This article from the University of Hawaii may be of interest to some folks. It discusses organic approaches to various soil needs. The article specifies that soil tests are the best starting point. However, they present photos and explanations of various plant problems and what deficiency probably causes the problem.

http://www.ctahr.hawaii.edu/tpss/research_extension/rxsoil/organic.htm

Lorna

Here is a link that might be useful: RX for Soil