Why is soil non-renewable?

Comments on John Gunn, Neil McKenzie and Paul Bertsch "Science can drive the sustainability of our precious soils, water and oceans", 14/07/2014

I find it difficult to understand the following statement by Paul Bertsch, that is, why soil is a non-renewable resource? I would have thought that it should be renewable unless it is not properly used. Certainly it is not very intuitive to me and likely to many readers.

Soil and land, even after misuse by some land users including farming not to mention appropriate uses, can still be rehabitated, one would think.

Perhaps Paul Bertsch can clarify and elaborate it in more detail.

"First, specific recognition of the soil resource is not common in national strategies. This is even though soil is a non-renewable resource (on multi-generational time scales) that underpins key life support systems, such as nutrient cycling, carbon sequestration, food, fibre, animal feed and biofuel feedstock production. It also represents one of the earth’s most complex and biologically diverse ecosystems."

While it is understandable that the soil in Australia is generally poor and we must pay attention to its proper and appropriate use, we should also guard biased arguments from interest groups, so we get a full and correct picture and do not over capitalise in soil related activities including probably research on it.