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Potential of an Eroding Urban Soil for the Phosphorus Enrichment of Streams: I. Evaluation of Methods
Author(s) -
Ryden J. C.,
Syers J. K.,
Harris R. F.
Publication year - 1972
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/jeq1972.00472425000100040022x
Subject(s) - chemistry , phosphate , phosphorus , liter , aeration , horizon , soil horizon , fertilizer , environmental chemistry , zoology , soil water , environmental science , mathematics , soil science , biochemistry , biology , organic chemistry , geometry , endocrinology
Eroding noncalcareous and calcareous soil horizons sampled on an urban development site sorbed a varying proportion of added inorganic phosphate (P). At an added P level of 600 µ g P/liter (30 µ g P/g soil in 50 ml of 0.1M NaCI), the A1 horizon showed a net release of P whereas the B1 and 3C1 horizons sorbed 96 and 53% of the added P, respectively. The appreciable release of P from the A1 horizon is attributed to the presence of a small amount of a moderately soluble P fertilizer‐soil reaction product. In simulated stream systems employing a solution/soil ratio of 1000:1, initial added P concentrations of 0 and 50 µ g P/liter, and adequate aeration, approximately 50% of the final P concentration was attained in less than 3 hours. Release of P (50 µ g P/liter) from the A1 horizon was independent of the initial P concentration. The B1 horizon released 10 µ g P/liter, twice that released by the 3C1 horizon, whereas these two horizons sorbed approximately equal amounts of added P. In a system containing a 1:1 mixture of the A1 and B1 horizons, the amount of P released by the A1 in the presence or absence of added P was greater than that capable of being sorbed by the B1 horizon. Initial P concentrations were shown to be more important than the solution/soil ratio in determining the extent of uptake and release of P by the soil horizons. The use of a 400:1 solution/soil ratio and low levels of added P (0 to 200 µ g P/liter) provides a useful basis for developing a routine test for evaluating the potential of eroding soils for the P enrichment of streams.