I have a research investigation that I got the results, I applied 4 different composting processes to vegetable waste (manure, manure+Effective Microorganisms, Effective Microorganisms and a control) I measured pH, temperature, mass and humid density through 3 months (divided in weeks), knowing this, to get the best and most accurate P value: should I get a P value for every month, or getting a general P value for each treatment and measurement is the best option?