Morphological homogeneity of soil series, Maracaibo plateau, Zulia state, Venezuela

Abstract

The objective of this research is to determine the morphological homogeneity of three soil series (Maracaibo, Los Cortijos, and San Francisco) located in the semi-arid sector (very dry tropical forest) of the Maracaibo plateau, Zulia State, Venezuela. The taxonomic units (soil families) that identify these series are: Typic Paleargids, fine loam, kaolinitic, isohyperthermic (Maracaibo and San Francisco) and Typic Paleargids, fine clay, kaolinitic, isohyperthermic (Los Cortijos). Ten soil profiles were described per series, in which sixteen morphological characteristics were identified. The Multiple Homogeneity Index (MHI), based on principal component analysis, was applied to calculate the homogeneity among the series under study and in each of the soil profiles described within them. The contribution of morphological variables to the homogeneity of the soil series was determined. The results allow us to establish a sequence of homogeneity among the soil series, as follows: San Francisco Series > Los Cortijos Series > Maracaibo Series. The IHM proved to be a useful tool for determining the morphological homogeneity of the soil series, as well as understanding the contribution of the morphological characteristics described in their horizons and soil profiles. The homogeneity sequences obtained in this study, together with the physicochemical homogeneity sequences determined in another study conducted with the same series, constitute the basis for defining soil taxonomic units at the series level, which would effectively contribute to soil correlation at the local, regional, and national levels.