This group includes young acid sulfate soil along the coastal zone or coastal swamp. They are poorly drained and medium-textural. Acidification often brings about soil constraints which inturn reduce yield at large. Soils in this group are Pattani (Pti), Ra Nga (Ra) and Ton Sai (Ts) series.

Problems: Strong acid or acid sulfate soils, potentially sulfuric acid muddy subsoil that always fix plant nutrient and release toxicity.

Management for rice: Prepare and spread 500-1,000 kg/rai lime into moist soils, logging water into soils to leach acid and salt. Mix crop residue with soils and leave for 3-4 weeks or apply 50-70 days green manure with LDD organic fertilizer or 16-20-0 chemical fertilizer, 35-45 days after transplanting.Farm ponds are recommended to preserve water to be used in dry season or for second rice .

Management for vegetable or orchard: Raised bed to 6-8 meters wide with 1.0-1.5 meters width and 0.5-1.0 meters depth drainage canal. Spread 500-1,000 kg/rai lime into the top soils beds and logging water into soils to leach acid and salt. Soils improvement with 2-3 ton/rai compose fertilizer or animal manure and chemical or LDD organic fertilizer. . Mix 20-35 kg. compose fertilizer or animal manure with 7 kg of lime in 50*50*50 cm. pit for growing orchard. Apply chemical or LDD liquid organic fertilizer with compose and animal manure at vegetative growth, before and after harvest. Apply 500-1,000 kg/rai broadcast lime into acid sulfate soils.