Sources of Variation and Performance of Nine Devices When Measuring Percent Residue Cover

Abstract

Nine devices were used to visually measure percent residue cover on 21 field sites in 7 states. Three or more observers measured 1000 points with each device at each site, with a total of 20 observers participating in the study. The residues were from crops of wheat, corn, cotton, sorghum, soybeans, and sunflowers. Cover ranged from an average of 11 to 84% for the 21 field sites. The measuring devices were four lines with various arrangements of bead markers, a 15.2-m steel measuring tape, and four wheels with markers located on or near the wheel perimeter.