COMPARATIVE ASSESSMENT OF PHYSICO-CHEMICAL PROPERTIES OF SOIL IN DIFFERENT ECOLOGICAL ZONES OF WESTERN NIGER DELTA, NIGERIA

¹Olisa C. O., ²Akinloye K.F., ³Idisi E.B. and ¹Eludoyin O.S.
1-Department of Geography and Environmental Management, University of Port Harcourt, Port Harcourt, Nigeria
2- Department of Geography, University of Ilesa, Ilesa, Osun State, Nigeria
3-Department of Environmental Management, Delta State University of Science and Technology, Ozoro, Delta State, Nigeria
Corresponding Email: olatunde.eludoyin@uniport.edu.ng

Abstract

The study examined the comparative assessment of physico-chemical properties of soil in different ecological belts of Western Niger Delta, Nigeria. Eight 20m x 20m quadrat were delimited in the natural vegetation in each of the rainforest (RF), mangrove (M), fresh water swamp (FWS) and guinea savanna (GS) ecological belts to collect soil samples. Soil samples were collected from the topsoil (0-15cm) and subsoil (15-30cm) and were taken to laboratory for further analysis. Descriptive statistics and inferential statistics were used for data analysis. Findings showed that in the topsoil, the silt content was highest in FWS (17.37±4.8%). The bulk density, total porosity and water holding capacity were slightly varied among the four ecological zones. In the subsoil, the mean soil moisture was significantly highest in the M (31.13±3.2%) and the silt content was highest in the RF. The soil moisture, sand, silt and clay were significantly varied among the ecological zones in both topsoil and subsoil. Findings revealed that soil pH was acidic in all the ecological zones. The organic C, total N, available P, exchangeable Mg and exchangeable acidity were considerably highest in the FS in both topsoil and subsoil. Significant variation was found in the soil moisture, sand, silt, clay, pH, organic C, total N, available P, Ca, Mg, K, CEC, Pb, Mn, Fe, Cu, and Zn among the ecological zones in both topsoil and subsoil. The study concluded that bulk density, total porosity and water holding capacity were slightly varied among the four ecological zones but soil moisture was highest in M. The organic C, total N, available P, exchangeable Mg and exchangeable acidity were considerably highest in the FWS while concentrations of Pb, Cu, Zn and Fe were highest in the topsoil of RF. It is recommended among others that the physical soil properties especially sand, silt, and total porosity in the topsoil should be maintained in the ecological zones to support the livelihood of soil biodiversity.

Keywords: Physical, Chemical, Ecological belts, Descriptive, Inferential, Topsoil, Subsoil