ABSTRACT Bean is among the most consumed and produced crops in Brazil. Given the high demand for food, the search for technologies and controllers to increase the efficiency of agricultural systems has grown. This study aimed to model artificial neural network (ANN) architectures to predict mechanical efficiencies in the semi-mechanized bean harvest. We used a multilayer perceptron network with three inputs (harvest moisture, threshing rotor rotation, and feed rate), two hidden layers of neurons, and one output (efficiency). We evaluated the efficiency in the header, separation on the threshing rotor, cleaning of sieves, and the total efficiency of the machine. ANN was processed by a scripted algorithm to model the network, alternate the number of neurons in hidden layers, as well as to select, test, and validate ANN with less error. ANN was validated by comparing its results with the experimental data. The architectures selected to predict efficiencies were 3-8-15-1 for the header, 3-9-7-1 for the thresher and separation, 3-5-11-1 for cleaning, and 3-15-10-1 for the total operation. ANN predicted satisfactory results with errors below 1% and a high hit rate, thus being valid to predict the efficiencies in the semi-mechanized bean harvest.

ABSTRACT Machinery traffic intensification has been recurrent in intensive agriculture in annual crops, which may lead to structural soil degradation and, consequently, a reduction of its productive capacity. Therefore, this study aimed to assess the influence of tractor traffic intensification on soil physical attributes and soybean yield components. The study was performed in an Oxisol under no-tillage for 10 years, using a randomized block design with five tractor traffic intensities (0, 2, 4, 6, 8, and 12 passes) and five replications. Density, porosity, macroporosity, microporosity, and penetration resistance were assessed in the soil and stem diameter, number of pods per plant, number of grains per pod, grain weight per plant, thousand-grain weight, and grain yield were assessed in the soybean crop. Tractor traffic intensification changed soil physical attributes, which were not limiting factors to soybean yield under the no-tillage system, providing higher stem diameter, number of pods per plant, grain weight per plant, and grain yield after 12 passes.

Práticas de manejo e semeadura mal conduzidas podem comprometer o meio ambiente e a rentabilidade da atividade agrícola. O objetivo deste trabalho foi estudar a ação de mecanismos sulcadores e a pressão da roda compactadora de uma semeadora-adubadora em plantio direto, na resistência de um Latossolo Vermelho distroférrico à penetração (RP), durante a semeadura da soja, sob três teores de água do solo. O experimento foi desenvolvido em esquema de blocos casualizados, arranjado em esquema de parcelas subsubdivididas, sendo as parcelas constituídas de três teores de água do solo (23,8; 25,5 e 27,5% b.s.), as subparcelas de dois mecanismos sulcadores (discos duplos e haste sulcadora) e as subsubparcelas de três pressões da roda compactadora (12,2; 18,5 e 24,1 kPa), com três repetições. O teor de água do solo promoveu diferença na RP com a profundidade, no leito de semeadura, independentemente do sulcador e da pressão da roda compactadora. O uso de haste sulcadora proporcionou menor RP comparada com o sulcador disco duplo, no leito de semeadura, independentemente do teor de água e da pressão da roda compactadora. A pressão aplicada pela roda compactadora de 18,5 kPa proporcionou as menores resistências do solo à penetração, quando a haste sulcadora foi usado. A RP foi menor na linha de semeadura do que na entrefileiras, até 20 cm de profundidade.

If inappropriately conducted, management and sowing practices may compromise the environment and the profitability of the agricultural activity. The aim of this study was to analyze the furrow opener mechanisms action and the level of load applied to soil firming mechanism in no-till, on the Oxisol resistance to penetration during soybean sowing, under three soil moistures. The experiment was arranged in split-split plot design, in which the plots were composed by three soil moistures (23.8; 25.5 and 27.5% b.s.), two furrow opener mechanisms sub-plots (double disks and furrow plough) and the split-split plot of three levels of load applied to soil firming mechanism (12.2; 18.5 and 24.1 kPa), according to randomized blocks design, with three replications. The soil moisture provided different resistance behavior to penetration with the depth, on the seedbed, independently of the furrow opener and the level of load applied to soil firming mechanism. The furrow plough use provided less soil resistance to penetration when compared to the double disk furrow opener, on the seedbed, independently of the soil moisture and the level of load applied to soil firming mechanism. The pressure applied by soil firming mechanism of 18.5 kPa provided the lower resistance to penetration, when the furrow plough was used. The soil resistance to penetration was less on the sowing line than on between rows, with 20 cm deep.

