Precision of tractor operations with soil cultivation implements using manual and automatic steering modes

The influence of satellite guidance on the operating precision of a John Deere 7230R tractor with a Väderstad Carrier 350 soil cultivation multi-implement was evaluated. The tractor-implement unit was operated in three steering modes: conventional when the tractor was operated manually and two steering modes, one which relied on satellite navigation with free access to the SF1 correction signal and one using paid subscription for the SF2 correction signal. The automatic steering system consisted of John Deere AutoTrac parallel tracking, StarFire 3000 antenna and GreenStar 3 CommandCenter display. In each mode, operating precision was tested at three travel speeds: 3, 6 and 12 km h−1. The experiment was carried out in 2013, on a farm in the region of Mazowsze, Poland, on a experimental plot with a surface area of 1.5 ha. Operating precision was analysed based on the combined operating width of two adjacent passes. Deviations from the optimal in-field operating routes, overlapped area (overlaps) and missed area (omissions) were determined.