Great question, Margie! You're right that there is no explicit reference to "land" in the list of what Job lost. However, my translation (NRSV) says that he and his children lived in "houses" rather than "tents" (Job 1:4 and 1:10). In fact one of the houses is destroyed in a great wind, killing his children (Job 1:19). In verse 1:10 the NIV uses "household" rather than "house," but it still uses "house" in 1:19 to describe what collapsed.
I think the implication is that Job would have owned that property, and also the surrounding fields to support all that livestock. At the very least, even a nomadic livestock owner, like Abraham, would have needed some "grazing rights." I am reminded of Abraham and Lot setting limits on where their flocks would graze to avoid squabbles among their shepherds (Genesis 13).
I don't have this interpretation on any particular authority, but it's the way these passages make sense to me.
I hope this is helpful -- please don't hesitate to "push back" if you're still not satisfied.