1 Aug 2022

Horticulture sector eyes new wood fibre tech

From Nine To Noon, 9:33 am on 1 August 2022

Wood fibre technology could be a game changer for New Zealand's horticulture industry and help reduce carbon emissions
Locally grown fruit, vegetables and plants are all generally grown in compost or potting mix containing peat.

Peat, a highly sought after ingredient, boosts production, retains nutrients and holds water but it is imported.

Mining of it has been banned recently in the UK and Ireland because of the high levels of carbon emitted in the process.

Dr Brian Jackson

Photo: supplied/befunky.com

Matamata company, Daltons, a supplier growing media has just imported the first wood fibre-processing machine, which will use wood chips from pinus radiatus trees to reduce its reliance on peat.

Dr Brian Jackson from the University of North Carolina, has been researching alternatives to peat for nearly 20 years.

He tells Nine to Noon peat has, in a global context, been the backbone of growing media and consumer market industry for almost a century, but businesses and individuals were now looking for new alternatives. Wood fibre was one and an exciting prospect.

“Wood fibre is a newer technology that has been shown to provide a renewable material and that’s certainly true here in New Zealand with the forest resources that you have and there’s a lot of opportunities here to use these wood fibres to create new growing media mixes and blends, both for the consumer market and for the professional grower to actually aid in their production, while also lessening the reliance on the imported peat.”

Peat reduction in products is both environmental driven, due to climate concerns and loss of habitat, but also due to supply chain constraints.

“There is a concern over the carbon that is released when peat is extracted from the natural bogs that are located globally, primarily in northern Europe and Canada," Jackson said. "So, there’s been an emphasis to identify other materials that could potentially have a less carbon footprint and be more sustainable for different regions of the world."

Availability in a growing market place was also a pertinent consideration, particularly for New Zealand,

“The growing media market is expanding globally, expected to increase over 400 percent between now and the year 2050… so more materials need to be available to help grow the plants in those systems," he said.

"It’s also important to note that supply chain disruptions, primarily transportation has been a nightmare for people shipping peat around the world. So it’s a combination of better environmental stewardship, and finding locally-sourced materials that can compliment or supplement peat to grow our crops.”

The process of adding the wood fibre into peat-based mixes is ongoing. The fibres won't replace the peat, but simply reduce the content in growing mixes.

“What we’ve learned from these engineered wood fibres is that actually new growing media materials can be made because the function and the inherent properties of the wood are quiet different." Jackson says.

"Wood fibre is very different than peat, so it’s impossible to ‘replace’ it. But I think the marriage of wood fibre and other materials leads to a lot of new product development that growers are really excited about.”

The peat will be reduced by 20 to 40 percent in growing mixes, depending on the product range.

The fibres are being produced from Pinus radiata waste products, bark and wood chip, Jackson says.

“The primary aim at this point is to use existing raw materials from the timber lumber industry so that no trees are being directly harvested for this… Right now there are forests being harvested specifically for this purpose, but there are a lot of other wood resources that are available to actually create and engineer these fibre products.

Scott Bromwich from Dalton's says the company began its relationship with Jackson about four years ago,

The company has created growing mixes for commercial nurseries for years and has been seeking local materials to use in those mixes, particular from Pinus radiata bark.

“So, for us it was like a natural progression and it's through Brian that we got exposed to this technology," he says.

The technology pointed to the way the world was heading regarding garden and growing mixes.

He says New Zealand’s approach to growing media had been informed by European practices, where there has been a heavy reliance on peat-based growing media. Now that is changing due to new global realities.

“In New Zealand of course, that’s a huge challenge for us because we’re at the bottom of the globe and I guess recent events around the world have really exposed us, with international shipping, just bringing products in because we always have done. So, we have real opportunity to start creating new mixes.”

Daltan's already has 20 percent fibre in some of its mixes. 

The wood is a by-product of the timber industry, with a waste portion of harvested wood  chipped. The company has used pre-existing relationships with Timberlands to source the product. “The quality of what we have in New Zealand is pretty unique," Bromwich says.

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