EVALUATION OF ONION PRODUCTION ON SANDY SOILS BY USE OF REDUCED TILLAGE AND CONTROLLED TRAFFIC FARMINGWITH WIDE SPAN TRACTORS

摘要

Growing of vegetables is often characterised by intensive field traffic and use of heavy machines. By implementing controlled traffic farming (CTF), compaction of the growth zone can be avoided. An experiment was established in an onion field on a coarse sandy loam. Treatments were applied in the field that for five years had been managed by seasonal CTF (SCTF), where harvest is performed by random traffic due to lack of suitable harvest machines. The main treatment was compaction with a fully loadedpotato harvester. The split treatment in the crossed split plot design was mechanical loosening. Bulk density, macroporosity, penetration resistance, water retention characteristics and yield were measured. Mechanical loosening caused improvements in the physical soil measurements and more roots were found in the upper soil layers. The highest yield was however found in the CTF simulation plots (19% higher than in the SCTF simulated plots). Using wide span tractors as a harvest platform will enable CTFin vegetable production. Avoidance of compaction will enable reduced tillage intensity and productivity can be improved both through higher yield of the area that is cropped and by a larger percentage of fields can be cropped area as less area will be needed for tracks.