Assessment of the spatial variability of soil chemical properties along a transect using multifractal analysis

Abstract

The spatial variability of soil properties can be assessed through concepts of scale invariance, fractals and multifractals. The aim of this study was to characterize the scaling patterns and structural heterogeneity properties of general soil chemical properties along a short (i.e. 52 m large) transect. Field measurements were carried out at the experimental farm of CIAM located in Mabegondo, A Coruña, Spain. The studied transect was marked following land slope, and 66 soil samples were collected at the 0-20 cm depth every 0.8 m. The soil properties analyzed were: pH (H2O ), organic carbon content, exchangeable Ca, Mg and K, exchangeable acidity (H + Al), exchangeable bases (SB), cation exchange capacity (CEC), percent base saturation (V) and extractable P. The soil properties studied showed various degrees of multifractality. The spatial distribution of pH was characterized by quasi-monofractal behaviour; CEC, (H+Al) and OM, presented a relatively low degree of multifractality, and the other soil properties studied showed stronger degrees of multifractality, being the highest one for Olsen extractable P. In general, the scaling features of the properties studied implied a multifractal nature, where the low and high density regions scaled differently.