Fragipan Horizon - Soil Geography of the USA: A Diagnostic-Horizon Approach - page 155

Fig. 15.2 Frequency distribution of fragic soil series by family (Bockheim and Hartemink 2013 )
15.4 Distribution of Soils with Fragipans
There are over 11 million hectares of soil mapping units containing fragipans.
Soils with fragipans occur in 28 states; however, they have been mapped domi-
nantly in the eastern USA: PA (3.2 million ha), Mississippi (MS; 3.0 million ha),
NY (2.3 million ha), Missouri (MO; 1.7 million ha), and KY (1.5 million ha)
(Fig. 15.3 ). Other states with abundant fragipan soils include Arkansas (AR),
Illinois (IL), Ohio (OH), IN, and Tennessee (TN). Seven soil series occupy more
than 500,000 ha each, including the Loring, Providence, Savannah, Grenada,
Mardin, Volusia, and Zanesville series. From our analysis, fragipan soils exist to
a very limited extent in New England and west of the 97 W longitude.
Grossman and Carlisle ( 1969 ) mapped fragipans in two broad regions and two
smaller regions; the two broad regions included the southern Mississippi River
valley and the inner coastal plain of the mid-Atlantic region; the two smaller
regions included the upper Great Lakes and southern Lake Erie regions. Franzmeier
et al. ( 1989 ) identified two broad bands of soils with fragipans in the Midwestern
USA, one extending northwest to southeast across MN, northern WI, and MI and a
second band extending from south-central MO northeast through southern IL, IN,
OH, and northern KY. According to Ciolkosz et al. ( 1992 ), 30 % of the PA soils
have fragipans. Soils with fragipans are used primarily for forestry, but they are also
used for grazing and depending on the depth to the fragipan for a variety of
agricultural crops (Grossman and Carlisle 1969 ).