In my salad days, I used to have white powder for testing nitrate accumulation in plants. I cut a stem of nitrogen loving plants (e.g., stingingnettle) and dipped it in that powder. In the presence of nitrates, the pwoder turned buish/purplish. I think that I got this recipe from an old Australian soil methods book of the 1950 vintage. I would like to test some mushrooms (e.g., morels after the fire retardant treatment of the site) and I would greatly appreciate any hints from the ECOLOG-L readers.
Adolf Ceska, Victoria, British Columbia, Canada
