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Phosphorus Sorption in Manured Atlantic Coastal Plain Soils under Flooded and Drained Conditions
Author(s) -
Vadas P. A.,
Sims J. Thomas
Publication year - 1999
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1999.00472425002800060025x
Subject(s) - subsoil , sorption , soil water , topsoil , chemistry , soil horizon , environmental chemistry , hydrology (agriculture) , flooding (psychology) , environmental science , zoology , soil science , geology , adsorption , biology , geotechnical engineering , organic chemistry , psychology , psychotherapist
Artificially drained, agricultural soils that are high in P and have seasonally fluctuating water tables may be significant nonpoint sources of P to Delaware's Inland Bays. Topsoil, unamended and amended with 4 g kg −1 poultry litter (PL), and subsoil horizons from two soil series in the Inland Bays watershed were flooded for 28 d and drained for 14 d at 25°C. Soil pH and redox potential (Eh) were measured (mV) and P sorption isotherms were constructed for each horizon under oxidized, flooded, and drained conditions. For each isotherm, P sorption maxima ( b max ), P sorbed at a solution P concentration of 1.0 mg L −1 ( b 1.0 ), and the equilibrium P concentration at zero sorption (EPC 0 ) were calculated. Flooding decreased Eh and increased pH, and draining returned Eh and pH to near initial values. Flooding and draining decreased b max in all horizons. The b 1.0 values were always significantly less than b max values; however, flooding and draining had inconsistent effects on b 1.0 values. Flooding increased EPC 0 in the unamended Pocomoke A horizon, but decreased EPC 0 in the same PL‐amended horizon. Draining reduced EPC 0 values in both Pocomoke A horizons. Flooding and draining had little effect on EPC 0 in other horizons. Our data suggest that land application of PL and fluctuating water tables may increase the potential for P loss from soils through both a decrease in soil P sorption capacity and an increase in solution P concentrations in topsoils.