敷地 and 土地: school grounds and land suitable for fields
Compare grounds associated with a school with rented land suitable for fields, preserving the facility relationship and stated suitability.
Grounds associated with a facility
敷地（しきち） means grounds or a site. 「学校の敷地には古い桜の木がある。」 says that an old cherry tree is on the school grounds. 学校の connects the site with the school.
The tree's presence is stated, but ownership of the land and the size of the grounds are not. The facility relationship does not supply legal ownership or permission conditions.
Land suited to a use
土地（とち） means land or ground. 「川の近くに畑に向いた土地を借りた。」 describes renting land near the river that was suitable for fields. 畑に向いた describes the land's suitability for use as fields.
借りた reports renting. Suitability for fields does not establish that fields were already made or crops grown.
A site's relationship and land use
The school's 敷地 is viewed through its relationship with a facility. The 土地 example describes land's suitability for a use. Grounds can also be land, so the words are not exclusive categories of places.
Land area alone does not decide between 敷地 and 土地. These examples identify the facility relationship, the modifier concerning use, and the stated presence or rental.
What relationships do 学校の敷地 and 畑に向いた土地 express? Does 借りた establish completed cultivation?
Show the answer and why
The first identifies grounds associated with a school, and the second identifies land suitable for fields. 借りた reports renting, not completed cultivation.