If horses or cattle have been on the pasture, a light Disc Harrow with 18" diameter pans will not cut such compacted soil. A heavier weight Disc Harrow with 20" diameter pans will probably not cut animal compacted pasture either.
How many acres do you want to renovate? What is the soil composition? ~~~~clay? loam? gravel? sand?
If it is a small area you can rip it with a Subsoiler, then roto-till. Subsoiling alone should improve ground productivity.
VIDEO:
using a subsoiler - YouTube
TBN LINK:
Google
Subsoilers cost $300 to $400 new. Consider only Subsoilers with shear bolt protection and a replaceable foot.
If it is a large area you will need to chisel plow, or moldboard plow, then Disc Harrow or roto-till to mix and smooth.
Plows and Subsoilers are PRIMARY tillage implements. Disc Harrows and PTO powered roto-tillers are SECONDAY tillage implements.
There are specialty pasture renovating implements but they are expensive.
LINK:
Hay King Renovators - Hay King - Miller
If it is a hay field, rather than a pasture which animals have compacted, another implement such as a Field Cultivator, may be satisfactory.