Este trabalho teve por objetivo avaliar as qualidades física e fisiológica de sementes de feijão-carioca Iapar 81, colhidas em sistema semimecanizado, utilizando-se de colhedora autopropelida. Foi avaliada a influência da velocidade de deslocamento (6,5; 8,8; 10,2 e 10,8 km h-1), da rotação do cilindro trilhador (430 e 480 rpm) e do efeito latente dos danos mecânicos durante o armazenamento das sementes (0; 60; 120 e 180 dias). Foram determinados a impureza, o índice de danos mecânicos, o vigor e a germinação das sementes. O efeito latente dos danos mecânicos foi avaliado pelo teste de vigor, pela germinação e pela condutividade elétrica. Os menores valores de impureza foram obtidos nas velocidades de 10,2 e 10,8 km h-1 e na rotação do cilindro trilhador de 430 rpm, enquanto não houve efeito da velocidade quando foram usados 480 rpm no cilindro trilhador. Os maiores valores de dano mecânico visível, vigor e germinação foram obtidos nas velocidades de 8,8; 9,9 e 9,2 km h-1, respectivamente. O menor valor de condutividade elétrica da solução de embebição das sementes de feijão foi obtido na velocidade de 7,7 km h-1, independentemente da rotação do cilindro trilhador. Trabalhando com rotação de 480 rpm no cilindro trilhador, obtiveram-se os menores valores de percentagem de impurezas, vigor e germinação, e maiores valores de dano mecânico e condutividade elétrica. O período de armazenamento por 180 dias não provocou queda na germinação e no vigor.

The objective of this work was to analyze the physic and physiologic quality of bean seeds. The bean seeds variety was the Iapar 81. The system of harvesting used was the semi-mechanized. The seeds were harvested by a combine, model Axial Flow 2388. The quality analysis that considered the influence of four operation speeds (6.5; 8.8; 10.2 and 10.8 km h-1), two threshing cylinder velocity (430 and 480 rpm) and latent effect of mechanical damages during seeds storage (0; 60; 120 and 180 days) was studied. The impurity content, the mechanical damage, the electrical conductivity, the vigor and the seed germination were determined. The smallest values of impurity content were obtained in the displacement speeds of 10.2 and 10.8 km h-1, on the threshing cylinder velocity of 430 rpm, while there was not any effect of the speed when 480 rpm was used. The largest values of mechanical damage, vigor and germination were obtained in the displacement speeds of 8.8; 9.9 and 9.2 km h-1, respectively. The smallest value of electric conductivity was obtained in the speed of 7.7 km h-1, regardless of the threshing cylinder velocity. By working with 480 rpm on the threshing cylinder velocity it was obtained the smallest values impurities content, vigor and germination, and larger values of mechanical damage and electric conductivity. The seed vigor and germination did not decrease with the storage time of 180 days.

Neste estudo, desenvolveu-se um modelo de simulação para analisar a dinâmica de um sistema a fim de controlar automaticamente a altura de corte em colhedoras. Este modelo foi implementado com base nas equações diferenciais, que descrevem a dinâmica da plataforma de corte, o comportamento do sistema hidráulico e o controlador. O sistema de controle realimentado simulado foi constituído de uma célula de carga, destinada a medir a força de contato entre o solo e o mecanismo de corte, um controlador PID e um sistema hidráulico de atuação, composto de uma válvula proporcional direcional de quatro vias e um atuador. Analisou-se a influência da velocidade de deslocamento da máquina (1,0, 1,5 e 2,0 m s-1), da pressão de suprimento do sistema hidráulico (6,8, 13,7 e 20,6 MPa), da massa da plataforma (40, 60 e 80 kg) e da força de contato de referência do controlador (200, 400 e 800 N) no desempenho do sistema de controle. Os aumentos na pressão de suprimento, massa da plataforma e força de referência, proporcionaram melhores condições para o funcionamento do sistema de controle proposto.

A simulation model to analyze the dynamics of a system to control automatically the cutting height in harvesters was developed. The model was developed using the differential equations that describe the dynamics of the cuttig platform, the behavior of the hydraulic system and the controller. The simulated feedback control system was composed by a load cell that measures the contact force between the soil and the cutting device, a feedback controller (PID) and a hydraulic system with proportional directional four-way valve and actuator. The effect of the following variables in the controller performance was analyzed: speed of the cutting device (1.0, 1.5 and 2.0 m s-1); pressure in the supply line of the hydraulic system (6.8, 13.7 and 20.6 MPa); ballast added in the cutting mechanism (40, 60 and 80 kg) and the contact force between the cutting device and the soil (200, 400 and 800 N). The developed model showed to be a useful tool for analyzing the dynamics of the controller. The increase in the supply pressure, mass of the cut platform and reference force provided better performance of the control system.