|Swan, James - IOWA STATE UNIVERSITY|
|Bargar, Bruce - IOWA STATE UNIVERSITY|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 3, 1995
Publication Date: N/A
Technical Abstract: Timing and placement of nitrogen application with a ridge-tillage system can affect the amount of nitrate leaching to groundwater. Tracer (Br- and fluorinated benzoates) movement and change with time of soil water under uncropped ridge-tillage was measured on Iowa soils formed in loess and glacial till. Soil water content was determined weekly by neutron probe and half-hourly by TDR measurements to a depth of 0.6 m or 0.9 m under ridge and furrow positions. Greater movement of soil water and conservative anionic tracers was observed under furrows than under uncropped ridges at both sites. Soil water content increased rapidly under furrows following rainfall, but changes were delayed and were smaller under ridges. Water and solute movement were simulated using a two-dimensional model, SWMS 2D.