Self-Propelled Soil Sampler: Evaluation for Efficiency in Obtaining Estimates of Wireworm Populations in Missouri Cornfields123

Abstract

A three-wheeled, self-propelled soil sampler was designed, constructed, and field tested. The average time required per sample when traveling 91.4 m between samples was from 3.5 to 3.9 min when one or three people were used to separate samples. The equipment operated adequately in wet or dry fields. A statistical comparison of the mean numbers of wireworms per m3[Melanotus Depressus (Melsheimer), M. verberans (LeConte), and Aeolus mellilus (Say)] for 10.2-, 7.6-, and 5.1-cm-diameter core sampling programs and for 10.2-, and 22.9-cm-diameter core sampling programs, all at one site, indicated no significant differences between the means of the respective sets of core sizes. These results suggested that any of the core sizes tested allow accurate estimates of wireworm populations. A projected cost analysis indicated that sampling programs in which 5.1 and 22.9-cmdiameter core sizes were used were ca. 47 and 32% more expensive, respectively, than those in which 10.2-cm-diameter cores were used. Sampling programs with 7.6-cmdiameter cores were ca. 12% more expensive than 10.2-cm-diameter cores. The cost per sample of this machine is apparently minimum when two, rather than one or three, people are used to take samples.