Abstract
Soil particle density is a critical parameter that affects soil properties, yet its assumed constancy across soil types overlooks significant variations. Also, soil organic matter plays a vital role in shaping soil properties, including particle density. This study investigated the relationship between particle density and soil organic matter in degraded kaolinitic soils of South-East Nigeria. Data were regrouped into predetermined particle density estimates—estimated, measured, and determined—and evaluated under different levels of soil organic matter. Results demonstrated that soil organic matter levels influence both particle density and bulk density, with higher soil organic matter levels associated with lower particle density and bulk density values. Estimated total porosity, computed using assumed particle density values (2.65 g/cm3), aligned well with the determined particle density (calculated with the ‘exact’ particle density values) across soil organic matter levels. However, total porosity measured through the water desorption method (measured total porosity) showed significant deviations from the other two methods, emphasizing the importance of soil organic matter and soil types in porosity estimation. The study also establishes relationships between different porosity estimates at varying soil organic matter levels, providing insights for suitable porosity computation methods. These findings contribute to understanding the impact of soil organic matter on particle density and accurate soil porosity assessment in tropical soils.
