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Phosphate retention in an agricultural stream using experimental additions of phosphate
Author(s) -
Macrae M. L.,
English M. C.,
Schiff S. L.,
Stone M. A.
Publication year - 2003
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/hyp.1356
Subject(s) - phosphate , environmental science , phosphorus , hydrology (agriculture) , vegetation (pathology) , perennial stream , stream bed , sediment , chemistry , streams , geology , geomorphology , geotechnical engineering , organic chemistry , pathology , computer science , medicine , computer network
In‐stream experiments involving additions of phosphate were conducted to determine the soluble reactive phosphorus (SRP) retention potential of a perennial first‐order stream that drains a 2·7 km 2 agricultural catchment in southern Ontario. SRP retention was determined in relation to highly elevated SRP concentrations under low flow conditions. Point source treatments of phosphate were added to three reaches of this stream during two time periods when baseline SRP concentrations were notably different (early summer and early autumn). The reaches selected varied with respect to streambed shape and gradient, direction of groundwater flow, and channel vegetation type and density. One of the three experimental stream reaches was dredged between the two sampling periods, so that all vegetation and the top 25 cm of sediments were removed. SRP retention in the stream ranged from 0·8 to 24·1 µg m −2 s −1 . Dredging the stream sediments did not alter the ability of the stream to remove SRP from the water column. SRP retention over the experimental reaches was generally 5–10% of the elevated concentration (0·7–4·2 mg l −1 , a factor of 8–53 above pre‐experiment conditions), although low‐flow conditions in the stream were conducive to retention by stream sediments. Copyright © 2003 John Wiley & Sons, Ltd.