ABSTRACT The quality of the basal cut of sugarcane during harvest can affect the longevity of the crop, and the cutting tool is one of the main causes of damage during harvesting. The aim of this study was to evaluate the performance of two cutting tools: an impact cutting system (ICS) using knives and a continuous cutting system (CCS) using saws. Laboratory tests were carried out to obtain the stalk damage index at different device travel speeds and to determine the invisible losses caused by each cutting system. The results showed that both cutting systems presented acceptable levels for the stalk damage index; however, the CCS obtained better cut quality, corresponding with decreased general damage. The invisible losses caused by the cutting tools in relation to the total harvested mass were 0.52% and 0.54% for the CCS and ICS, respectively. The highest invisible losses were obtained at speeds of 2, 3, and 4 km h-1 for the ICS, showing a statistical difference in relation to the CCS. No statistical difference was noted for both the systems at 5 and 6 km h-1.

RESUMOA descompactação do solo pode ser realizada de diversas formas dentre as quais a mais comum no meio agrícola é a realização da operação de subsolagem. Com a evolução dos equipamentos e a eletrônica embarcada tem-se a possibilidade de variar a profundidade do subsolador e realizar a descompactação de modo otimizado. O presente trabalho objetivou estimar o gasto energético de um subsolador operando em diferentes tamanhos de áreas e em profundidades variáveis de subsolagem. Foram utilizados um trator 4 x 2 (TDA) e um subsolador de cinco hastes sendo este todo instrumentado com equipamentos que possibilitaram as análises de consumo horário de combustível, consumo operacional de combustível, patinagem, velocidade média, capacidade de campo efetiva, força média na barra de tração e potência média na barra de tração. A partir dos resultados obtidos no campo foram simulados, em uma planilha eletrônica, diferentes tamanhos de áreas, sendo o subsolador operando em profundidade fixa (PF) e variável (PV). Constatou-se que a economia de tempo de trabalho com (PV) em relação à (PF) variou de 1,85 a 6,34%. Houve redução no consumo de combustível de 6,42 a 25,69%, utilizando-se (PV) em relação à (PF).

ABSTRACTSoil decompression can be performed in several ways, the most common in the agricultural activities is the subsoiling. With the evolution of the embedded devices and electronics it is possible to vary the depth of the subsoiler and to perform decompression in an optimized way. The present study aimed to estimate the energy expenditure of a subsoiler operating in areas of different sizes and varying depths of subsoiling. A tractor 4x2 (FWA) and a subsoiler with five rods instrumented with equipment was used which enabled the analysis of hourly fuel consumption, operational fuel consumption, skating, average speed, effective field capacity, medium strength in traction and average power bar at the drawbar. From the results obtained in the field, were simulated in different electronic spreadsheets areas of different sizes with the subsoiler operating at fixed (PF) a variable depth (PV). It was found that the working time savings in PV in relation to PF ranged from 1.85 to 6.34%. A reduction in fuel consumption of 6.42 to 25.69% using PV in relation to PF was observed.