When I bought my Virginia farm 22 years ago, some areas had clay so hard it bent my shovel. I asked local tree-trimming crews to drop 2 feet of non-walnut wood chips on the proposed garden for free. I threw a little fresh horse manure onto the mix and was stunned in 6 months that the worms, bacteria, etc. did their job to break down much of the wood chips revealing perfect soil when I pushed aside the top layer to make foot paths.
If a dump truck can't get to your backyard, have them drop the load where they can and use a wheelbarrow. It's pretty easy to carry horse manure in a car, just tarp everything before adding containers of manure. Adding a hitch to a small car is worth investigating. I used my vintage Mercedes as a 3/4 ton pickup. Lowe's rents their truck by the hour or day, but it is first-come/first-serve. Sometimes it is worth renting a UHaul/Penski pickup for a day to get a year's worth of hauling done.
Try to find horses who aren't fed grain, chemical wormers, and meds which aren't good for the soil critters you are feeding. I use one-day old horse manure on top of perennials (asparagus, horseradish) and around shrubs as well as piling it over old sprouting potatoes on the ground with great results. I suspect it is because my horses are healthy and mostly chemical-free.
I agree with everyone who said, "feed the soil critters" which to me means keeping soil covered year-round (cover crops, chips, leaves, cardboard, weeds, mash, coffee grounds), only digging swales in heavy rain areas or small depressions to catch water in dry areas, and avoiding lime and chemical fertilizers. I avoid jerusaleum artichokes and gojis which are invasive in my region.
If you like animals, consider some chickens, goats, or mini horses. They are lots of work, but also fun and can help improve the land if you do it right.
Unrefined salt is essential for soil critters. Several of my horse winter paddocks were overrun with thousands of yellow dock plants, especially where the horses poop making the high nitrogen environment perfect for weeds and too rich for grasses. I switched back to feeding my horses Redmond Salt instead of white refined salt and within 2 months the yellow dock disappeared and was replaced with grasses. Redmond salt is heavy and expensive, but I am lucky the East Coast supplier is 45 minutes away. A cheaper option to add beneficial salt is Korean Natural Farming and Jadam recipes, most of which can be made from items already in your pantry.
I have had luck with products from Farm for Profit which I sprinkle on some of my paddocks by walking with a gallon container with holes poked in the lid. I can now dig post holes by hand with a clam shell digger in less than 10 minutes where I sprinkled FFP additives.
BTW, I currently operate my 97-acre horse farm without a tractor or truck. My hunter moves hay bales for me with his ATV a few times a year (otherwise I roll them by hand with the help of a friend). He also carries fence supplies to the lower pastures. Otherwise, I walk and carry my supplies and tools. Occasionally, I recruit the horses to do some of the heavy carrying.
Keep us posted on your progress.
