Healthy soil and sustainable growing

["Greg and April" <gregandapril@earthlink.net>]

The carbon came from the wood chips.

When I was saying chips, I wasn't talking about chunks, but, something more 
along 1/2-3/4 inch max.    Shreds might have been a better term.

You can look up the data that New Alchemy used ( they have 69 references, 
but I'll just give a few ):

Compost:

Poincelot R.    1972
The Biochemistry and Methodogy of Composting.
Connecticut Agriculture Experiment Station
Bulletin 727    March 1972
New Haven Conn

Digested Manure:

Hog:
Taiganides, Eliseos P. 1963
Characteristics and Treatment of Wastes from a Confinement Hog Production 
Unit
PhD dissertation, Iowa State Univ.
Science and Technology, Agriculture Engineering.
Available from University Microfilm Inc.
An Arbor Mich #63-5200 ( 177 pg )

Cow:
Hart, Samuel    1960
Sludge Digestion Tests of Livestock Manures
Dept. Agr. Engr. Univ. of Calif. Davis
Offprint manuscript.

The amount of methane generated is based on several factors including waste 
material used ( even manure from different animal types can vary the 
amount ), the temperature, the time in the unit, and even the amount of 
dissolved solids in the slurry ( since it's the dissolved solids that 
actually do the job ).


Costs to build units vary, with such things as the materials used. 
Smaller units can be built from scrap 55 gal barrels that can be had for 
free, if you know where to look.    They can be made from concrete if that 
is your style and your budget    I built one out of a 3 gal pickle jar, when 
in high school, just to see if it would work, using dog manure ( from when 
the neighbors dog would go in our yard ) and it did.


Some rough figures.
(from Methane Digesters for Fuel Gas and Fertilizer )

Cattle manure
100%    1.4 cu Ft ( per lb of Volatile Solids)  65% CH4

Chicken manure
100%    5 cu Ft    59%

Chicken manure /
paper pulp
31%/69%    7.8 cu Ft    60%

Chicken manure /
grass clippings
50%/50%    5.9 cu Ft    68%

( from Hand Book on Bio Gas and It's Applications )
4 cattle ( as we can see above they are not the best source ) and a 5 cu m 
( 177 cu Ft ) gas unit, and retain for 50 days you will be producing 1.55 cu 
m of gas @ 20*C ( 54.7 cu Ft @  68* F ) every day.

How long it takes to repay initial investment is highly dependant on the 
amount invested, and what the gas is worth to the person using it.

The digester built by John Fry ( that I mentioned a month or so ago ) on his 
hog farm ( average 1000 hogs ), cost him about $10,000 to build, and 
produced 8000 cu ft of bio gas a day ( 4,680 BTU's a day ).    His figures 
showed that this was worth $7.57 a day in Santa Barbara Cal. in 1973, or 
$16,578 in 6 years just for the gas alone, and not for any fertilizer value. 
So his return of investment, was less than 6 years.

Another way to look at it:

Average cost per Hog to build: $10
Average amount of Bio gas per hog: 8 cu ft a day
Average number of BTU's per hog: 4.68 each day
Amount of liquid fertalizer: Approximately 500 gal every 3-4 days ( 125 - 
170 gal / day ) - for an average of 1000 hogs.

As mentioned above, even as few as 4 cattle can produce 54 cu ft of bio gas 
each day, and used effectively, that is enough to provide supplemental CO2 
and keep a green house warm on chilly nights.

It all comes down to how people apply the resources that are available. 
Let manure do nothing over fall and winter, or use it to heat a greenhouse 
in winter that might otherwise go unheated.    What is the value of growing 
cool crops in the middle of winter in the green house?    That is something 
that people will have to figure out and decide for themselves.    Is there 
value in fresh out of season crops?    If so how much?

Every week I meet people that say " I didn't know that " or " I thought you 
couldn't ... "

Personaly, I think the problem with digesters is, people don't try because 
they thought they couldn't ....    Until more people do try, we will never 
know for sure.

Many people still think that cars can only run on something that comes out 
of the fuel pump at the gas station, and don't think that they can make it 
them selves, because that is what they are used to thinking ( not to mention 
brainwashing ).


Greg H.



