Yup, I recommend a zero-till method. There is a guy out my side that has been running zero-till grain crops on a massive scale and even won himself some awards in the process. Instead of a plough, sow, harvest, it will be a mulch, sow, harvest instead. So if you have to combine this basic permaculture system with the knowledge you already have about microbial gardening, it would go mulch, INNOCULATE, sow, harvest
OK so let's say ploughing IS needed. There is a whole other way of doing this. You need 2 pigs and a pen that is designed to move, along with 5 chickens in a moveable chicken dome. First you spread some mulch on the area your pigs are about to come onto, and innoculate with Lacto B. The pigs get moved onto this patch, it will take them a day or two max to get the soil worked over. Then they move along to the next mulched patch, and your chicken-dome gets moved over the pigs' old range. The chickens will then further loosen the top fine layers and add some super-potent fertilizer to boot. And the chickens will take care of any unwanted seeds left over from your pig-food. Once they have moved on, your soil should be incredibly potent. A final mulch and then legumes and I can guaranteed near-perfect plants leaving behind a very well-structured soil.
Permaculture is the way forward. If you can get some old Oyster-Mushroom cakes to add to the soil in the last phase, this would probably be the best thing you could do for the soil. Mushroom Compost is a by-product of mushroom farming and comes pretty cheap if you know where to go find some.
The above is probably the fastest way to get your soil recovering. Just remember that is will always be sandy, this process can not add clay particles. But it will become a silty loam, by far the best and fastest of soils to grow in. And as you continue the practice of building the soil with organic matter, it will continue improving. I have seen these methods at work and employ them myself, I have no need for pig-and-chicken tractors in my small garden, though, but I will be starting some up in the coming months to convert a nice big piece of depleted grazing into good gardens for my mum's farm. I promise to take and show pics, but this is still a month or what away from now...
Always AMPED to help out far as these things go, Rrog! Just happy I can put some useful info down in a thread that has served me more than I can ever express. Seriously, mate, some real game-changing info on this thread of yours!