Soil great group

Argiudol

Of the Udol suborder; it has a clay accumulation horizon (argillic): clay washed from the surface accumulated lower.

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.

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.

Most common surface texture
Silt loam
Most common drainage
Well drained
Typical effective depth
100 cm

Where it is found

According to the 1:500.000 national map, it covers about 15.374.822 ha, spread over 151 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
Buenos Aires7.629.101 ha
Santa Fe3.750.733 ha
Entre Ríos1.628.855 ha
Corrientes843.863 ha
Córdoba793.590 ha
Chaco324.329 ha
Tucumán153.887 ha
Formosa141.396 ha
Santiago del Estero101.096 ha
Misiones7.973 ha

Districts where it is most common

It also appears on the detailed maps of: Buenos Aires, Corrientes, Entre Ríos, Misiones, Santiago del Estero.

How productive it is

Where it is the main soil of the map unit, the productivity index has a median of 38 (low); half of the units fall between 31 and 47.

Land capability

II
III
IV
V

class I: 1% · class II: 13% · class III: 65% · class IV: 11% · class V: 9%

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.

Subgroups on the maps

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.

Corrientes

San Gregorio · San Juan · Ordenavia · Tres Marias · Estancia Naranjito · El Yacare · San Ignacio · A? Curupi · ?andubay · Potrero 9 Monzon · Maria Isabel · Aeropuerto · El Control I · Pedro Diaz Colodrero · Ombu · La Correntina · Aguay · San Jose · La Nela · Santa Maria

Entre Ríos

Escriña · Crespo · La Emiliana · Banderas · Tezanos Pinto · Los Charrúas · Arroyo Los Bayos · Lazo · Puntas del Gato · Tacuaras · Palmarito · Arroyo Masitas · Estancia Los Amigos · La Blanqueada · La Lidia · General Racedo · Colonia Once · Cuatro Bocas · Gonzalez Calderón · Arroyo Genacito

Buenos Aires

Tres Arroyos · Cinco Cerros · Mar del Plata · Balcarce · Azul · Tandil · Laprida · Pillahuinco · Necochea · Loberia · La Delicia · O Higgins · Rojas · Cobo · Semillero Buck · La Oriental · Solis · Teodelina · Ramon Santamarina · Gouin

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