Controlled traffic farming (CTF) is a crop production system in which the crop zone and traffic lanes are distinctly and permanently separated. In practice it means that all implements have a particular span or multiple of it and all wheel tracks are confined to specific traffic lanes.
A number of projects have been conducted in recent years related to controlled traffic in the vegetable industry. These range from research projects on the TIA Vegetable Research Facility at Forthside to projects conducted on commercial farms in conjunction with growers, and desk top studies of various aspects of controlled traffic.
All field-based projects have provided evidence of improvements in soil physical conditions as a result of implementing controlled traffic. The changes in soil physical conditions have led to reductions in the amount of tillage required, very substantial improvements in infiltration and improvements in porosity in the soil. No projects have run long enough to demonstrate consistent yield advantages, although there is some evidence of improved quality in some vegetables.
There are still many gaps in our knowledge of how to gain widespread adoption of controlled traffic in the vegetable industry. The industry relies on a diverse range of machinery which is a challenge to the objective of integrating machinery dimensions in order to ensure traffic always travels on the same wheel tracks. Seasonal controlled traffic is a more achievable objective in the short term. Seasonal controlled traffic aims to align all tillage, crop establishment and crop management operations on the same wheel tracks, but accepts that achieving track gauge and working width compatibility across a number of different harvesters is unlikely to happen in the short term.
Seasonal controlled traffic still requires track gauge and working width compatibility for all operations other than harvest, and is reliant on satellite guidance maps to allow the tractor to return to permanent wheel track locations after harvest. The soil improvements are not as great as those obtained with fully integrated controlled traffic, but there are benefits to be gained. A set of guidelines have been produced as an aid to those considering making the change to controlled traffic (Guidelines, PDF 487KB)