Chuck Banshee wrote:
On Mon, 16 Jan 2012 01:02:23 +0000, Chuck Banshee wrote:

I found
this interesting paper from the Journal of Agricultural and Food
Chemistry, 2007, 55, pages 8657-8663 titled:
Use of Human Urine Fertilizer in Cultivation of Cabbage
(Brassica oleracea)––Impacts on Chemical, Microbial, and Flavor
Quality

I forgot to post the URL to the scientific paper:
http://www.nku.edu/~longa/classes/ca...cs/cabbage.pdf

I find it suspect that they found the urine-fertilized cabbage tasted
'better', as I would have expected no differences between commercially
fertilized and organically fertilized (i.e., urine-fertilized)
cabbage.

Still - my question is HOW best to keep the nitrogen in the compost
from turning into ammonia gases and simply venting away.

Interesting question. The conversion from urea, uric acid etc to ammonia is
going to be done by some microbe. I think the risk is that if you make the
environment unsuitable for that class of microbes it will be unsuitable for
others that are more useful. Another possibility is to try to bind the
ammonia so it isn't lost as a gas. Ammonium ions ought to bind to clay and
humus colloids which have significant cation exchange capacity. Also cold
composting, maintaining it damp and ensuring the pH isn't too high will all
reduce the loss of ammonia to the air.

I think the widespread use of urine as fertiliser is limited by lack of a
suitable collection mechanisms and the yuck factor. The latter is composed
of the reaction to the smell and the belief that it is "dirty". The yuck
factor is a big issue. People are often aghast at the idea of water derived
from treated sewerage being used in the normal water reticulation system,
despite evidence that the water would be as safe or safer than collected
ground water.

The smell issue is commonly accepted as not a show stopper when using
manures. Poultry manure or poultry bedding which contains large amounts of
manure can produce a most revolting stench far worse than human urine but
this doesn't stop them being used at least in agricultural settings. If I
lived in a built-up area I would be restricted in using such fertilisers due
to having regard for neighbours.

If you ask Mr or Ms Public is urine safe to use on the garden they will
probably tell you that you can catch diseases from it. This isn't true in
general. It may possibly be true if the donor has a urinary tract
infection, such a person would very probably be aware of the illness and so
should cease donating until they are well. In the absence of such an
infection fresh urine in sterile. It could also become infected if stored
in such a way that it became a growth medium for microbes that originated
elsewhere. If you are adding it to your compost or even directly to the
soil this is hardly likely to be an issue. As the article points out the
few pathogens found cannot easily get into the cabbages. Bring up your kids
to pee on the lemon tree!

As the price of oil (and so synthetic nitrogenous fertilisers) goes up we
may find some creative person who can find a way to collect urine cheaply
instead of sending it down our rivers and out to sea and then having to use
power to fix atmospheric nitrogen in its place.

David