N inorg refill hack

[marcadella]

The vegn_N_uptake() function refills the N inorg pool to reach 0.2 kg N m-2. With this we get the following GPPs for p-model and gs_leuning respectively:

If we remove this adjunction of N, we get the following:

Questions:

• Was this a hack? If so, there is something wrong with the models because they no not perform as expected without the refill.
• If this was not a hack would it make more sense to refill to reach the initial_Ninorg rather than the hardcoded value 0.2?