Something I stumbled upon while surfing. It is an excerpt from The Santa Barbara Society Newsletter.
"Our own Bryce Augustine spoke to the society about Orchid Physiology. Augustine graduated from UCSB with a BA in botany and currently is the owner of Monsoon Flora Orchid Lab, which he has run since 1991. He is also an AOS judge."
"As for fertilizer, Augustine uses 20-20-20 during orchid growing periods. He prefers Urea based nitrogen because its availability to plants is related to temperature. At warmer temperatures, when plants are actively growing, Urea based nitrogen is also readily accessible."
Anyone interested in reading the article use this link
http://www.orchidsb.net/resources/2006_06.pdf.
This is not the first time that I have read about Urea being recommended.