Just a quick post on our soil blocking recipe. I always get asked about this and usually point people to the All Sun farm recipe, but I have refined this recipe over the last few years.
Here's my mix:
2.5 part coco peat (aka coir)
I don't like the small bricks that you can get in Bunnies etc. as you need to soak them. It is very hard to mix all the other ingredients together well after that. I would say that the bricks are detrimental to the mix unless you soak them and then dry them again and that takes a long time (like a week). I buy it by the bale from Elders in Windsor in a dry form. It is compressed but not like the bricks.
2 parts home-made compost
Worm castings also work great but unfortunately nothing you can buy (like potting mix) seems to work
0.5 part fine basalt dust
That can be hard to find for some people so you can use river sand or horticultural sand. DO NOT USE ANY OTHER SAND. Other types of sand (like sand pit or Sydney sand do not work. It's not that they don't work as well but they actually make the seedlings fail catastrophically. Sandpit sand, Sydney sand, brickies sand etc. hold too much water. Your seedlings will turn in to a fungal mess. Try it at your peril.
And some nutrients...
I don't have a specific measure for these but I use a double hand scoop of each for a full wheel barrow as a guide.
You can get this from rural supplies and horse type places. It should cost about $100 for a 25kg bag.
Be aware of what you are getting. The "meal" part is important. If you try and get the finely ground water soluble kelp, it will cost around $800 per bag.
It is a really vital part of the recipe while your soil is poor.Unfortunately this is hard to get in the 'burbs by the bag (as opposed to the tonne- you can get it from YLAD in Young by the tonne). If you find somewhere please let me know.
I get it from a rural supplier in Queensland when I visit relatives. I bought 100kg 3 years ago and still have 20kg left.
I only use this is the recipe during the warmer months, ie. Sept - March. Plants don't feed as much during the winter and I find using it then promotes fungal growth. I would say it's essential for summer.
*Note: the phosphate and blood and bone should be provided by your compost mix through the use of dynamic accumulators