First I allowed the livestock to mob-graze the area. (Actually they mob grazed the area prior to me erecting the pallet fence.) That means confine them to a small section where they are forced to eat all the edible greenery right down to the dirt. Another option could have been to use the lawn tractor and mow the grass super short. But I was concerned about the rocks that sometimes poke up. Hitting one could break the mower. So using the livestock was a far safer, cheaper option.
After moving the livestock out I found only a few weeds they did not touch. Those I either pulled out or cut off at soil level. Just about everything green was gone, eaten down to the brownish thatch. I harvested as much of the manure as I could for use in the current gardens. If this land was not lava land, I could run a reverse tine rototiller over it or custom hire a plow to turn the land. But neither are feasible here. Rocks, rocks, rocks everywhere! That might look like nice ground but I challenge you to dig a shovel into it. Initially breaking this ground will require me to use an o-o bar or a pick.
Next I applied some nitrogen. This could have been in the form of composted manure, diluted urine, manure tea, or commercial lawn fertilizer. I opted to use chelated (I used old rusty nails) urine since I had several gallons on hand. Chelated urine contains nitrogen in a form more readily available to the plants. For this project I diluted the urine by adding two cups to a gallon of water. I sprayed the fertilizer so that the surface of the soil was just wet all over. Happily I got a light rain the evening after spraying, washing the solution into the plant root zone. Now I will wait for the grass to start regrowing.
About a 7-10 days from now the pasture should be green all over with a sudden flush of new growth. Once the growth is about an inch high I will spray a light coating of herbicide. With the grasses being so short very little herbicide will be needed. Saves money plus adds less chemical to the environment.