Figure 10.

Domain-wide N input and output from the three different year simulations (2010 to 2012) with the comparison of domain-wide inorganic N fertilization between (a) EPIC-simulated and U.S. Geological Survey (USGS) reported and (b) the overall N budget with all N sources and pathways of N leaving the field. Total input includes the sources from fertilization, fixation, and deposition. Total loss includes the pathways from runoff (surface and subsurface with tile drainage), sediments, percolation, volatilization, and denitrification. Net mineralization is the internal N source from soil organic matter excluding immobilization and organic fertilization and Harvested is the N in harvested plants. The difference between total input + net mineralization and total loss + harvested represents the soil N pool at the yearend.