Physico-Chemical Properties And Heavy Metal Status Of Wetland Soils Supporting Rice Production In ,Ini Local Government Area, Akwa Ibom State :- Ekpenyong, Idongesit O

Abstract

The sustainability of rice cultivation in wetland ecosystems is highly dependent on the physico-chemical properties and heavy metal status of the supporting soils. This study investigated the physico-chemical characteristics and concentrations of selected heavy metals in wetland soils used for rice production in Ini Local Government Area of Akwa Ibom State, Nigeria. Composite soil samples were collected from five major rice-producing sites within the area at a depth of 0–20 cm and analyzed using standard laboratory procedures. The results revealed that the soils were generally acidic with pH ranging from 4.7 to 5.6, and exhibited moderate organic matter content (1.85–2.96%). Total nitrogen ranged between 0.09–0.18%, available phosphorus from 6.2 to 12.7 mg/kg, and exchangeable cations such as calcium (2.43–4.86 cmol/kg), magnesium (1.12–2.05 cmol/kg), potassium (0.18–0.37 cmol/kg), and sodium (0.14–0.31 cmol/kg) were within moderate levels. The cation exchange capacity (CEC) ranged from 8.2 to 13.5 cmol/kg, suggesting moderate nutrient retention potential. Heavy metal analysis indicated that concentrations of lead (Pb), cadmium (Cd), chromium (Cr), and zinc (Zn) in the soil samples were below the critical limits for agricultural soils as defined by WHO/FAO standards. Mean values recorded were: Pb (3.1 mg/kg), Cd (0.21 mg/kg), Cr (1.9 mg/kg), and Zn (12.4 mg/kg), suggesting minimal contamination and low ecological risk. These findings indicate that the wetland soils in Ini LGA are generally suitable for rice cultivation with low risk of heavy metal toxicity. However, periodic monitoring is recommended to ensure the long-term health of the soil and safety of the rice produced.

Keywords: Wetland soils, physico-chemical properties, heavy metals, rice production, Ini LGA, Akwa Ibom State