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Halting the Upward Trend in Soluble Phosphorus Transported from a Grassland Catchment
Author(s) -
Smith R. V.,
Lennox S. D.,
Bailey J. S.
Publication year - 2003
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/jeq2003.2334
Subject(s) - eutrophication , drainage basin , environmental science , phosphorus , drainage , hydrology (agriculture) , grassland , agricultural land , christian ministry , nutrient , land use , zoology , agronomy , ecology , chemistry , geography , biology , geology , philosophy , cartography , geotechnical engineering , organic chemistry , theology
An upward trend in soluble reactive phosphorus (SRP) concentrations in Northern Ireland rivers leading to increased eutrophication has been reported for the last two decades. To identify if a similar trend could be observed in land drainage waters SRP and other P fractions were measured weekly from 1989 to 1997 in land drainage from a 9‐ha grassland catchment in Northern Ireland that had a mean P surplus applied of 23.4 kg P ha −1 yr −1 Regressions of annual median concentrations of P fractions in land drainage waters against time for 1989 through to 1997 showed significant increases of SRP and soluble unreactive phosphorus (SUP) of 2.4 and 1.2 μg P L −1 yr −1 , respectively. However, the annual flow‐weighted concentrations and loads of all P fractions did not show significant increases with time. During the period 1998–2000 a change of management was introduced when only maintenance dressings of P were applied to the catchment according to Ministry of Agriculture, Fisheries and Food guidelines. This resulted in significant reductions in SRP concentrations in 2000 compared with 1997.