Using groundcover to stop soil erosion

HEALTHY FARMING FUTURES

KEEP IT COVERED: THE IMPORTANCE OF GROUND COVER

21 OCTOBER 2022

The top six inches of soil is an incredibly valuable resource for us as it supports our soil microbiome and grows the food, forests and grasslands we all depend on. Unfortunately, exposed topsoil can be easily lost to wind and water erosion, and the processes that create new soil can take hundreds of years.

Terrain NRM’s Landcare Leader Sally Fields says that using cover crops, mulch and holistic grazing practices are important tools we can use to fast track the soil building process and protect soil from erosion.

“Many farmers are incorporating these tools to improve soil health and farm fertility. Increasing organic matter and keeping a living root in the ground maximises water infiltration and also ensures the sunlight energy is converted into sugars for the plants and the soil microbes they rely upon,” she said. “It’s a living system – bare ground is akin to shutting shop and we need to avoid it at all costs”.

John Gargan is a grazier and horticulturalist and has planted sunn hemp into an existing perennial pasture as part of his soil building process to improve pasture health. “In just one year the topsoil has increased from about 6cm to 17cm. The pasture’s looking really rich and nice – it should have high protein levels in it so the cattle will do well,” he said.

Healthy, covered soil also acts like a sponge that soaks up the water and keeps it there for crops to access, whereas bare soil has no protection and becomes hydrophobic. Rain will run off it, taking the topsoil with it.

WATCH ABOVE: Keep it Covered

In the Mutchilba Dimbulah irrigation area, farmers have been involved in trials comparing different mulch sources in their lime orchards. Improvements in soil health have been observed as a result of keeping their ground covered.

Lime farmer Michelle Milicevic says she’s noticed her mulched ground is a lot softer and holding water better. “We don’t have to water as much. Previously, during the really dry part of the season we’d be watering every three days or so, and now we can go five to six days without watering,” she said.

Ms Fields said the ability of soil to hold water will become increasingly important as rainfall patterns continue to change. “A megalitre of water will set farmers back by $4000 in some places. With those kind of prices it makes sense to utilise rainfall efficiently.”