ABSTRACT Operational speed influences the soil preparation quality, the first established according to the working set performance and its traction capacity. The experiment's objective is to determine the influence of working speed on energy and operational performance of an agricultural tractor with Full-Powershift transmission when performing a harrowing operation. We conducted the experiment using lines, in a randomized block design. It had four operational soil preparation speeds, with seven repetitions, totaling 28 experimental units. We measured the following parameters per worked area: slipping, engine rotation, specific and per hour fuel consumption, strength, power, and yield on the drawbar and operating speed. Additionally, we analyzed soil profilometry parameters concerning the mobilized area and working thickness. We also evaluated the variance of the collected data and, when significant, submitted it to a regression test. The data showed that higher operating speeds result in greater operational performance and reduction of the energy demand of the mechanized set under study. In addition, this increase doesn't have a beneficial effect on grid fluctuation, not affecting the quality of soil preparation.

ABSTRACT Automatic production management (APM) is a tool that assists in the operations of agricultural tractors, increasing yield and energy efficiency. The objective of the experiment was to compare the energy and operational performance of a 373-kW articulated tractor equipped with APM and manual mode of engine transmission and rotation, across different real-world speeds. The experiment was conducted in a randomized block design with five replicates, using a split-plot arrangement with two system modes (manual and automatic) in the plots and four real-world speeds (4, 6, 8, and 10 km h-1) in the subplots, totaling 40 experimental units. The evaluated variables were: wheel slippage; engine rotation; hourly and specific fuel consumptions; drawbar force, power, and yield; operating speed; and engine thermal efficiency. The variance of the data was analyzed using Tukey’s test for the first factor, and regression analysis for the second factor and interactions. The automatic mode showed lower engine rotation and wheel slippage without compromising the other variables. The use of this mode showed energy advantages at 4 and 6 km h-1 by resulting in less fuel consumption per hour. In addition, the manual mode presented higher thermal efficiency at lower speeds than the automatic mode, which showed a linear increase.

RESUMO O gerenciamento automático de produtividade (APM) presente no trator agrícola é uma ferramenta importante que auxilia na operação, aumentando a eficiência e rendimento energético. O objetivo do experimento foi comparar o desempenho operacional e energético de um trator articulado de 373 kW equipado com APM e com o modo manual da transmissão e rotação do motor, sob diferentes velocidades reais. O experimento foi conduzido no delineamento de blocos casualizados em esquema de parcelas subdivididas, sendo as parcelas constituídas de dois modos de transmissão (manual e automático) e as subparcelas de quatro velocidades reais (4, 6, 8 e 10 km h-1), com cinco repetições, totalizando 40 unidades experimentais. Foram monitorados a patinagem dos rodados, rotação do motor, consumo horário e específico de combustível, força, potência e rendimento na barra de tração, velocidade operacional e eficiência térmica do motor. Os dados coletados foram submetidos à análise de variância, sendo o primeiro fator analisado pelo teste de Tukey, e o segundo fator e as interações por análise de regressão. No modo automático a rotação do motor e a patinagem dos rodados foram menores sem comprometer as demais variáveis. Além disso, este modo, a 4 e 6 km h-1, demonstrou uma vantagem energética, que requer menor consumo de combustível por hora. Além disso, o modo manual apresentou maior eficiência térmica em velocidades mais baixas quando comparado com o modo automático, que apresentou um aumento linear.

RESUMO A qualidade desta operação de preparo do solo pode ser mensurada por equipamentos denominados perfilômetros, fornecendo informações quanto a rugosidade, área mobilizada, empolamento e espessura do solo trabalhada. Porém, trata-se de equipamento antiquado, com elevadas horas de trabalho no campo e escritório. Assim, o objetivo do trabalho foi construir um perfilômetro eletrônico utilizando triangulação a laser e sensores de ultrassom para medição de perfis de solo mobilizados digitalmente. Em seguida, os resultados obtidos foram comparados com os obtidos com um perfilômetro de barra deslizante tradicional para avaliar a precisão e eficiência dos sensores. Para o experimento conduzido em ambiente controlado, adotou-se o delineamento inteiramente casualizado. As variáveis foram mensuradas, sete vezes, através dos três perfilômetros (eletrônico a laser, eletrônico a ultrassom e o tradicional) nos perfis original, elevado e mobilizado do solo. Verificou-se que o perfilômetro eletrônico com ultrassom diferiu na totalidade das mensurações em relação ao perfilômetro convencional, com o sensor a laser apenas na rugosidade modificada. mobilizada trabalhada Porém tratase trata se antiquado escritório Assim digitalmente seguida controlado adotouse adotou casualizado mensuradas vezes original Verificouse Verificou convencional modificada

