A real property that has been assessed as an agricultural unit which is owned by 3 or more persons is rules by provisions as laid down in sections 2 to 6 of the present Act relative to common ownership rights. An agreement between owners, which is in contravention with these provisions, shall be non-valid (sect. 1). The owners shall be represented by a representative who shall be registered in the real property register. The representative shall act current transactions in accordance with direct