This is not an issue of insufficient sources, but on of drop rate. 50 earth can be harvested in 4-5 piles. Getting 24 or so loam will require 20 or so piles, meaning you have close to 200 earth to deal with.
Plus, with the odds so low, all it takes are a few bad rolls of the RNG to leave you harvesting 25-30 piles. That is nearly half the piles in Kalvana!
I'm sure TS has spreadsheets for all this, so they know the numbers -- but I am curious why they want the game to play this way.
I've never had a loam supply issue myself, as I hoard it in an SDB, but (unless I'm forgetting something) loam is the only thing that works like this and it's kinda weird.