Using RTK GPS and OptiSurface software to manage deep and rutted wheeltracks in CTF and raised bed systems

By Tim Neale (Director) PrecisionAgriculture.com.au

Email: info@precisionagriculture.com.au , Phone: +61428157208

Presented at the  

First International CTF Conference
25 – 27 February 2013
Toowoomba Queensland, Australia

ABSTRACT

Deep and rutted wheeltracks often occur in CTF (Controlled Traffic Farming) systems, as a result of the vertical soil compaction under the track, as well as the improvement of soil where there is no compaction. In some cases however, wheel tracks can get progressively worse to a point where they are unmanageable, and can be the cause of erosion and ponding. This has been particularly the case in the past two years in Australia, where many areas have seen above average rainfall.

This paper examines how new technology can help to prevent and manage wheeltracks, and correctly position run direction, in CTF and raised beds systems. Case studies from Central Queensland, Southern Queensland, New Zealand, and Africa are used to demonstrate its use.

Using RTK (Real-time Kinematic) GPS collected from the farmers’ tractor and a new software program, (OptiSurface) we can now ascertain in any part of a field where:

1. Ponding or erosion is likely to occur in the landscape, prior to any rainfall occurring;

2. The impact of wheeltrack depth or bed design on ponding depth and runoff; and

3. The impact of farming direction on ponding and runoff, at a given wheeltrack depth.

Results from real world case studies have shown:

• Changing farming direction resulted in approximately a 2/3 reduction in ponding volume given 20cm deep wheeltracks on a Southern Queensland farm.

• Reducing the width of raised beds in New Zealand from 1.8m to 1.5m, but maintaining the track width, led to a reduction in maximum runoff velocities from a simulated storm by almost 20%

• A central Queensland farm was able to reduce ponded area by 50% simply by changing run direction

• Adding a 20cm deep wheeltracks on a paddock in Sudan resulted in the ponded area increasing from 44% to 88% of the field.

This paper will also examine methods to remediate deep wheeltracks, as well as methods to prevent them from deepening in the first instance.