Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 6, 2003
Publication Date: November 6, 2003
Citation: GASTON, L.A., KOVAR, J.L., SAUER, T.J. PREDICTING PHOSPHORUS LOSS IN RUNOFF USING A DISPLACEMENT TECHNIQUE. ASA-CSSA-SSSA ANNUAL MEETING ABSTRACTS. 2003. CD-ROM. MADISON, WI.
Runoff phosphorus (P) is often poorly correlated with soil P determined using batch extraction methods. A miscible displacement technique that relates P eluted from a short soil column to P in runoff (by multiplying effluent P concentration at any time by separately measured runoff at that time) was tested using published P runoff data for Clarksville (loamy-skeletal, siliceous, semiactive, mesic Typic Paleudults) and Nixa (loamy-skeletal, siliceous, active, mesic Glossic Fragiudults) soils, with and without poultry litter. The relationship between measured P concentrations in field runoff and predictions from the miscible displacement method was better than obtained relating runoff P to soil P extracts. Unlike previous results using the displacement method with coarser textured soils, however, predicted concentrations of runoff P were generally somewhat greater than in field runoff. The depth of soil used in the displacement columns (1 cm) may have been greater than the depth of soil in the runoff /soil solution mixing zone.