Self-cover cropping systems and the plusquam-annual: New tools for cropping system sustainability

Annual grains form the basis of human diets and thus agricultural systems, but the seasonal fallow phases inherent in their production pose environmental challenges. While cover cropping and perennial grains offer potential solutions, both currently carry significant practical hurdles to wide-scale implementation. Here we introduce self-cover cropping systems - achieved through post-harvest crop regrowth - to deliver cover crop-like ecosystem services with fewer challenges. As a corollary, we define plusquam-annuals (meaning "more-than annuals") as a distinct, novel crop growth habit characterized by a single grain harvest followed by regrowth with no expectation of a second grain harvest. We suggest viable plusquam-annual cereals may already exist and offer a conceptual framework that invites empirical exploration with both applied and theoretical significance for supporting sustainable agricultural systems.