Innovative kelp extracts boost barley yield in nutrient efficiency trials
Researchers at The James Hutton Institute working on a collaborative project exploring how kelp extracts can enhance nutrient management in farming, have reported promising results from a controlled glasshouse experiment that aimed to determine whether the kelp extracts could improve nutrient uptake under fertiliser-limited conditions.
The trial focused on mitigations against the effects of nitrogen limitation in barley and phosphorus limitation in beans.
UK farmers are under increasing pressure to maintain productivity while reducing fertiliser dependency. Integrating seaweed-derived supplements could improve nutrient use efficiency, reducing carbon emissions while simultaneously enriching soil fertility.
The project, ‘Assessing Sugar Kelp Extracts as a Nutrient Management Tool’, is being led by Algapelago Marine Ltd, with support from Innovate UK and several leading industry partners, working closely with fellow kelp cultivators, Atlantic Mariculture Ltd, as well as research partners, the Hutton and the UK Agri-Tech Centre.
It focuses on three key goals: sustainable extraction and preservation of new seaweed biostimulants, demonstrating evidence for improved nutrient use efficiency and understanding grower needs and market potential.
“The glasshouse trial is now completed and initial results indicated that the tested new seaweed extracts all had significant positive effects on barley grain yield at certain nitrogen levels. This is an excellent result, and we hypothesise that this indicates an improvement in how the barley plants assimilate and use nitrogen. We are testing this by analysing the plant material for differences in nutrient uptake and the soil samples for changes in microbiota composition.”
Dr Gordon McDougall, Head of Plant Biochemistry and Food Quality Group
Atlantic Mariculture has taken the lead in developing sustainable extraction and preservation techniques using cultivated Saccharina latissima (sugar kelp) as feedstock.The company has refined several wet processing methods that avoid the need for energy-intensive drying or milling, creating a route to year-round production that minimises waste while maximising recovery of valuable bioactive compounds. By relying on cultivation rather than wild-harvested kelp, it aims to demonstrate that seaweed-based agricultural inputs can expand sustainably without depleting marine ecosystems.
Dr Adrian Macleod, Innovation Manager at Atlantic Mariculture, said: “As demand for marine biomass continues to grow, seaweed cultivation offers a scalable and sustainable route to meeting future resource needs. Cultivation enables consistent quality and supply while actively supporting Scotland’s Blue Carbon Action Plan and the Circular Economy Act 2024. By growing seaweed rather than harvesting it from the wild, we can deliver ecosystem services and create new opportunities for sustainable marine products.”
Through interviews with growers, ranging from small one-acre market gardens to 3,500-acre arable farms, the team at Algapelago Marine Ltd identified widespread interest in on-farm trials, particularly within arable, fresh produce and soft-fruit sectors. Reducing dependence on expensive chemical fertilisers emerged as the most common reason for exploring alternatives.
“What this project and market research shows is there is a desire to use seaweed-based biostimulants, but there is still some scepticism from farmers about the ‘how and why’. Grounding the development of these products in sound data and combining this with understanding the needs of the sectors, will help to remove some of these barriers.
Martin Sutcliffe, Head of Agri-Systems at the UK Agri-Tech Centre
The trials at the James Hutton have clearly given a strong indication that biostimulants can be a part of the solutions to driving up production, increasing yield and sustainability while reducing the sector’s traditional reliance on fertiliser use.” To register interest in upcoming field trials, contact Kerr Jeferies: kerr@algapelago.com
