Morphology and characterization of ditch soils at an Atlantic Coastal Plain farm

Some materials in drainage ditches that have traditionally been referred to and studied as sediments may be soils. In this study, we described and characterized materials found within agricultural ditches at the University of Maryland Eastern Shore Research Farm (Princess Anne, MD). Sixty-nine profiles were described in 10 ditches ranging in length from 225 to 550 m. Particle size, pH, and organic C were analyzed on 21 representative profiles. The materials met the definition of a soil in that they supported rooted vegetation. Samples of initial parent material were not collected; however, evidence was observed that horizons had formed through pedogenic processes including organic matter humification and accumulation, structure formation, Fe oxidation and reduction, sulfuricization, sulfidization, translocation, and bioturbation. Ditch soils were generally A horizons formed in loamy alluvial sediments eroded from loess-derived topsoil over gravelly and sandy C horizons formed in Coastal Plain sediments. Soil structure was described in 75% of A horizons. Redoximorphic features were described in 41% of A and 63% of C horizons. Organic C ranged from 0.4 to 124 g kg^-1. Monosulfidic black oozes were observed on some soil surfaces; geological sulfidic materials were observed at depth. Shallow ditches (<1.5 m) tended to have structure and a layer in the substratum with a bright matrix color. Deep ditches (1.5-4 m) tended to have high n value, structureless sola, and Fe-depleted subsoil horizons. The presence of plants and the operation of pedologic processes may significantly affect ditch ecosystems and environmental functions.