ABSTRACT The quality of soil tillage can be measured with a specific device called profilometer, which provides information on roughness, mobilized area, blistering, and thickness in disturbed soils. However, it is an outdated device, requiring many hours of field and office work. Thus, the objective of the present work was to develop an electronic profilometer using laser triangulation and ultrasound sensors for measurement of digitally mobilized soil profile. The results obtained were compared to those acquired with a conventional sliding bar profilometer to evaluate the accuracy and efficiency of the sensors. The experiment was conducted in a completely randomized design under a controlled environment. The variables were measured seven times using the three profilometers (laser, ultrasound, and conventional) in the original, elevated, and mobilized soil profiles. The electronic profilometer with ultrasound differed in all the measurements when compared to the conventional profilometer, which differed from the laser sensor only in modified roughness. roughness area blistering soils However Thus profile environment laser, (laser original elevated profiles

ABSTRACT The evaluation of the physical attributes of the soil in cultivated areas is essential for understanding the impacts of agricultural operations, especially those with intense machine traffic. Therefore, the present study aimed to evaluate the physical attributes of the soil submitted to silage with different mechanized sets. A randomized block design was adopted with three treatments: forage harvester with a one-row cutting platform (T1), forage harvester with a three-row cutting platform (T2), and T2 with a forage harvester with a conveyor wagon. Before ensiling and 24 hours after the operation, intact samples of soil classified as Latossolo Vermelhoamarelo álico, intact, were collected to determine the micro, macro, and total porosity, soil density, and volumetric soil water content according to the methodology proposed by the Brazilian Agricultural Research Corporation (Embrapa). After ensiling, the resistance to soil penetration was measured with an electronic manual penetrometer, before and after ensiling, at the A horizon of the soil in the layers of 0.0-0.2 m and 0.2-0.4 m. We analyzed the data by establishing the confidence interval using the t-test at 10% probability. The sets reduce the macroporosity and total porosity of the soil in the 0.0-0.2 m and 0.2-0.4 m soil layers. T2 promoted greater total density in the 0.0–0.2 m layer. The silage increased the resistance to soil penetration to a depth of 0.15 m.

RESUMO A avaliação dos atributos físicos do solo em áreas cultivadas é essencial para a compreensão dos impactos das operações agrícolas, especialmente aquelas com intenso tráfego de máquinas. Sendo assim, o objetivo do trabalho foi avaliar atributos físicos do solo submetido a ensilagem com diferentes conjuntos mecanizados. Adotou-se um arranjo experimental de blocos casualizado com três tratamentos: ensiladora com plataforma de corte de uma linha (T1), ensiladora com plataforma de corte de três linhas (T2) e conjunto ensiladora T2 com carreta de transportadora. Antes da ensilagem e 24 horas após a operação, coletou-se amostras de solo classificado como Latossolo Vermelho-amarelo álico, intactas para determinar a micro, macro e porosidade total, densidade do solo e umidade volumétrica conforme metodologia proposta pela Empresa Brasileira de Pesquisa Agropecuária (Embrapa). Após a ensilagem mediu-se a resistência à penetração do solo com um penetrômetro manual eletrônico, antes e após a ensilagem, no horizonte A do solo nas camadas de 0,0 a 0,2 m e 0,2 a 0,4 m. Analisou-se os dados estabelecendo o intervalo de confiança conforme o teste t, a 10% de probabilidade. Os conjuntos reduzem a macroporosidade e porosidade total do solo, nas camadas de 0,0 a 0,2 m e 0,2 a 0,4 m. T2 propiciou maior densidade total na camada de 0,0 a 0,2 m. A ensilagem aumentou a resistência à penetração do solo até a profundidade de 0,15 m do mesmo.

