Ecosystem services of perennial grain crops

Agriculture faces mounting pressure to produce food, feed, and renewable biomass from a finite land base while safeguarding soil and environmental quality for future generations. Perennial grain crops have emerged as a promising strategy to address these challenges by producing edible grain alongside substantial vegetative biomass, maintaining continuous soil cover, and developing deep, persistent root systems. A key strength of perennial grains is the provision of multiple ecosystem services. Evidence to date indicates that perennial grain systems can reduce nitrate leaching, lower nitrous oxide (N₂O) emissions, increase carbon sequestration, improve soil structure and nutrient retention, enhance on-farm forage value, and promote biodiversity. Reduced reliance on tillage and external inputs may further decrease fossil fuel use and environmental externalities. In addition to these, perennial grains may provide cultural and aesthetic benefits, such as improving landscape aesthetics, and supporting local traditions and practices related to agriculture. This review synthesizes current knowledge on the ecosystem services provided by perennial grain crops and identifies critical research gaps related to their quantification, trade-offs, and scalability. Robust quantification can support economic valuation, providing a foundation for policy and market incentives that favor the adoption of perennial grain systems and add valuable biomass material to support the green transition.