In 723, as a part of the land cultivation promotion program, Sanze-isshin Law (a law allowing farmers who cleared new lands to own them for a period of three generations) was promulgated and the private ownership of newly cultivated land was approved though it had a time limit.
翌年（723年）には開墾推進政策の一環として三世一身法が発布され、期限付きではあるが開墾農地（墾田）の私有が認められた。