Regenerative wheat management: The relative effects of farm practices on the biodiversity of invertebrates

Abstract Bioinventories of agroecosystems can underscore the conservation benefit of ecologically intensive crop management. Regenerative agriculture attains outcomes of improved soil health, water cycling, biodiversity, profit, food nutrition and farmer wellness by reducing reliance on chemical inputs and increasing the ecological diversity of croplands. We measured how different regenerative and conventional management practices that contribute to these systems outcomes affect invertebrates in wheat systems. We examined foliar (sweep samples) and ground‐foraging (quadrat samples) invertebrate communities across 43 wheat fields from eight northern US states and two Canadian provinces in 2022 and 2023. We applied a scoring system to each wheat field based on a series of farm management practices. A total of 15,162 specimens were collected from the foliage, and 2295 specimens were collected from the soil surface. Omnivores, herbivores and predators were the most commonly collected trophic groups, and 96% of specimens were 0.6–5 mm in length. Different geographic regions had distinct invertebrate communities, which contributed to the overall diversity. Wheat fields that employed more regenerative practices had significantly greater foliar invertebrate abundance and greater ground‐foraging invertebrate abundance, taxonomic richness and species diversity (Shannon H). Use of organic amendments and avoiding fertilizers, herbicides, insecticides and fungicides led to greater foliar and ground‐foraging invertebrate abundance, species richness and diversity (Shannon H). Grazing integration practised prior to the wheat crop had no significant effects on invertebrates, and cover crops only enhanced ground‐foraging communities. Pest populations were similar in conventional and regenerative management systems and were below economic levels in all but one field. Although farm management practices do not occur on their own, this work suggests that several practices are as damaging to invertebrate communities as insecticides are. Also, regenerative management of wheat fields can be an important tool for promoting a diverse invertebrate community.