic compactor machines. Rammer compactor machines perform impact soil compaction. This is more efficient than static compaction. The machines are often used in places where a high degree of compaction is needed, and where the space for operation is limited. The complexity of this type of machine makes design optimisation through traditional prototype testing impractical. This has pointed to the need for a theoretical model and simulation procedure for predicting the dynamic behaviour of the machine. To be useful for optimisation the theoretical model and simulation procedure must be verified. By concurrently working with theoretical modelling, simulations, experimental verifications, and optimisation an efficient analysis support for product development is achieved. This co-ordination works both ways in an iterative manner: experimental investigations are used to verify theoretical models and simulations; and theoretical models and simulations are used to design good experiments. This Complete Approach concept enables better decisions to be made earlier on in the development process, resulting in a decrease in time-to-market and improved quality. In this thesis, the Complete Approach concept is applied to a rammer soil compactor machine. An introductory iteration is described. The good agreement between theoretical and experimental results indicates that the theoretical model and simulation procedure should prove useful in introductory optimisation studies. The thesis discusses reasons for the remaining discrepancy and suggests improvements in both the theoretical model and the experimental set-up for future iterations. / I arbetet studeras det dynamiska beteendet av en jordpackningsmaskin. Syftet är att bygga upp en verifierad modell som kan ligga till grund för vidare produktutveckling. Ett samordnat arbetsätt, Complete Aproach / <p>http://epubl.luth.se/1402-/02/index.html</p>
74

Coarse-Graining Fields in Particle-Based Soil Models / Medelfält från partikelbaserade markmodeller

Ahlman, Björn January 2020 (has links)
In soil, where trees and crops grow, heavy vehicles shear and compact the soil, leading to reduced plant growth and diminished nutrient recycling. Computer simulations offer the possibility to improve the understanding of these undesired phenomena. In this thesis, soils were modelled as large collections of contacting spherical particles using the Discrete Element Method (DEM) and the physics engine AGX Dynamics, and these entities were analyzed. In the first part of the thesis, soils, which were considered to be continua, were subjected to various controlled deformations and fields for quantities such as stress and strain were visualized using coarse graining (CG). These fields were then compared against analytical solutions. The main goal of the thesis was to evaluate the usefulness, accuracy, and precision of this plotting technique when applied to DEM-soils. The general behaviour of most fields agreed well with analytical or expected behaviour. Moreover, the fields presented valuable information about phenomena in the soils. Relative errors varied from 1.2 to 27 %. The errors were believed to arise chiefly from non-uniform displacement (due to the inherent granularity in the technique), and unintended uneven particle distribution. The most prominent drawback with the technique was found to be the unreliability of the plots near the boundaries. This is significant, since the behaviour of a soil at the surface where it is in contact with e.g. a vehicle tyre is of interest. In the second part of the thesis, a vehicle traversed a soil and fields were visualized using the same technique. Following a limited analysis, it was found that the stress in the soil can be crudely approximated as the stress in a linear elastic solid.
75

Soil compaction and the effect on infiltration in urban green environments : A study based on field measurements and HYDRUS 1D modelling

