Every year we have a soil consultant come out and take soil samples - we then test them for levels of nutrients that the turf needs. We also test the tissue of the grass to determines what nutrients are in the plant, this gives me an idea of what the plant has and what is available to the plant. Last week we took samples to get this testing done. We also took samples of our water to determine salt levels and other contaminates.
We found 4" roots on our poa greens, that is good for this time of year.
Every other year we will perform a physical analysis of the soil to determine how the greens drain and if the rootzone of the soil is adequate. This will give us the information we base our aerifications on.