----- Original Message ----- 
From: "TradingPostPaul" <tradingpost@riseup.net>
To: <livingontheland@lists.ibiblio.org>
Sent: Friday, April 28, 2006 13:21
Subject: [Livingontheland] Biogas etc./ was Fertilizer use by crop in Brazil


> There is always some nitrogen loss, and the longer it waits before 
> composting the more loss.  Regardless of what a TV program claimed, 
> frankly I doubt that any method can turn wood chips into actual finished 
> compost in two months - unless they're shredded into finer particles 
> first.  Another thought: if much of the carbon compounds are removed in a 
> biogas unit, how much of the carbon is left for the compost? We do want 
> those carbon compounds in the soil too, don't we?  I don't believe the New 
> Alchemy people said what kind of "garden compost" they were comparing with 
> the digested sludge. Without knowing the source and condition of the 
> compost, the comparison isn't useful.  And a dry sludge end product should 
> certainly have a higher percentage of nutrients per ton than fresh manure, 
> due to moisture loss.  Pit composted manure would likely show the same 
> nutrient increase per ton after drying.
>
> One figure I haven't seen is how much usable methane can be produced from 
> how many livestock, horses, cattle, etc. And how long it would take for a 
> given biogas digester to repay it's initial cost, figuring in the labor 
> involved. I suspect the low return is the reason we've never seen the 
> numbers on payback.  Manure digesters have been experimental for a long 
> time, and from what I've seen they're always subsidized one way or 
> another, much like ethanol.  I'd like to see something showing it's 
> practical for the small farmer in terms of investment and ongoing labor 
> required.
>
> paul, tradingpost@riseup.net
> ---------------
> The outstanding scientific discovery of the twentieth century is not 
> television, or radio, but rather the complexity of the land organism. Only 
> those who know the most about it can appreciate how little we know about 
> it.
>   - Aldo Leopold in  Round River, 1933
> *********** REPLY SEPARATOR  ***********
>
> On 4/28/2006 at 12:26 PM Greg and April wrote:
>
> > How do you figure that?    How do you think that nitrogen is removed?
> >
> > The nitrogen compounds stay with the liquid as ammonia mixes with the
> > water.
> >
> > In fact IIRC, water will absorb gaseous ammonia, that is the concept
> > behind
> > the old "Icy Ball " and other ammonia / water absorption refrigerator
> > systems.    Water in the first chamber absorbs gaseous ammonia, lowering
> > the
> > vapor pressure, then with the lower vapor pressure allows more liquid
> > ammonia to evaporate thus cooling the second chamber.
> >
> > Most of the ammonia formed in a biogas unit, absorbs into the water/slurry
> > in the unit.
> >
> >
> > About 3 yrs ago, I saw a program on TV, about a bio gas unit, that
> > recovered
> > methane from manure, and the resulting liquid was still so rich in
> > nutrients
> > that they would shred aspen and mix the resulting chips with the liquid
> > and
> > compost it.    A mound of aspen chips 30ft high would reduce to finished
> > compost in about 2 months.    If the liquid was not rich in Nitrogen,
> > about
> > all that would happen is that it would fungus ( take a very long time to
> > break down ), not compost.
> >
> >
> > It is true, that if you leave manure out, exposed to the weather, it will
> > lose nitrogen through liquid evaporation and/or through leaching ( as seen
> > if a bale of hay is left out in the open ), but, in the case of a biogas
> > unit, the nutrient rich liquid is retained, and used elseware, after much
> > of
> > the carbon is removed, in the form of CO, CO2, CH4, you might lose a small
> > amount of nitrogen, but, that part that you may lose is but a fraction of
> > the total.
> >
> >
> > The New Alchemy Institute ( Methane Digesters for Fuel Gas and Fertilizer
> > )
> > calculates that garden compost has from 1.4 - 3.5 % ( dry weight )
> > nitrogen,
> > while digested cow manure sludge has from 2.7 - 4.9 % ( dry weight )
> > nitrogen and that jumps to 6.1 - 9.1% with digested hog manure.
> >
> > The fact that digested sludge has higher amounts of nutrients than compost
> > ( even compost made under cover so nutrients are not baked out by the sun
> > and leached out by the rain, is backed up by The National Institute of
> > Industrial Research ( India ).
>
>
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