Refers to land used for grazing livestock or a grassy field; a common agricultural term.
Cows are eating grass in the pasture.
Vast grasslands stretch out around here.
牧草地 emphasizes the grassy grazing land itself, whereas 牧場 refers more broadly to the farm or ranch as a whole, including its buildings and business.
牧草地 specifically means pastureland kept for grazing livestock, whereas 草原 is the broader word for any grass-covered area.
Compound of 牧草 (bokusō, 'pasture grass') + 地 (chi, 'land').