Impacts of rye cover crop on ground-dwelling beneficial arthropods

Corn (Zea mays L.) and soybean (Glycines max L.) are two widely produced crops in the United States, both with demand and value rising threefold throughout the last decade.  Increased production poses significant environmental concerns as both corn and soybean require large inputs for cultivation.  Alternative management strategies, such as the planting of a rye (Secale cereal L.) cover crop, may decrease the costs of production by reducing soil erosion and decreasing pest pressure.  We reasoned that the use of a rye cover planted within a corn-soybean annual rotation will positively increase abundance of ground-dwelling, beneficial arthropods compared to corn-soybean rotations without a rye cover crop.  We measured the ground-dwelling arthropod community in two states over a two year period.  In 2011, we used pitfall traps to measure the activity-density of ground-dwelling arthropods in corn and soybean plots grown with and without a rye cover crop at two locations within Iowa at five times throughout the growing season.  In 2012, we expanded our investigation to include a third location in Missouri and sampled with pitfall traps four times throughout the growing season.  Arthropods captured were identified, quantified, and assigned to feeding guilds.  We detected significant differences in the arthropod activity-density among sampling locations and dates, but did not observe any differences between plots growth with or without a rye cover crop.  Rye cover crops provide agronomic advantages when incorporated in conventional corn or soybean production, but how this cover crop is managed may alter rye’s benefits to the arthropod community.