Edmonton's soil is generally clay—made up of finely textured rock. When our soil contains the right amount of organic matter, it is great for growing food. Soil that runs out of organic matter becomes depleted and then compacts. Depleted clay soil feels hard underfoot or like digging into concrete.
The best way to ruin our soil is to pull up roots, remove detritus, and leave soil bare.
To lighten our clay soil, incorporate carbon-rich organics (Browns) with one-time rototilling or double digging. Autumn leaves, clippings, twigs and small branches, coffee grounds, sawdust — just about anything you have on hand. Follow that up with a layer of mulch, a centimetre of finished compost, and water lightly.
Compost Crops are another way to build deep, rich soil. Between your rows, plant grasses (deep roots to bust clay layers), cover crops (broad leaves to shade soil), and legumes (Nitrogen fixers). As your desired plants grow, cut these crops back and let the tops fall on the soil. Green mulch feeds the bacteria that will provide Nitrogen to your plants.
Mulch protects the soil from sun and wind and prevents a layer of "dust mulch" (dead soil) from creating a crust that keeps rain from soaking in and leads to erosion. That's right, no more hoeing.
Remember: When restoring soil, take care to not add too much compost. Browns are the soil builders.
Learn more about soil science on this PennState U page.