Issue with FERTCOM.DAT

[Carlos Alberto Arnillas]

Hello

I just recently noticed that the FERTCOM.DAT values for Elem-N, P and K are wrong, same with manure. According the manual they should be 52, 53,  54, and 68, respectively. However, in the FERTCOM.DAT file they are 53, 54, 55 and (I believe) 1. I checked the values with the latest example from the APEX downloadable file, and the problem is still there. The problem is more relevant because the .SUB file in the latest example version have the automatic fertilizer options set to 0, which forces APEX to use the internally defined fertilizer values (i.e., 52, 53,  54, and 68). Because I set auto-K on, APEX added the fertilizer 54 to the plots... but the fertilizer 54 was P, not K, according to the internal coding. Therefore, my plots had massive amounts of P added to them.

I checked the EPIC FERTCOM.DAT file. Elem-N, P and K are in a different position in the table. I am not familiar with EPIC, so not sure if a similar problem may occur there.

I hope you won't had to face a similar problem. For now, I'm just setting the .SUB files so that APEX will look for the right line and deactivating the auto-K fertilization.

Thanks to Luca, for all your help troubleshooting this!

best,

Carlos Alberto

[Jaehak]

Thanks for reporting this. It's important that we keep the user manual current as we update the models. We will get this resolved in the next update of the model.