David, sorry to have to use this wacko's post to reply to an old discussion about whether only salts from commercial chemical fertilizers can burn plant roots, or whether they can be burned by ammonia from decomposing proteins as well. I was rummaging around old "postings", and found this.
It is part of an ancient discussion that Fran and I had about the merits of fresh vs. aged organic fertilizers (poop).
From: "FarmI" Newsgroups: rec.gardens.edible Subject: Ping Billy Date: Sat, 23 Aug 2008 18:54:34 +1000
The Rodale book of composting By Deborah L. Martin, Grace Gershuny
I have found the Rodale books are good ones so what it said made sense to me.
It says of fresh vs rotted/aged manure that: i) in the composting process, manure can lose up to half it's moisture content and thus concentrate nutrients ii) nitrogen in composted manure is fixed whereas in fresh, it's soluble iii) solubility of P and K is greater in composted manure and on P.125 it says
that "when manure is added directly to the soil, it generally releases highly soluble nitrates that behave similarly to chemical fertilisers,
** as well as ammonia, which can burn plant roots and interfere with seed germination." **