This study aimed to evaluate the effect of penetration rate and the size of the cone base on the resistance to penetration under different soil moistures and soil bulk density. The experimental design was completely randomized in a 4x2x2x2 factorial arrangement, with the factors, soil bulk density of 1.0; 1.2; 1.4 and 1.6 Mg m , penetration rates of 0.166 and 30 mm s -1 and areas of the cone base of 10.98 and 129.28 mm 2 resulting in 32 treatments with 8 replicates. To ensure greater uniformity and similarity to field conditions, samples passed through cycles of wetting and drying. Only the interaction of the four factors was not significant. Resistance values varied with the density of the soil, regardless of moisture and penetration rate. Soil penetration resistance was influenced by the size of the cone base, with higher values for the smallest base independent of moisture and soil bulk density. The relationship between resistance to penetration and moisture is not always linear, once it is influenced by soil bulk density. Reduction in the area of the cone leads to an increase in the soil resistance to penetration.Key words: soil bulk density, soil moisture, methodology.Resistência do solo à penetração em função da velocidade de penetração, tamanho da base do cone e diferentes condições do solo , resultando em 32 tratamentos com oito repetições. Visando dar maior uniformidade e maior semelhança às condições de campo, as amostras passaram por ciclos de umedecimento e secagem. Apenas a interação dos quatro fatores não foi significativa. Os valores de resistência variaram com a densidade do solo, independentemente da umidade e da velocidade de penetração. A resistência do solo à penetração foi influenciada pelo tamanho da base do cone, com a menor base apresentando os maiores valores, independentemente da umidade e da densidade do solo. A relação entre resistência do solo à penetração e umidade nem sempre é linear, pois é influenciada pelo valor da densidade do solo. A diminuição do tamanho da base do cone provoca incremento no valor da resistência do solo à penetração.Palavras-chave: densidade do solo, umidade do solo, metodologia.

While the pre-harvest sugarcane burning is a disused practice, green harvest requires changes concerning ratoon cultivation due to the presence of a thick layer of straw. The experiment, conducted in a mechanical green harvesting area cultivated with sugarcane, consisted of two stages: in the first stage, the mechanical straw cutting performance of flat disks with different geometry edges was evaluated, considering two types of disks and 10 replications in a completely randomized design; in the second stage, the effect of soil chiseling on both sides of planting lines, using shanks with straw cutting flat disks, was assessed, as well as fertilizer deposition form. The experimental design in the second stage was completely randomized, with seven treatments and five replications. Treatments consisted of a combination of two straw cutting disks (smooth or toothed edge), chiseling presence or absence, and fertilizer deposition forms (broadcast, on the planting line, and incorporated into chiseling furrows). The toothed disk differed from the smooth one, presenting lower values of horizontal and vertical forces, and torque. The agroindustrial variables pol (%), brix (%), fiber (%), and ATR (kg Mg -1 ) were not influenced by the fertilizer deposition form and soil chiseling. However, the localized fertilizer deposition increased crop yield when compared with broadcast fertilization. KEYWORDS:Saccharum officinarum, cutting disk, mulching. ESCARIFICAÇÃO DO SOLO E LOCALIZAÇÃO DO FERTILIZANTE NO CULTIVO DA SOQUEIRA DE CANA-DE-AÇÚCAR RESUMO:A colheita da cana-de-açúcar com queima é prática em desuso, e a de cana crua está exigindo mudanças na forma de cultivo da soqueira devido à presença da espessa camada de palha. O experimento, desenvolvido em área de colheita mecanizada de cana-de-açúcar sem queima, constou de duas etapas: na primeira, avaliou-se o desempenho mecânico de discos planos de corte de palha com geometria de bordas diferentes, considerando dois modelos de discos e 10 repetições sob delineamento inteiramente casualizado. A segunda etapa do experimento teve como objetivo avaliar o efeito da escarificação do solo em ambos os lados das fileiras de plantas, por meio de hastes, munidas de discos planos de corte de palha e da forma de deposição do fertilizante. O delineamento experimental adotado na segunda etapa foi o inteiramente casualizado, com sete tratamentos e cinco repetições. Os tratamentos foram compostos da combinação dos dois modelos diferentes de discos para corte da palha (borda lisa ou dentada), presença ou ausência de escarificação e formas de deposição de fertilizante (a lanço, sobre a fileira e incorporado no sulco de escarificação). Os valores das forças horizontal, vertical e do torque exigidos pelo disco de corte de palha dentado foram inferiores ao do disco liso. As variáveis agroindustriais pol (%), °brix (%), fibra (%) e ATR (kg Mg -1 ) não foram influenciadas pela forma de deposição do fertilizante e escarificação. No entanto, a deposição do fertilizante de forma localizada propor...

