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livingontheland - Re: [Livingontheland] Fertilizer use by crop in Brazil

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  • From: "Greg and April" <gregandapril@earthlink.net>
  • To: "Healthy soil and sustainable growing" <livingontheland@lists.ibiblio.org>
  • Subject: Re: [Livingontheland] Fertilizer use by crop in Brazil
  • Date: Fri, 28 Apr 2006 12:26:16 -0600

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 ).


Greg H.



----- Original Message ----- From: "TradingPostPaul" <tradingpost@riseup.net>
To: <livingontheland@lists.ibiblio.org>
Sent: Friday, April 28, 2006 9:45
Subject: Re: [Livingontheland] Fertilizer use by crop in Brazil



You can't extract only the combustible gases without losing nitrogen with it. And you can't put the nitrogen back in the manure. Further, any time lapse betwen the producting of manure and composting it means serious loss of nutrients, as studies in Rodale's earlier book on compost showed. My old copy of Compost detailed the figures, something like 50% loss of nutrients in a day or two, but I don't have it handy right now to give the exact numbers.

The process of making biogas invariably reduces its nutrient value to the soil. Personally, in a fossil fuel-deficient agriculture I'd think it's far too valuable for soil building to waste it producing fuel.

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 8:24 AM Greg and April wrote:

I'm going to disagree with this statement.

Nitrogen has no energy value, there for it would be a waste of time to
remove it for energy purposes.

The most common way to extract energy gasses ( to my knowledge ) would be
Biogas, which while it may have traces of N, is mostly CO, CO2, CH4, and
some H2S. Removing N from the manure, means only you are reducing the
energy value of the Biogas.

Greg H.


----- Original Message ----- From: "TradingPostPaul" <tradingpost@riseup.net>
To: <livingontheland@lists.ibiblio.org>
Sent: Thursday, April 27, 2006 22:10
Subject: Re: [Livingontheland] Fertilizer use by crop in Brazil



Taking the gases for energy leaves the manure without the nitrogen to
add
to the soil, and without the nitrogen it's hard to compost. Rodale
recommended composting manure to preserve its nutrients, then adding it
to
the soil, rather than just spreading it on the fields to lose much of
its
nutrients to the air.


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