The big question...
What is the right pH soil level for them 'figs' in particular?
I used to think that figs like slightly sweet/alkaline soil (just above 7)?
Somebody else suggested otherwise; slightly acidic (just below the neutral 7)?!
Rutgers Unv. claims that a 6.0 to 6.5 pH is best; at least for most veggies...
It has something to do with the optimal soil-nutrient-absorbing-power-of-plants
in general.
I have seen a (scientific) graph - nutrient-absorbing vs. soil-pH before;
but right now, I cannot find it.
See: Soil and Nutrient Management (Liming Soils):
As for me, I tend to just add a handful (or 2) of lime with the soil mix (non-scientific).
One very well known real fig-expert is Chris D. of Belleclare, NY.
He is a big-believer in adding mucho 'granular limestone' for figs.
On my visits, I remember noticing al the white-stuff (1/2"+ layer)
on the surface of all his potted figs...
See:
Also, if used, go for lime that has both Ca and Mg elements in it...