help on choosin right model for data

Thank you for your answer.

The problem is I don't have multiple sensors for each mulch*fertilizer
combination. So no repetitions.
Technically it was not suitable ti have so many sensors in the field.
For each combination (there are 12 of them : 4 fertilizers x 3 mulches) I
set up only one sensor in the field but I made sure everything was in the
same repetition (If you remember experiment is a two factorial split-plot in
three repetitions).

Also sensors collected data through the whole day, every 10 minutes, for the
whole vegetative seson (3,5 monts).

Josipa Perkovic