Soil compaction is a problem that affects most of the tilled areas of Brazil, being caused by several factors, such as overloading and intense machine traffic, use of unsuitable tires for applied load and inflation pressures outside the recommendation, machines in the field with the water content of the soil not recommended and several other problems.
There are available several models and systems of measuring soil compaction in Brazil; however, the sensors of the equipment require processing and interpretation of data.
The objective of this work was to design and evaluate a prototype to identify compacted layers of agricultural soils in real time and in varying depths. The equipment was designed to be mounted on the front of the tractor with the vertical movement, for introduction in the soil, controlled by the tractor central hydraulic system.
The calibration of the equipment had been carried out in two areas of the NEMPA Tests – test Core of machinery and Agricultural Tires, using compaction detector device calibrator, a penetrometer, in which the index values of cone (IC) have been entered in the data collector for comparison with an average of correlation R2 = 0,90.
After calibration of the equipment has been carried out the test response time between the data obtained by the front sensor and times of ascent and descent of the tine. Then the comparative test between the usual systems with fixed depth 0.35 m with regular equipment of instrumented stems, with variable depth, being measured the parameters of time, fuel consumption fuel consumption, operating force in traction bar, average power, average speed, skating, effective field capacity of tractor and equipment response time.
The results showed that, with equipment commanding the operation of chisel plough is used with variable depth, obtained a reduction of 26% operational fuel consumption ( L ha-1) and there was an increase of 14% in effective field capacity (ha h-1). The reactions of the proposed equipment to change depth of scarification coincided with the locations and values obtained from soil mechanical resistance indicated by penetrometer, showing good data accuracy. The instrumented system produced maps that showed the spatial variability of soil mechanical resistance, with resolution, sampling density and higher operational capability when compared to surveys conducted with the cone penetrometer, indicating that there had been overestimation of compression by the equipment condition.
