Long-Term Sustainability Implications of Diverse Commercial Pollinator Mixtures for the Conservation Reserve Program

Abstract

The persistence of Conservation Reserve Program (CRP) seed mixtures following planting is crucial for the long-term support of pollinator habitat; however, the role of disturbance regimes and their interactions in supporting this ecosystem service are largely unknown. This study set out to evaluate how ecological disturbances (prescribed burn, light disking, or fallow control) and commercially available diverse species mixtures (‘Hamilton’, ‘Bamert’, and ‘Holland’) affect pollinator habitat and the flowering period of commonly used CRP species mixtures. Specifically, three pollinator species mixtures were assessed for plant stand dynamics (plant density, yield, and dual-use pollinator-lignocellulosic feedstock potential); the resulting soil properties; and the total bloom count during the growing season. Following 5 years after their establishment, the proportions of flowering pollinator species varied by disturbance regime × seed mixture (p < 0.05), with the burned Hamilton and disked Holland plots having the greatest pollinator species percentages. Overall, if the long-term stability of pollinator blooms is a key consideration for management, the Hamilton mixture should be disturbed via prescribed burning, while the Holland mixture should be disked, owing to a species-specific disturbance regime preference. However, post-senescence yield and soil health properties did not vary (p > 0.05) across pollinator mixtures or disturbance regimes. Pollinator mixtures could also be harvested as a lignocellulosic feedstock without damaging pollinator habitat and providing comparable biomass for regional feedstocks; however, seeding mixtures and disturbance regimes should be considered based on desired residue usage for long-term sustainable CRP pollinator habitat.