Jim, I feel your pain as well. I quit reading at the "tomb" / "tome" part, I thought "tomb" was an apt descriptor for some of those books as you would probably be dead before you finished reading it.
Elaine, your findings are the same as I came up with a few years back and with my limited curiosity on the subject (meaning, I probably wouldn't understand what they were talking about anyway), I didn't pursue the issue any further.
From my favorite orchid book "UNDERSTANDING ORCHIDS" by WILLIAM CULLINA, which has an excellent chapter on 'Fertilization and Nutrition'. I would recommend this book just for this chapter alone. Here are a few lines taken from "UNDERSTANDING ORCHIDS" regarding urea:
"Related to this is the question of urea, which is a synthetic form of organic nitrogen that must be broken down into ammonium by microorganisms around the roots of plants or by the plants themselves before it can be absorbed. Urea is added to soluble fertilizers because the nitrate and ammonium are so soluble that they readily leach out of the pot. Urea is in effect timed-release form of nitrogen that makes ions available over several weeks, so if you apply fertilizer only occasionally, the plants won't be starved of nitrogen. The problem for orchids - especially epiphytic species growing on mounts - is that conditions are not ideal for breaking down urea. In a pot of soil or in the ground, where moisture and temperature are more constant, microorganisms can do their work more efficiently. An organic, water-retentive mix like Pro-Mix would also provide conditions in which urea could be utilized. On a slab of cork, however, conditions are obviously different. Though bacteria are likely to be living in the
rhizospere ( the microscopic zone around a root where leachates, mostly sugars, oozing from the root foster colonies of microorganisms that help the root scavenge nutrients), my guess is that most of the urea gets washed away before it can be absorbed. This is obviously wasteful, so check the label to make sure you're getting a low-urea formulation. Some fertilizers sold specifically for orchids state that they are low in urea."
Are you familiar with the FirstRay web site, it contains a plethora of information on orchids and various other things, you could spend days reading through it. Here is a link to his site, drop do down to "Site Map", click on it and take your pick.
http://www.firstrays.com/
Here is a link to an article on Fertilizers on Rays site. I have only read a snip-it of this article so don't know what it contains but there is mention of urea in it.
http://www.firstrays.com/PDF/P...
Good luck in your research!!!
