View source for Revised Necromancer Handbook (3.5e Guide)/You want the Best you can get

=====The Importance of being Desecrated=====
Desecrate is an effect that is of astounding importance to a Necromancer. Any Undead created within a desecrated area gains an unnamed bonus to all its Hit Dice, and the cost of using it is minimal compared to actually making undead in the first place, so failing to desecrate before making undead is inexcusable. Desecrate can also be used to cut off an area from sacred power (whether it is sacred to a good or evil god even, so the fact that Good clerics can’t normally cast this spell is one of the many reasons that in official D&D: Evil Wins), and even makes turning checks more difficult. That includes Rebuking checks, so beware that your Desecrate aura is going to interfere in you controlling your own undead, so plan accordingly. Desecrate is not available as a Wizard spell, but its effects can be replicated by Black Water (from It’s Raining Outside) or Lesser Planar Binding (as always, mid-level fiends come to the rescue of the arcane necromancer – A Zovyut can desecrate all day for free if you happen to be an Infernal Bargainer, and a Maurezhi can just do it).