Steve also repeated one of best definitions of permaculture that I've come across...
Permaculture is an approach to designing human settlements and agricultural systems that is modelled on relationships found in nature.I must try and remember that next time someone asks me what permaculture is!
Steve also questioned 'what is food?' and thought maybe we needed a new definition. So much of our food comes from monoculture, and have been brought down to the lowest common denominators: grasses (wheat, rice etc), potatoes and maize.
However, I think the question isn't 'what is food', but 'what food is appropriate to grow in a given environment?' For example, as Steve pointed out, in the UK we should be growing nuts (walnuts, hazel nuts, chestnuts) rather than cereal like wheat (or at least growing more nuts and less cereal). Our environment is highly suitable for nut growing and nuts are high in protein and carbohydrates and are more nutritious than wheat. Nuts can be ground into flour and used for baking. And from a permaculture/agroforestry perspective, nut trees can fit really well in a diversified agricultural system.
One example Steve showed was of nut trees with wheat growing underneath (see - you can have your cake and eat it!). As the leaves on nut trees come out quite late, wheat can be sown in the autumn when the nut tree has lost it's leaves (which go into the soil and add nutrients). The wheat starts growing before winter sets in, stops during winter, then gets growing again in early spring once the temperatures start rising. By the time it gets to summer, the leaves on the nut tree will be out, but by this point the wheat isn't doing much photosynthesising. Therefore the shade of the tree does not impact on the wheat as it now putting its energy not into photosynthesis, but into using the energy stored in the plant to develop the grain.
Getting the initial design and spacial relationships right is very important. The nut trees should be planted carefully so they are not too close together. With careful design you get two yields from one area of land (and probably more but I'm just limiting this to nuts and wheat for as an example).
As someone who rather loves her potatoes and fresh bread from the farmers market, I don't want to give them up. But Steve's talk did make me think about how what I see as key food items, wheat and potatoes, is quite limited and not necessarily giving me the best nutrients. Wheat is grown in as a monoculture in the UK in a way that is clearly unsustainable. However, if we shift what we think of as key food products, and start using agroforestry techniques to diversify, we have the opportunity to grow more food locally that suits the UK environment, build resilience (because if would be less likely that both crops would fail in a given year), and of course we would get to try lots more new ways of eating yummy food.
Thanks to Steve Newman for such an inspiring talk, and for Phil Pritchard from Oxford Permaculture for organising it. I know it's a cliché, but it really was, food for thought!