The factor that resulted in less available farmland and more privatized farmland during the Industrial Revolution is enclosure.
Enclosure refers to the process of consolidating small landholdings into larger farms, which often involved the fencing off of common lands that were previously accessible to free use by the community. This led to significant changes in land ownership, often transferring land from common use to private ownership. As a result, less land was available for farming in a communal sense, and it became more privatized as large landowners sought to increase agricultural efficiency and productivity. This shift contributed to urbanization as displaced peasant farmers migrated to cities in search of work.