The highest level of soil classification. There are presently 11 soil orders, including 1) Entisols, 2) Inceptisols, 3) Spodosols, 4) Ultisols, 5) Alfisols, 6) Vertisols, 7) Oxisols, 8) Histosols, 9) Andisols, 10) Aridosols, and 11) Mollisols.