Didn't read the postings yesterday so the thread about hay stacks is way down the pages, so I'll do a new thread.
To make a hay stack with pole in center: I've helped Daddy make them in earler days. I guess the purpose of the pole in the center is to make a more uniform stack to shed water. I'm in SC where it rains(usually). Keeping hay from spoiling in the dry states has to be easier.
We would first dig a shallow hole since we didn't have a post hole digger until later and set the pole in it. Pole didn't have to be deep in the ground since the hay was going to support it. Scrap lumber or tree limbs were then laid on the ground in about a 12 foot circle.Purpose was to keep the hay off the ground. Hay was pitched on the lumber, taking care to keep it in a more or less circle and walking around on it to pack it down to make best use of the space and to better shed water. The diameter of the stack was steadily decreased as the stack grew taller until at the top there was barely space to walk around. The pole had been sharpened at the top and Daddy would, at the last, take a big fork full of hay and force it over the sharp end of the pole. This was called capping the stack and the purpose was to keep water from going into the stack around the pole. A properly made stack would preserve hay better than a round bale sitting on the ground.
When time came to feed the hay, hay was taken off the top. Sometimes a piece of canvas was put at the top after feeding started to shed water off the opened stack.
As I recall, hay stacks didn't last too well after the first year. Nobody that I recall made round piles without the pole in the center.
KEH