Soil subgroup

Natrustalf 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.
SuborderUstalfAlfisol from subhumid to semi-arid climate (ustic moisture regime).
Great groupNatrustalfWithin the Ustalf 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.

Most common surface texture
Loam
Most common drainage
Moderate
Typical effective depth
80 cm

Where it is found

According to the 1:500.000 national map, it covers about 288.782 ha, spread over 9 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
Chaco222.929 ha
Formosa65.853 ha

Districts where it is most common

How productive it is

Where it is the main soil of the map unit, the productivity index has a median of 20 (low); half of the units fall between 20 and 25.

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 Natrustalf subgroups

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