Coated fertilizer
From PLANTFACTS.OSU.EDU
1. Granular fertilizer which has been coated with a material of known permeability to allow for the controlled release of nutrients into the soil.

This is Sulfur Coated Urea, it is an example of a coated fertilizer.
Source: http://www.johndeerelandscapes.com/_Products/better_fert.asp
