Asian Journal of Plant and Soil Sciences

Inland Valley Swamp (IVS) soils are important for rice production in Sierra Leone, but their acidity and associated fertility constraints can vary substantially among sites. This study characterised the physicochemical properties, acidity status and major fertility limitations of selected IVS soils in Moyamba District to support site-specific soil management. Fifty-one IVS sites were sampled during February and March 2024. At each site, ten soil cores from a depth of 0–20 cm were composited, air-dried and sieved to 2 mm before laboratory analysis. Soil pH, exchangeable acidity and Al, available P, organic C, exchangeable Ca and Mg, and particle-size distribution were determined. Descriptive statistics, Pearson correlation analysis, principal component analysis, cluster analysis and a composite constraint-priority framework were applied. Soil pH ranged from 3.90 to 6.65, with a mean of 4.79 ± 0.54, and 80.4% of the sites were strongly or very strongly acidic. Low Mg affected all sites, while very low available P, low Ca, high or very high exchangeable acidity, and high Al saturation affected 78.43%, 54.90%, 49.02% and 25.49% of sites, respectively. Three principal components explained 69.72% of the total variance, four clusters defined contrasting management domains, and 88.2% of sites had high or very high management priority. These findings indicate that acidity management should be integrated with P, Ca and Mg management and tailored to site-specific soil conditions.