some research findings

I've been doing some digging around and found out some interesting stuff.
http://asap.sustainability.uiuc.edu/members/dananderson/documents/org-prod/
Bill Liebhardt, 2001. OFRF Information Bulletin, Summer 2001, #10.
This report found that the assumprion that organic crop yields would necessarily be much lower than intensively grown crops isn't the case. Yields in some crops were lower, but only by around 5%. He said "for a total of 154 growing seasons for different crops, grown in different parts of this country on both rain-fed and irrigated land, organic production yielded 95% of crops grown under conventional high-input conditions.”
This doesn't seem so bad. I'm sure that better food disatribution and storage could save the other 5%. Wasting less food would certainly help make up the shortfall.

The BBC website also had some interesting info at http://www.bbc.co.uk/bloom/flash.shtml#/actions/growyourown.shtml
I've copied a chunk of their article in below.
"Research suggests feeding each of us contributes around 1700kg of CO2 a year, but scientists are a long way off pinning down exactly how much of that you'll save by growing-your-own:
You will save the most CO2 by growing foods which have the highest CO2 impact such as Mediterranean-style veg, (courgettes, peppers and aubergines) salads and tomatoes. We eat them all-year-round, out of season, which means they must be grown in energy-demanding heated greenhouses (here or abroad) or flown over. The UK is fairly self-sufficient all year round in carrots and potatoes, so growing these won't save as much CO2, but will save you money
According to one study if you grow 5kg of tomatoes instead of buying them in a UK supermarket (grown in season in the UK), you could save the equivalent of up to 45kg of CO2 and around £20
...Growing your own food reduces food transport on the roads - a quarter of all UK heavy lorries on roads are carrying food between farms, processing units, food storage deports and supermarkets
Climate change projections suggest arable crops will need heavy irrigation in future if they are to survive in the south of the UK, and food crops may be even less secure in some developing countries. Growing your own food is one way to adapt to these changes"

So I've learned that from a climate change point of view, it's best to grow foods that would otherwise need to be imported or grown in heat, such as tomatoes. Well that's fine, but I don't think I'll be able to grow enough to meet my needs through the winter and unless I set up a canning factory or buy a huge freezer, or make an awful lot of chutney (and I can't use chutney in all of my cooking!), how would I store them anyway? To be really strict about this I'd have to stop buying canned tomatoes.

I wonder what difference there is in energy usage between canning and transporting to the UK and producing in the UK on my allotment and then freezing in my freezer. Hmmm...

starting out

We (my partner John and myself) have had an allotment now for about two and a half years. It's in south Leeds and consists of heavy, slow-to-drain clay. We've tried to garden with organic principles, although we did use glyphosate based weedkiller to clear the plot initially (it was completely overgrown).

Since then I've decided I want to do the whole organic thing in a more sustained way and to embrace the principles of permaculture. Permaculture is all about growing in a sustainable way, reducing dependence on fossil fuels and cultivating the soil in a sympathetic way.

Permaculture is heralded as the solution to the looming shortage of oil.

This oil shortage is something we should all be worried about.

Basically, at some point in the future, we may even have already passed the point, oil production is going to go into decline, there are limited reserves of hydrocarbons under the earth's surfaces and we are using them up very rapidly. This is going to spell hardship, famine and conflict unless we can find a way to free ourselves from our dependence on oil. And we are dependent. It is estimated that in 1804 the world's population was around the billion mark. By 1927 it had reached the 2 billion mark, by the millennium it was around 12 billion. Some of this growth is due to improved access to more effective medications and health care, sanitation etc. One of the major factors, however, has been due to our ability to harness the stored sunlight in oil and gas reserves. We use oil, gas and other hydrocarbons for fuel, manufacturing fertilizers and pesticides, treating and preserving and processing food, and we do this on a massive scale. Our food production techniques and industrial and oil dependent. However, when our fossil fuel supplies start to decline we will need to use an alternative source of energy if we are not to see food shortages, famine and wars over increasingly scarce resources. We simply cannot afford to continue depending on a resource that is going to become increasingly scarce.

Now, I'm a bit of a sceptic. I really want to believe that permaculture can offer a sustainable and realistic alternative to oil reliant methods, but I do have some concerns. Here's a few of them. Can permaculture offer equivalent yields to oil dependent methods from the same acreage of ground? If it can't then we will have to either take more land into cultivation - and there's not much cultivable land left on this little earth that isn't already cultivated so that doesn't seem like a good option, or we are back with the problem that food production will decline, leading to the aforementioned hardship, famine and conflict.

What crops can you grow using permaculture? I've heard that one of the main principles of permaculture is to keep the ground covered and to plant growing plants into it. OK, that's fine for cabbage and pumpkins, but some crops, such as parsnips and carrots need to be sown direct. Can I still grow these crops?

How labour intensive is permaculture? Will I need to put in lots of hours of work? Actually, I've heard it's less work than traditional cultivation. I'll have to see for myself I think.

Will I have the resources I need to hand in inner city Leeds to be able to run a permaculture allotment? I don't have a ready supply of animal manure to do lots of mulching, not having a large vehicle to be able to collect dung from the local stables. I've heard that mulching is crucial, so I'm a bit concerned how I will manage - this may be a very short and unsuccessful experiment if I can't get the materials I need.

So, the plan is to continue cultivating my allotment, while I go away and do some research. As I find out more I will start to apply the principles to my allotment. Hopefully I will find out for myself that it is a good alternative to oil dependency, at least on my little allotment. However, I'm not optimistic that it will have the answers for an antire world dependent on oil produced food, but I really hope that I'm wrong about that one.