YOU GOT IT!!! The only catch is to make sure the doo is not fresh, but composted. Even by spring it could be way to much nitrogen in there if it's not already got a head start. If you get it from the Atlanta APD stables, you can ask for the composted doo.

GGG - what is the APD?

My friends can't believe that I really, truly do want a truckload of poop for my birthday. They are saying "you will be mad if your husband actually gets you that!" NO! I will be ecstatic!

Thanks!

APD might be Atlanta Police Department?

Yup. I don't know where you are located bagsmom, but the APD has free poop!
Fresh stuff in the front, you gotta ask for the aged stuff they save out back.

I think that adding manure (even not fully composted) in the fall to your garden should do fine. What I would do is to spread it, add a layer of some fall leave(preferably chopped my mower) on it, and turn it or till it. This way the worms and micro organisms will get busy and by the spring planting time the soil will be fine.
I do not get free horse poo but I rake a lot of leaves.
Last year I fished all the earthworms that I could find from here and there and put them in my garden. Now they are there waiting for more leaves.
So any fall plans like these are better than no plans at all.
Also, I will add some lime to raise the PH, and some gypsum to break down the red clay also.

APD - duhhhhhh. I should have figured that out on my own! Thanks everyone! I'm excited!

Horses are animals with one stomach. Animals who digest with one stomach are usually recommended to have their fresh feces well composted before using in a garden, especially for food, but also in case you are touching the soil with your bare hands. Spreading uncomposted manures can lower the temps at which the nitrogen in them burns and so they don't burn any nasty organisms hot enough. They may not be fully composted by planting time. So I really do recommend you use pretty well composted poo just to be sure.