Dung Beetles, Cattle and Carbon

A female dung beetle (Bubas bison) can lay eggs up to 50cm deep into soil below a cow pat

With PHCC’s long history of supporting our community to establish dung beetles in the landscapes our Regional Agriculture Landcare Facilitator, Mick Davis, was excited to attend the “Dung Beetles & Biochar” workshop in Donnybrook on Oct 29^th, supported by staff from the Leschenault Catchment Council and Southern Forest Landcare Alliance.

While Australia has several hundred species of native dung beetles that make use of the fibrous pelleted dung produced by kangaroos, wallabies and other native mammals, most are unable to cope with the large quantities of dung produced by introduced livestock, particularly cattle. Therefore using imported dung beetles is required.

The workshop provided participants with information on the life cycle and regional abundance of 8 of these introduced species, which are locally bred specifically for farmers in WA. These species are broadly grouped as Summer-active and Winter-active, and their persistence in the landscape is governed by factors like how surface dung is managed (time of ploughing), use of pesticides (like the ‘Dectins’ group of chemicals used to control parasites in stock, which can kill dung beetles) and annual variations in climate.

One of the main activities of dung beetles is that they collect balls of dung and bury them in the subsoil, within which they lay their eggs. This process aerates the soil, brings nutrient rich subsoil (e.g. clays) to the surface and inoculates the adjacent soil with beneficial bacteria and fungi. This process helps to cycle nitrogen (N), phosphorus (P) and trace elements back to the soil surface, making them available to plants once again.

Following the information session, the group then stretched their legs and took a field tour to learn about a dung beetle monitoring program supported by UWA and CSIRO. In partnership with local farmers and supported by local landcare groups, the monitoring program aims to identify when and where different dung beetles are active, as a way to inform future beetle releases into known gaps across WA and Australia.

As you do when you’re at a dung beetle workshop, everyone then began enthusiastically turning over cow pats looking for signs of dung beetles! At least two species were recorded and the beetles from the sampling were bottled up to be sent to UWA where the species will be identified and the data added to the national dung beetle database.

Towards the end of the workshop everyone heard about how feeding cattle biochar (a form of carbon often created through manufacturing processes) has been shown to increase animal health, provide a pathway for the added carbon to enter the soil, increasing soil heath and nutrient availability. Animals fed biochar as a supplement to their food then deposit the carbon in their dung, which is then buried by the dung beetles.

Armed with this knowledge participants left Donnybrook with a new appreciation for the ways to encourage dung beetles on farms, how to manage farming practices to better support these ecosystem engineers and how these small animals can have a big impact on farm productivity, the environment and the community.

If you want to know more please contact Mick via email at mick.davis@peel-harvey.org.au or phone 6369 8800.