Here is a recent soil sample I am working on:
test sample.JPG
The cations here are well balanced. And, when I look at the pH, low and behold, it is...6.4
Lime had not been applied to this ground in 2 years according to the owner.
You still need to then calculate what the crop needs will be for the season. Also, Calcium is easily knocked off the soil chain by rain. Nitrogen use, especially soluble forms, effect C too.
This is why I like supplying Calcium via Calcium Nitrate. I supply Magnesium via Epsom salt (magnesium sulfate). Potassium via my base fert blend that also has N and P and micros like Fe, Mn, Z, Cu, etc