Urban Soils and Their Potential Role in Water Quality Degradation.

Rapid population growth in recent years has impacted Florida’s water resources.  Many studies have linked the degradation of water quality to runoff originating from new residential construction, urban land uses and activities, such as fertilization, septic system use, pesticide/herbicide applications, and industry, that are associated with population growth.  Selected physical and chemical properties, including particle size analysis, bulk density, Mehlich 3 P, and Mehlich 3 P saturation ratio (PSR) were determined on soils samples collected from the surface and subsoil of new (<1 year) and established (>10 years) residential landscapes in central and south Florida.  The soil textural class of all collected soils was sand or loamy sand.  Soil bulk density ranged from 0.5 to 2.37 g cm^-3 in established landscapes, suggesting that some soils are highly compacted.  Soils collected from established landscapes had higher Mehlich 3 P and Mehlich 3 PSR (31 mg kg^-1 and 0.11, respectively) than soils collected from new landscapes (86 mg kg^-1 and 0.43, respectively).  Soils from established landscapes are more likely to be a source of P to runoff or leachate, probably due to repeated applications of fertilizers that added nutrients to the soil in excess of plant needs.