ABSTRACT:The aim of this study was to develop a an automated bench top electronic penetrometer (ABEP) that allows performing tests with high rate of data acquisition (up to 19,600 Hz) and with variation of the displacement velocity and of the base area of cone penetration. The mechanical components of the ABEP are: a supporting structure, stepper motor, velocity reducer, double nut ball screw and six penetration probes. The electronic components of ABEP are: a "driver" to control rotation and displacement, power supply, three load cells, two software programs for running and storing data, and a data acquisition module. This penetrometer presented in compact size, portable and in 32 validation tests it proved easy to operate, and showed high resolution, high velocity in reliability in data collection. During the validation tests the equipment met the objectives, because the test results showed that the ABEP could use different sizes of cones, allowed work at different velocities, showed for velocity and displacement, were only 1.3% and 0.7%, respectively, at the highest velocity (30 mm s-1) and 1% and 0.9%, respectively for the lowest velocity (0.1 mm s-1).KEYWORDS: soil compaction, soil resistance to penetration, velocity test, cone index. DESENVOLVIMENTO DE UM PENETROGRAFO ELETRÔNICO AUTOMÁTICO DE BANCADA RESUMO:O objetivo deste trabalho foi desenvolver um penetrógrafo eletrônico automático de bancada (PEAB) que permita realizar ensaios com alta taxa de aquisição de dados (até 19.600 Hz) e com variação da velocidade de deslocamento e da área da base do cone de penetração. Os componentes mecânicos do PEAB são uma estrutura de sustentação; motor de passo; redutor de velocidade; fuso de esferas com castanha dupla e seis sondas de penetração. Os componentes eletroeletrônicos que fazem parte do PEAB são um "driver", para controle de rotação e deslocamento; fonte de alimentação; três células de carga; dois softwares para execução e armazenamento de dados, e um módulo de obtenção de dados. O penetrógrafo apresentou tamanho compacto, portabilidade e, em 32 ensaios de validação, mostrou-se de fácil operação, elevada resolução, rapidez e confiabilidade na obtenção dos dados. O equipamento atendeu aos objetivos propostos, pois os resultados dos ensaios permitiram observar que o PEAB comporta diferentes tamanhos de cone e possibilitou trabalhar com diferentes velocidades, sendo as incertezas para velocidade e deslocamento, respectivamente, de apenas 1,3% e 0,7% na velocidade mais alta (30 mm s-1) e de 1% e 0,9% na velocidade mais baixa (0,1 mm s-1).

The genus Amaranthus comprises several species of the Amaranthaceae family whose leaves and seeds are regularly consumed as food by populations in several countries, among which Brazil is not yet included. The objective of this work was to evaluate the productive potential of amaranth (Amaranthus cruentus cv. BRS Alegria) as a function of different seasons and sowing densities in succession to the soybean crop in the region of Lucas do Rio Verde, MT. The experimental design was a randomized complete block design, with four replications, in a 5x4 factorial scheme. The first factor refers to the five sowing seasons (16/02/2013; 26/02/2013; 05/03/2013; 20/03/2013 and 05/04/2013) and the second factor the four sowing densities (11.4, 20.0, 28.5 and 37.1 ppt m-2). The evaluated characteristics were: plant height (AP, in meters); stem diameter (DC, in millimeters); panicle length (CP, in millimeters); dry panicle mass (MSP, in g); dry mass of stalk (MSC, in g); sheet dry mass (MSF, in g); total dry mass (MST, in g); final population of plants (POP, in plants ha-1); productivity (PROD, in kg ha-1). The experimental data were submitted to analysis of variance and when means were significant the Tukey test to was utilized to compare the means. There was significant difference (p>0.05) in sowing density between the seasons, thus validating the variation of the desired sowing density between the seasons. The obtained real population and the different seasons of sowing were adopted as sources of variation of the other evaluated attributes. The later sows determined a longer time interval between sowing and panicle emission, as well as harvesting. The cumulative precipitation until the panicle and harvesting emission showed a great reduction as a function of the planting times. It is concluded that the productivity of the Amaranth crop is influenced directly by the number of plants per square meter and by the sowing season in succession the soybean crop.

Vegetable species, capable of diversifying production in the second crop of the Cerrado, producing grains rich in protein and providing dry matter for off-season, are most welcome. The amaranth presents these characteristics, however its cultivation is little known in Brazil. The adequate availability of nutrients for this plant, under cerrado conditions, has not yet been defined and these soils, in turn, are of low natural fertility, deficient, mainly, in phosphorus. Before this senary, the present work was developed with the objective of evaluating agronomic and productive aspects of amaranth cv. BRS Alegria, cultivated in succession to soybean, underwent increasing doses of Pittelkow et al.; JEAI, 39(4): 1-9, 2019; Article no.JEAI.49828 Original Research Article