Quicquid plantatur solo, solo cedit

Quicquid plantatur solo, solo cedit (Latin, "whatever is affixed to the soil belongs to the soil") is a legal Latin principle related to fixtures which means that something that is or becomes affixed to the land becomes part of the land; therefore, title to the fixture is a part of the land and passes with title to the land. Consequently, whosoever owns that piece of land will also own the things attached.
Another way to look at it is by interpreting the Latin principle as 'that which is attached to the land becomes a part of the land'; use of the word "soil" is a more literal translation.
The key issue is the degree of permanence a purported fixture has to the piece of land in question. An antique fireplace set into a house's living room wall has a high degree of permanence and would therefore benefit from the principle.
Conversely, if that same fireplace has ornaments loosely attached to the floor at either end, those ornaments would be very unlikely to benefit from the principle. However, if those same ornaments were bolted to the floor, they would almost certainly pass the principle's test.
The purpose of the principle is to ensure that a purchaser of land does not acquire title or ownership of something which is not intended to pass with the land. The principle also ensures that correct title does pass to a purchaser in the event that a previous owner attempts to assert that a fixture was a chattel and therefore belonged to them.
The principle has particular relevance to landlord and tenant law. If a tenant is coming close to the end of his or her agreement and aims to remove a particular item attached to the landlord's property, the principle exists to remedy this.