Pasture Rent and Mortgage Interest

My primary residence is our family farm.  I'm not filing a schedule F this year.  Our only income was passive pasture rent ($1800) which I'll report on schedule E.  I have a mortgage on the entire property.  Is there any benefit to deducting a portion of the mortgage interest against the rental income vs the normal itemized deduction on the 1040.  If so, what methods are used for determining how to split the interest between the 2.