Terra rossa (soil)

Terra rossa ( Italian for "red soil") is a type of red clay soil produced by the weathering of limestone. When limestone weathers, the clay contained in the rocks is left behind, along with any other non-soluble rock material. Under oxidizing conditions, when the soils are above the water table, iron oxide (rust) forms in the clay. This gives it a characteristic red to orange colour.

Terra rossa is typically found in regions with a Mediterranean climate but can also be seen elsewhere, for example in Prince Edward Island, Canada.

Compared to most clay soils, terra rossa has surprisingly good drainage characteristics. This makes it a popular soil type for wine production. Among other wine regions, it is found in La Mancha in Spain and Coonawarra in Australia.

In pedology, red Mediterranean soil, also known as terra rossa (Italian for "red soil") is a soil classification that has been formally superseded by the formal classifications of systems such as the FAO soil classification, but that is still in common use. The terra rossa classification was still, as of 1997, a part of the national soil classifications of countries such as Israel and Italy. The UNESCO/FAO World map equivalents are the chromic luvisols (a sub-order of the luvisols), and the USDA soil taxonomy equivalent is the rhodustalfs (a sub-order of the ustalfs).

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