Swedish agricultural researchers at Chalmers University of Technology are investigating how integrating grass and clover leys into cereal-dominated crop rotations can yield protein feed, reduce imported soy dependence, and produce fiber-rich industrial materials. According to Chalmers researchers Christel Cederberg and Göran Berndes, expanding green biorefineries in arable farming regions addresses both soil health and European protein supply challenges.
The Agricultural Case for Grass and Clover Leys
Growing leys—specifically grass and clover—is an established practice in Swedish agriculture, but cereal-dominated arable farming regions use them less frequently. According to Christel Cederberg, a professor of sustainable agricultural systems at Chalmers, farmers understand that growing grass and clover improves soil quality. However, the primary challenge remains finding a stable market for the harvested biomass resource, as reported by Chalmers.
Introducing these leys into cereal crop rotations provides multiple positive effects on soil structure and the surrounding environment. These benefits include maintained soil fertility, enhanced conditions for agricultural biodiversity, and more circular nutrient systems, according to Cederberg. Furthermore, the shift helps mitigate negative impacts from agricultural pesticides.
Extracting Plant Protein to Replace Imported Soy
The push toward green biorefineries gained momentum when Swedish researchers observed pilot facilities in Denmark. According to Göran Berndes, a professor of biomass and land use at Chalmers, Danish researchers began extracting protein from fresh grass to produce an alternative protein feed. Adopting this approach across a wider scale allows European agriculture to reduce its reliance on imported soy protein.
Imported soy is frequently associated with extensive environmental problems abroad. By biorefining protein directly from freshly harvested grass and clover leys, farmers can substitute a portion of that imported feed with locally sourced plant protein. The extraction process separates the protein fraction from the rest of the plant material, creating a functional animal feed component.
Fiber-Rich Residual Streams and Industrial Applications
Protein extraction leaves large quantities of fiber-rich residual streams behind in the biorefining process. Historically, these agricultural by-products primarily supplied material for biogas production. However, researchers are actively exploring a wider array of industrial possibilities for the remaining biomass.
According to Göran Berndes, potential applications for the fiber-rich biomass include biochar, textile manufacturing, and carbon capture initiatives. Captured carbon dioxide can either be stored permanently underground or utilized as an industrial feedstock to replace fossil carbon dioxide. Despite these diverse possibilities, Christel Cederberg emphasizes that these technological applications remain in early development stages requiring further research.
Climate Resilience and Farmland Pressures
The ability of agricultural soils to withstand extreme weather events became particularly pressing following the summer of 2026. Repeated heatwaves and prolonged rainfall deficits depleted soil moisture reserves across significant portions of Europe. In August 2026, the European Commission’s Joint Research Centre (JRC) documented worsening prospects for multiple summer crops alongside severe agricultural losses in heavily impacted regions. The prolonged drought conditions also fueled extensive forest and wildfires across the continent.
Expanding the total land area dedicated to grass and clover leys offers a pathway toward building more climate-resilient agricultural soils. Cederberg notes that while research confirms long-term soil resilience benefits, transforming regional land-use patterns requires sustained agricultural development and established commercial markets for all harvested fractions.
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