Saruman's economic infrastructure unexplained?

[A_Brandybuck]

I think, that Saruman's economic infrastructure is based on the production, which Isengart naturally have. I think, that Isengart itself must have a nearly autarc system or the possibility of being nearly autarc.
In the time before the coming of the Rohirrim, Isengart was an outpost in the nearly deserted fields of Calenardhon. The people living in Isengart must have fed themselven alone (I suppose).
That would mean, that there was an existing infrastructure on which Saruman could build his own economic infrastructure.
We know from Saruman, that he is a cunning head and we know also, that Saruman have some economic skills, because of the story with the tobacco and the Shire.
So, it is likely, that he did some trade not only with the pipeweed in the Shire, but also in other things. He had the mountains and the Dunlendings directly in front of his home. Consequently there was a potential of trade there.
We know also, that Saruman had many activities in the region of Dunlendings. Dunlendings were in his army and they succumb to the propaganda of Saruman (thinking that the Rohirrim are very cruel to his prisoners of war). I think, that such a propaganda needs some time and trust on the side of the Dunlendings towards Saruman. This time and this trust could Saruman had gained through economic things.

Which I can't explain with this theory is, how Saruman could feed thousands of orcs. But I find the Dol Guldor theory very good. ;-)

[Gil-Galad]

Hmmm...with the Dol Guldur theory, perhaps Sauron sent some of his food stuffs to Saruman? through the black gate to Dol Guldur, then across the river and trhough Rohan

[Kuruharan]

I don't know that food would necessarily have to come from Mordor. Hunting would be good in the forest, and some food could be grown locally.

[The Elf-warrior]

Saruman did grow some food in the area. From Chapter 8 of Book III:

Beneath the walls of Isengard there still were acres tilled by the slaves of Saruman; but most of the valley had become a wilderness of weeds and thorns.

[A_Brandybuck]

I think there is no doubt, that the food, which is cultivated in Isengard, is not enough for the thousands of orcs and similiar things.
In the meantime I doubt, that the food came the whole way from Mordor to Isengard. It is too risky for them. Such a supplying could be easily discovered by the 'enemy'.
What is about the theory about the 'lands' beyond the gap of Rohan? He could have bought the food in this lands. From the Dunlendings or later from the Shire (like the tobacco).

Or I remember, that I read somewhere, that there is the possibility to cultivate some food on plains in the mountains (I mean the Dwarves did that). Saruman could have lied his acres in Isengard idle to give noone the possibiliy to be suspicious. Instead of cultivate in Isengard, his could have 'out-sourced' the production of food to the near mountains.

[Gil-Galad]

hmmm... maybe he found a stash of welath in the tower and used to to buy his food from the shire... oh i just thought of something, Saruman could have got his food from Rohan because he wasn't at war with them yet, so he could have got the supplies he needed from them...maybe even gondor...keep in mind that Saruman was not originally evil