15. If any claim, question or difference shall arise between the landlord and the tenant under the foregoing provisions hereof, not being a matter which, otherwise than under the provisions of this paragraph, is required by or by virtue of the Act or section 19 of the Agriculture (Miscellaneous Provisions) Act 1963 (notice to remedy breach of tenancy agreement) or regulations or orders made thereunder or the foregoing provisions hereof to be determined by arbitration under the Act, such claim, question or difference shall be determined, in default of agreement, by arbitration under the Act.