sumisu: I want to avoid any kind of religious discussion here, so hopefully readers will take what I have to say with it's natural intent.
Soil has to have a number of components. First, there needs to be a bedrock. Then a layer of shale or some other sedimentary rock. Next a layer of rocky clay. This is how the vast agronomy of the earth's soils have for their foundations.
Now here is where the gardener returns the soils to native growing conditions. The clay is to retain nutrients for the deepest roots. If one is growing heaths (Erica), then the next layer is sandy clay with a slight bit of organic matter around the root ball. There should be only a half inch of organic mulch near the plants. One of the disasters with ornamental gardening and the applications also apply for vegetable and fruit trees, is too much mulch.
The three inch dogma is bs. During any typical winter, too much mulch provides bedding for a home for mice and voles and the like. They will feed off the bark of Yews, Junipers, Heaths, etc.; often girdling the plants and thus killing them.
Now to "root" crops (they're usually tubers or hypocotyls). Their layer needs to be a sandy (or limestone grit) and compost mixture.
Let me do an aside here. Composting just needs ample moisture and turning twice a day. Have several piles going, so you're only adding material to the newest pile. Ensilage fork works great for a small operation.
Okay, back to the root crops. The scantest amount of mulch is used here. Be prepared for massive yields. With a previous organic garden I sold a good amount of root crops to local health food stores. Parsnips are the killers. However, don't harvest them, until after the first good frost. You will thank me later.
Now to woodland plants, etc. If you are in Zone Seven and colder, then you have to have Wintergreen (Gaultheria procumbens). They love the shade. Since we are not dealing with aquaculture here, it will be presumed that all woodland plants like moisture, but well-drained soil (no wet feet). It's a two-layer project. First, a sandy/clay/compost mixture. Then a pure compost layer. Anything planted in this soil can stand about an inch of mulch. If you composted properly, the soil is nearly neutral. So for things like blueberries, mix some mulch throughout the top two layers to provide enough acid. Do the same thing with potato varieties that are susceptible to scab.
When I had an ornamental nursery, I often planted pots right into the ground. They were mulched in, so they were easy to yank out.
Once a soil area is amended, it truly can become a no-till. A little hand tiller or trowel is all that's needed for small plants and/or seeds.
"Keep your state off of my body"
"When in doubt, empty the clip."
