I've cut and pasted my comments from another
thread.
.....
Salmonberries occupied 20000 square feet of my best soil. All of it was dealt with using a hedge cutter.
It would be best to
fence grazing animals on to the space once the initial clearing is done. They prevent regrowth.
I manage all pathways at the farm, using the same machine. Loppers are used to cut larger branches, but the bulk of it can be done with a hedge cutter. It is vastly faster than running around with a hook knife or any other human-powered tool.
.....
For best single season results, without the help of grazing animals, do your first cut in the spring. Canes cut easier when they are damp. I often plan this sort of work for just after a rain. After being cut in the spring the plants will quickly put up new growth. Cut this just before your dry season. Rake it all up during the heat of late summer. Continue cutting new growth. Once the initial cutting and gathering is complete a fit person
should be able to manage more than 10,000 square feet in one day. Every cutting weakens the plant and reduces the vigor of new growth.
In some cases a
lawn mower could be used to continue the process. On rough ground, a string trimmer might work better.
Once you've headed down the road to eradication, it's important to continue. Don't allow them to get 3 feet high and store away more
energy.
Something dense and easy to kill, like buckwheat can be planted amongst the stumps of nearly dead canes.
In British Columbia, blackberries tend to grow in the same areas as big leaf maple. Berry groves stop once they get to the dense shade of these
trees. Therefore, this is an ideal spot to compost berry canes. There isn't
enough light for them too take off and compete with the trees.