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Beyond Peat, potential peat alternatives for Irish horticulture

Beyond Peat, potential peat alternatives for Irish horticulture

To highlight the work being done to meet that challenge, we spoke to the core Beyond Peat Mushroom team: Senior Research Officer Helen Grogan, Technologist Brian McGuinness, Specialist Advisor Donal Gernon, and Research Officer Eoghan Corbett.

TResearch Summer 2023

Peatlands are natural reservoirs of carbon and biodiversity, the demise of which fuel climate change and environmental damage on a global scale. European governments are tackling the challenge to minimise carbon emissions and safeguard biodiversity through directives on climate, habitats, green energy and environmental sustainability. While most extracted peat in Ireland was used for electricity generation in power stations (which has now stopped), around 3% (2018) was used for commercial horticulture, including mushrooms, where a peat-based layer called ‘casing’ is essential for high-quality crops. Finding a replacement for peat is a major challenge, due to its excellent water-holding properties and consistency.

How did the Beyond Peat Mushroom team come about?

Teagasc have been conducting mushroom research to support this important sector of Irish horticulture for over 50 years, which is one of the most efficient worldwide, producing top quality mushrooms for export. We needed to address the sector’s heavy reliance on peat to make mushroom casing more sustainable into the future. This led to the Beyond Peat project being established in 2021. It aims to build a research platform for sustainable growing media in Ireland, to tackle uncertainty around the availability and supply of peat for the horticultural sector.

What are the team’s main priorities?

To provide independent, evidence-based advice to growers to aid transitions away from peat use. A major aim is identifying and assessing the performance of peat-alternative materials derived from bio-renewable sources or as by-products of Irish industry and agri-food production. We also aim to utilise novel methods to transform these materials into usable growth media components and assess how they might be blended for best effect.

There are some key focus points for peat alternatives. Any raw materials used must be more environmentally sustainable than peat. Alternative blends should achieve similar yields and be of consistent quality compared to peat-based casing as the industry is a high-volume/low-margin business. Finally, alternative blends must be affordable in comparison to peat.

What are some of the key tools you used for this project?

Water availability and retention are critical aspects of a good casing, so we’ve invested in next-generation sensors that can be placed inside the casing layer during growth to measure water characteristics. These sensors help build up a picture of how water behaves in the casing layer during mushroom growth and development, allowing us to compare the attributes of novel peat-free blends with standard peatbased casing.

The Ashtown Mushroom research unit is a pilot scale mushroom growing facility, designed and built to our specific needs. Unlike a commercial facility, we’ve needed to develop equipment and methods to deliver crops on a small scale with minimal staff input, yet to commercial standards. We have designed a bespoke filling line which allows us to efficiently fill various containers with substrate. Once crops are completed, mushroom and compost waste is cooked out with steam to prevent pest and disease transmission, after which it is processed on-site using an aerobic digester to produce a composted product.

"The Irish mushroom industry is one of the most efficient in the world, producing top quality mushrooms for export."

What makes this work so important in the context of Irish agriculture?

The Irish mushroom sector produces top quality mushrooms throughout the year. It is worth €130 million at farm gate and exports 80% of total production to the UK. It currently employs over 3,500 people in rural locations, so it makes an important contribution to rural economies.

There’s an ever-increasing drive for more sustainable and circular agricultural practices. As the circular economy expands, this will increase competition for previously undervalued materials. By evaluating how best to make use of these resources now, the Beyond Peat project has an important role to play in highlighting what resources will shape sustainable, economical and safe horticultural production into the future.

TResearch Summer 2023

Brian McGuinness measures the colour and quality of mushrooms. Any peat alternative casing must result in high-quality white mushrooms. These mushrooms are not up to standard as they are blemished and bruised.

What does the future of your research look like?

In recent years, the mushroom industry has been investing in progressive, renewable technologies, which has greatly benefited the sector by reducing input costs. Mushroom picking automation is the next trend that will be introduced into the sector over the coming years as labour costs increase and availability of suitable staff decreases. In 2021 and 2022, webinars were held assessing the suitability of automation systems and their financial implications for Irish mushroom producers. This work will continue in the years ahead as we support the sector’s transition toward automation.

In addition to the impending loss of peat as a mushroom casing ingredient, the sector faces pest and disease control challenges due to pesticide resistance and the loss of approved synthetic products. We’re in a unique position to trial emerging biocontrol technologies against a wide range of mushroom crop diseases, and anticipate future work in this area to assess innovative disease control methods. 

Read more articles from TResearch May 2023