A New Groundlevel in Florida: Urban Soils Forming in Fill Material.

Florida is undergoing rapid urbanization and a significant amount of residential development involves the construction of homes on fill material.  There is a concern that soils forming in urban fill materials are a poor substrate for turfgrass and horticultural plants.  In the case of Lakewood Ranch (Manatee County, Florida), the soil survey has not been updated since the development of the community and it does not contain soils data applicable to the current soils that are forming out of fill material.  Surface soils (0-6 cm, 6-30 cm) have been collected from Lakewood Ranch within 5 developments spanning over an age range of 20 years (0, 1, 5, 13, 20 years old).  Preliminary data indicate soil carbon and nitrogen contents were similar among the two sampled depths (0-6 cm, 6-30 cm) in the younger developments.  Higher soil carbon and nitrogen contents are observed in the 0-6 cm depths compared to the 6-30 cm depth in the 13 and 20 year old developments.  Ongoing data collection involves measuring soil bulk density, pH, and phosphorus availability.  High variability in the fill material characteristics will also be discussed.