Eco system mown down by ignorance
REGULAR readers of this column already know that I have a thing about mowing. Also dentist drills, vacuum cleaners, leaf blowers and chainsaws.
To me, they are all high pitched, necessary evils to be avoided when possible. My wife says it is innate sloth. In truth, though, it goes deeper. It is a lizard brain thing.
I was drawn recently to ponder the painful subject of growing grass only to cut it down in its prime. I had spent two and a half months working on a new book, Cry Me a River.
This account of Steve Posselt's journey down the Murray Darling river system paints a terrifying picture of the impact of our land management on our rivers. Posselt concludes that we have reduced our river systems to drains and killed the landscape in the bargain.
He observes that the natural landscape works like a sponge, absorbing and holding water in good years that is released gradually, keeping the landscape alive during drought years.
With the natural sponges drained, mined and exposed, the land is now vulnerable to drought.
On The Generator, we recently interviewed a farmer who had invested in extra fencing to create many small paddocks so he can move his stock out of a paddock before the grass gets eaten right down. His logic is that water and sunlight are free resources that he needs to maximise.
If the grass is eaten right down, then valuable sunlight is being wasted.
As a result of this “Cell pasture management” he now has lush pasture that soaks up rainfall and delivers it deep into the soil.
He measured that he now has about 700 tonnes of root matter per hectare. This compares to his neighbour's paddocks that have 15!
Same species of grasses, same species of sheep, a slightly lower stocking rate and so slightly lower profits in good years, but more than 40 times the water, carbon and soil microbes. After rain, his neighbour's topsoil washes away, exposing dry subsoil.
I pondered Posselt's drains and Marsh's grasses last week as I walked by the river.
Landcare is regenerating the riparian forest along a 200-metre stretch of the river bank. This blocks the council mowers from a narrow sliver of the river bank where the town parks meet the mangroves.
Where council mowers no longer go, the grasses have grown a metre high and the ground underfoot is boggy and spongy. Three months before, it was all one broad sweep of lawn.
Simply letting the grass grow has reduced evaporation and the runoff of water to the point that a well kept lawn has become a bog.
The natural environment is a sponge that holds water and releases it slowly. Nah duhr! How is it that we can absorb a statement like that intellectually but not see what it means until we are actually standing in it?
Every time we expend precious energy on mowing grass, we increase evaporation and run off. As well, we produce methane from the rotting grass.
Every time we unblock a meandering stream to make it flow faster, we rob the surrounding landscape of the opportunity to soak up more water.
Lawn is great for sporting grounds and picnic areas, but unless you need to spread the picnic tartan or toss the bocce balls, you should let the grass grow longer.
In fact, you should plant out the lawn with food trees and ground covers and build a living landscape that you can eat.
Rediscover your natural sponge. It may well feed and water you in the hard times ahead.
- Giovanni is the founder of The Generator, on air Bay FM 99.9 this morning 9am-11am.