This soil group consists mainly of poorly drained and fine-textured that commonly occur on low-lying terrain of brackish water deposits, former tidal flat or flood plain. This soil group is strong acidic and moderate fertility. Soils in this group are Ayutthaya (Ay), Bang Khen (Bn), Bang Nam Prieo (Bp), Maha Phot (Ma) and Tha Kwang (Tq)