Novikova, Anastasia January 2023 (has links)
The consequences of recent flooding and extreme rain events have highlighted the importance of proper urban planning and preventative measures for storm water management. As cities become more urbanized the significance of permeable surfaces such as parks and other urban green spaces increases which infiltrate the water into the ground. Agricultural research has for many years emphasized the effect of compaction on soil parameters and how, not only the crop yield reduces but also how the infiltration decreases. This thesis aims to study how the infiltration rate, bulk density and soil resistance changes with compaction through field experiments where a vehicle is let to roll over an urban green area. The thesis will also simulate rainfall over five theoretical soils that can be found in urban environments exposed to compaction to determine what significance compaction has on surface runoff. The modelling software HYDRUS-1D will be used so simulate rain fall events on the different soils. The rain events simulated will be based on the five hyetographs that best represent Sweden’s rain events, based on historical data. A CDS rain will be simulated as well. They will be simulated for a 2, 10 and 100 year return period. A literature study will also be conducted to determine how relevant freeze-thaw cycles are to the soil parameters. It is since previously known that freeze-thaw cycles can improve aggregate stability, increase soil particle fragmentation which can lead to less soil penetration resistance and even partially return the soil conditions to those prior to compaction, but the process does not extend to layers beyond 40 cm. The field experiment results showed a clear decrease in infiltration rate with increasing number of vehicle passes. There was no clear correlation between bulk density and the number of vehicle passes. This result is attributed to the relatively light weight of the vehicle used as well as the heterogeneity of the soil. The cone penetration measurements showed an increasing resistance with increasing number of vehicle passes for only one of the three measured sites, with the most resistance being measured in a pathway on the green area. The insignificant results of one of the two other sites are attributed to wet weather conditions and unknown underlying material. The HYDRUS 1D simulations showed that a higher sand content mitigates the effects of soil compaction and leads to less runoff. The soil classified as sand (93% sand) had no runoff, the loamy sand (80% sand) had mild runoff. When comparing a sandy loam (60% sand) and a clay soil it is concluded that the sandy loam is more sensitive to soil compaction as more compaction leads to more runoff compared to the non-compacted scenario. The clay soil has little variation between the compaction scenarios but has generally more surface runoff in total. Soil texture therefor affects the surface runoff more than soil compaction. Most amount of runoff was generated by the two hyetographs which had a late peak intensity, most likely due to the soil already being saturated when the peak occurs. The runoff also increases with the return period of the rain event for both the hyetographs and the CDS rain.
76

Growth response and adaptability of acer rubrum and acer XFREEMANII cultivars to soil compaction

Fair, Barbara A. 13 July 2005 (has links)
No description available.
77

Growth and Physiology of Several Urban Tree Species in Soils Disturbed by Construction Fill or Compaction

Day, Susan D. 24 August 1999 (has links)
Experiments were conducted to determine the effects of applying fill soil around existing trees and mechanisms for species tolerance to soil compaction, both common site disturbances in urban forestry. Groups of 22-year-old white oak (Quercus alba) and 13-year-old sweetgum (Liquidambar styraciflua) were subjected to one of three treatments: a control, fill (20 cm of subsoil spread over the root zones), and compacted fill (same as fill soil, but compacted). Additionally, individual trees had tree wells (fill soil pulled away from trunks), or not. After three years, treatments had no consistent effect on tree growth, chlorophyll fluorescence, or soil respiration. However, soil treatments disrupted normal soil moisture patterns at both sites. Roots of white oak grew into fill layers, although overall root growth was not significantly affected by treatment. Sweetgum roots grew very little into fill soils. However, root distribution shifted upward in the original soil under uncompacted fill. Other factors associated with raising the soil grade, such as soil trafficking and root severance, may be largely responsible for the tree decline often attributed to construction fill. Another experiment investigated the relationship between tolerance of wet soils and the ability to grow in compacted soils. It was hypothesized that tree species tolerant of wet soils would have opportunities for root growth in compacted soil when high soil moisture reduced soil strength. Seedlings of flowering dogwood (Cornus florida), a species intolerant of inundation, and silver maple (Acer saccharinum), a bottomland species, were grown in a loam soil maintained at various combinations of soil strength and soil matric potential. In moderately compacted soil (1.5 g cm-3 bulk density), maple seedlings, but not dogwoods, had greater root growth rate, root length per plant, and ratio of root length to root dry weight in the wet soil (0.006 MPa soil matric potential) than in the moist and dry soils (0.026 and 0.06 MPa, respectively). No such effect was detected in highly compacted soil (1.7 g cm-3). It can be concluded that silver maple roots can grow in moderately compacted soil when high soil water content decreases soil strength, whereas dogwood is unable to take advantage of this opportunity. / Ph. D.
78

