[Tagging] Areas of bare soil (clay, silt, loam) such as badlands?

[Joseph Eisenberg]

How should areas of bare soil, such as badlands, be tagged?

Currently there are documented tags for dry areas of bedrock, stones and sand:

natural=bare_rock, natural=shingle,  natural=scree, and natural=sand

For tidal areas, beaches and wetlands there's also natural=beach,
natural=shoal and wetland=mud

However, there's no documented, common tag for dry areas of exposed
clay, silt or mixed soil.

natural=badlands has been used 5 times, but this is rather specific
and may not be well-known outside of North America:
https://taginfo.openstreetmap.org/tags/natural=badlands

natural=desert is common, but includes all kinds of vegetated and
unvegetated arid areas; many of these can be tagged with natural=
grassland, heath, scrub, sand, scree etc.

natural=clay has been used twice:
https://taginfo.openstreetmap.org/tags/natural=clay

natural=earth has been used 20 times:
https://taginfo.openstreetmap.org/tags/natural=earth

natural=bare_earth has 23 uses:
https://taginfo.openstreetmap.org/tags/natural=bare_earth

There's also natural=pebbles with 67 uses
(https://taginfo.openstreetmap.org/tags/natural=pebbles)
and natural=gravel 90 times -
https://taginfo.openstreetmap.org/tags/natural=gravel

But most of those could be scree or shingle, which would be more specific.

Would it be best to describe the type of soil, like natural=clay,
=silt, =earth, =pebbles, =gravel?

Should mappers use surface=* without another top-level tag?

Should natural=bare_earth be used in general for clay and other bare soils?

Or is natural=badlands best to describe the specific feature of an
arid area where the bare soil is exposed due to erosion?

- Joseph