Pedological processes such as gleization and organic matter accumulation may affect the vertical distribution of P within agricultural drainage ditch soils. The objective of this study was to assess the vertical distribution of P as a function of horizonation in ditch soils at the University of Maryland Eastern Shore Research Farm in Princess Anne, Maryland. Twenty-one profiles were sampled from 10 agricultural ditches ranging in length from 225 to 550 m. Horizon samples were analyzed for total P; water-extractable P; Mehlich-3 P; acid ammonium oxalate-extractable P, Fe, and Al (Pox, Fe ox, Alox); pH; and organic C (n = 126), Total P ranged from 27 to 4882 mg kg-1, Pox from 4 to 4631 mg kg -1, Mehlich-3 P from 2 to 401 mg kg-1, and water-extractable P from. 0 to 17 mg kg-1. Soil-forming processes that result in differences between horizons had a strong relationship with various P fractions and P sorption capacity. Fibric organic horizons at the ditch soil surface had the greatest mean Pox, Feox, and Alox concentrations of any horizon class. Gleyed A horizons had a mean Feox concentrations 2.6 times lower than dark. A horizons and were significantly lower in total P and Pox. Variation in P due to organic matter accumulation and gleization provide critical insight into short- and long-term dynamics of P in ditch soils and should be accounted for when applying ditch management practices.
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Water Science and Technology
- Waste Management and Disposal
- Management, Monitoring, Policy and Law