checkerboard biomes with extreme hills and extreme hills edge. Apatite for DAYS.
A single vein will last you for days as it is now. literally days of continuous running of a single farm.
one apatite ore-block yields from 1 to 5 apatite, + whatever extra you get from fortune if you have that.
each piece of apatite you combine with 2 sand gives 8 fertilizer. or if you use ash instead of sand it yields 16 fertilizer.... (making peat farms and peat fired engines a little more efficient than before, because you can double your apatite output with them).
for instance. a peat farm uses 10mU (milliUnits?) of fertilizer per peat made. each fertilizer represents 2000mU. so 1 fertlilizer yields 200 peat. you should be able to get 2 ash per 3 peat. (200/3)*2= 133 ash.
that was from a single fertilizer, so after making the first 8 by combining one apatite gem with 2 sand you should be set to get 16 per apatite gem after that.