A high-diversity/IPM cropping system fosters beneficial arthropod populations, limits invertebrate pests, and produces competitive maize yields

In the United States, current crop production often favors simplified rotations of maize and soybeans in conjunction with a heavy reliance on synthetic inputs that consequently degrade environmental health and increase production costs, without necessarily improving yields. While often stigmatized as underperforming compared to conventional systems, “sustainable intensification” of cropping systems offers an alternative that relies on crop rotation diversity, continuous crop cover, and integrated pest management to combat pests. Within a long-term no-till systems experiment, our main goal was to determine if a high diversity-IPM system (HiDiv-IPM) could compete with a low diversity-preemptive pest management system (LoDiv-PP) in terms of invertebrate pest management, biological control, and maize establishment and yield. Our results suggest that early-season pests, particularly caterpillars, reduced maize establishment by 10 % in the HiDiv-IPM system compared to the LoDiv-PP system. Both our simple and more diverse rotations suffered from slug damage that reduced crop establishment, however, overall slug abundance and damage tended to be equal. Despite lower seedling establishment and greater caterpillar damage, maize in the HiDiv-IPM rotation yielded similarly to the LoDiv-PP rotation, suggesting that other factors, such as higher levels of predation evident in the more diverse rotation or possible nutrient- and soil quality-related issues, contributed to productivity. These results support the notion that a HiDiv-IPM system can compete with a LoDiv-PP system and, contrary to the most common approach for controlling insects in maize production in the U.S., aggressive, preemptive pest management was not necessary to achieve competitive yields.