Server crashed and I got inspired(bored). So I thought I would through an idea out for you guys. Composting.
Ways I could see it working.
You create a compost bin that takes the average Q of food/seeds thrown into it. After a week(like wine), it will turn to dirt/compost. The Q of the dirt is the square root of average Q food times Q bin.
Now retriving the dirt could work two ways.
A)You could dig from the compost in the same way you dig from the ground.
B)It could work like container and you take out the dirt once it is ready.
Composting decomoses, so you wouldn't get a 1:1(food to dirt) ratio. The amount returned would be more or less around 1:2 or 1:3.
Maybe adding worms to the compost could either increase Q or speed up the process.
I made it basic since I dought we want to make it too complex with acidy level, balance between carbon to nitrogen and minerals.
=Possible use=
With farmable dirt, you should be able to improve the Q of your soil. I don't think it should just be the average between the two. The best I could think of (for now) was...
if soil< compostQ:
soil=+√ (compost-soil)
if soil > compostQ
soil=-√ (compost-soil)
... not sure how good/bad that idea is. Let me know if you have a better idea.
Also improving Q of the dirt shouldn't regenerate if depleted. Infact it should always want to return to a certain level of Q if not maintained.