Most of the people I have helped in the past, didn't understand that what I was guiding them to do was for the long term instead of the short term. It is easy to want everything Right Now! But the really successful gardener or farmer is planning 10 years ahead or more (if they are smart about their soil).
I totally subscribe this point, and I would actually wait for as much as necessary, but the people who asked for my help want to try anyway..and I might tell them to find some other advisor if they are not willing to wait for securing long term result, but...yeah decided to help them anyway and to this end I'm trying to hold them back as much as I can, so that some more wise decisions a least can be made.
So from your explanation about the gypsum: should I gather that it is not very important if the Ca content is high because when plants will be growing there, the microbiology will buffer any Ca excesses?
I also gather that I can lay the gypsum on top of the compost layer before the decompaction starts. so it will get mixed in.
Still not sure how much gypsum should I aim for. Mollison suggests 30 t/Ha, would it be safe to assume such a figure?
You suggest to use good, not pollluted compost. What are the parameters of a good compost according to your experience (apart from what you mention already)? So that I can check the company specs and make some informed decision before buying any.
And also if it matters that that compost can be on the alkaline side seen that the soil is already alkaline.