For another thread, I looked up the use of urine in compost to replace nitrogen.
But I don't understand the chemistry of exactly how it all works as a compost activator and as a fertilizer.
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After reading all the references shown below, I'm still a bit confused about how urine acts as an organic compost aid.
Here's what I can figure out so far ...
It seems while undiluted urea has an NPK of roughly 46-0-0, human urine is already vastly diluted, with an NPK of about 12:1:2. Even so, human urine must still be further diluted something like 1:10 to be applied directly to growing plants because of the chance of something called 'burning' (or 1:20 in potted plants because of salt buildup in constricted containers).
But how does it work in a compost pile?
As far as I can tell, urease in the compost soil breaks the urea molecule (NH2)2CO first into ammonium carbonate (NH4)2CO3 and then into ammonium
2NH4 and carbon dioxide (CO2 gas) & finally into ammonia molecules (NH3 gas) and water.My main problem is what to do to make sure the nitrogen remains in the compost soil and isn't vented to the atmosphere as a gas.
Since ammonia is highly miscible in water, forming NH3(aq), I assume if I keep the compost soil moist, that will hinder venting of the nitrogen as an ammonia gas. Lower winter temperatures should also keep the ammonia more in the soil than as a gas. Apparently I can raise the pH and the amount of organic matter, which should keep some of the ammonia in the compost.
Do you have any experience in this?
REFERENCES:
- Urea:
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