12 Soil Orders

There are twelve different soil types in the United States spread throughout the country. The alfisols soils have an argillic, a kandic, or a natric horizon and a base saturation of 35% or greater.  The andisols include weakly weathered soils with much volcanic glass as well as more strongly weathered soils. The aridisols are too dry for mesophytic plants to grow. The entisols have little or no evidence of development of pedogenic horizons. The gelisols have permafrost within 100 cm of the soil surface and/or have gelic materials within 100 cm of the soil surface and have permafrost within 200 cm. The histosols are mostly soils that are commonly called bogs, moors, or peats and mucks. The inceptisols have lost bases or iron and aluminum but retain some weatherable minerals. The mollisols have a dark colored surface horizon and are base rich. The oxisols have gentle slopes on surfaces of great age. The spodosols are soils in which amorphous mixtures of organic matter and aluminum, with or without iron, have accumulated. The ultisols horizon that contains an appreciable amount of translocated silicate clay and few bases. And lastly, the vertisols have a high content of expending clay and that have at some time of the year deep wide cracks. Georgia is mostly made up of ultisols and a small amount of spodosols and inceptisols.