ABSTRACT
The main problems that motivated American soil scientists to work on a new classification were the following:
The previous classification did not give objective criteria for distinguishing the taxa of the higher levels, the borders between most classes were fuzzy, the diagnostic soil properties were generally subjective, and global relationships among soils were not clear.
Ambiguous terminology led to misunderstanding: as the scale of soil survey increased, different soils were often described under the same name.
The absence of quantitative criteria for soil diagnostics led to difficulties in the work of practical soil surveyors.
The old classification did not readily incorporate soil series.
