Rendzina is a dark, grayish-brown, humus-rich soil. It is one of the soils most closely associated with the bedrock type and an example of initial stages of soil development. It is usually formed by weathering of soft rock types: usually carbonate rocks (dolomite, limestone, marl, chalk) but occasionally sulfate rocks (gypsum).

This is one of the most interesting of the soil names; it originates from a Polish colloquial word "rzędzić", which means "to chat": the soil of this type contains a significant amount of gravel and stones, which, during plowing, produce various sound effects (clicking, screeching, etc.), i.e., "talk" to the ploughman.

The term is used for a class of shallow soils over limestone, in which the topsoil is calcareous – i.e., it contains free calcium carbonate, which gives a fizz if dilute acid is dripped onto a soil sample. This makes for a very distinctive soil. The rendzinas in Wales, UK, for example constitute a simple A-C profile, a dark calcareous topsoil immediately over shattered limestone. Because the soils are shallow and stony, there is much semi-natural vegetation to be found in these areas. The plant communities are distinctive, with much scrub and calcareous grassland, often with unusual or even rare species.

The term 'rendzina' appears in various soil classification systems, both current and obsolete.

See also

• 1938 USDA soil taxonomy
• Downland
• FAO soil classification