Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2003
Publication Date: 1/1/2004
Citation: Gollany, H.T., Clapp, C.E., Molina, J., Linden, D.R., Allmaras, R.R., Layese, M.F. 2002. Carbon and nitrogen dynamics in the soil-plant continuum: measured and simulated. Meeting Abstract. Proceedings of natural organic matter in soil and water. North Central Region Symposium. p. 68.
Technical Abstract: Maintaining crop production level with reductions in terrestrial greenhouse gases requires effective residue and fertilizer management. Our objectives were to: 1) quantify the effect of nitrogen (N) application rates on N losses; 2) examine the role of residue returned on N transformation and losses; and 3) verify the capability of the NCSWAP/NCSOIL model to simulate the dynamics of N and N15 in the soil-plant system. A long-term continuous corn study was initiated on a silt loam soil in 1980 at Rosemount, MN. Conventional tillage plots with two levels of application rates (20 and 200 kg N/ha) and two types of residue management (residue removed, and residue returned) were used to calibrate the model. For the same amount of N15 added (0.8 kg N15/ha), concentrations of N15 in the corn and soil organic matter (SOM) were higher for the 20 than the 200 kg N/ha treatments. The model accurately predicted N15 in the SOM at 0- to 15-cm depth for both fertilizer rates and residue management. The predicted cumulative N loss during 30-years simulation indicates more NO3 leaching to below 1m-depth for residue removed than residue returned plots, while higher denitrification rates were predicted for the residue returned than residue removed.