Controlled traffic farming—From research to adoption in Australia

Efficient mechanisation is a major factor underlying the high productivity and low cost of most Australian crop production systems. Efficiency has generally been associated with greater work rates, achieved by using equipment of greater power and weight. This trend has continued until very recently, despite a reduction in tillage for weed control.

Scientists have warned of erosion and soil structural degradation caused by tillage and traffic, but tillage, rather than field traffic was seen as the major problem, and reduction of tillage as the solution. Reduced tillage has provided major benefits, but adoption has occurred slowly and sustained zero tillage is still rare, except in controlled traffic farming systems.

The first part of this paper presents research evidence of the direct cost, practical impact and long-term effects of wheel traffic on cropped soil. Direct cost is associated with the energy requirements of disturbing wheeled soil. Practical impact occurs as a result of the lost opportunities and additional operations associated with wheel ruts. Long-term productivity and environmental impact occur because wheel traffic reduces plant available water and increases runoff and erosion.

In controlled traffic all equipment wheels are restricted to compacted permanent traffic lanes, so that soil in the crop beds and traffic lanes can be managed respectively for optimum cropping and optimum trafficability. Controlled traffic farming recognizes the symbiosis between controlled traffic and zero tillage in providing opportunities for more productive and sustainable farming of soil uncompromised by wheel effects.

The beneficial effects of controlled traffic have been demonstrated in widely different soils and mechanisation systems (e.g. Australia and China), and it has been vigorously advocated in both the USA and Europe, but large-scale adoption has been rare. The second part of this paper discusses cropping system response to controlled traffic farming, and the program which led to large-scale adoption in Australia. This happened first in extensive grain production, but adoption has since occurred in many Australian farming systems, supported by the availability of high-precision field guidance systems and a greater range of compatible equipment.

Controlled traffic farming reduces soil degradation and the energy requirements of cropping. It is also more productive, and its practicality and economic viability have been clearly demonstrated in enthusiastic farmer adoption, and the formation of an Australian Controlled Traffic Farming Association.