I have some clay based soil which seems to be full of nutrients. After a quick phonecall I found out that this patch of land where I've discovered this soil was used as a compost heap for 30 years previous (a private heap in a garden, just plant matter, grass and such). I noticed this patch of the garden through letting it overgrow and seeing the difference between grass and plants growing there. The difference was quite silly really. I would say that the grass growing there was 100% improvement over anywhere else in the garden. Easily noticably thicker, lusher, greener and taller. The plants did amazingly well there too. There's no difference in the light this patch gets so I'm guessing the difference is coming from the soil. So I want to have a play with it.

Being clay based I know it won't work properly in a pot. Air won't get through it and I guess it will retain too much moisture for too long. What I wanted to know is if I could turn this soil into a compost, so that air will get through and the moisture will release and retain right. My heads telling me I can so, if it is indeed possible, how can I do it?

We used to hand mix our own potting mixes at a nursery I used to supervise. We used sterilised, sieved soil, coco fibre and coarse sand/grit (7:3:1). Bearing in mind we (three of us) used to grow in excess of 60,000 bedding plants a year (plus tropical/temperate/fruit and vegetables) there was a lot of mixing going on.

Nice one Mephitis.

How do I sterilize?

We used to buy it in by the lorry load, pre-sterilised using steam, it used to arrive still steaming.

The problem with sterilisation is it kills everything in the soil, all the microherd so if you sterilise you'll need to innoculate with rootgrow or other friendly stuff like that.

The problem with home sterilisation is the bulk aspect of it. Baking in the oven at 130-150C for 30 minutes will do it, but this will take ages if you want any great quantity. Other than fires in the garden with metal bins of soil I don't really know how you'd go about it sorry.

Damn. I wanted to keep all the life in it. I got a sample earlier today to look at and there's allsorts in it. Found a crazy flat worm in it too. Thanks bro, I'm on it.

cheap / old / freecycled microwave in the shed or garage ?
couple of litres at a time
remove any worms first though..

like Mephitis said you'l probably need to reintroduce a microherd.

I've never done that before. I've read felixs thread and seen loads of posts detailing macro and micro life. Should be fun. Hopefully I'll learn something too. I've got a big garden so I can probably knock up some form of steaming system and get away with it. Time doesn't really matter. I just wanna have a play. I'm sure this soil is packed with good nutes. We'll see. Thanks TS

great question!
the reason that patch grows so well is because its so healthy as im sure you know and hence why you want to keep the soil life in there, its allready bursting with beneficial life. i expect its nigh on perfect garden soil.
you can start a pile off with it, like a booster type thing because of its high microbal content but you cant turn it into compost as it were. you could try extracting the life from it and into water by brewing it up as an AACT. i would be tempted to brew up some castings and add that to the soil so to increase the beneficial dominance and then add it to your mix as a high quality top soil