ZKC Controller described a low altitude alert event apparently caused because of an altitude assignment below the Minimum IFR Altitude (MIA) published altitude. The reporter suggested MIA altitude information be provided on the RADAR display.

Narrative

I was vectoring Aircraft X for a VOR approach to Runway 03 at FOE. I descended Aircraft X to 3;000 FT since that is the minimum altitude for the approach; also thinking that was the Minimum IFR Altitude (MIA). I observed an MSAW alert while Aircraft X was descending out of 4;000 FT; immediately checked my low altitude map; and still thought the MIA was 3;000 FT. After closer evaluation of the map; I found that the area where I had vectored Aircraft X had a MIA of 3;200 FT. At this time; Aircraft X was already established on the final approach course at 3;000 FT. I never observed Aircraft X descend below 3;200 FT prior to being established on the final approach course. The low altitude Controller charts located above the RADAR scopes are very cluttered and can be difficult to obtain information from in a timely fashion. A feature available on all low altitude sector maps that displays the MIA directly on the RADAR scope would be the best solution to prevent events of this sort. The current practice of using the Controller chart to determine MIA; MVA; etc.; and not having this information available to display on the RADAR scope is inefficient; impractical; and at times unsafe.