Improving Soil on the Canadian Shield

Improving Soil on the Canadian Shield

For those of you who don't know, the Canadian Shield is a huge area of pretty much solid bedrock covered by a thin layer of soil.

The bedrock, being quite impervious to water, prevents rainfall from penetrating all that deep and results in large areas of shallow lakes, swamps, and exposed rocky outcrops.

The soil that builds up under these conditions, does so in a water logged, anaerobic environment which results in a peaty, acidic soil.

And here lies the challenge. How to increase soil PH, introduce air, and retain sufficient water so that plants suitable for food production and other practical uses can grow properly.

Ben Falk is a permaculturist who happens to live in a very similar landscape. Here are some of his observations:

The use of swales in this landscape has some interesting effects. It lifts the soil up off the water table so that tree root systems don't get waterlogged. 

In a situation where there is very little topsoil to work with, biomass can be used to build up swale mounds in conjunction with the typical swale as Ben explains here:

Notice that the trees don't need to be lifted too far off the water table to make a huge difference.

Finally, Ben talks about the water retention ability of swales even in a situation where very little topsoil exists: