VARIABILITY OF SOIL BULK DENSITY AND PENETRATION RESISTANCE IN A SEASONALLY WETLAND IN ADO EKITI

ABSTRACT This study investigated soil bulk density and penetration resistance in a seasonally wetland located behind the Central Mosque of Ekiti State University, Ado-Ekiti, Southwest Nigeria, with emphasis on the influence of soil moisture, texture, and organic matter on selected soil physical and chemical properties. The study area is a low-lying floodplain subjected to seasonal inundation under a humid tropical climate. A systematic grid sampling design was adopted over a 100 m × 60 m farmland, and soil samples were collected from sixty (60) representative sampling points at a depth of 0–20 cm. Undisturbed soil samples were collected using a core sampler for bulk density determination, while disturbed samples were collected for laboratory analysis of soil texture, organic matter, and other soil properties. Penetration resistance was measured under wet-season field conditions. Data obtained were analyzed using descriptive statistics and Pearson correlation analysis with SPSS (IBM Version 20.0). Results showed that soil bulk density ranged from 0.72 Mg m-3 to 1.50 Mg m⁻³, indicating moderately loose soil conditions typical of seasonally wet environments. Penetration resistance generally decreased with increasing soil moisture. The soil was classified as clay loam. Clay content showed strong positive correlations with water retention capacity (r = 0.82, p < 0.01) and cation exchange capacity (r = 0.76, p < 0.01), and a strong negative correlation with saturated hydraulic conductivity (r = −0.71, p < 0.01). Penetration resistance showed a significant positive correlation with bulk density (r = 0.71, p < 0.01) and a negative correlation with organic matter content (r = −0.67, p < 0.01). Organic matter content also showed positive correlations with water retention capacity (r = 0.49, p < 0.01) and cation exchange capacity (r = 0.58, p < 0.01). The study concludes that soil moisture, clay content, and organic matter are major factors influencing soil structure, water retention, and soil strength in the seasonally wetland during the wet season.