Inorganic N and P

[Alfonso Albacete]

Hello,

I am trying to model N and P balances in my watershed. I am especially interested in inorganic nutrients. I have tried to include the fertilizers in the Editor, but I did not get any inorganic nutrients in the balances. Thus, I am wondering how to include the fertilizers in the Editor to get a correct output of the inorganic N and P. 

Looking forward to your reply. Thank you in advance.

Kind regards,

Alfonso Albacete

[Luqman Hakim]

Hi Alfonso,

I'm not an expert in SWAT+, but I'd like to share what I've learned in case it helps.

If you have already assigned fertilizers in SWAT+ Editor but are not getting the expected inorganic N and P outputs, I would first recommend checking whether the fertilizer has been correctly assigned in your model.

Specifically, check the Land Use Management section and make sure that your land use/plant is assigned to a management schedule that actually includes fertilizer application.

If that looks correct, the next step is to verify whether the fertilizer operation is being executed during the simulation. You can do this by checking either:

• SWAT+ Check outputs, or

• the output.sqlite file in your project directory.

In the mgt_out table, verify that the fertilizer operations are present. If no fertilizer operations appear there, it may indicate that the management schedule is not being triggered as expected.

I hope this helps, and hopefully someone with more experience can provide additional insights if needed.

Regards,

Luqman Hakim