One of the driving forces behind getting a tractor was to allow us to start rehabilitating the precious soil on the Rock Farm. Our aim is to create a balanced and healthy soil that supports low impact grazing.
One paddock on the Rock Farm is predominantly native pasture with remanent red box, red stringy bark and brittle gum trees. I have been encouraging the regrowth of thousands of young trees around the older trees, and have been pleased to find the odd drooping she-oak – a vital food source for the Glossy Black Cockatoo.
One problem in this paddock is patches of Sifton Bush (Cassini Arcuata). This native plant is an invasive weed, producing vast quantities of seed and rapidly colonising bare soil.
The mature sifton bush plant can produce up to 4 billion seeds a year. It is unpalatable to most grazing animals and has been suspected of causing poisoning in lambs. It is a declared weed in our area and we have a responsibility to control it.
The NSW dpi has an excellent page describing the Sifton Bush and its control. http://weeds.dpi.nsw.gov.au/Weeds/Details/253
Whilst we have worked hard to clear some areas through pulling plants, it is hard work and time consuming. I had used my mower for a few trials – but it was really hard work for the mower and was causing too much damage (to the mower). Burning is not effective due to the large amount of seedling reinfestation following a fire event.
And so our preferred method for larger areas of infestation is mulching.
Lucie the tractor has a 2.4 metre wide drum muncher that is effective at shattering the larger stems and mulching the leaves. As this breaks down, it returns organic matter to the soil, hopefully improving the soil structure and microbial activity.
The disadvantage of this method is that some of the sharp stumps remain, making it treacherous to drive a car over the mulched section. Also some of the younger plants aren’t effectively broken down and may shoot again from damaged stems.
The end result is a paddock that not only looks a lot better, but has improved organic matter in the soil. We have observed grasses recolonising the areas I have mulched as they receive better light and less competition from the sifton bush.
I expect to re-mulch these areas in another couple of years and perhaps take the opportunity then to re-mineralise the soil. It wont be a quick process as soil takes tens of thousands of years to form, and a heartbeat to destroy. It is all good fun and I am really enjoying the challenge of improving the Rock Farm.