Comparison of soil water retention at field and laboratory scales

Abstract

Water content and soil water matric potential are measured in different soil volumes and at different spatial scales in the laboratory and in the field. The objective of this work was to use a large database to compare field and laboratory water retention. The database consisted of 135 datasets for soil horizons of various textures. Coarse‐textured soils had the average difference between field and laboratory water contents close to zero. On the contrary, fine‐textured soils with the sand content <50% had field water contents substantially smaller than the laboratory water contents in the range of water contents from 0.45 to 0.60 cm3 cm−3 A quadratic regression explained 70% of variability in field water contents as computed from the laboratory data. A fractal scaling of the bulk density could contribute to the observed field–lab differences in volumetric water contents for the range of high water contents.