what is a hydric soil and what characteristics should one have?
A hydric soil is a soil that is saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions in the upper part. 1  This definition can be broken up into three component parts: 2  The soil is saturated, flooded or ponded. Saturated conditions are often the result of a high water table.
The physical, chemical and biological properties which make hydric soils recognizable are the result of complex biogeochemical processes occurring over many years. Hydric soils usually have a water table, or the top of a zone of saturation, within one foot from the soil surface during the growing season. This shallow water table excludes oxygen and so creates a reducing environment, especially in the upper part of the soil profile. As a result, mostly hydrophytic plants proliferate -- such as rushes, cattails, sedges and skunk cabbage. Most soils, including hydric soils, are dominantly composed of minerals such as quartz, feldspars, clay minerals, etc. However, hydric soils commonly have a build-up of organic matter at the soil surface, for reasons described above, which can make the surface horizon dark colored. If the organic matter content (measured as organic carbon) is greater than 20 to 30% of the soil's weight (depending upon clay content) and this organic-rich layer is over 16 inches thick, then it is considered an organic soil.