Submitted to: Soil Science Society of America Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/1/2007
Publication Date: 3/1/2008
Citation: Vaughan, R.E., Needelman, B.A., Kleinman, P.J., Rabenhorst, M.C. 2008. Morphology and Characterization of Ditch Soils at an Atlantic Coastal Plain Farm. Soil Science Society of America Journal. 72:660-669. Interpretive Summary: Land drainage for agricultural, construction, and public health purposes has been a prominent landscape feature in the United States and Europe for over four centuries. As drainage ditches typically intercept or border agricultural fields, they are a key link between farm land and surface waters. To facilitate the systematic study of drainage ditches, this study surveys materials found in ditches and describes the processes that led to their current properties. In doing so, it is clear that many materials in drainage ditches that have been described as sediments are actually soils and therefore can be readily classified and mapped. Extrapolation of study findings will support the systematic management of drainage ditches and aid in improved management for water quality protection.
Technical Abstract: Some materials in drainage ditches, which have traditionally been referred to and studied as sediments, may be soils. In this study, we described and characterized materials found in agricultural ditches at the University of Maryland Eastern Shore Research Farm (Princess Anne, MD). Sixty-nine profiles were described along 10 ditches ranging in length from 225 to 550 m. Particle-size, pH, and organic carbon were analyzed on 21 representative profiles. The materials meet the definition of a soil in that they supported rooted vegetation and had distinguishable soil horizons formed through pedogenesis. Pedogenic processes operating in these soils include organic matter humification and accumulation, structure formation, iron oxidation and reduction, sulfuricization, sulfidization, translocations, 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 carbon ranged from 0.4 to 124 g/kg. Monosulfidic black oozes were observed on some soil surfaces; geological sulfidic materials were observed at depth. Shallow ditches (less than 1.5 m) tended to have structure and a layer in the substrata with a bright matrix color. Deep ditches (1.5 to 4 m) tended to have high n-value, structureless sola, and iron-depleted subsoil horizons. Studies of the chemical, physical, and biological processes operating in ditches should integrate an understanding of the role of pedological processes if soils are present.