Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/9/2000
Publication Date: 11/9/2000
Citation: Logsdon, S.D. 2000. Characterizing soil structure by rotated core desorption and the odr transect method. ASA-CSSA-SSSA Annual Meeting Abstracts. CD-ROM. Madison, Wisconsin.
Technical Abstract: Typical soil physical measurements such as bulk density and hydraulic conductivity are often inadequate for characterizing soil structural properties. Alternatively this study investigated the oxygen diffusion rate (ODR) transect method to determine macropore spacing and the rotated core desorption method to determine macropore volume, both measured on intact samples. The ODR samples were collected three different ways to allow for horizontal transect measurements in the laboratory: 1) square soil samples excavated by hand and coated with paraffin on the sides, 2) round soil cores collected with a hydraulic sampler and contained in plastic liners, and 3) soil cores contained in square plastic holders made from plastic pop bottles. The samples with paraffin on the side were not stable when wet. The round cores were first used for rotated core analysis and then ODR analysis immediately after final equilibration, while the sample was still horizontal. Unfortunately the hydraulic probe had compressed the samples somewhat, biasing the results. The square plastic samples were stable when wet and not compressed during sampling.