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United States Department of Agriculture

Agricultural Research Service

Title: Ground Beetle (Coleoptera: Carabidae) Assemblages in Organic, No-Till, and Chisel-Till Cropping Systems of the Mid-Atlantic Region

Authors
item Clark, Sean - BEREA COLLEGE
item Szlavecz, Katalin - JOHNS HOPKINS UNIVERSITY
item Cavigelli, Michel
item Purrington, Foster - OHIO STATE UNIVERSITY

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 9, 2006
Publication Date: September 29, 2006
Citation: Clark, S., Szlavecz, K., Cavigelli, M.A., Purrington, F. 2006. Ground beetle (coleoptera: carabidae) assemblages in organic, no-till, and chisel-till cropping systems of the mid-atlantic region. Environmental Entomology. 35:1304-1312.

Interpretive Summary: Ground beetles are among the most common insects in agricultural systems. Because they play potentially important ecological roles—some are general predators and some eat weed seeds—the impact of cropping systems on their abundance and species diversity could help in designing cropping systems that are less dependent on pesticide inputs than current conventional systems. We compared ground beetle assemblages in organic, no-till, and chisel-till cropping systems at the USDA Beltsville Farming Systems Project in Maryland. The cropping systems consisted of three-year rotations of corn, soybean, and wheat that were planted to corn and soybean during the two years of field sampling (2001-2002). Each year ground beetles were sampled in the spring, summer, and fall. A total of 2313 specimens, representing 31 species, were collected over the two years of sampling. The eight most common species represented 87% of the total specimens collected. In 2002, ground beetle relative abundance, measured species richness, and species diversity were greater in the organic than in the chisel-till system. Similar trends were found in 2001 but no significant differences were found in these measurements. Multivariate statistical analysis based on the 10 most abundant species showed that the carabid assemblages were most unique in the organic system. Relatively few differences were found between the no-till and chisel-till systems. The results indicate that the combination of practices used in the organic cropping systems favored carabid abundance and favored different species than did the practices used in the two conventional systems. Further research is warranted to understand the specific practices responsible for differences found in this study and to assess the ecological impacts of these differences. This research will be of particular interest to organic farmers who tend to have a strong interest in soil biology.

Technical Abstract: Ground beetle assemblages were compared in organic, no-till, and chisel-till cropping systems of the USDA Farming Systems Project in Maryland. The cropping systems consisted of three-year rotations of corn (Zea mays L.), soybean (Glycine max (L.) Merr.), and wheat (Triticum aestivum L.) that were planted to corn and soybean during the two years of field sampling (2001-2002). Each year ground beetles were sampled using pitfall traps during three, 9 to 14-day periods corresponding to spring, summer, and fall. A total of 2313 specimens, representing 31 species, were collected over the two years of sampling. The eight most common species represented 87% of the total specimens collected and included: Scarites quadriceps Chaudoir, Elaphropus anceps (LeConte), Bembidion rapidum (LeConte), Harpalus pensylvanicus (DeGeer), Poecilus chalcites (Say), Clivina impressefrons LeConte, Agonum punctiforme (Say), and Amara aenea (DeGeer). Canonical variates analysis based on the 10 most abundant species showed that the carabid assemblages in the three cropping systems were distinguishable from each other. The organic system was found to be more different from the no-till and chisel-till systems than these two systems were from each other. In 2002, ground beetle relative abundance, measured species richness, and species diversity were greater in the organic than in the chisel-till system. Similar trends were found in 2001 but no significant differences were found in these measurements. Relatively few differences were found between the no-till and chisel-till systems. The estimated species richness of ground beetles based on several common estimators did not show differences among the three cropping systems. The potential use of ground beetles as ecological indicators is discussed.

Last Modified: 10/30/2014
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