Them Dwarven folk.

[Aganzir]

Originally Posted by zxcvbn

Actually they DID purchase all their food supplies. Atleast whenever there were communities of Elves or Men nearby.

That's not logical. The dwarves were intelligent enough to realise what happens if a war breaks out or there's some other catastrophe which stops trade. And even if Gimli could set Galadriel's hairs in imperishable crystal, I doubt the dwarves were able to preserve food in the same way.
No, they had to be able to produce food also on their own.

Originally Posted by zxc

And whenever Dwarves were isolated from Elves and Men, they hunted animals and gathered wild roots instead of farming or herding. Example: the Petty Dwarves.

Maybe small families and communities did, but that's not enough to feed a considerable sized society.

Originally Posted by zxc

Maybe they were just poor at farming and herding? They certainly didn't seem to have much harmony with nature.

So maybe they were the ones who developed fertilizers and industrial agriculture? To Tolkien's view of things that would probably mean about the same as "not much harmony with nature."

Originally Posted by HoME XII

Thus there grew up in those regions the economy, later characteristic of the dealings of Dwarves and Men (including Hobbits): Men became the chief providers of food, as herdsmen, shepherds, and landtillers, which the Dwarves exchanged for work as builders, roadmakers &tc.

I believe this is what you meant. However, I fail to see it says trade with Men was the only source of food for dwarves. Rather, I think it profited Men most to sell food- and that most of the food the dwarves bought came from Men.

Originally Posted by Alfirin

Maybe Terry Prachett is right and dwarves really do have a fondness for eating rat.

Originally Posted by zxc

And as for the Shire being too far way for trade, how do you think the Dwarves knew of pipe weed?

Smoking of pipe-weed spread among Dwarves from Bree, says the Prologue. I don't remember what else has been said about pipe-weed, but it's hard to believe it grows only near the Shire, so trade isn't necessarily needed for the dwarves to get it.

**

And now that I think it, mushroom farming sounds even more and more probable. A union between Aulë and Yavanna- things that grow underground and are eaten by Aulë's folk. How romantic.