RESUMO O desempenho do mecanismo dosador de semente é avaliado de acordo com a uniformidade da deposição ao longo da operação e sua interferência na qualidade das sementes. O objetivo do experimento foi avaliar a influência da utilização do grafite, na homogeneidade de deposição e no índice de quebras das sementes de arroz, distribuídas com dosador de fluxo contínuo sob diferentes taxas de exposição do rotor acanalado. As sementes de arroz foram tratadas com 4 g de grafite por quilograma de semente e densidade de semeadura de 100 kg ha-1. O delineamento experimental foi inteiramente casualizado, em fatorial duplo (2 × 5), sendo o primeiro fator o uso do grafite e o segundo a taxa de exposição (20; 40; 60; 80 e 100%) do rotor. A densidade de semeadura e o coeficiente de variação foram coletados por gravimetria, com auxílio de célula de carga. A utilização de grafite como lubrificante sólido diminui os danos mecânicos, no entanto prejudicou a homogeneidade de distribuição das sementes. O aumento da taxa de exposição do rotor interferiu negativamente o coeficiente de variação da distribuição e positivamente sobre o índice de quebras das sementes de arroz, não alterando a densidade de semeadura. Desta forma, o uso do grafite como lubrificante sólido para semeadura de grãos finos distribuídos a partir do rotor canelado torna-se promissor.

ABSTRACT The performance of the seed metering mechanism is evaluated according to the deposition uniformity during its operation and interference in the seed quality. The study aimed to assess the influence of graphite on the deposition homogeneity and the break index of rice seeds, distributed with a constant flow metering device with different exposition rates of the fluted roller. The rice seeds were treated with 4 g of graphite per kilogram and had a sowing density of 100 kg ha-1. The completely randomized design was arranged in a double factorial scheme (2 × 5). The first factor was the use of graphite, and the second was the fluted roller exposition rate (20; 40; 60; 80; and 100%). The sowing density and the coefficient of variation were collected by gravimetry using a load cell. The use of graphite as a solid lubricant decreased the mechanical damage. Nevertheless, it also reduced the homogeneity in seed distribution. The increase of the roller exposition rate negatively interfered with the coefficient of distribution variation and positively with the break index of rice seeds, not influencing the sowing density. In this way, the use of graphite as a solid lubricant for sowing small grains distributed from the fluted rotor becomes promising.

RESUMO A roda do trator agrícola interage diretamente com o solo, afetando seu desempenho energético e operacional. Diversos trabalhos estudam as particularidades entre configurações de rodado buscando interpretar o tipo e arranjo mais eficiente de rodagem, entretanto ainda há uma demanda de estudos que elucidem a tomada de decisão quanto a necessidade da troca do tipo de rodado ou melhoria do arranjo pré-existente. O experimento teve como objetivo avaliar o desempenho energético do trator agrícola quando equipado com rodas radiais simples e diagonais duplas no eixo traseiro, em operação de gradagem intermediária. O experimento em faixas foi conduzido no delineamento de blocos casualizado, nas parcelas dois arranjos de rodados (radiais simples e diagonais duplas) e nas subparcelas quatro velocidades alvo (4, 6, 8 e 10 km h-1), com quatro repetições, totalizando 32 unidades experimentais. Foi monitorado a patinagem dos rodados, rotação do motor, consumo horário e específico de combustível, força, potência e rendimento na barra de tração, velocidade operacional e eficiência térmica do motor. Os dados coletados foram submetidos a análise de variância e, quando significativo, ao teste de Tukey e análise de regressão. Os pneus radiais simples proporcionaram acréscimo da velocidade e força na barra de tração sem acréscimo do consumo de combustível, proporcionando, consequentemente, um incremento no desempenho energético e operacional em operação de gradagem intermediaria.

