I'm sure most people will have already seen woodland soil but just in case anyone is wondering why permaculture is a good idea:
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A Farm for the Future BBC2
Moderator: Peak Moderation
- biffvernon
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Good stuff about the programme at http://transitionnetworknews.wordpress. ... he-future/
and
http://transitionculture.org/2009/02/23 ... l-viewing/
and you can download the film from http://www.mininova.org/tor/2313068 which may or may not be legal, I wouldn't know.
and
http://transitionculture.org/2009/02/23 ... l-viewing/
and you can download the film from http://www.mininova.org/tor/2313068 which may or may not be legal, I wouldn't know.
Hi mrb. Thanks for that. Really interesting.mrb wrote:I think this is a bit of a straw-man, you give worst case for compost and best case for animal manure?Billhook wrote:while I'd be the first to agree the potential benefits of well rotted compost, it has limitations bpth in scale and in content.
Re scale, supposing I wanted to displace agribiz fertilizers in just one country over say just one million ha.s - at best I'll fence the crops being grown to make the compost to exclude deer & rabbits (high and small mesh) or risk losing a lot and need to plant a far greater area.
I'll also have the massive workloads of mechanized plowing, cultivating, harvesting, loading, carting, stacking, and turning the yield and then turning again, loading, carting and spreading the many million tonnes of product.
By comparison, traditional mixed farming (on which sundry popular modern approaches are based) firstly uses low large mesh fences only to enclose stock while hedges are re-established (hedges don't exclude deer or rabbits) and then relies on the livestock to collect most of the herbage.
Then, while sheep are mostly wintered out in the UK, many cattle and ponies are wintered in (barns & stables) (and are fed on hay and fodder crops harvested and carted to storage) both for their shelter and to save the pastures getting poached to hell and to have the dung fall where it can be readily stacked to mature.
Surely there will be greater losses for manure, I have tried to give equivalent examples below. (Of course these scenarios will have different outcomes re: nutrients and advantages/disadvantages.)
Animal manure:
growing->harvesting->transport(to storage)->storage->transport(to animals)->fed to animals->manure collected->manure transported->manure composted->manure spread
Compost:
growing->harvesting->transport(to heap)->composted->compost transported->compost spread
Animal manure(in situ)
growing->animals "harvest" crop
Green manure:
growing->"harvest"
Is it not true that many (most?) organic farms use animal manure from non-organic farms? I believe that there are already local shortages of animal manure and this would only get worse with an increase in organic farming. IMO this is the real problem of scale with organic farming! Was this not something mentioned in the program - organic farming being reliant on conventional farming and all that that entails.
Here I agree a closer approximation is extensive use of green manures instead, a farmer who has seen fit to undertake this approach is Iain Tolhurst (here are some more) (An article on this very subject by Iain Tolhurst.)Billhook wrote:All of which saves a vast amount of extra work that compost demands, that no farmer I know of has yet seen fit to undertake.
The nearest approach is the occasional growing of a green manure crop for plowing in as part of a normal crop rotation.
Agreed it's a mixed bag, and depends greatly on what type of animal/green manure/compost.Billhook wrote:Secondly, re. content, it would be a mistake to assume that dung is either standard or no better than compost, (which also varies greatly).
AFAIUI, dung holds far more developed compounds that are both better retained by the soil and far more easily assimilated by the growing plants, but I am not expert in this matter.
However green manures seem more flexible.
Some grow quickly, some fix nitrogen, some have deep roots that both bring up nutrients from the subsoil and improve soil structure, they can be mulched or composted (in situ or elsewhere) or any combination of the above!
Perhaps by some specific measure it is more valuable (perhaps by weight, or time, or X?) but it can't be in every situation and maybe not in most?Billhook wrote:Personally, it seems to me that anything that can be composted is usually better fed to the pigs, whose dung is far more valuable as a fertilizer.
By what measure of efficiency?contadino wrote:It speeds the whole process up dramatically, and makes it more efficient.
I can't see how it is possible to more efficiently produce food calories or useful fertiliser using animal manure than green manure or compost (if both are using best practice)?
"Livestock excrete 70-80 percent of the nitrogen, 60-85 percent of the phosphorus, and 80-90 percent of the potassium fed to them."
Both green and animal manures release about 50% of nitrogen (I imagine it is similar for the other nutrients?) in the first year or so and then slow down.
Using the nutrients via an animal will always result in lower *total* amounts, although it's possible they may be more available or somehow "better".
