Influence of Cover Cropping and No-Tillage Practices on Community Composition of Soil Arthropods in a North Carolina Agroecosystem

Abstract

Winter legume and grain cover crops preceding corn, Zea mays L., grown using conventional and no-tillage methods were investigated for their effect on population dynamics and community structure of soil arthropods. Hairy vetch, Vicia villosa Roth, supported higher below-ground arthropod population densities and a more taxonomically diverse fauna than crimson clover, Trifolium incarnatum L., or wheat, Triticum aestivum L. Pest and beneficial soil arthropods were most abundant in no-tillage corn preceded by hairy vetch. Diversity of soilarthropod species was higher under no-tillage than conventional tillage. Divergences in community structure of soil arthropods among cover crop species, evident early in the season, dissipated by midseason. Arthropod predators were more numerous in no-tillage than conventional tillage systems regardless of previous cover crops. Although no-tillage practices promoted a more trophically balanced soil arthropod community than conventional tillage during early and mid season, in 1987 seedling corn plants in no-tillage vetch treatments sustained significantly higher (P < 0.05) damage from the southern corn rootworm, Diabrotica undecimpunctata howardi Barber, than in other treatments. Tillage system preference was shown by herbivores: Seedcorn maggot, Delia platura (Meigen), occurred in large numbers in conventional tillage, and southern corn rootworm populations were high in no-tillage, especially following legume cover crops.