Soil subgroup

Hapludol tapto cumúlico

It has a dark surface horizon buried under newer sediments.

What the name says

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

Taxonomic orderMolisolSoil with a thick, dark surface horizon rich in organic matter (the mollic epipedon), with more than half of its exchange capacity occupied by calcium, magnesium, potassium and sodium. It forms under grassland.
SuborderUdolMolisol humid climate (udic moisture regime): the profile almost never spends more than three months dry.
Great groupHapludolWithin the Udol 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 cumúlicoIt has a dark surface horizon buried under newer sediments.

What it means for farming

They are the soils agricultural lands par excellence: the Pampas grassland formed them and most of Argentine agriculture is done on them. They retain water and nutrients; its limitation, when there is one, is below: clay, sodium, calcareous hardpan or drainage.

It dominates the Pampa Arenosa of the west of Buenos Aires and the south of Córdoba and Santa Fe: soils looser, with good drainage, which depend more on rain.

Where it is found

It does not appear on the national map; on the detailed maps it adds up to about 6.967 ha, across 6 districts.

ProvinceArea
Entre Ríos6.967 ha

Districts where it is most common

It also appears on the detailed maps of: Entre Ríos.

Other Hapludol 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