erosion

WATCHING GRASS GROW

Ever since I went to the Friends of Grasslands workshop in 2014 I’ve been itching to try my hand at revegetating native grasses, rather than only trees and shrubs.

PB030862Of course, that’s not all that easy to do.  Sue McIntyre has some good suggestions, but we are mostly forced to deal with weeds where we can, and hope that native grasses and forbs can do all right on their own.

On both farms, my parents made a big effort to “improve” the pasture with introduced grasses such as phalaris, clovers, and lucerne, which increase the carrying capacity for sheep  (you hope),  but need fertilizer and water to survive. During the “Millenium Drought” from 2001-2008, it was the native grasses that kept at least some coverage on the bare hills because of their ability to withstand lack of water.

I thought that there was some affinity between native grasses and rocks in particular, because that’s where I saw most of the remnant forbs and wildflowers. That was, until we had a visit from someone who’d worked at Esdale in 1970-71 and was very proud of having ripped all the hills he could with a tractor on a dangerous tilt and enthusiastically sowed introduced pastures.    The area we fenced for a Box-Gum woodland reserve was one of the ones that was just too steep to plough.box-gum-lower-planting-2-june-2014
I think the survival of native grasses has been highest on the back hills also partly because  the water supply was limited in the hot seasons, so it was less often grazed in high summer when the native grasses are seeding.  I’ve been working on making it possible to do more rotational grazing by improving the water supplies (digging a waterhole, adding troughs), but that may mean more summer grazing and less native grass.  Just locking the gate against sheep isn’t a great option though, because the land can be quickly overrun with wild oats, saffron thistles and other weeds.   It’s all a balancing act.

In the meantime, I had an opportunity to create a new area of native grasses on Adnamira when I had an old dump area covered up and levelled to provide access to one of our revegetation areas.   Continue reading

WASHING AWAY PART TWO – STICKS AND STONES

One way to stop topsoil from disappearing from under our feet is to use loose vegetation. Anything from grass and weeds to big logs will help catch it as it flows past.

The Southern ACT Catchment Group ran a workshop recently with Cam Wilson from Earth Integral as the expert advisor on how to make the best use of sticks and stones on small areas of erosion before they become large ones.

a knee-deep gully

A knee-deep gully

“Start small” Cam advised. “If the erosion hole is deeper than your knees, it’s probably too big for a beginner”.   Continue reading

WASHING AWAY – PART ONE – DAM IT UP

Topsoil is that thin band of living matter that lies across the landscape.  Except when it is undermined or dissolved by rain and carried downhill into first the gullies, then the waterways, leaving the water silty and the landscape denuded.

Boggy Creek erosion spiresAs a child I loved to play among the eroding soil spires where you could imagine yourself in a miniature Grand Canyon.  My little brother Andrew made endless tracks for his Matchbox cars in the walls of the gully near the house we now call Wombat Hollow.  Occasionally he and I would help the erosion along by creating bucket-powered rivers and flood catastrophes that would flush the tiny battered vehicles over cliffs and down to their doom.

The traditional way to discourage gully erosion is to throw in some old car tyres, kitchen equipment, broken fences and spare car bodies, and hope they will collect silt.  This sometimes even works. Continue reading