HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Sander, T. Articles by Gerke, H. H. Search for Related Content PubMed Articles by Sander, T. Articles by Gerke, H. H. GeoRef GeoRef Citation Agricola Articles by Sander, T. Articles by Gerke, H. H. Related Collections Soil Methods/Instrumentation Structure and Properties Soil Analysis Soil Physics

SOIL PHYSICS

Noncontact Shrinkage Curve Determination for Soil Clods and Aggregates by Three-Dimensional Optical Scanning

Institute of Soil Landscape Research, Leibniz-Centre for Agricultural Landscape Research (ZALF), Eberswalder Strasse 84, D-15374 Müncheberg, Germany

^* Corresponding author (till.sander{at}zalf.de).

The classical saran resin method for determination of the soil shrinkage characteristic (SSC) curves based on volume determination of saran-coated clods is limited by water penetration during submersion, requires correction for the volume of coatings, and does not account for swelling. This study compared a novel noncontact method for SSC curve determination with the classical saran method. Natural, irregularly shaped clods of 18 to 45 g detached from four horizons of a clayey to loamy Chinese paddy soil were capillary saturated to a matric potential of –4 cm. During air drying, the changing clod volume was repeatedly measured by three-dimensional optical scanning and the water content determined gravimetrically. After resaturation of the same clods, measurements were repeated with the saran method. Optical scanning of clods from various positions resulted in sets of point clouds that required comprehensive data processing. The final three-dimensional volume objects were generated by adaptive triangulation. When assuming 0.3 to 0.8 g of water penetration for the saran method and a correction to account for a 20 and 18% loss of mass of air- and oven-dry saran coatings, respectively, the SSC curves of the two methods were relatively similar. Spearman's rank correlation coefficient was 0.88 at the 95% confidence level. Errors for the new three-dimensional method may occur during manual data processing. The new, three-dimensional optical method is suitable to determine the SSC curve of relatively small, irregularly shaped clods with low to medium shrinkage in a wide range of water contents.

Abbreviations: 3-D, three-dimensional • MB, megabyte • MEK, metyl ethyl ketone • SSC, soil shrinkage characteristic

This article has been cited by other articles:

				A. M. Rossi, D. R. Hirmas, R. C. Graham, and P. D. Sternberg Bulk Density Determination by Automated Three-Dimensional Laser Scanning Soil Sci. Soc. Am. J., November 1, 2008; 72(6): 1591 - 1593. [Abstract] [Full Text] [PDF]