As for speed, common crops (e.g. red clover, oats) used as fodder or green manures will obviously take the same amount of time (or less fro green manures) to grow.
Pros/cons of each approach...
Animal manure:
Pros:
Some animals may improve soil structure
Some animals may eat weeds root 'n all
Cons:
Ammonia volitization
Some animals may degrade soil structure (compaction)
May contain weed seeds
May contain bacteria - E. Coli/salmonella
May contain parasites
Worse greenhouse gas output (Lots of methane!)
Green Manure/Compost:
Pros:
Likely to improve soil structure
May bring micro/macro nutrients from sub soil
Likely to suppress weeds
Prevents soil erosion (vs. bare ground in winter say)
Less greenhouse gases emitted for same amount of nutrients
Cons:
Possibly requires more human labour (although I would say unlikely)
All this is open to debate of course but I don't think the case for animal manure is as strong as many believe.
You know I've been wondering about the relative merits of compost vs manure since my introduction to permaculture a few years ago. I think it should be an important part of research. I can't help thinking that the pig would 'lose' more energy from the system in the form of heat and movement, compared with the composting process, but then you have a lot of soil born life reproducing and giving off heat in the composting process. The pig would also have to be returned to the soil on death, possibly via human excrement in order to run a closed system. Obviously humanure should be returned to the land in any good permaculture system if one is not to rob the soil of the closed sysetm.
I guess that you would have to follow nature to some degree and rely that evolution has got it right. Natural grassland would have been subjected more to occasional browsing and fertilisation by animals, and some composting action in autumn as the grasses and herbs die back.
Woodlands would have seen alot of composting of leaf fall, breakdown by fungus of dead wood and also seen some dunging by woodland creatures.
So if we're trying to mimic the huge productivity of a woodland in forming an edible forest, then my guess would be to leave it to nature. Let the leaf fall compost in place and run a few chickens and maybe an occasional couple of weaners?
Jim
For every complex problem, there is a simple answer, and it's wrong.
"Heaven and earth are ruthless, and treat the myriad creatures as straw dogs" (Lao Tzu V.i).
For every complex problem, there is a simple answer, and it's wrong.
"Heaven and earth are ruthless, and treat the myriad creatures as straw dogs" (Lao Tzu V.i).
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In case anyone's interested - someone's started a peak oil thread on the POV website
http://www.bbc.co.uk/dna/mbpointsofview ... ad=6377944
I've posted a reply, but it's still being moderated
http://www.bbc.co.uk/dna/mbpointsofview ... ad=6377944
I've posted a reply, but it's still being moderated
Believe in the future - Back to Nature
- biffvernon
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The beeb wrote back to my request for a DVD:
So I told them that they've missed out on the fiver I'd have given them and have had to download it for free off 'tinternet.Dear Biff
Thank you for your recent communication regarding the availability of the above programme.
I am sorry to have to disappoint you but upon investigation I can confirm that we have no immediate plans to clear and release this title on DVD. Your correspondence will be kept on file as each quarter we review public enquiries and often revisit titles which are frequently requested.
We appreciate all of the feedback that we receive from the viewing public, so thank you again for your correspondence.
Yours sincerely,
2Entertain DVD Enquiry Team
Hi guys,
We've just seen someone has put our whole film onto google video
http://video.google.com/videoplay?docid ... 8943461860
and here's the embedded code, if anyone is interested
<embed id="VideoPlayback" src="http://video.google.com/googleplayer.sw ... en&fs=true" style="width:400px;height:326px" allowFullScreen="true" allowScriptAccess="always" type="application/x-shockwave-flash"> </embed>
We've just seen someone has put our whole film onto google video
http://video.google.com/videoplay?docid ... 8943461860
and here's the embedded code, if anyone is interested
<embed id="VideoPlayback" src="http://video.google.com/googleplayer.sw ... en&fs=true" style="width:400px;height:326px" allowFullScreen="true" allowScriptAccess="always" type="application/x-shockwave-flash"> </embed>
-
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- Contact:
And if you want to download the film directly (without the need for Torrents) you can do so here:Tim Green wrote:Hi guys,
We've just seen someone has put our whole film onto google video
http://video.google.com/videoplay?docid ... 8943461860
and here's the embedded code, if anyone is interested
<embed id="VideoPlayback" src="http://video.google.com/googleplayer.sw ... en&fs=true" style="width:400px;height:326px" allowFullScreen="true" allowScriptAccess="always" type="application/x-shockwave-flash"> </embed>
http://www.darkoptimism.org/links.html# ... gy%20links