From The Land
Exotics and sheep restore farmland
Willows, poplars, chestnuts, oaks and bamboo are used as fodder and to regenerate farm soils and streams, running against the official preference for native species—and yet by any measure of health, the landscape is flourishing.
Soils are friable and well-structured, ensuring that any moisture that falls on the farm stays there.
Streams flow permanently, in contrast to when Peter and Kate Marshall and their children Keith, Gus and Rita, bought the former dairy farm ‘Woodford Lagoon’ in 1990.
At the time, the farm—now 250 hectares—was “ruined”, Mr Marshall said, with no permanent water; compacted, acidic soil with no ‘A’ horizon, and dozens of hectares infested with broom bush.
In one spot, water penetrated only about two centimetres deep during a 10 hour immersion under a flood.
For much of the property, the first step toward health has been a Yeomans plow towed behind a low-ground pressure Antonio Carraro 4WD tractor. With a seven-tonne break-out on the tynes, the plow rips to 700 millimetres deep, shattering compaction and opening up the soil volume available to plant roots.
“We’ve got some areas where we excluded the stock 20 years ago and the soil still hasn’t loosened up,” Mr Marshall said. “But the minute we’ve passed a Yeoman’s through it, everything comes to life.”
Only sheep and goats are allowed back on the uncompacted soil, because the Marshalls have found that cattle hooves apply enough pressure to cause the farm’s soils to “plastically fail”, or compact beyond a point where natural processes can undo the damage.
Goats have been an essential tool in the farm’s regeneration. Killing the broom with chemical wasn’t an option, Mr Marshall said, because it encourages the seeds scattered beneath the bush to germinate, requiring another dose of chemical—an ongoing vicious cycle.
Instead, the Marshalls introduced goats to continually defoliate the mature bush and its seedlings. They settled on the Boer as the most fence-friendly and productive breed.
Between goats, fire, mulching, blading and soil improvement—strategies designed to encourage competitive species as well as kill broom—the bush has been eliminated as a problem on Woodford Lagoon and is now being dealt with on a recently purchased block, ‘Sunnyside’.
Having worked hard to manage broom, the Marshalls then introduced what some consider to be a range of other weeds.
Willows, poplars, chestnuts and oaks and bamboo have all played central roles in other human cultures, where they have been valued because of their utility, nutritional value to livestock and, in the case of the trees, their ability to coppice, or quickly reshoot after lopping.
The Marshalls are using non-invasive single-sex varieties in a grazing system they call “lop and drop”, which utilises the 20 tonnes per hectare per year of timber and vegetative growth produced by their deciduous trees.
Lopped limbs, “long fodder”, are fed to Suffolk sheep or the goats. The leaves provide a high-protein feed, utilising nutrients drawn from deep within the soil, and are high in condensed tannins, Mr Marshall said.
That means that less digestive activity is needed by livestock, and subsequently less methane is produced. New Zealand research suggests that condensed tannins also improve twinning rates in sheep.
Browsing lopped limbs up off the pasture conserves grass, and reduces the parasite load in livestock. Lopped poles are also nibbled free of bark, which prevents them from reshooting where they lie.
“Once you get used to the sight of poles on the ground, having these big chunks of carbon lying around the landscape are a good thing for many different reasons,” Mr Marshall said.
“They roughen up the landscape, so wind speeds are slower near the ground.
“You get different pasture species establishing against the chunks of logs as they rot down.
“And the logs act to trap debris on the hill slopes very effectively.
“This system mightn’t suit someone else with a different aesthetic view. But it suits us, and we think it suits our landscape.”