Aggregation Status and Physicochemical Properties of Forested and Cultivated Soils of Southeast, Nigeria

Soil aggregation, nutrient content and soil structural stability varied with the land use type are largely involved in agronomic classification of soils. A study was conducted in four different types of soils designated as forested and cultivated. Samples 0-25 cm depth collected in duplicate from these soils were air dried at room temperature and subjected to laboratory analysis for physicochemical properties and aggregation status. Results showed sand fraction to be high in cultivated soils and silt + clay in forested soils. Cultivation decreased the concentration of organic carbon (7.0% - 2.5%), nitrogen (0.7% - 0.25%), and available P (0.5-0.18) mgkg-1 in all studied soils. The pH measured in soil water showed lower value in cultivated ones (5.5-6.0) as against forested samples (5.5-6.5) respectively. Exchangeable bases, base saturation, exchangeable acidity and structural stability tested with different indices all decreased following cultivation. Thus, the result findings revealed that cultivation causes different impacts on the studied soils. Therefore, adequate farm management practices on the soils can ensure their stability and nutrient improvement for maximum production.