Epigeal insects in an organic cover crop-based reduced tillage cropping system

Organic cover crop-based reduced tillage cropping systems can provide a number of benefits compared with conventionally-tilled systems, including enhanced soil quality, biodiversity, nutrient supply and retention, erosion control, pest regulation, greenhouse gas mitigation, productivity, energy efficiency, and profitability.  Despite the many benefits associated with these systems, many challenges remain to be resolved before they can be widely adopted by organic growers.   The presence of abundant living and terminated cover crop biomass can influence insect communities and population dynamics of pest and beneficial arthropod species. By adjusting cash crop planting date, growers can reduce risk for damage from early-season insect pests associated with a high residue environment.  We evaluated epigeal arthropod communities in organic maize and soybeans no-till planted on three dates into a mat of hairy vetch and triticale (for corn) and cereal rye (for soybean) terminated by rolling.  Cover crops were terminated and maize and soybeans were planted on three dates (early, middle, late) to test the effect of these practices on crop damage by early-season arthropod pests and predators.  The most common pests detected using pitfall traps include true armyworm, variegated cutworm, and slugs.   Pest populations are highest in the early cover crop termination/cash crop planting date and declined through the middle and late planting dates.  Predators, predominantly spiders, ground and rove beetles, and hymenopteran parasitoids were more abundant and diverse than herbivores, and plant damage has not been significant.  Predators were more abundant and diverse in hairy vetch residue than in cereal rye residue.