Tillage System Effects On Upland Cotton Yield and Development In Virginia

Longest, Robert Joseph 18 April 2017 (has links)
Identifying the proper tillage system which provides the best agronomic benefits for cotton production in the coastal plain soils of Virginia was the basis for this research. Strip-tillage was evaluated from 2015-2016 on-farm to determine the effects of annual and biennial treatments on plant growth and lint yield, as well as measuring the impacts on soil compaction. Also, small plot tillage experiments were conducted from 2013-2016 assessing no-till, conventional tillage, minimum tillage, and strip-tillage as well as the subsequent effects of these systems on four cotton varieties. Biennial strip-tillage produced similar lint yields to annual strip-tillage at 3 of 4 locations, with only one location showing a significant difference in lint yield of 135 kg ha-1. Persistence of subsoil tillage within the row from the previous year was observed at some locations and plant heights were not different at all locations, although annual strip-tillage provided deeper potential rooting depths both early season and at harvest. In short term tillage systems, minimal penalties in plant growth and lint yield were observed in no-till verses the other systems, primarily associated with greater soil compaction, shorter plant heights, and lower yields. An overall 8% reduction in yield was found with no-till systems, with no significant differences in yield among tillage systems observed in any year. Varietal effects on plant growth and yield were observed annually, with FM 1944 GLB2 being the shortest plants, and DP 1321 B2RF having the tallest plants. No tillage by variety interaction was observed, supporting the idea that varieties respond similarly across tillage systems. / Master of Science
79

Aplicação da penetrometria na quantificação da compactação do solo / Penetrometer application for soil compaction quantification

Mome Filho, Edison Aparecido 18 July 2012 (has links)
A agricultura moderna sofre grande impacto da mecanização devido ao aumento do tráfego e do peso do maquinário. A cana-de-açúcar (Saccharum officinarum L.) é uma cultura altamente mecanizada e, devido ao tempo de sua permanência no campo, o solo fica muito suscetível à compactação, processo dependente de diversos fatores intrínsecos e extrínsecos deste, podendo ser revertido através de técnicas, como subsolagem ou aração profunda. Porém, tais técnicas geram altos gastos de energia e capital, sendo que alguns manejos, como o controle do tráfego agrícola, contribuem para diminuição da carga exercida sobre o solo e dos custos de produção. Diversos aparelhos foram desenvolvidos para a apuração de atributos do solo diretamente no campo, visando averiguar áreas a serem manejadas por causa da compactação. A penetrometria é uma técnica muito utilizada na verificação de áreas com problemas de compactação, entretanto, existem diversos penetrômetros, que possuem modos de atuação diferenciados. Os objetivos deste estudo foram verificar a eficiência de dois penetrômetros com diferentes modos de introdução da haste metálica no solo (automático e manual) e a correlação dos índices obtidos (resistência à penetração) com outros atributos do solo (teor de água). Os resultados comprovaram que o teor de água no solo altera os resultados de resistência a penetração e a utilização de equações de regressão não linear expressam bem a relação entre estes dois atributos do solo, podendo ser utilizado para correção dos dados antes da comparação de diferentes sistemas de manejo. O ajuste das medições de resistência de acordo com o teor de água no solo diminuiu o intervalo de confiança da média na comparação de diferentes manejos, o que melhora a comparação de atributos que apresentam alta variabilidade, como a resistência do solo a penetração. Os dois métodos de utilização do penetrômetro (Manual e Automático) apresentaram diferenças significativas nas medições, de modo que houve uma tendência das medições manuais superestimarem os valores de resistência. / Modern agriculture has suffered a large impact of mechanization due to increased of traffic and the weight of the machinery. The sugarcane (Saccharum officinarum L.) crop is highly mechanized and, since it is a semi perennial crop, the soil is very susceptible to compaction, a process dependent on a number of intrinsic and extrinsic factors that can be reversed through techniques, such as deep tillage or subsoiling. However, these techniques are expensive, and some crop managements, such as traffic control, contribute to reduction of production costs and the load on the soil. Several devices have been developed for the determination of soil attributes in the field, aiming to determine areas to be managed because of compaction. The penetrometer is a widely used equipment in the verification of areas with compaction problems. However, there are several penetrometers, which have different action mode. The objective of this study was to verify the efficiency of two penetrometers with two modes of introduction of the metal rod into the soil (automatic and manual) and the correlation of obtained data (penetration resistance) with soil water content. Results showed that the soil moisture modify the penetration resistance data and the use of non-linear regression equations express well the relationship between these two soil properties and can be used for correction of the data before comparing different management systems. The modeling of soil resistance measurements with soil moisture decreased confidence interval of the mean in the comparison of different management systems, which improves the comparison of attributes that have high variability, as the soil resistance to penetration. The two penetrometers methods (manual and automatic) showed significant differences in data measurements, showing a tendency for manual measurements overestimate the values of soil resistance.
80

