Garden with Insight v1.0 Help: Soil patch next day functions: automatically fertilize if necessary

Automatic fertilization occurs if all of these conditions are met:

1. The auto fertilize option is on;
2. the number of days since this soil patch was auto fertilized is at least as many as the minimum interval between auto fertilizations (a parameter);
3. at least one of the plants in the soil patch is not a legume;
4. at least one of the plants in the soil patch has not been fertilized as much as is allowed annually per plant (a parameter); and
5. the smallest (worst) nitrogen stress factor among all the plants in the soil patch is smaller than the nitrogen stress factor that triggers auto fertilization.

When auto fertilization does occur, the quantity of N fertilizer added (as nitrate) depends on parameters for the amount of N fertilizer to apply and on the amount of nitrate already in the soil. The quantity of P fertilizer added (as labile P) is determined by attempting to maintain the same amount of labile P in the plow depth (0.2 m) as was present when the soil patch was created (which would be a normal amount for the soil type). Both the nitrate and labile P are added to the second soil layer only.

calculation of nitrogen stress factor
EPIC Auto Operations
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