11.140  What constitutes adverse possession under claim of title not founded on written instrument.  For the purpose of constituting an adverse possession, by a person claiming title, not founded upon a written instrument, judgment or decree, land shall be deemed to have been possessed and occupied in the following cases only:

1.  Where it has been protected by a substantial enclosure.

2.  Where it has been usually cultivated or improved.

[1911 CPA § 17; RL § 4959; NCL § 8516]