Windrow burning is commonly used for the control of weeds in retained stubble systems. By removing the spinners from the rear of the header the stubble, trash and weed seeds are directed into a narrow windrow. From here the farmer can elect to burn the stubble thus destroying the weed seeds in the process. The windrows are usually burnt in late summer or early autumn when the fire bans have been lifted.
Unfortunately the stubble windrows can contain spilled grain which provides an excellent food source for mouse populations. The stubble windrow also provides a great deal of shelter for mouse population during cool conditions. By keeping these factors in mind CWFS has conducted observations in the Wyalong area. These observations were conducted at four key seasonal times. The research is a component of the GRDC stubble project as well as the surveillance and forecast for mouse outbreaks in Australian cropping systems project.
The increase in the amount of windrows being burnt in the area is theorized by CWFS to impact on mouse populations in two ways.
- A possible increase in mouse populations due to a concentrated food source as well as the windrows providing shelter for the animals.
- A possible decrease in mouse populations by concentrating the mice into a narrow windrow and incinerating them in combination with a reduction of time in which spilled grain and stubble is available for the mice.
From data collected over the four observational periods there were no conclusive results to suggest that the mouse populations were impacted by the windrows. It is suggested that the availability of water or moisture was the limiting factor which prevented mice from initially entering and colonizing either of the control sites. However if there were significant rain events that fully saturated the windrows there would have been significant moisture for mouse colonization.
The cards recorded a high level of activity after rainfall events within the control plots. It appears that windrow burning and sowing activities had a negative impact on mouse populations by the loss of habitat and the concentration of their food source.
In conclusion when it comes to reducing mouse populations ability to persist, the burning of windrows should take place as soon as possible. after the lifting of fire bans. Concentrating their food source into a specific location may also assist in a targeted approach to mouse control.
If you would like access to the full paper to see how we went about the project feel free to click the link below.