Soil and crop responses to a “light” version of Controlled Traffic Farming in Switzerland

Abstract

Traffic induced soil compaction, as well as the associated negative effects on soil structure and soil functions can be reduced by the use of permanent traffic lanes for all field vehicles – known as Controlled Traffic Farming (CTF). Adapted to the small-scale agriculture in Switzerland, a simplified version may be applicable. In the current study, we evaluated the implementation of a “CTF-light” system in the Swiss Central Plateau specifically for heavy machines used for crop protection, fertilisation and harvesting. During a three-year trial (2015–2017), we investigated the practicality of this “CTF-light” system by using standard machinery on 17 study sites. The effects of permanent lanes on soil penetration resistance, water infiltration rate, bulk density, macropore volume and yields were evaluated. Harmonising machine working widths was challenging and required intense planning, however, we were able to realise “CTF-light” on all sites. After three years of controlled trafficking, we observed developing differentiation of soil properties. In untrafficked areas, there was a tendency of decreased penetration resistance and bulk density as well as an increased infiltration rate and macropore volume. This significantly increased maize yield, which is very sensitive to soil compaction. For other field crops, no consistent yield differences have yet been determined. The technical and organisational effort to realise permanent traffic lanes for heavy standard machines is not to be underestimated.