Winds of Change at Avoca

What do you get when you mix a herd of cattle with a windy, sandy hilltop? More often than not, a fair bit of wind erosion!

That is until you construct a windbreak, which is exactly what Craig Forsyth and the Mingenew Irwin Group (MIG) have done at Craig’s Irwin property, Avoca.

Shelterbelts are not a new practice to most farming systems, yet Craig’s challenge was to construct a shelterbelt system that also incorporated perennial shrubs to enable adaption to erosion and climate variability.

The Mingenew Irwin Group exhibited this idea last week with a field walk at Avoca, sharing the methodology and benefits of constructing a three-row shelterbelt.

So how did they do it?

The innovation was chosen by Craig in response to the Future Farm Industries CRC’s ‘Enrich’ project, which demonstrated that by integrating rows of trees and shrubs into pasture grazing systems, farmers can reduce feed gaps, increase whole-farm profitability by up to 20 per cent, provide shelterbelts for stock, and slow wind movement across the landscape thus reducing wind erosion.

Native trees and shrubs are well-adapted to the climatic conditions at Avoca. They provide practical options to reduce risks of production in a variable climate and reduce the impacts of extreme weather events.

Craig and the Mingenew Irwin Group began this farm demonstration project last year with support from NACC’s Sustainable Agriculture Program’s Innovative Farm Demonstration Site project, through funding from the Australian Government’s National Landcare Programme.

NACC Natural Resource Management Officer Sarah Gilleland attended a field walk of the site recently, during which Craig explained the ”nuts and bolts” of the demonstration.

He explained that plantings began in the winter at Avoca, on a sloping block composed of light, sandy soils as the situation of the slope, which faces west, exposes it to year-round southerly and easterly winds.

These winds increase the risk of erosion across the hill, particularly when ground cover is low during the summer months, and the lack of shelter results in uncomfortable conditions for livestock, threatening productivity.  Native trees were planted with outer rows of native shrubs in response to this.

Shrubs to the Rescue

Dean Revell, head of Revell Science (and NACC Board Director), explained on the day that the outer rows of shrubs act as a source of feed for Craig’s cattle whilst also creating a windbreak.

“When trees are planted in rows, with no lower layer, this can create a tunnel effect of wind, thereby worsening the impacts of wind erosion and cold winds for livestock,” said Dean.

“As the plantings are still young, it is difficult to determine the effect they have on wind speed in the paddock. The shrubs have established well however, and Craig is confident in their success and ability to provide feed for livestock during the summer months.”

In response Craig said:  “I think it’s fantastic! I was a bit concerned at first, as it didn’t look like much was going to grow,but now they’ve come up really well.”

The tree species involved in the trial were less successful, which Dustin Chatfield of Chatfields Nursery suggested may have been due to choosing less-hardy species, grazing from rabbits and kangaroos, and/or not planting the seedlings deep enough.

“You can almost bury seedlings to protect them from the sun and wind and in most cases they will still grow, so long as their growth tip is out of the soil”, said Dustin before giving a planting demonstration.

He also explained the value of planting the seedlings in furrows, which encourages the collection of water around the seedling, increasing its chance of survival.

The paddock at the shrub site at Avoca. Picture: Helene Metzinger
The paddock at the shrub site at Avoca. Picture: Helene Metzinger

The farm demonstration will provided many interesting results, with participants of  the field walk taking a keen interest in learning about the most efficient method for establishing new plantings, the importance of selecting the appropriate species to the site, and stock management after planting.

Anna Maxted of the Mingenew Irwin Group commended everyone who was involved in the project, saying that she was very happy with the results and was looking forward to seeing how the site develops in the long-term.

To learn more about other farm demonstration projects funded through NACC, please go to the Farm Demonstration web page.

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