Soil order

Aridisol

Soil arid climate: water is lacking most of the year and the profile accumulates what the rain cannot wash away (carbonates, gypsum, salts) or clay from more humid times.

What it means for farming

Without irrigation there is no agriculture: they are soils of native woodland, extensive grazing or, with water, irrigated oases (Mendoza, San Juan, the valleys of the NOA).

Aridisoles on the maps

Argid

Aridisol with a clay accumulation horizon, inherited from a more humid past climate.

Ortid

Aridisol without clay horizon.

Salid

Aridisol with a horizon of salts more soluble than gypsum (salic horizon).

The definitions are a plain-language summary of the USDA Keys to Soil Taxonomy. The formal definition includes thickness, color and percentage thresholds that are left out here.

Sources