MORPHOLOGY AND PHYSICOCHEMICAL PROPERTIES OF URBAN SOILS IN CALABAR MUNICIPAL, CROSS RIVER STATE, NIGERIA

Abstract

Urbanization can alter inherent soil fertility, affecting the ability of soils to support and sustain crop production. This study evaluated the morphology and physicochemical properties of coastal plain soils in Calabar Municipality, Cross River State, Nigeria. Three soil profile pits were dug along a toposequence (crest, middle slope, and valley bottom) and examined using standard field and laboratory procedures. Morphological observations showed that the soils were moderately developed, with textural classes ranging from sandy loam in the surface to sandy clay loam in the subsurface, and colors from very dark brown (10YR 2/2) to strong brown (7.5YR 5/8). The results of soil physical properties indicated sand to be dominant (41–81%) over other particle size classes and bulk density values between 0.95 and 1.65 g/cm³. Furthermore, the results of soil chemical properties revealed strong acidity (pH: 4.2–5.7), low organic carbon (0.84–1.52%), total nitrogen (0.07–0.25%), and available phosphorus (4.25–6.37 mg/kg). Exchangeable bases and micronutrients were moderate; however, extractable Fe and Zn were dominant over Cu and Mn, particularly in the crest position. The combined findings indicate that the fertility indicators of the soils are moderate but constrained by acidity. Sustainable soil management practices such as liming, compost addition, and organic amendments are therefore recommended to improve soil fertility and structural stability for enhanced crop production.