coh
Imperial Masterpiece
Again, Sandy...you can get chemical (powder or liquid) fertilizers that are urea-free. You don't have to go organic. I'm not saying that you shouldn't, just putting it out there.
Regarding the topic in this thread...the suggestion posted by Markyscott is an interesting way of looking at it. I would imagine their testing was based on soil (peat) type potting mixes? So may not translate perfectly to a completely inorganic soil. Regardless, we have another situation where people are doing it both ways and no one seems to have any complaints. Which means that it probably doesn't really matter. I would still think, though, that if your tree and soil are on the dry side, there is some potential for excessive fertilizer uptake. How dry is too dry, I don't know.
Regarding the topic in this thread...the suggestion posted by Markyscott is an interesting way of looking at it. I would imagine their testing was based on soil (peat) type potting mixes? So may not translate perfectly to a completely inorganic soil. Regardless, we have another situation where people are doing it both ways and no one seems to have any complaints. Which means that it probably doesn't really matter. I would still think, though, that if your tree and soil are on the dry side, there is some potential for excessive fertilizer uptake. How dry is too dry, I don't know.