Wide span – re-mechanising vegetable production

Abstract

Vegetable production is characterised by intensive traffic, particularly during harvest. While tillage is used to remediate harvest-induced soil compaction and prepare seedbeds, both traffic and tillage require significant energy input and negatively impact soil physical and biological properties. Traffic compaction can be permanently eliminated from the crop growth zone by controlling traffic. This requires all implements to have a particular span, or multiple of it, and all wheel tracks to be confined to specific traffic lanes. The production, environmental and economic benefits of Controlled Traffic Farming (CTF) have been demonstrated commercially in the Australian grain and sugar industries. CTF adoption in the vegetable industry is challenged by the difficulty of achieving compatible track gauge and working width across a diverse range of equipment. Wide-span (gantry) tractors (WS) offer a new mechanization pathway for the industry. A WS tractor, spanning 6-12 m, allows multiple conventional implements of different widths to be mounted within the confinement of the span. A prototype Danish WS tractor equipped with an onion harvester shows that mounting harvest equipment on a WS platform is likely to be no more complex than modifying conventional tractor driven or self-propelled harvest machines to allow CTF. Wide, non-trafficked crop beds could provide yield increases of up to 20% in some crops, purely by growing more plants per ha of land, as less area is required for wheel tracks. Improvements in soil structure through the use of CTF can lead to further yield improvements, reduce energy use, and improve water use efficiency, infiltration and drainage. Using a mixed vegetable crop rotation as a modeling case study, it is estimated that CTF based on WS tractors could substantially improve the productivity and environmental sustainability of vegetable production.