Water-storing gels are mixed into soil to help plants survive drought, but most are made from synthetic polymers that can leave microplastics behind. AgroBiogel, a company in Tulln an der Donau, Austria, with links to the BOKU University of Natural Resources and Life Sciences, makes Retentis, a hydrogel from lignin, the glue-like substance in wood that pulp mills separate as a by-product. It swells with water, releases it to roots, and breaks down in the soil.
The European Innovation Council granted €2,384,900 towards a €3.41 million project to take Retentis from pilot production to industry. It did: in July 2025 a full-scale plant was commissioned at the AustroCel pulp mill in Hallein, raising output from a few kilograms a day to about a tonne. Retentis is certified for organic farming in three countries. How much of it is being sold is not public.
Company file
- Legal entity
- AgroBiogel GmbH, Tulln an der Donau, Austria (VAT ATU76442878)
- Academic partner
- BOKU University, Vienna
- Product
- Retentis, lignin-based soil hydrogel
- Production
- Full-scale plant at AustroCel Hallein (commissioned July 2025)
- Certification
- Organic farming inputs in Austria, Spain and Germany
- Markets
- Home and garden, substrate producers, landscaping, forestry, agriculture, industry
- EIC project
- AgroBiogel International Scale-up, 1 Jul 2022 to 31 May 2025
- EIC funding
- Blended finance
Where AgroBiogel Stands Today
AgroBiogel sells Retentis online to gardeners and to professional users, and its news pages in 2025 and 2026 describe uses in vineyards, lawns, reforestation with the forestry company Witasek, and the restoration of the rose garden at Salzburg's Mirabell Gardens. The company claims Retentis "reduces water consumption by up to 40%". It featured in a Der Standard supplement on Austrian agriculture in September 2025.
The Technology: Lignin That Holds Water
Lignin makes up a large share of wood and is mostly burned for energy at pulp mills. AgroBiogel turns it into a hydrogel, a network that absorbs many times its weight in water. Mixed into soil or substrate, it stores water from rain or irrigation and releases it as the soil dries, and, unlike superabsorbent polymers made from petrochemicals, it degrades naturally. Its partnership with AustroCel places production directly at a lignin source.
"Reduces water consumption by up to 40%."
AgroBiogel, on RetentisWhat the EIC Project Promised, and What CORDIS Shows
The project ran from July 2022 to May 2025. The CORDIS report says production was scaled "from a few kilograms per day to approximately one ton per day", with a full-scale plant at AustroCel Hallein commissioned in July 2025; that "more than 40 extensive field trials" were completed; that Retentis gained organic certification in Austria, Spain and Germany; and that a quality management system was set up. It does not report sales.
- Industrial-scale productionDeliveredAbout one tonne a day at Hallein.
- Field validationDelivered40+ trials across sectors.
- Market approvalsPartialOrganic certification in three countries; registration continuing.
- International salesNot shownNo sales figures published.
What Has Happened Since the Award
The Money
When the award was announced in December 2021, Trending Topics reported €3.4 million in total: about €2.4 million of grant and a planned EIC Fund equity investment of about €1 million. In August 2024 Raiffeisen Beteiligungsholding announced that a consortium of Raiffeisen Beteiligungsholding, Elemental Beteiligungs GmbH, Spectrum Value Management and FSP Ventures had invested "a seven-figure sum" for growth and new markets. Whether the planned EIC equity was paid has not been announced. AgroBiogel's website lists support from Austria's promotional bank aws and the EIC. Austrian company filings were not accessible for this article.
What cannot be checked
How much Retentis is sold, the company's revenue, whether the planned €1 million of EIC equity was invested, and independent data on the water savings are not public.
Why Europe Should Care
Europe is restricting intentionally added microplastics, which affects synthetic soil additives, while droughts are pressing farmers and foresters. A biodegradable water-retainer made from a European industrial by-product answers both, and it is now produced at industrial scale in Austria.
What the project promised
International scale-up of a lignin-based agricultural hydrogel.
What the record shows
A tonne-a-day plant, 40+ field trials and organic certification; no public sales figures.
The Verdict
Built for scale, waiting for demand data
AgroBiogel did the hardest industrial step the EIC funded: it moved production into a pulp mill at a scale of about a tonne a day. The product is on sale and used in visible projects. Whether farmers and foresters are buying it in volume, and whether its water savings hold up independently, are what the public record does not yet show.
AgroBiogel has not been asked for comment for this article. It is based entirely on public records, company statements and EU project data, linked throughout.
