THE FLORIDA STATE UNIVERSITY ARTS AND SCIENCES ...

look at the data shows that it fails to predict the denitrification rate for data at both the
upper end of the scale as well as the lower end of the scale.
Predicted
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APEX - Denitrification Rate : Predicted Vs. Actual
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Actual
Figure 1.2 Predicted denitrification rates based on equations Equation 1.3 and Equation
1.5 (All Data, n=220).
In all fairness to the APEX model it must be noted that it is designed as an agro-
ecosystem model that simulates crop production as a function of weather, soil conditions,
and production practices employed (e.g., tillage types, tillage frequency and crop
rotations).
EPIC was developed and designed originally to explore the impacts of soil erosion on
crop productivity (Williams et al. 1983). The model EPIC, and the models that have
evolved from it, such as APEX, have been applied extensively to cropping systems
worldwide on a variety of soils and cropping systems.
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