In article ,
"David Hare-Scott" wrote:
Tropical rainforest is often on leached soil where most of the
nutrients are actually in the trees. Saying that this environment
doesn't accumulated soil and therefore no forest will do so does not
necessarily follow. Particularly where temperate forests were
cleared for crop land you can certainly increase the amount of
carbon stored by converting them to pasture or back to forest. But
your point about reaching a maximum and then not storing any more is
correct.
Citation, please.
Note that we were talking about changes to land use not sequestering carbon
in less decomposable forms. I was told the amount that can be stored has
limits in a course by Dr Judi Earl who put me on to Dr Christine Jones. The
latter is the local guru on agricultural carbon sequestration. The reason
given is that as decomposable carbon builds up the microbes that break it
down also build up until the rate they are breaking down reaches the rate of
build-up, in other words an equilibrium is reached. The position of the
equilibrium depends on the land use and methods but you will still get one
sooner or later. This is ignoring the carbon stored above ground in forests
etc but you can see that it also has a maximum value depending on what is
grown.
Here is one quote:
"The capacity of soil to store decomposable organic carbon by
physical protection within micro-aggregates or other organomineral
complexes seems to be finite.
Once these complexes are saturated any added decomposable
organic carbon cannot be protected from decomposition.
Even if this capacity has been severely depleted it can be resaturated
rapidly (e.g. within 30 years by growing pasture)."
Which is from he
http://www.amazingcarbon.com/PDF/Lei...N_ARMIDALE.pdf
This site
http://www.amazingcarbon.com
has a huge amount of material on this topic. I haven't read it all. If you
also google on:
carbon sequestration "christine jones" site:.au
you will get much more. She is of the view that paying farmers to do
sequestration is a solution to climate change. I think we must try many
solutions because until you try you don't know for sure what the effect will
be and also there are political, economic and social limits on the extent
that any given solution can be adopted thus we are likely to need a
multi-pronged approach to succeed.
Also I would not want to push only sequestration solutions because the
fossil fuel industry will try to seize on any method of dealing with climate
change (eg "clean coal") as long as it allows them to keep on burning and
that is very undesirable for many reasons apart from the increase in
atmospheric CO2.
David
The pdf was a good romp with soil "C" saturation rates varing from 30
years to 20,000. Part of Salatin's putative success with topsoil
building would have to be that he is returning more "C" to the soil than
"N", so it would seem that this isn't a rudderless enterprise.
I share your concern about coal, and since we have already breached the
Rubicon for the CO2 greenhouse effect at 450 ppm, if you factor in the
influences of the other greenhouse gasses (CH4, NO2, O3, H2O). If our
politicians weren't such whores, it would be a simple matter of
maximizing those activities that ameliorate greenhouse gases, and the
continuous reduction of those activities that aggravate it (fossil
fuel). Of course this would need to factor in, transitioning those
employed in fossil fuel extraction into different employment, and the
screams of "socialism" from the lunatic fringe.
Building topsoil would still have the salubrious effects of:
1) cessation of the use of chemical fertilizers, which encourage some
bacteria to devour the organic material in the soil (topsoil)
2) stops the release of NO2 from the fertilizer, which is a greenhouse
gas.
3) stops the pollution of ground and run off water, thus improving
the quality of drinking water, and cutting off the cause of ocean
dead zones.
4) At the very least, what remaining topsoil would be protected by the
permanent ground cover, and there is the expectation that we may add
to it.
5) Additional topsoil (because there is more of it, and it is made from
organic material) would effectively sequester CO2 to some extent.
Again the question is where to put the decimal point, not "if one is
needed". Peter Bane (google the name) puts the sequestration
potential at being equivalent to the US production of CO2.
6) Increased topsoil leads to increased absorption of rain fall,
recharging aquifers, and reducing chances of flooding.
7) Increased meat production on grassland instead of in CAFOs, means that
70% of antibiotics in this country won't go into meat animals,
thereby creating antibiotic resistant strains of bacteria.
8) Less grain will be needed to divert into CAFOs
9) Fewer CAFOs means fewer stinking lagoons of animal excrement, that
won't be dumped into public water ways, or find its way into ground
water.
10) Gives us a good source of complete proteins (beef and chickens), for
healthy, growing kids.
Hopefully the above would also inspire more small farmers to return to
mixed use farms as Community Supported Agriculture (CSA).
This is the first time that I have heard of "Phytolith Occluded Carbon".
Unless we can grow sugarcane it in Ohio, to make methanol as a
replacement for fossil fuel, it sounds as it it is of limited utility. I
don't think the plant is suited to the weather in most of this country,
and I would hate to see farmland given over to just CO2 sequestration.
It seem to me that fast growing forests that can be converted to
charcoal would give both habitat, clean water and air, and sequestration.
Anyway, thanks for the citation.
--
- Billy
"Fascism should more properly be called corporatism because it is the
merger of state and corporate power." - Benito Mussolini.
http://www.democracynow.org/2010/7/2/maude
http://english.aljazeera.net/video/m...515308172.html