IMPACTS OF DIVERSE, REDUCED-DISTURBANCE AGROECOSYSTEMS FOR PEST CONTROL
In Pennsylvania, almost 2/3 of conventional row crop growers practice no-till to reap soil health benefits and save on labor and fuel costs. For organic growers, this is much more challenging as tillage is the primary way that weeds and other pests are managed. For my PhD, I worked on a collaborative project focusing on strategies for reducing tillage in organic row cropping systems and their cascading effects on insect communities and biological control. Our collaborative goal was to identify practices that allow for reduced-tillage within a rotation, with minimal costs to yield, soil nutrient cycling, weed management, or insect pest management. Tillage is often heavily relied upon in organic crops to kill weeds, incorporate fertilizer sources, and disrupt the life cycles of insect pests that spend part of their life in soil. Tillage can be labor-intensive, weaken soil structure, and deter predatory arthropods, however. We relied on methods such as roller-crimping cover crops to create a weed-suppressive mulch without tillage or inter-seeding cover crops between cash crop rows to allow the establishment and termination of cover crops without full tillage. I investigated how preceding cover crops, tillage regime, and inter-seeding affect predators such as spiders, ground beetles, and harvestmen. I also tried to tease apart the relative contributions of these predator groups to management of pests in these systems.