This group of soils are of poorly drained and shallow that always occur mainly on low-lying of alluvial terraces and erosional surface. Coarse fractions compose mainly of iron stones or laterlitic gravels. The underlying material beneath gravelly layer is mottled of plinthic clay. They are low fertility. Soils in this group are Kan Tang (Kat), On (On), Phayom Ngarm (Pym), Sa Ton (Stn), Tung Khai (Tuk) and Yan Ta Khao (Yk) series.

Problems: Very shallow soils with stones or laterite which is not suitable for agriculture should be left to be forest or fast growing trees.

Management for rice: Rice could be grown on thick soils with mixture of crop residues into moist soils and leave for 3-4 weeks. If managing by green manure, it should be the mixture of 6-8 Kg/rai of 50-70 days Sesbinia rostrata or S. speciosa with 16-16-8 chemical fertilizer or LDD liquid organic fertilizer after 1-2 weeks. Top dressing again with 15-15-15 chemical fertilizer, 35-45 days after rice transplanting. Farm ponds are recommended to preserve water to be used in dry season or second rice crop. If vegetables or legume will be planted, furrows would be constructed with application of 3-4 ton/rai compose or animal manure with chemical or liquid fertilizer.

Management for vegetable or orchard: Vegetable or orchard could be well grown on thick soils. Raised bed to 6-8 meters wide with 1.0-1.5 meters drainage canal. Raised bed around the beds then apply 3-4 ton/rai compose fertilizer or animal manure with chemical fertilizer or LDD liquid organic fertilizer. Apply 25-50 kg of compose fertilizer or animal manure into 75*75*75 meters pit to grow orchard. Apply compose fertilizer or animal manure with chemical fertilizer or LDD liquid organic fertilizer at vegetative growth, before and after harvesting. Farm ponds and water management are recommended to preserve water to be used in dry season.