Spatial variability of soil porosity under reduced tillage in a Humo-Ferric Podzol

Abstract

The spatial and random variability of soil bulk density, water-filled pore space and macroporosity, which are important indices of soil physical quality in a humid soil moisture regime, were studied in soil samples taken from direct-drilled rotations at Charlottetown, Prince Edward Island. Classical statistics indicated variation was low for bulk density (CV = 3.0–5.8%) and water-filled pore space (CV = 7.4–10.3%), and medium (CV = 15.7–29.6%) for macropore volume. Spatial variation determined using variograms indicated some degree of spatial structure. The ability of variograms to divide sample variance into random and spatial components allows improved estimation of soil sampling size and spacing. Key words: Geostatistics, soil sampling, direct-drilling, humid climate