In article ,
Chuck Banshee wrote:

On Sun, 15 Jan 2012 19:14:17 -0500, Frank wrote:
I'd also post in rec.gardens for someone there who knows more plant
biochemistry than me, but the urea in urine is no different from urea
used in fertilizer. Sometimes pure ammonia is injected into soil as
fertilizer and as you point out, water will hold it there.

Or wash it away into aquifers, or public water ways. The amount of
ammonia needed to produce the same yield from a field will increase as
the organic material (OG) in the field's soil breaks down and
diminishes. Discing OG into the field disrupts the soil structure and
ecology.

With urea, you needn't spare its application, as you have a lifetime
supply of it. Do spread it around though, as you can get salt (ionic
compounds that result from the neutralization reaction of an acid and a
base) build ups if it only supplied to one small area of soil.

The Bottom Line

• Ideal soils, from a fertility standpoint, are generally defined as
containing no more than 5% OM by weight or 10% by volume

• Before you add organic amendments to your garden, have your soil
tested to determine its OM content and nutrient levels

• Be conservative with organic amendments; add only what is necessary to
correct deficiencies and maintain OM at ideal levels

• Do not incorporate organic amendments into landscapes destined for
permanent installations; top dress with mulch instead

• Abnormally high levels of nutrients can have negative effects on plant
and soil health

• Any nutrients not immediately utilized by microbes or plants
contribute to non-point source pollution


I switched the sci.chem to rec.gardens. Thanks for the advice.

Googling for a comparison paper of urea fertilizer and urine, 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 - Impacts on
Chemical, Microbial, and Flavor Quality".

Interestingly, as you intimated, they found that the urine was as good or
better than the commercial stuff.

More interesting to the point, they recommended 'no more than 6 months'
storage of the collected urine! I'm amazed as everything else I read said
that the urine should be used within 24 hours because of ammonia (gas)
formation.

I'm sure it works - but - I want to better understand the whole process
so that the maximum nitrogen gets into the compost as usable nitrogen and
not vented to the atmosphere as ammonia.
--

Billy

E Pluribus Unum

Every gun that is made, every warship launched, every rocket fired signifies in the final sense, a theft from those who hunger and are not fed, those who are cold and are not clothed. This world in arms is not spending money alone. It is spending the sweat of its laborers, the genius of its scientists, the hopes of its children. This is not a way of life at all in any true sense. Under the clouds of war, it is humanity hanging on a cross of iron.
- Dwight D. Eisenhower, 16 April 1953