Distribution of pyrite depth and soil properties in fresh water swampland in North Candi Laras Sub-district, South Kalimantan Province

Abstract

One of the challenges of swamp land utilization for agricultural uses is the existence of pyrite (FeS2), especially in the top soil. The aim of this research was to study the distribution of pyrite position with depth and soil properties in fresh water swamp land in North Candi Laras Sub-district, Tapin Regency, South Kalimantan Province. Pyrite layer was determined by using hydrogen peroxide (H2O2) and its unique reaction was marked by foam existence with soil pH <2.5. Ten soil samples analyzed to determine physical and chemical properties. The result of this research showed that pyrite depth varied from 25 cm to >100 cm. The depths of pyrite material were grouped into 25 to 50 cm, 51 to 75 cm, 76 to100 cm, and 101 to 150 cm. The closer to the river, pyrite depth in the soil was deeper. The pyrite depth affected soil pH and cations. Soils containing pyrite material were very acidic with an average field soil pH 4.0 to 4.5. Cation Ca, K, Na levels were higher with the shallower pyrite depth in the soil, meanwhile Mg was almost same in all pyrite depth groups. The information of pyrite position within the soil is useful for controlling water table management to prevent pyrite oxidation.