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Land Development Department Library



            4. Diagnostic horizons, properties and materials

                     Diagnostic horizons and properties are characterized by a combination of attributes
            that reflect widespread, common results of the processes of soil formation or indicate
            pecific conditions of soil formation. Diagnostic materials are materials that significantly influence
            pedogenetic processes or are indicative of them. (Table 1-3)


            Table 1   Diagnostic horizons


                          Diagnostic Horizons                             Diagnostic Horizons

             1.   Anthraquic horizon                         20. Natric horizon

             2.   Argic horizon                              21.  Nitic horizon
             3.   Calcic horizon                             22.  Petrocalcic horizon**

             4.   Cambic horizon                             23.  Petroduric horizon**

             5.   Chernic horizon                            24.  Petrogypsic horizon**

             6.   Cryic horizon**                            25.  Petroplinthic horizon

             7.   Duric horizon                              26.  Pisoplinthic horizon

             8.   Ferralic horizon                           27.  Plaggic horizon**

             9.   Ferric horizon                             28.  Plinthic horizon

             10.  Folic horizon                              29.  Pretic horizon**

             11.  Fragic horizon                             30.  Protovertic horizon

             12.  Fulvic horizon**                           31.  Salic horizon

             13.  Gypsic horizon**                           32.  Sombric horizon

             14.  Histic horizon                             33.  Spodic horizon

             15. Hortic horizon                              34.  Terric horizon**

             16. Hydragric horizon                           35.  Thionic horizon

             17. Irragric horizon                            36.  Umbric horizon**

             18. Melanic horizon**                           37.  Vertic horizon

             19. Mollic horizon


            Remarks:  ** not found in Thailand










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