Saturday, December 08, 2007

The permaculture design process starts with a base map (done) and proceeds to a site survey, which includes such items as landform, climate, soil evaluation, existing plants and biodiversity, access, etc. David Holmgren, one of the co-originators of the permaculture concept (along with Bill Mollison) published an excellent case-study of his own site, Hepburn Permaculture Gardens: 10 Years of Sustainable Living, and therein explains that he studied how the land had been used historically before he embarked on a site survey, which relates to the situation at the time of the survey.

Where we live used to be part of a farm. Our next-door neighbours, Philippe and Maryvonne, with their children Tangui and Lisane, live in what used to be the farmhouse. Our house used to be a large wooden barn storing straw and hay bales and housing a rudimentary milking parlour and our holiday gîte, a cob and stone building, used to be a little stable. Kysinia, another neighbour, supplied some photos of how our property and land used to look at the point of sale by the retiring farmers, Roger (French, so pronounced “Ro-jh-ay”) and Denise. The land has served up many surprises: such as when we started work on the gite garden—having impatiently omitted the soil survey—and hit a concrete hard-standing almost with the first thrust of the spade (see my blog of 3rd February).

One of the next stages of our developing permaculture smallholding is the installation of a Solar tunnel, a brand of polytunnel, to extend our growing season and enable us to grow a greater variety of crops. Where to put it? We considered access, sun and shade, provision of water and what other purposes could make better use of the site, before choosing the spot. When we looked at the “historic” photos of the land (see second photo at top) it was evident that it used to be a driveway suitable for heavy agricultural vehicles and was thus likely to comprise lots of aggregate of differently sized stones but little soil. We re-considered the placement but felt that, for the reasons we’d originally chosen it, we should stick with it.

I then spoke to Paul, our pig-farming neighbour, and asked his advice. Both he and another neighbour, the venerable Annick, remember there being a small storage building at that site, adding further layers of historical information to the photos.
We agreed that it was worth passing Paul’s plough over it, with it’s huge tines that apparently wouldn’t be damaged if they encountered large stones and lumps of concrete. This would loosen the heavy clay soil enough for me to get in their with spade and hands and pull out the worst of it and then make a decision what further to do. Once the plough had passed, it was evident that the ground was in far better condition than we’d hoped for and it appears that the hardcore and stones were laid from the now-absent building and thus the land that it actually stood on was just compacted earth.

Paul then offered to go and change the plough for the harrow and give the earth another go over, which would level out the ground and save about a weeks digging with a garden spade or two days with a borrowed rotovator. It took him less than five minutes and I think is completely compatible with permaculture principles (thank God!) in fact, David Holmgren himself justified using large earth-moving machinery at the set-up stage of his own project. What wouldn’t be so appropriate for us is to find excuses to use the diesel-powered plough on the same bit of land every year.


scarlet said...

Solar tunnels look interesting. Could you tell me why you've chosen to buy that particular brand - I've been looking at loads online and I must say I don't know where to begin when it comes to making a choice!!

Stuart and Gabrielle said...

Hi Scarlet,

We read the advice in Gardening Under Plastic by Bernard Salt, where he described the Solar Tunnel as halfway between a greenhouse and a polytunnel. It seems easier to erect and doesn't involve burying the edges of the sides to get the plastic taught. The mountings screw into the earth and can be removed to re-site the tunnel. Have a look at their website

By the way, don't bother with The Polytunnel Companion by Jayne Neville, which I think is a right old con, next to useless ... unless you want to buy my copy off me at a favourable rate!

Hope this helps.

mandarine said...

I have mixed feelings with the use of titanic diesel horsepower on permaculture projects. On the one hand, I completely understand the point of putting some fossil energy in the initial investment, but on the other hand, will such techniques, materials and fuels be available to everyone on Earth, or is this just for 'rich' permaculturists? In addition, such power near at hand allows shortcuts and can do a lot of damage in no time, whereas having to do it manually or with animal labor, I am sure I will think twice before playing around with dirt and rocks.

Stuart and Gabrielle said...

Thanks for your comment, Mandarine. I do agree with you that one should always think twice before taking a diesel-powered shortcut and also hard landscaping and I hope that's what we've done. As our project progresses, we'll have less need / temptation to go down this route.