Aplicação da penetrometria na quantificação da compactação do solo / Penetrometer application for soil compaction quantification

Edison Aparecido Mome Filho 18 July 2012 (has links)
A agricultura moderna sofre grande impacto da mecanização devido ao aumento do tráfego e do peso do maquinário. A cana-de-açúcar (Saccharum officinarum L.) é uma cultura altamente mecanizada e, devido ao tempo de sua permanência no campo, o solo fica muito suscetível à compactação, processo dependente de diversos fatores intrínsecos e extrínsecos deste, podendo ser revertido através de técnicas, como subsolagem ou aração profunda. Porém, tais técnicas geram altos gastos de energia e capital, sendo que alguns manejos, como o controle do tráfego agrícola, contribuem para diminuição da carga exercida sobre o solo e dos custos de produção. Diversos aparelhos foram desenvolvidos para a apuração de atributos do solo diretamente no campo, visando averiguar áreas a serem manejadas por causa da compactação. A penetrometria é uma técnica muito utilizada na verificação de áreas com problemas de compactação, entretanto, existem diversos penetrômetros, que possuem modos de atuação diferenciados. Os objetivos deste estudo foram verificar a eficiência de dois penetrômetros com diferentes modos de introdução da haste metálica no solo (automático e manual) e a correlação dos índices obtidos (resistência à penetração) com outros atributos do solo (teor de água). Os resultados comprovaram que o teor de água no solo altera os resultados de resistência a penetração e a utilização de equações de regressão não linear expressam bem a relação entre estes dois atributos do solo, podendo ser utilizado para correção dos dados antes da comparação de diferentes sistemas de manejo. O ajuste das medições de resistência de acordo com o teor de água no solo diminuiu o intervalo de confiança da média na comparação de diferentes manejos, o que melhora a comparação de atributos que apresentam alta variabilidade, como a resistência do solo a penetração. Os dois métodos de utilização do penetrômetro (Manual e Automático) apresentaram diferenças significativas nas medições, de modo que houve uma tendência das medições manuais superestimarem os valores de resistência. / Modern agriculture has suffered a large impact of mechanization due to increased of traffic and the weight of the machinery. The sugarcane (Saccharum officinarum L.) crop is highly mechanized and, since it is a semi perennial crop, the soil is very susceptible to compaction, a process dependent on a number of intrinsic and extrinsic factors that can be reversed through techniques, such as deep tillage or subsoiling. However, these techniques are expensive, and some crop managements, such as traffic control, contribute to reduction of production costs and the load on the soil. Several devices have been developed for the determination of soil attributes in the field, aiming to determine areas to be managed because of compaction. The penetrometer is a widely used equipment in the verification of areas with compaction problems. However, there are several penetrometers, which have different action mode. The objective of this study was to verify the efficiency of two penetrometers with two modes of introduction of the metal rod into the soil (automatic and manual) and the correlation of obtained data (penetration resistance) with soil water content. Results showed that the soil moisture modify the penetration resistance data and the use of non-linear regression equations express well the relationship between these two soil properties and can be used for correction of the data before comparing different management systems. The modeling of soil resistance measurements with soil moisture decreased confidence interval of the mean in the comparison of different management systems, which improves the comparison of attributes that have high variability, as the soil resistance to penetration. The two penetrometers methods (manual and automatic) showed significant differences in data measurements, showing a tendency for manual measurements overestimate the values of soil resistance.

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