Soil subgroup

Natracualf petrocálcico

It has a petrocalcic horizon—the calcareous hardpan: cemented calcium carbonate—within the meter and a half. Limits the useful depth for roots and water.

What the name says

Soil Taxonomy names are built from parts, and each part says something about the soil. From general to specific:

Taxonomic orderAlfisolSoil with a clay accumulation horizon (argillic or natric) and good base saturation, but without the thick, dark surface of a Molisol.
SuborderAcualfAlfisol with excess water: saturated near the surface part of the year, with redox depletions.
Great groupNatracualfWithin the Acualf suborder, it has a natric horizon: accumulation of clay with a lot of exchangeable sodium, which disperses the clay and blocks the passage of water and roots.
SubgrouppetrocálcicoIt has a petrocalcic horizon—the calcareous hardpan: cemented calcium carbonate—within the meter and a half. Limits the useful depth for roots and water.

What it means for farming

Acceptable fertility, but the surface layer is thinner and poor in organic matter. In the Pampas region many Alfisoles are sodic or floodable (Natracualfes) and are left for livestock.

The sodic soil of the low-lying areas of the Pampa Deprimida and the plains of Salado: it floods in winter, hardens in summer, and sodium limits almost everything that is not natural grass.

Where it is found

It does not appear on the national map; on the detailed maps it adds up to about 950.803 ha, across 22 districts.

ProvinceArea
Buenos Aires950.803 ha

Districts where it is most common

It also appears on the detailed maps of: Buenos Aires.

How productive it is

Land capability

VI
VII

class VI: 30% · class VII: 70%

Taken from the maps that include this data. A map unit with several soils has a single index, and it is only attributed to the dominant soil.

Other Natracualf subgroups

Soil series

Series are the specific soils, named after places, that detailed maps describe under this name. Two properties with the same series have the same soil.

Buenos Aires

San Gabriel · Miñana · La Paulina · La Emma · San Isidro · Las Margaritas · Coronel Bunge · Tecua · Estancia La Margarita

Soils it shares map units with

Several soils share each map unit. These are the ones most often found alongside this one: on a property, you will likely find them in the nearby low ground or on the next rise.

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