Thanks for the great and helpful replies y'all.
We currently have four horses...too many for the land we have. This pasture was just a field that we did nothing with, i.e., no fertilizer, no weed killer, etc. We just cut it once or twice per year, then we got the horses. They manage to eat all the grass, leaving the little yellow flowers here and there. Where they have eaten, it's pretty bare. We tried over seeding one year, kept the horses off of it for a few weeks, but no new grass came up that we could see.
I talked to the farmer we buy hay from and he mentioned that he 'starts over' every few years in the fields he grows hay in. So I thought 'starting over' as if we were planting a yard would be the best thing to do. It sounds like it isn't.
We don't feed the horses in the pasture, but we haven't done the soil sample and some of the other things mentioned.
Since I am planning on getting a real tractor (
bx2200, FEL, mmm) soon, I thought I might as well find out what other implements would be helpful in rejuvenating and then maintaining this pasture.
I was concerned about using fertilizer/herbicides given that our horses are on it.