You can create two sales. Make the land a 2nd sale, all by itself. Allocate what you consider an appropriate portion of the sales price and sales costs to that sale and reduce those items for all the other items sold. It can all be done through the depreciation screen. 

EDIT - for the land portion - check the box for Form 4797, Part 1.  For all the other assets link then and indicate a 1 for section 150 in the field Blank=1245, 1=1250, 2=.....