The operational performance of the agricultural tractor can be increased by adjusting parameters such as tire inflation pressure, axle mass distribution and gauge opening, which is a very divergent factor in controlled-traffic production. The objective of the experiment was to measure the energy performance of a 93 kW agricultural tractor in intermediate grading operation in two slopes (flat and sloping) and three gauge configurations (closed, intermediate and open) in mobilized soil. Energy performance was determined from the following parameters: slip, engine speed, actual effective speed, hourly and specific fuel consumption; strength, power and performance on the drawbar. Turbo pressure and temperature monitoring was also performed at six different engine points. The experiment was conducted in double factorial arrangement (2 slopes and 3 gauges), with four replications, totaling 24 plots. Data were analyzed for normality and homoscedasticity of the residues, after ANOVA and when significant, the means test. Tilts and tire gauges did not differ statistically, so it can be concluded that depending on the operation do not interfere with operating performance.

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.

The success of the application of granular fertilizers (GFs) in planting rows depends on the uniformity and performance of product dispensing systems, which are influenced by external factors. The objective of this study was to determine the outflow rates of two GF formulations (GF1 04-14-08 and GF2 04-30-10) using three types of fertilizer spreader—with one spiral roller (A), two spiral rollers (B), or a fluted roller (C)—and three operating speeds (1,11, 1.94, and 2.77 m s-1). The following parameters were determined in GFs: density, angle of repose, water content, and segregation (particle size). In the designed test bench, GFs were transferred from a reservoir to a spreader, and ultimately to a container, where they were weighed, and data were transmitted to the data acquisition system (DAS). A total of 7,560 outflow data points were collected (g s-1) and subjected to descriptive analysis of measures of central tendency, dispersion, asymmetry, and kurtosis, and Shewhart control charts were generated. Particle density and segregation were significantly different between the GFs, whereas the angle of repose and water content were not significantly different. The bench design and the DAS allowed measuring the outflow of GFs in different spreaders and demonstrated that this parameter was influenced by particle segregation. The segregation of GF1 was higher than that of GF2. The outflow variability at the speed of 1.11 m s-1 was lower, and the spreader with a fluted roller had the highest uniformity and was the most suitable for application with variable rates.

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.

The decision-making capability of the machine to harvest grains must consider a lower fuel consumption with a higher operating velocity allied to a greater performance of the grain cleaning system, along with lower rates of the damage and waste produced. This study aimed at evaluating the operational performance and the energy efficiency of two axial harvesters, having different trail and separation systems in the soybean seed harvest. The experiment was carried out in a completely randomized block design in 500-m bands, consisting of two factors, namely two axial harvesters (single and double rotor) and six target velocities (3, 4, 5, 6, 7, and 8 km h-1). Regarding the operational energy performance, the hourly fuel consumption, operational speed, operational field capacity, fuel consumption per area and mass of the harvested grain, and the handling capacity of the harvest were evaluated. The harvesting performance parameters, such as the percentage losses in the platform and the trail system, broken grains, impurities, and the pods, which did not undergo threshing, were evaluated. The results obtained showed that the single-rotor harvester had a better energy efficiency, while the double-rotor harvester had a better operational performance. The double-rotor harvester was agronomically more efficient.

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.

An adjustment of the agricultural tractor is necessary to achieve energy efficiency, which can be done through the correct distribution of mass between the axles for each operating surface. This research evaluated different distributions of mass between axles in a 93 kW tractor equipped with auxiliary front-wheel drive, on two soil surfaces. The experiment was carried out in strip design, with a double factorial scheme (2 x 3), with two soil surfaces (mobilized and firm) and three mass distributions between axes (35/65%, 40/60% and 45/55%), with five repetitions, totaling 30 parcels. The slippage parameters of the front and rear wheelset, engine rotation, hourly and specific fuel consumption, force, power and yield on the drawbar, displacement speed, engine thermal efficiency, traction coefficient, rolling resistance, and yield in traction. On firm soil, the energy performance of the tractor was superior in relation to the mobilized one, which allowed greater tractor and drawbar performance with lower specific fuel consumption. The use of a 35/65% between-axle mass distribution provided maximum traction for the mechanized set, resulting from the reduction in energy expenditure generated by skating and; consequently, the maximum use of the energy made available by the mechanized set. However, the maximum conversion of energy contained in the working fuel is obtained with the 45/55% setting.

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.