Comportamento operacional de associações entre sulcadores e discos de corte para sistema de semeadura direta

Abstract

RESUMO:O objetivo foi avaliar o desempenho operacional quanto ao requerimento de tração, consumo energético e eficiência de trabalho de associações entre eleme ntos de corte dos resíduos culturais e de rompedores do solo, em função da velocidade de deslocamento. Este trabalho foi realizado em propriedade agrícola situada no município de Santa Maria (RS), em solo classificado como Argissolo Vermelho e textura francoarenosa. O experimento foi composto por 24 combinações de tratamentos, em um esquema fatorial de 2x3x4. Estes foram obtidos pela interação dos fatores sulcadores (haste e disco), discos de corte (sem disco, liso e ondulado) e velocidades (1,11; 1,67; 2,22 e 2,78 m s -1 ). Os dados de desempenho do trator foram adquiridos com a utilização de instrumentação eletrônica. As associações entre sulcador e disco apresentaram melhor desempenho nas velocidades de 1,11 e 1,67 m s -1 por exigirem menor força de tração e consumo de combustível. Além disso, o uso de discos permitiu uma redução da ampliação da força de tração quando a velocidade passou de 1,11 para 2,78 m s -1 . A haste exigiu maior demanda de tração do que os discos desencontrados, e ambos, ao serem comb inados com os discos de corte, tiveram suas demandas aumentadas. Outrossim, a mobilização do solo não foi influenciada pela velocidade. PALAVRAS-CHAVE:Semeadora-adubadora, Relação máquina-solo, Ensaio de máquinas agrícolas, Haste sulcadora, Discos duplos desencontrados, Mecanismo de corte. OPERATING PERFORMANCE OF FURROWERS AND CUTTING DISKS ASSOCIATION FOR NO-TILLAGE SYSTEM ABSTRACT:The objective was to evaluate tractor operating performance regarding traction application, energy consumption and work ing efficiency in association of crop residue cutting implements and soil breakers as the travelling speed. Experiment was performed at a farm in Sa nta Maria (RS ), Brazil. Local soil was classified as Red Ultisol with sandy loam texture. The experiment consisted of 24 treatment combinations in a 2x3x4 factorial scheme. The combinations were composed by interactions furrowers (furrow opener fixed and rotary), cutting disks (without disk, plain disk, and undulating disk) and travelling speeds (1.11, 1.67, 2.22 and 2.78 m s -1 ). Tractor performance data were acquired through electronic instrumentation. Furrower and cutting disk association had improved performance at speeds of 1.11 and 1.67 m s -1 for requiring less traction and fuel consumption. Furthermore, disks reduced required traction at speed range of 1.11 to 2.78 m s -1 . On the other hand, furrow opener device demanded higher tractions than mismatched disks; and both of them combined with cutting disks had increased demand too. Likewise, soil mobilization soil was not influenced by speed.

Disturbance of Ultisol soil based on interactions between furrow openers and coulters for the no-tillage system

“…Cepik et al (2005), when evaluating the volume of soil disturbance by a row crop planter with five lines, fitted with hoe openers, according to the speed, found a mean value of 121.80 and 135.90 m³/ha, showing a 12% increase when sowing speed went from 1.25 m/s to 1.81 m/s. However, Bellé et al (2014) and Gassen et al (2014), when evaluating hoe openers for soil scarification, and Francetto et al (2015), when analyzing furrowers of planters, found no influence of increased speed on soil mobilization.…”

Specific demands to the traction of cutting discs and furrow openers for the no-tillage system

“…When associated to the smooth disc coulter, the demand was kept constant, presenting an average value of 19.01 kN m -1 . When integrated to the offset fluted coulter, the highest speeds provided a significantly higher requirement than the lowest ones, going from 19.26 kN m -1 to 24.80 kN m -1 , which can be related to the greatest contact area with the soil enabled by this mechanism, so there is a larger area of mobilized soil, demanding greater tractive force (Francetto et al, 2015). This condition was also evidenced when associated to the doubledisc furrow opener, with an initial value of 18.46 kN m -1 in the speed of 1.11 m s -1 to 28.16 kN m -1 in the speed of 2.78 m s -1 .…”

“…Thus, the use of cutting discs associated to the hoe opener provided a decrease in the Reo extension, while when associated with double-disc causes the increase of this extension, especially for the condition with the smooth disc. This fact can be explained because the use of cutting discs associated to the hoe opener provides a reduction in the increment of traction demand and maintenance of the soil mobilization with the increment of travel speed, according to Francetto et al (2015). The mathematical function that describes the performance of the associations regarding the specific operational resistance according to the speed, the measurement of the proximity degree (R²) and its first derivative, besides the inclination of the line of the derivative function in relation to axis y, are shown on Table 4.…”

“…The energy requirements of soil preparation operations depend on the type of soil and the handling it has previously experienced. In addition, Andreolla and Gabriel Filho (2006), Mak, Chen and Sadek (2012) and Francetto et al (2015), concluded that the tractive force is also influenced by the type of trenching mechanism employed in the seeder, as well as the soil physical conditions, as it is affirmed by Conte et al (2011) and Seidi (2012), and by the work depth Munkholm;Nyord, 2013). These factors are very important, especially with the use of the no-tillage system (Altikat;Celik;Gozubuyuk, 2013), considering that, according to Francetto (2014), they are the ones that determine the choice of association between the cutting mechanisms of the crop residues and the opening of a furrow.…”

Força De Tração E Potência Demandada Por Mecanismos De Corte E Sulcadores De Semeadora-Adubadora

“…Desta forma, o requerimento do primeiro foi 24,49% maior que o do segundo, sendo causado principalmente por uma maior profundidade de atuação deste sulcador, o que acarreta uma elevação na necessidade de energia para suprir o maior atrito gerado entre a ferramenta e o solo. Os resultados estão de acordo com os encontrados por Andreolla e Gabriel Filho (2006), Seki, Benez e Silva (2012) e Francetto et al (2015).…”