Soil subgroup

Argiudol petrocálcico

It has a petrocalcic horizon—the calcareous hardpan: cemented calcium carbonate—within the meter and a half. Limits the useful depth for roots and water.

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 groupArgiudolWithin the Udol suborder, it has a clay accumulation horizon (argillic): clay washed from the surface accumulated lower.
SubgrouppetrocálcicoIt has a petrocalcic horizon—the calcareous hardpan: cemented calcium carbonate—within the meter and a half. Limits the useful depth for roots and water.

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 is the emblematic soil of the Pampa Ondulada: Pergamino, Rojas, Arrecifes. Deep, dark, well drained, with a textural B that retains water but can slow down roots when it is very clayey.

Where it is found

It does not appear on the national map; on the detailed maps it adds up to about 2.349.779 ha, across 21 districts.

ProvinceArea
Buenos Aires2.349.779 ha

Districts where it is most common

It also appears on the detailed maps of: Buenos Aires.

How productive it is

Land capability

III
IV

class II: 1% · class III: 53% · class IV: 44% · class VI: 2%

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 Argiudol 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

Tres Arroyos · Cinco Cerros · Balcarce · Azul · Pillahuinco · La Delicia · Olavarria · La Loma · Cascada · Tandil · Guillermo

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