Soil subgroup

Ocracualf udólico

It looks like a Udol: it has a dark, almost mollic surface in humid weather.

Ocracualf is a name from the 1975 taxonomy, which many INTA soil survey maps were made with. The current edition no longer has this group: today it would be classified as Epiacualf or Endoacualf.

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 groupOcracualfWithin the Acualf suborder, it It has a clear surface and is poor in organic matter (ochric epipedon).
SubgroupudólicoIt looks like a Udol: it has a dark, almost mollic surface in humid weather.

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

According to the 1:500.000 national map, it covers about 177.477 ha, spread over 5 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
Santa Fe174.776 ha
Chaco2.701 ha

Districts where it is most common

Other Ocracualf 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