By far the most effective way to manage soil compaction
is through the use of controlled traffic farming systems.
Controlled traffic farming (CTF) is a farming system that permanently separates wheel traffic lanes from the soil in which the crop grows, with equipment running on the same track width. It is based on the simple logic that crops grow better in soft soil and wheels work better on roads. Many factors go to make up a successful CTF system, but the most important are:
- all tractors, equipment, harvesters etc. need to have the same track width, or a multiple of it
- all equipment working widths being a module of the track width
- being able to accurately return to the same wheel track locations year after year, which is made possible with a GPS guidance system
- using the narrowest tyres possible on all equipment
- planning farm layout to maximise logistics efficiencies and minimise erosion risk.
Controlled traffic works equally well for crops planted on raised beds or on the flat. It is a system where compaction can be managed for benefit.
CTF is being taken up in the grain and sugar cane industries due to the many benefits offered. These include:
- Reduced energy requirements for tillage and traffic, therefore reduced fuel use and reduced capital investment in tractors
- Improved soil structure for crop growth
- Improved soil biology (health)
- Improved infiltration and water holding capacity, therefore more efficient storage and use of rain and irrigation water and reduced run-off and erosion
- Reduction or removal of yield variations due to soil type and management differences
- Higher, more uniform yield
- Improved timeliness, therefore more effective and targeted crop management opportunities
- Reliable double cropping programs.
CTF adoption in the vegetable industry anywhere in the world, although an important start has been made in the Tasmanian industry through projects funded by Horticulture Australia Limited and the National Landcare Program. The complexity and diversity of the industry is a significant challenge in meeting the first requirement of common wheel track spacings across all equipment. Nevertheless, apart from those listed above, CTF has the potential to offer many potential benefits and opportunities for the vegetable industry, including:
- Fewer clods in root crop harvest leading to reduced harvest costs
- Fewer clods gives the opportunity to improve tuber recovery, therefore fewer volunteer potatoes
- Improved crop quality and more even maturity
- Elimination of tillage opens the way for direct drilling which allows:
- use of cover crops and crop residue retention
- reduced soil erosion off crop growth areas
- improved moisture retention
- reduced weed pressure
- reduced energy use and labour requirements
- use of semi-permanent drip irrigation in consecutive crops, resulting in reduced foliar disease pressure
- Smaller, simpler machinery
- More effective application of precision farming techniques.
Research and commercial experience in other parts of Australia show that controlled traffic will significantly reduce the effects of soil compaction in crop growth zones. Controlled traffic farming still creates compaction, but it is isolated away from the crop growth zone. In fact, a major benefit of controlled traffic comes from concentrating the compaction in a defined track. Doing this largely avoids the need to deep rip to remove compaction, and can reduce the fuel used in tillage by up to 50%.
CTF can be used as a platform for many improvements in cropping systems. When there is a need to use wheels in crop production, it makes a lot of sense to keep them away from the soil in which the crop grows - controlled traffic farming is able to meet that challenge, and is one of the most significant advances in crop production systems in the last 30 years.