ABSTRACT The farm tractor wheel interacts directly with the soil, affecting its energy and operational performance. Several works study the particularities between configurations of wheelset seeking to interpret the most efficient type and arrangement of the wheelset. However, there is still a demand for studies that elucidate decision-making regarding changing the type of wheelset or improving the pre-existing arrangement. The experiment aimed to evaluate the energy performance of farm tractors equipped with Single radial and Dual diagonal wheels in rear axle in intermediate harrowing operation. The experiment was conducted in a randomized block design. Two-wheel arrangements (Single radial and Dual diagonal) were used in the blocks, and four target velocities (4, 6, 8, and 10 km h-1), with four replicates in the subblocks, totalizing 32 experimental units. Slip of wheels, engine rotation, hourly and specific fuel consumption, force, power, and efficiency in the drawbar, operational velocity, and engine thermal efficiency were monitored. The data collected were submitted to analysis of variance and, when significant, to the Tukey test and regression analysis. The Single radial tires provided an increase in velocity and drawbar force without increasing fuel consumption, consequently providing an increase in energy and operating performance in intermediate harrowing operation.

RESUMO O estabelecimento de lavouras de grãos no Brasil é um importante processo industrial na cadeia agrícola, exigindo a correta deposição do fertilizante granulado no sulco de semeadura e avaliações mais eficientes, precisas e sustentáveis na operação, que podem ser obtidas com o controle estatístico do processo. Este estudo foi realizado com o objetivo de avaliar o efeito da velocidade angular em diferentes inclinações do mecanismo de dosagem helicoidal sobre a deposição de fertilizante granulado. Uma bancada eletrônica automatizada foi usada para avaliar a qualidade de deposição de fertilizantes granulados considerando diferentes velocidades angulares (1,11, 1,94 e 2,77 m s-1) e inclinações longitudinais e transversais (+15, +7,5, 0, −7,5 e −15°), com dosador helicoidal por transbordamento. Os dados de fluxo foram coletados e submetidos à estatística descritiva e ao controle estatístico do processo. O mecanismo de medição apresentou variações esperadas, com desempenho aceitável sob controle de processo. Os valores de vazão do fertilizante granulado aumentaram com o aumento da velocidade, destacando-se inclinações longitudinais de +7,5 e + 15°, proporcionando maior deposição de fertilizante.

ABSTRACT The establishment of grain crops in Brazil is an important industrial process in the agricultural chain, requiring the correct deposition of granular fertilizer over the sowing furrow and more efficient, precise, and sustainable assessments in the operation, which can be achieved with the statistical process control. This study aimed to assess the effect of the angular velocity on different inclinations of the helical metering mechanism on the granular fertilizer deposition. An automated electronic bench was used to assess the deposition quality of granular fertilizers considering different angular velocities (1.11, 1.94, and 2.77 m s-1) and longitudinal and transverse inclinations (+15, +7.5, 0, −7.5, and −15°), with the helical doser by overflow. Flow data were collected and submitted to descriptive statistics and statistical process control. The metering mechanism showed expected variations, with acceptable performance under process control. The values of the flow rates of the granular fertilizer increased as velocity increased, standing out longitudinal inclinations of +7.5 and +15°, providing higher fertilizer depositions.

ABSTRACT The efficiency of agricultural tractor transmission has been improved over the years, with new concepts such as Continuously Variable Transmission (CVT) and Full Powershift (FPS) evolving in advanced technologies. Both options seek to offer the farmer greater operational results with lower energy expenditure, necessitating studies to assess the effectiveness of these technologies and define the best choice for each purpose. The objective of this work was to evaluate the energy efficiency of two tractors equipped with CVT and FPS transmissions. For this, a strip experiment was conducted in a randomized block design, that analyzed, in addition to CVT and FPS transmissions, target velocities of 4, 6, 8 and 10 km h-1. Operational energy performance parameters were evaluated, such as slippage index, engine rotation, operational velocity, fuel consumption, power available and efficiency on the drawbar, turbo pressure and temperatures of air intake and exhaust gas. Based on the results obtained, the tractor with FPS transmission was more energy efficient in most of the analyzed parameters, requiring 16.31% less in hourly fuel consumption, and providing 16.29% more in the traction bar yield, however, with lower operational velocity compared to the tractor with CVT transmission.

