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ARS Home » Research » Publications at this Location » Publication #92765
Title: SOYBEAN MOISTURE CONTENT MEASUREMENT BASED ON IMPACT FORCE PARAMETERS

Author
item STEWARD, BRIAN - UNIV OF ILLINOIS
item HUMMEL, JOHN

Submitted to: International Conference on Precision Agriculture Abstracts & Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/20/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Accurate measurement of grain moisture content is required for correct yield measurement. Currently, yield monitors use moisture sensors that have a sensing blade inserted into the grain flow. Under some harvesting conditions, particularly heavy weed infestations, plant juices can wet the sensing blade and cause erroneous moisture readings. The juices tend to be sticky, and are not easily wiped from the blade by the flowing grain. Consequently, erroneous moisture readings continue for some time after the harvester has passed through the weedy area. In this research, we were investigating an alternative real-time grain moisture sensing technique. We hoped to show that the moisture content of soybeans was related to the impact force produced by dropping a soybean on a force sensor. We showed that a large sample of impacts would be needed to obtain the necessary moisture prediction accuracy, and that the technique would work only in a limited range of moisture contents.

Technical Abstract: Previous work has shown that force-time curves for impacting soybeans vary with soybean moisture content. This paper documents an effort to characterize the nature of the relationship between a parameter developed from the force-time curve and soybean moisture content. The underlying objective was to determine if impact force sensing could be used to reliably make real-time moisture measurements for yield monitoring applications. A parameter, C, based on the peak force and duration of the force-time curve was calculated. C was regressed onto moisture content using a polynomial model. The model fit the data with R2 = 0.84 and 0.76 for the Conrad and Jack cultivars, respectively. The variability in C increased as moisture content decreased, and the strength of the relationship between C and moisture content decreased with increasing moisture content.