[permaculture] A Golden Opportunity

David david at h4c.org
Fri Dec 14 02:14:13 EST 2007


Norris,

Norris Thomlinson wrote:
> Last week I posted a short series on my blog about the need (or lack 
> thereof) for nitrogen-fixing plants in small plots where the residents 
> recycle their urine into the garden.  Based on Martin Crawford's figure of 
> one pee (half a litre) containing about 5.6 grams of nitrogen, and using 
> his numbers for nitrogen demand of different food forest canopy plants, I 
> calculated that one person's annual urine should meet the nitrogen needs 
> of 4100-5100 square feet of forest garden.
>
> You can read the full post at: 
> http://farmerscrub.blogspot.com/2007/12/nitrogen-fixers-vs-liquid-gold.html
>   
"One adult on an ordinary diet will produce from 100 to 250 grams of 
feces per day. On a vegetable diet, an adult will produce from 300 to 
400 grams per day. (Respectively, 0.22 to 0.55, and 0.66 to 0.88 pounds 
per day.) Feces are usually neutral to slightly alkaline in pH, 24% to 
27% TS [total solids] (dry weight), with a C/N [carbon-nitrogen ratio] 
of 6 to 10, nitrogen 4% to 6% of TS, VS [volatile solids] is 85% of TS. 
Normal values for urine are 1 to 1.6 liters volume per day, average pH 
6.0, 4% to 6% TS, with a C/N of 0.8, nitrogen 15% to 18% of TS, VS is 
72% of TS. (That's 1.06 to 1.69 quarts volume produced daily). Every 
liter of urine weighs about 1,020 grams. Every quart of urine weighs 
about 2.9 pounds." [The Complete Biogas Handbook, p 69.]

*Substance*

	

*%N*

	

*%C*

	

*%H**2**O*

	

*Comments*

Human, feces

	

4-6

	

 

	

73-75.0

	

reported variations

         feces

	

5.0

	

40.0

	

74.0

	

median

         mixed

	

10.9

	

26.0

	

92.0

	

median

         urine

	

15-18.0

	

 

	

95-96.0

	

reported variations

         urine

	

16.5

	

13.0

	

95.0

	

median

   [Ibid, p 37]

I hope the table (just above) survived...

d.

-- 
David William House
	503-678-5162 (home)
	503-206-1001 (cell)

	"The Complete Biogas Handbook" www.completebiogas.com

	"Make no search for water.   But find thirst,
	And water from the very ground will burst."
	   (Rumi, a Persian mystic poet, quoted in Delight of Hearts, p. 77)




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