Diverse Prairie Mixtures Stabilize Biomass Yields for Sustainable Aviation Fuel Production

Societal Impact Statement Meeting global demand for sustainable aviation fuel will require the additional production of vast quantities of plant biomass, which does not compete with food production or degrade sensitive ecosystems. Our multisite experiment shows that sowing diverse native prairie seed mixes—and managing them without intensive inputs—yields a more reliable biomass supply across heterogeneous landscapes than single‐species plantings, while simultaneously restoring habitat and building soil carbon. These findings give farmers and policymakers a low cost, nature‐positive strategy for delivering consistent sustainable aviation fuel feedstocks that support both climate mitigation and biodiversity goals. Summary Efforts underway to decarbonize the airline industry are expected to drastically increase commercial demand for sustainable aviation fuels (SAF), and lignocellulosic feedstocks with low carbon intensity scores are needed to achieve greenhouse gas mitigation goals. Diverse mixtures of perennial prairie species have the potential to serve as an SAF feedstock that does not compete with existing food production systems while providing a suite of valuable ecosystem services. However, spatial variability in biomass productivity remains a hindrance to the viability of local refineries. This challenge will be amplified if production is to be sourced from a distributed network of heterogeneous fields. Highly controlled (i.e., weeded) grassland biodiversity experiments demonstrate that increasing species richness can improve yield and reduce variability across sites, but this has not been rigorously tested in low‐input, perennial biofuel cropping systems. To this end, we conducted a 7‐year regional biodiversity experiment, seeding 1, 4, 8, 12, or 24 native perennial species across nine edaphically and climatically distinct sites. We found some evidence that increasing seeded richness enhanced biomass yields across sites, but this was largely due to the inclusion of relatively low performing grass monocultures. In contrast, adding species reduced cross‐site variability relative to monocultures regardless of their productivity, and this result was robust to the effects of nitrogen fertilization. Our results suggest that sowing diverse mixtures reduces the need for site‐specific planting designs across distributed production fields, offering a practical means of implementing a dependable SAF feedstock supply chain across varied landscapes.