Grants or mortgages of trust real estate may be made to secure the performance of a contract of the trustor or any other person. Unless otherwise specifically provided in the deed of trust or otherwise specifically agreed in writing by the trustor and the beneficiary at the time of acquisition, an interest in the trust real estate acquired by the trustor after the execution of the deed of trust shall run to the benefit of the trustee and beneficiary as security for the contract for which the trust real estate is granted or mortgaged as if the interest had been acquired before execution of the deed of trust.
NMS § 48-10-9