The Potential estimation of soil fertility based mineral types in Papalang areas, Mamuju Regency, West Sulawesi

Commonly mineral is the soil inorganic material composed of various chemical elements. They become an important source of plant nutrients. The research objective is to determine the soil's physical properties and microscopically identified, including color, form, mineral shape, size, and quantity. A soil sample was taken at the top layer (0-20 cm) and bottom layer (20-50cm). We determine the types of minerals and identify nutrient-carrying minerals to assess soil fertility level in the Papalang areas, Mamuju Regency, West Sulawesi. This research's methods are the survey by observing and describing soil profiles in the field, laboratory analysis, identifying soil-forming mineral through thin section method used a polarizing microscope. Based on mineral analysis results, the types of minerals identified as quartz, biotite, and k-feldspar are the primaries silicate minerals. The weathered mineral dominant was biotite, with a percentage ranged from 5-15%. The amount of k-feldspar mineral ranged from 5-15%, measuring 0.04-0.3 mm. The opaque is an oxide mineral, found in all profiles in the top and bottom layer, about 5-15%, with a size of 0.01-0.8 mm. Clay is the secondary minerals from alteration of primary minerals at 35-60%. The research results showed the potential of soil fertility in the Papalang areas classified as low criteria.