Green biorefineries could transform European agriculture with grass-based protein

Swedish farmers have long known that rotating cereal crops with grass and clover improves soil quality and reduces environmental damage. But in regions where grain dominates the landscape, these nitrogen-fixing plants remain uncommon. The barrier has always been practical: without a buyer for the harvested biomass, there is little reason to devote precious farmland to them.

Researchers at Chalmers University of Technology began asking a different question. What if the grass and clover themselves became the product? In 2024, Danish scientists demonstrated that fresh grass could be pressed to extract protein, creating a feed supplement that might replace the soy imported into Europe by the ton. Christel Cederberg, a professor of sustainable agricultural systems at Chalmers, and her colleague Göran Berndes recognized the opening immediately. A green biorefinery—a facility that processes freshly harvested grass and clover into multiple marketable products—could solve the market problem while addressing a cascade of environmental concerns tied to European agriculture's dependence on imported soy.

The concept is straightforward in principle. Fresh grass and clover arrive at the facility and are pressed. The protein separates out and becomes animal feed. But the biomass does not stop there. The fiber-rich residue left behind can be converted into biogas for energy, or processed into biochar, textiles, or even captured as carbon dioxide for industrial use. Nothing is wasted. The protein replaces soy, which carries its own environmental weight—pesticide use, nutrient runoff, and pressure on South American land that drives deforestation. Switching to grass protein would reduce those harms substantially while creating more circular nutrient systems and preserving soil fertility in European agricultural landscapes.

The soil itself stands to gain the most from this shift. Long-term field experiments conducted over decades show that diverse crop rotations including grass and clover leys increase the organic matter content of soil. This matters more than it might sound. Soil rich in organic matter holds water better, allowing roots to penetrate deeper during dry periods. It resists compaction and erosion. In the summer of 2026, when repeated heat waves and prolonged drought depleted soil moisture across parts of Europe and the European Commission's Joint Research Centre reported severe crop losses, the resilience that comes from higher organic matter became suddenly visible. Cederberg emphasizes that this is not a quick fix for a single dry summer but a long-term strategy—the kind of soil development that unfolds over years.

The practical work has been underway since 2023 through a Swedish-Danish collaboration called Green Valleys, which operates demonstration facilities in Sweden and Denmark. The researchers have learned that the technology itself is only one piece of a much larger puzzle. Handling different types of grass and clover biomass under varying weather conditions, maintaining product quality, managing logistics and infrastructure, establishing the right business model—these challenges are not trivial. A modeling study examining the large-scale introduction of perennial grass across more than 81,000 areas in the EU and the UK found that when accounting for effects on other crop yields and the potential to replace soy, the additional global demand for agricultural land was relatively small. In some scenarios, land requirements actually decreased.

Yet green biorefineries remain rare. The barriers are both practical and economic. These are complex systems to build, and investment costs have risen in recent years. The agricultural, feed, and food markets operate on thin margins where low prices dominate decision-making. Stakeholders hesitate to invest without confidence that long-term policy conditions will remain favorable. Berndes notes that willingness to invest depends on stable policy signals—assurance that the conditions supporting such ventures will not shift abruptly. The technology works. The soil science is sound. The environmental case is clear. What remains uncertain is whether the economic and political infrastructure will align to bring green biorefineries to scale.