Tidal marsh area in Indonesia is as wide as 20 million hectares and is potential to be developed as agricultural land. Bulungan Regency, North Kalimantan Province which has expansive tidal area, has been reclaimed partially to develop crops in transmigration pattern. However, rice productivity in that area is still low, which amounts for 3 tons per hectare. This is because tidal marsh area is generally associated with pyrite sediments, which, if not processed with the right technology would be an acid sulfate area unfit to support plant growth.