Analysis of Soil Erodibility in Foramadiahi Village, Pulau Ternate District

Abstract

The research objective was to quantify the erodibility factor across representative land units and to determine the key soil properties that control spatial variations in K. A total of seven soil profiles were selected based on land unit stratification, followed by field description, composite sampling (0–30 cm), and laboratory analysis of texture, organic carbon, permeability, and aggregate stability (M value). Erodibility was calculated using a combined empirical–analytical approach following the USLE method. Results indicated that the K-factor varied substantially among profiles, ranging from very low (0.09) to moderately high (0.38). High values were associated with soils containing higher silt fractions, lower organic carbon, and weaker aggregate stability, while low values were linked to clay-rich soils with better structural cohesion. Spatial variability of K reflects the influence of volcanic parent materials, slope steepness, and land management practices common in Foramadiahi, including mixed gardens and spice plantations. These findings imply that land units with higher erodibility require priority soil conservation interventions such as increased vegetative cover, organic matter inputs, and structural measures like terracing, particularly on mid- and upper-slope positions. The study provides essential baseline information for evidence-based land management and contributes to erosion risk assessment on small volcanic islands. Overall, the quantified erodibility patterns highlight the need for site-specific conservation planning in the steep, rainfall-sensitive environment of Mount Gamalama.