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Phosphorus Losses in Furrow Irrigation Runoff
Author(s) -
Westermann D.T.,
Bjorneberg D.L.,
Aase J.K.,
Robbins C.W.
Publication year - 2001
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/jeq2001.3031009x
Subject(s) - surface runoff , loam , phosphorus , hydrology (agriculture) , environmental science , eutrophication , sediment , irrigation , soil water , manure , fertilizer , zoology , agronomy , chemistry , soil science , nutrient , ecology , geology , biology , paleontology , geotechnical engineering , organic chemistry
Phosphorus (P) often limits the eutrophication of streams, rivers, and lakes receiving surface runoff. We evaluated the relationships among selected soil P availability indices and runoff P fractions where manure, whey, or commercial fertilizer applications had previously established a range of soil P availabilities on a Portneuf silt loam (coarse‐silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid) surface‐irrigated with Snake River water. Water‐soluble P, Olsen P (inorganic and organic P), and iron‐oxide impregnated paper–extractable P (FeO‐P s ) were determined on a 0.03‐m soil sample taken from the bottom of each furrow before each irrigation in fall 1998 and spring 1999. Dissolved reactive phosphorus (DRP) in a 0.45‐μm filtered runoff sample, and iron‐oxide impregnated paper–extractable P (FeO‐P w ), total P, and sediment in an unfiltered runoff sample were determined at selected intervals during a 4‐h irrigation on 18.3‐m field plots. The 1998 and 1999 data sets were combined because there were no significant differences. Flow‐weighted average runoff DRP and FeO‐P w concentrations increased linearly as all three soil P test concentrations increased. The average runoff total P concentration was not related to any soil P test but was linearly related to sediment concentration. Stepwise regression selected the independent variables of sediment, soil lime concentration, and soil organic P extracted by the Olsen method as related to average runoff total P concentration. The average runoff total P concentration was 1.08 mg L −1 at a soil Olsen P concentration of 10 mg kg −1 Soil erosion control will be necessary to reduce P losses in surface irrigation runoff.