TEXTURAL AND MINERALOGICAL PROPERTIES OF HYDROMORPHIC SOILS IN ONDO, SOUTHWESTERN NIGERIA: ITS IMPLICATIONS FOR PEDOGENESIS AND NUTRIENT RESERVE POTENTIALS

Abstract

The research analyzed two hydromorphic soil pedons in Ondo, Southwestern Nigeria, to assess a correlation between particle-size distribution and mineral composition as indicators of nutrient-reserve capacity. Particle-size analysis indicated that the soils are coarse-textured, primarily composed of sand (mean 84.2%), with silt (8.0%) and clay (7.8%) fractions. The silt/clay ratio of 1.06 suggests moderate weathering and textural immaturity. Mineralogical analysis indicated a predominance of quartz (67–76%), succeeded by mica (5–20%), feldspar (6–15%), matrix materials (2–8%), heavy minerals (1–3%), and minor rock fragments (~1%). The elevated quartz content and sandy texture indicates a silica enrichment, minimal secondary-clay development, and restricted leaching under intermittent hydromorphic conditions. Recalculated abundances of quartz, feldspar, and rock fragments suggests a low to moderate potential for nutrient reserves. Agriculturally, these soils exhibits low fertility and nutrient-holding capacity; however, improvements can be achieved through addition of organic matter, enhancement of drainage, and application of fertilizers. The soils are classified as quartz-rich, texturally immature hydromorphic soils characterized by low mineral nutrient reserves, which are typical of humid tropical lowland landscapes. The findings indicated that Ondo hydromorphic soils exhibited physical maturity; though chemically deficient, characterized by low nutrient reserves and restricted cation-exchange capacity. Effective management strategies that improve organic matter and nutrient cycling are crucial for maintaining agricultural productivity in these soils.