Riverbourne was developed  back in the early 70's. The land at the back was cleared with bulldozers, this resulted in the little topsoil there being pushed off. The result was an acidic orange clay surface, extremely high in Aluminum, which after 30+ years was covered in grass, which, regardless of rainfall, never grew higher than that of a bowling green!

Two years ago we put out 125 kg/ha  Mo superphosphate mixed with 10 kg/ha of Mount Barker subclover. The paddock was shut up for 12 months. The clover grew to 200-250mm high, was allowed to seed and die back in the summer.
This resulted in forming some humus and top soil, and last year the grasses grew tall, mainly microlaena, and was grazed through winter at 6 dse/ha.
There is some trend against using super, but apart from putting tons of poultry  shed litter on the paddock, you can't get growth, thus, no organic matter and no microbes.The microbes and fungi act as a digestive system for the plants, making the locked up nutrients available for the plant's growth.

When we first came to Riverbourne, about seven years ago, the pastures were of poor quality, and the only stock had been a few horses. Since running dorpers, and fencing into small paddocks, the grasses have improved dramatically. I think the dorpers have largely contributed to this by their grazing habit of constantly moving whilst being non selective in their choice of grasses, this means their manure is spread over the whole paddock, and the humus is building up in the soil. They don't tend to just graze a sweet spot, until they have eaten the whole plant roots and all! (My Merinos used to do this, especially in dry times).
Microlaena is a very important grass on the Southern tablelands, being winter active, highly nutritious and responds well to increases fertility, and it is this native grass in which we have seen most improvement.
Of course  it is important to remember that every time you send an animal off the farm, it takes with it a lot of minerals that have come from yours soil. These need to be put back either by application to the soil, or, better I think, by providing mineral licks, we use a powdered lick, though a lot of farmers find  lick blocks are satisfactory.