Experimental study of the implement-and-tractor aggregate used for laying tracks of permanent traffic lanes inside controlled traffic farming systems

Traffic-induced soil compaction is a serious drawback of modern agriculture. However, controlled traffic farming (CTF) systems, which have been adopted worldwide, are useful strategies of lessening this problem. In CTF systems, the crop zone is clearly separated from the permanent traffic lanes (PTL), which are used exclusively for the movement of the machine-and-tractor aggregates. The CTF systems are implemented both with and without the use of the GPS systems. When navigation-aid is not used, the first positioning of the PTL tracks is an essential operation, in which the aggregate intended for this task must perform a sufficiently straight movement. This paper reports the assessments concerning the PTL tracks laid by an experimental aggregate, which consisted of a four-wheel drive tractor and a tillage implement operating in the “push” mode. This aggregate formed tracks with a sufficiently small dispersion (10.30 cm2) and a fairly low (not more than 0.09 Hz) frequency of their fluctuations in a horizontal plane. Furthermore, during the tests, a rather close positive correlation between the bearing angle φ of the tractor and the turning angle α of its driven wheels was registered and the maximum value of the related correlation function was 0.9. Moreover, the phase (time) shift between the disturbing torque and the response to it by the tractor operator did not exceed 0.75 s. The use of the proposed aggregate allowed laying tracks with a depth of 21.2 ± 0.3 cm and vibrations in a longitudinal vertical plane, whose dispersion was not more than 2 cm2 and was concentrated in a fairly narrow frequency range from 0 to 1.78 Hz.