Anywhere from "none" to "lots and lots". Calcareous soil is soil high in calcium (lime) content. it has nothing to do with the percentage of humus, which is decayed organic material.

If you mean calcareous, it is a soil composed partly of calcium carbonate. It refers to "chalky" soils with a high lime content.

bangar soils are calcareous in nature and hav a loe organic content(humus). but it is very productive and fertile soil.

A. B. A. Brink has written:

'Soil survey for engineering' -- subject(s): Engineering geology, Soil surveys, Soil-surveys, Soils, Testing

'Engineering geology of Southern Africa' -- subject(s): Engineering geology, Southern Africa

It depends on the context - in geology they maybe called limestone deposits. In a corrosion sitaution they may be called calcareous deposits