The influence of tillage in sugar beets on beneficial, edaphic arthropod communities, and the arthropod-mediated ecosystem services they provide

Soil tillage can impact beneficial arthropod survival either directly or indirectly; thereby, potentially impacting ecosystem services (e.g. weed seed feeding and predation on pests) they provide. Our study investigated the impact of two tillage regimes (spring plow and zone tillage) on resident beneficial arthropods, along with their associated arthropod-mediated ecosystem services, in sugar beets in western Nebraska (2012 & 2013 growing seasons). Beneficial arthropod abundance and species richness was measured throughout the growing season through pitfall trapping. Weed seed-removal rate was measured for four weed species (yellow foxtail, barnyardgrass, lambsquarters, and kochia) in both tillage practices. Additionally, prey-removal was measured using waxworms as surrogate prey. Ground beetles were the most abundant beneficial arthropod taxa collected in both tillage types and years, showing no impact of tillage practice on abundance. Other taxa (Staphylinidae, Araneae, and Chilopoda) showed a higher abundance within zone tillage conditions. A few ground beetle species (n=7) dominated the total number of individuals caught, although the species composition of these dominant species varied slightly between the two years. Weed seed removal was higher in the zone tilled plots for all weed species tested. In contrast, the probability of prey-removal was not influenced by tillage, but the time of day (day or night) affected prey-removal rates. Our results indicate that tillage does not impact all arthropod taxa and the ecosystem services they provide equally.