In the Murrumbidgee, with the rapid uptake of cotton production there has been a trend to continuous production systems, with some farmers doing as many as 5 consecutive cotton crops. With the intensity of production and a move to bigger machinery, particularly 40t pickers that are commonly used when the ground is damp, there is an increase in the amount of compaction. This is resulting in changes in the crop physiology as well as a tightening of irrigation intervals due to a decrease in the water holding capacity of soil and shallowing rooting depth that the plants are able to achieve.

This project aimed to demonstrate the differences between standard and controlled traffic practices (3m centres) and water infiltration rate and irrigation practices on farms in the Murrumbidgee catchment. As there are currently have no farms moving to controlled traffic, it will be about demonstrating to the grower soil properties that are present in the continuous cropping system we currently have, as well as bringing someone with the experience of switching to controlled traffic to showcase the benefits seen on that farm. The first season of BG III will also mean reduced tillage from pupae busting enabling monitoring of expected increased infiltration from business-as-usual scenarios under BGII.

The researcher was able to get some good data from a number of different sites that have had different management. This coupled with infield probes has resulted is some solid information as the compaction that is happening in our region and the effects that they are having on water infiltration.The engagment of Dr Michael Braunack from the CSIRO as part of the local field day to discuss what was happening to local soil, and look at the option of controlled traffic. The information that gathered has resulted in a good base for further work in the local region.