Preferential Flow Effects on NO3-N Losses with Tile Flow
Jaynes, D. B.
Colvin, T. S.
Ahuja, L. R.
The variation in continuity and geometry of macropores over the growing season can affect subsurface drain ‘tile’ water and nitrate-nitrogen (NO3-N) concentrations in tile water. This study analyzes the patterns of tile flows and nitrate-nitrogen (NO3-N) concentrations in tile water in relation to rainfall events using field measured data as well as invoking the macropore option of the Root Zone Water Quality Model (RZWQM98). The increase in NO3-N concentration in tile flow during the growing season in comparison with the decrease in NO3-N concentrations after the crop harvest following heavy rainfalls support the role of dual flow theory, soil matrix flow and preferential flow. These results and model simulations suggest that variation in macropore during the growing season can have significant effect on tile flow and NO3-N concentrations in tile water for soils similar to the study area.
This proceeding is published as Bakhsh, A., R. S. Kanwar, D. B. Jaynes, T. S. Colvin, and L. R. Ahuja. "Preferential Flow Effects on NO3-N Losses with Tile Flow." In Proceedings of the 2nd International Symposium on Preferential Flow Water: Movement and Chemical Transport in the Environment, ASAE Publication Number 701P0006 (David Bosch and Kevin King, eds.). (2001): 41-44. DOI: 10.13031/2013.2080.