FEAture is actually intended for application as a low volume foliar application. I have applied 6 lb of the powder per acre in 50 gallons per acre a few days before a special event. Yes, customers do ask if I can get the grass greener before a party. Works best on lawns that already have everything else in order. Will do very little for a starved or dried out lawn. Does not do much on my lawns because iron and micronutrients are already a key part of the program.
Iron, specifically iron sulfate is used as a "hardening agent" in England, Australia, and New Zealand. This is applied in the cooler months of the year when forcing grass to be green with more nitrogen is not appropriate. They also tout better resistance to disease, stiffer turf, and of course, nice color. I have to wonder what cool season grasses would do if treated in a similar manner vs more urea.
They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.
Benjamin Franklin 1775
Sell not virtue to purchase wealth, nor Liberty to purchase power.
Benjamin Franklin Poor Richard's Almanac1738