Click on “Download PDF” for the PDF version or on the title for the HTML version.
If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.
Field Testing of DRAINMOD-N II for North Carolina Soils
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.orgCitation: Paper number 032368, 2003 ASAE Annual Meeting . (doi: 10.13031/2013.14989) @2003
Authors: M. A. Youssef, R. W. Skaggs, G. M. Chescheir, J. W. Gilliam
Keywords: DRAINMOD-N, DRAINMOD, simulation models, nitrogen, water quality, drainage
The nitrogen simulation model, DRAINMOD-N II, was field-tested using 6 years of data from an artificially drained site located in the North Carolina Lower Coastal Plain. The test site is nearly flat with a very poorly drained sandy loam soil under natural conditions. Four experimental plots, planted to a corn-wheatsoybean rotation and managed using conventional and controlled drainage, were used in this study. Simulation results showed fair to good agreement between observed and predicted annual nitrate-nitrogen (NO3-N) leaching losses. The absolute normalized error (NE)was less than 5% in 6 out of 24 simulated plot-years and less than 25% in 12 out of 24 simulated plot-years. The high errors in predicting annual NO3-N leaching losses were mostly induced by errors in predicting water table depth and drainage rates. DRAINMOD-N II did an excellent job in predicting cumulative NO3-N leaching losses over the whole simulated period. Cumulative NO3- N leaching losses over the six-year period was over-predicted by 2.1% for one plot and under-predicted by 5.9- 10.2%. The strong dependence of DRAINMOD-N II performance on the accuracy of the hydrologic simulation was manifested in the close association between predicted cumulative drainage and NO3-N leaching losses. Results of this study showed the potential of DRAINMOD-N II for simulating N dynamics and turnover in agroecosystems. However, this evaluation of DRAINMOD-N II should be regarded as incomplete since it relied primarily on literature rather than field and/or lab measurements to parameterize the model. Further research is needed to test DRAINMOD-N II based on independent measurement of model input parameters.(Download PDF) (Export to EndNotes)