ABSTRACT Uniformity in the deposition of granulated fertilizers in the seed furrow is essential for crop development and productivity. Quantitative (dose and flow) and qualitative factors (segregation and formulation) influence granulated fertilizer distribution throughout its application. This experiment aimed to compare the deposition of two granulated fertilizers with different chemical formulations (04-14-08 and 04-30-10), using the helical overflow metering mechanism at three different operating speeds (4.0, 7.0, and 10.0 km h−1), simulated on an electronic bench. The granulated fertilizers were analyzed for particle size, density, angle of repose, and water content. On the other hand, the deposition data were subjected to descriptive statistics and frequency histograms. The angle of repose and water content did not differ between fertilizers, while the density difference was not significant. The granulated fertilizer 04-30-10 presented the most uniform particle size compared to the granulated fertilizer 04-14-08. The higher particle size uniformity was responsible for a more homogeneous deposition in the seed furrow for the granulated fertilizer 04-30-10 at a speed of 4.0 km h−1, followed by 7.0 km h−1.

RESUMO A introdução de novas tecnologias a bordo das máquinas agrícolas é constante, para maior desempenho energético e eficiência operacional. Recentemente, sistemas de gerenciamento eletrônico são capazes de realizar a seleção da marcha e rotação do motor automaticamente, visando o menor consumo horário de combustível. O objetivo do experimento foi avaliar a eficiência energética e operacional do trator agrícola com gerenciamento automático da transmissão e rotação do motor, submetido a tração de diferentes cargas. O experimento foi conduzido no delineamento de blocos casualizado, em faixas de 50 m, com dois fatores: o sistema de gerenciamento automático da transmissão e rotação do motor (com e sem) e três cargas diferentes aplicadas na barra de tração, com quatro repetições. Os dados coletados foram submetidos a análise de variância e ao teste de Tukey. O sistema de gerenciamento automático da transmissão e rotação do motor proporcionou redução de 20% no patinamento, aumento de 10% na velocidade operacional e economia de 28% no consumo horário de combustível.

HIGHLIGHTS Electronic gear selection and autonomous engine rotation management bring benefits to tractor driving. The electronic management responded positively to the increase in the traction load. The use of electronic management software should be more widespread among farmers and researchers.

RESUMO A eficiência em tração do trator agrícola pode ser maximizada ajustando a massa total e sua distribuição entre os eixos. O objetivo do experimento foi determinar a configuração de distribuição de massa entre eixos e velocidade de deslocamento que proporcione maior eficiência em tração na operação de gradagem. O experimento foi conduzido no delineamento em blocos casualizados no esquema fatorial 2 × 3, com cinco repetições, sendo o primeiro fator duas distribuições de massa entre eixos e o segundo fator três marchas. Os dados coletados foram submetidos à análise de variância e ao teste de Tukey. A condição que maximiza o desempenho do trator corresponde a 39% da massa total no eixo dianteiro e 61% no eixo traseiro, com marcha que proporcione velocidade próxima a 10 km h-1.

ABSTRACT The traction efficiency of the agricultural tractor can be maximized by adjusting the total mass and its distribution between the axles. The experiment’s objective was to determine the configuration of mass distribution between axles and the displacement speed that provides greater traction efficiency in the harrowing operation. A randomized block design in a 2 × 3 factorial scheme with five replications was used. The first factor was two mass distributions between axles, and the second factor was three gears. The collected data were submitted to analysis of variance and the Tukey test. The condition that maximizes the tractor’s performance corresponds to 39% of the total mass on the front axle and 61% on the rear axle, with a gear that provides speed close to 10 km h-1.

