Afforestation affects vertical distribution of basic soil characteristics and taxonomic status of sodic soils

Abstract

Afforestation, settled before 60–90 years and adjacent solonetzic grasslands, representing the natural vegetation cover were compared in this study based on their basic soil characteristics (pH, CaCO3 content, soil organic carbon (SOC), and exchangeable sodium percentage (ESP)) up to 2 m depth. The assumption was that the plantings of arbour vegetation can change soil characteristics of sodic soils not only in superficial layers but even in larger depths. Grasslands and forest soils were compared by standardised depths. Afforested soils showed lower pH in the depth at 0–100 cm, and slightly higher SOC content in subsoil (20–100 cm). CaCO3 content was significantly different (higher) only at the depth of 50–100 cm in afforested soils. Remarkable differences in ESP values were measured. Afforestation had in almost every layer (0–20, 20–50, 50–100 and 150–200 cm) a significant lower ESP value than grassland soil samples from the same depths. As the value of the ESP is relevant from soil classification purposes as well, the leaching of sodium also can change the taxonomic status of the soils from soils with natric horizon, to soils with Sodic or Bathysodic qualifiers.