Date of Award
Master of Science
Bobby L. Bledsoe
John I. Sewell, Zachary A. Henry, Fred D. Tompkins
An instrument for use by farmers and agricultural research workers to quickly, accurately, and economically determine the moisture content of hay in the windrow would significantly improve the efficiency of forage crop production. However, no method or technique has been shown to be a successful tool for obtaining such determinations simply, precisely, and with easily portable equipment. An experiment was desig-nated to field test a commercially available conductance-type moisture meter and to identify needed revisions of the meter or a measuring technique that might improve its accuracy. An experimental conductance-type meter was also built and tested in an attempt to develop a more accurate method for hay moisture content measurements. Three electrical moisture meters, a hydraulic compression device, sample probe, hay sample chopper, and other related swithing gear were purchased or designed and constructed. The meters were tested on three different hay types, at various sample pressures, and at two geographical locations. The performance of the meters was compared to oven drying moisture determinations. Results of these series of tests revealed several factors which affect the accuracy of the meters as determined from simple linear regression equations relating meter readings to actual hay moisture content. 1. The use of a cylindrical holder eliminated error caused by the prod pins completely penetrating the windrowed hay and entering the soil surface. 2. Sample pressure affected meter readings. No specific pressure was best overall, but a constant pressure was mandatory for consistent results. 3. Fields, type of crop, or time of test also affected meter readings and calibration equations. 4. Chopping of hay samples improved the accuracy and consistency of meter readings. 5. No one single meter proved to be statistically better than the others tested.
McDonald, Joseph Keith, "Evaluation of rapid reading hay moisture meters for field use. " Master's Thesis, University of Tennessee, 1976.