Definitely soil test.
That said, I absolutely spread all the horse manure, bedding, hay waste (what little there is, try to prevent it) on my fields first. Not doing that is like throwing money away.
Like goodhors, I spread directly on my fields. I maintain a good worming program and let time do its thing. I prefer that to keeping a manure pile, it cuts down on flies and odor to spread it out. So we clean directly into the spreader, and I spread it immediately on whatever area of the field is up next (in lines). I keep track of where I have been and work my way around the farm. Once you get the hang of it you can get good even coverage and a nice rotation. Even in winter with a little snow I can keep it pretty accurate. I keep it going all winter if I can, only stopping if the snow gets too deep to pull the spreader. This winter was so mild I was able to keep my spreader up all winter, which made me super happy…no manure pile at all! Things horse people care about…
On a very small property with a lot of horses you might have too much organic matter. I have 7 horses and about 14 acres nonwooded, so I can easily use all mine.
Not spraying for weeds properly is also like throwing money away. Weeds take up resources your grass ought to be using.
