Tramline establishment in controlled traffic farming based on operational machinery cost

This paper presents a targeted approach for the estimation of the operational machinery costs on an annual basis in controlled traffic farming (CTF) systems. The approach combines four sub-models based on existing algorithmic approaches, to evaluate the consequences in terms of machinery performance of different driving directions when establishing tramlines in a CTF system. The first two sub-models refer to the geometrical attributes (overlapped areas, effective and turning travelled distances, coordinates of the tramlines, headland passes, etc.) of the field–machinery combination, while the other two models are related to the execution of material handling operations (i.e., fertilising and harvesting) under the restrictions imposed by the CTF. A case study is presented regarding two fields for a reduced tillage machinery system. Based on the results, it was shown that in the CTF the rule that the driving direction parallel to the longest field edge is the optimal one does not apply. Specifically, in the case of the second field, there is a cost decrease of 9% in terms of annual operational cost when the direction of the tramlines is changed from parallel to the longest edge of the field to parallel to the shortest one. This divergence from the conventional rule is caused by the traffic restrictions imposed by the CTF system and the subsequent differences in the resulting overlapped areas in spraying and seeding, unloading times in harvesting, in-field transport in fertilising, and headland turnings, for each specific driving direction.