Effects of rye cover crop on arthropod communities

Corn (Zea mays L.) and soybean (Glycines max L.) are widely produced crops in the United States, both with demand and value rising rapidly throughout the last decade.  Increased production poses significant environmental concerns as both corn and soybean require substantial inputs for cultivation.  Alternative management strategies, such as the planting of a rye (Secale cereal L.) cover crop, may decrease the impacts of production by reducing soil erosion and decreasing pest pressure.  Management of arthropods is an important component of corn and soybean production, with communities in both crops composed of pest and beneficial species, such as natural enemies of insect pests and weed seeds.  In 2011, we measured how a rye cover crop planted within a corn-soybean rotation affected key beneficial and pest arthropod taxa at two locations in Iowa.  We tested the hypothesis that pest abundance is diminished in the presence of a rye cover crop compared to conventional corn and soybean production; conversely beneficial arthropods would be more abundant.  Ground cover was estimated to measure the differences in habitat for ground-dwelling arthropods.  Pest and beneficial arthropod abundance was measured using pitfall traps and sweep nets.  Percent ground cover, pests communities, and beneficial communities did not significantly differ between the presence or absence of rye cover crop grown in both corn and soybean plots.  Rye cover crops have many advantages when incorporated in conventional corn or soybean production; however, how this cover crop is managed may alter the benefits to the arthropod community.