Soil subgroup

Natracualf mólico

It has a dark surface rich in organic matter, almost like that of a Molisol.

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.
SubgroupmólicoIt has a dark surface rich in organic matter, almost like that of a Molisol.

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.

Most common surface texture
Silt loam
Most common drainage
Imperfect
Typical effective depth
100 cm

Where it is found

According to the 1:500.000 national map, it covers about 179.490 ha, spread over 11 districts.

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National map units that list it. The scale is 1:500.000: good for seeing the region, not a single property.

ProvinceArea
Córdoba167.042 ha
Chaco6.904 ha
Santiago del Estero5.543 ha

Districts where it is most common

It also appears on the detailed maps of: Buenos Aires, Santiago del Estero.

How productive it is

Land capability

IV
VI
VII

class IV: 14% · class VI: 29% · class VII: 57%

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

Tandileofu · General Piran · Faustina · San Sebastian · Azcuenaga · Tandileufu · Estancia Renana · Los Leones · Huemul

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