ABSTRACT
The publication of a second edition of Soil Taxonomy in 1999 was a benchmark event that, among other things, enabled us to evaluate the progress of soil classification over five decades. The quest for a single international system will continue to be elusive for another few decades, and Soil Taxonomy will still have imperfections. However, it is a living system in the sense that it serves a function. Because of this and the fact that it has been amenable to changes without major alterations to the basic structure, the system will continue to serve in the future, needing refining only when knowledge and applications warrant it. Facts determined by precise observation, experimentation, and measurement minimize prejudicing the future, and are the building blocks of a classification system. Systems built solely on empirical relationships among facts or genetic theories falter quickly. As there are relics of classification systems around the world, we considered that it would be useful to elucidate some of the lessons learned during this glorious period of Pedology. These 28lessons will be useful when further refinements are attempted. They will also be useful to others when they embark on a similar exercise, and to some countries that are developing national systems.
