Soil damage by tractor pulling

Between 2002 and 2006, tractor pulling events were carried out once a year on a deep luvisol on arable farm land in Niederbipp (BE). Since severe mechanical stress was anticipated particularly within the track area, the authorization of the event was subject to conditions stipulated by the cantonal soil protection service with the aim of guaranteeing a minimum protection of the soil from lasting damage to its structure (compaction). The organizers of the tractor pulling event repeatedly questioned or even ignored these conditions. In sequel to particularly serious non-compliance in 2004, soil physical analyses were carried out on the event grounds, to record and evaluate the extent of soil damage on the basis of reproducible measurements. The analyses showed that compliance with the stipulated conditions could prevent severe damage to the soil structure in the subsoil of the track area and that hence, the imposed conditions are justified. The study further suggests that conditions aiming at the protection of the areas surrounding the track and compromised by the logistics of the event, should also be stipulated. Considering the damage potential associated with recreational events on arable soils, such events should in general be authorized only under severe restrictions. The soil damage observed in the particular case of tractor pulling furthermore raises the question whether area-related proof of ecological performance-payments are justified for agricultural areas where such events are held.