ABSTRACT Studies on the longitudinal distribution of seeds in the sowing row seek to improve crop homogeneity, thus generating high productivity. In this context, seed tubes must be analyzed for their angular curvature. Thus, this study aimed to evaluate the influence of the seed tube curvature on the longitudinal distribution of corn and soybean seeds at different speeds. Two experiments were conducted completely randomized in a double factorial design. The first factor consisted of the seed tube curvature (straight and curved) and the second factor consisted of sowing speeds (1.11, 1.39, and 1.67 m s−1 for corn and 1.39, 1.67, 1.94, and 2.22 m s−1 for soybean), with five replications. The parameters analyzed to measure the longitudinal distribution were the number of seeds per meter, average spacing, double, flawed, and acceptable spacings, coefficient of variation, and precision index. The results were subjected to normality and homogeneity tests of residuals, followed by an analysis of variance and Tukey test, when significant. The curved seed tube showed the highest efficiency in the measured parameters for both corn and soybean. The increase in sowing speed had a negative influence on the evaluated parameters, especially in the soybean crop.

ABSTRACT The technological innovation in agriculture seeks to improve the performance of mechanized assemblies and, currently, rubber half-tracks are a valuable solution for agricultural tractors, combining traction performance and less soil compaction. The objective of the experiment was to evaluate the operational and energy performance of double wheeled versus rubber half-tracked agricultural tractors in the soybean sowing. The experiment was conducted in a strip-plot design with a double factorial arrangement (2×3). The first factor consisted of a tractor with double wheels on the front and rear axles versus a tractor with single wheels on the front axle and rubber half-tracks on the rear axle, while the second factor consisted of three different gears, with five replications, totaling 30 experimental units. The collected data were subjected to analysis of variance and, when significant, to the Tukey test. The sowing operation carried out with the half-tracked tractor was the most efficient in most of the analyzed parameters, allowing higher operational and energy efficiency in the soybean sowing.

RESUMO A resistência à penetração do solo (RSP) é empregada como indicadora da compactação, por estar relacionada a importantes atributos do solo e das plantas, e por ser uma medida de fácil obtenção. Sua determinação com o uso do penetrômetro orienta para as melhores estratégias de manejo do solo, favorecendo assim o desenvolvimento das culturas. O objetivo deste estudo foi desenvolver e validar o penetrômetro eletrônico de acionamento hidráulico georreferenciado, facilitando a obtenção da RSP. Para tanto foram realizadas 36 leituras de 0 a 0,60 m de profundidade da RSP com os penetrômetros manual e hidráulico em duas áreas. Os resultados de RSP foram analisados estabelecendo-se os intervalos de confiança pelo teste t (p ≤ 0,10), a cada 0,05 m de profundidade, e o georreferenciamento através da raiz do erro quadrático médio (RSME). Constatou-se que ambos penetrômetros apresentaram similaridade na mensuração da RSP e do georreferenciamento dos pontos.

ABSTRACT Soil penetration resistance (SPR) is used as an indicator of compaction, as it is related to important soil and plant attributes and is an easily obtainable measure. Its determination with the use of the penetrometer guides to the best soil management strategies, thus favoring crop development. The objective of this study was to develop and validate the georeferenced hydraulic driven electronic penetrometer, making it easier to obtain SPR. For this, 36 SPR readings from 0 to 0.60 m depth were performed with the manual and hydraulic penetrometers in two areas. The SPR results were analyzed by establishing the confidence intervals by the t-test (p ≤ 0.10) at each 0.05 m depth and the georeferencing was analyzed through the root mean square error (RMSE). It was found that both penetrometers showed similarity in SPR measurement and in the georeferencing of the points.

ABSTRACT The hydraulic remote control system allows the transfer of energy from the engine through a flow of hydraulic oil to engines and implements pulled by agricultural tractors, which can interfere with its energy and operational performance. This study aimed to evaluate the interference of the number of remote control valves in use on the operational and energy performance of an agricultural tractor, using a productivity management system. The experiment was conducted in a strip-plot design, with five replications and three treatments, which consisted of the number of remote control valves in use (1, 2, or 3), totaling 15 experimental units. The results were subjected to normality and homogeneity tests and analysis of variance, followed by the Tukey test when it was significant. The highest number of valves in use interfered with the operational speed, power and efficiency on the drawbar, specific fuel consumption, and engine thermal efficiency, thus reducing the energy and operational performance of the agricultural tractor.