Soil subgroup

Haplustalf tapto árgico

It has a buried clay horizon (argillic): an old soil was covered by newer sediments, and the current soil formed on top.

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 groupHaplustalfWithin the Ustalf suborder, it It is the simplest of the suborder: it does not have a clay horizon or any other feature that places it in a more specific group..
Subgrouptapto árgicoIt has a buried clay horizon (argillic): an old soil was covered by newer sediments, and the current soil formed on top.

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.

Where it is found

It does not appear on the national map; on the detailed maps it adds up to about 996 ha, across 2 districts.

Districts where it is most common

It also appears on the detailed maps of: Salta.

How productive it is

Where it is the main soil of the map unit, the productivity index has a median of 44 (average); half of the units fall between 38 and 44.

Land capability

II
III

class II: 62% · class III: 38%

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 Haplustalf 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