Soil great group
Natracualf
Of the Acualf suborder; it has a natric horizon: accumulation of clay with a lot of exchangeable sodium, which disperses the clay and blocks the passage of water and roots.
What the name says
Soil Taxonomy names are built from parts, and each part says something about the soil. From general to specific:
| Taxonomic order | Alfisol | Soil with a clay accumulation horizon (argillic or natric) and good base saturation, but without the thick, dark surface of a Molisol. |
|---|---|---|
| Suborder | Acualf | Alfisol with excess water: saturated near the surface part of the year, with redox depletions. |
| Great group | Natracualf | Within the Acualf suborder, it has a natric horizon: accumulation of clay with a lot of exchangeable sodium, which disperses the clay and blocks the passage of water and roots. |
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.
The sodic soil of the low-lying areas of the Pampa Deprimida and the plains of Salado: it floods in winter, hardens in summer, and sodium limits almost everything that is not natural grass.
- Most common surface texture
- Silt loam
- Most common drainage
- Poor
- Typical effective depth
- 75 cm
Where it is found
According to the 1:500.000 national map, it covers about 11.975.202 ha, spread over 167 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.
| Province | Area |
|---|---|
| Santa Fe | 2.754.617 ha |
| Buenos Aires | 1.892.815 ha |
| Salta | 1.530.765 ha |
| Santiago del Estero | 1.508.333 ha |
| Formosa | 1.425.540 ha |
| Chaco | 1.127.301 ha |
| Córdoba | 1.021.618 ha |
| Corrientes | 235.477 ha |
| Entre Ríos | 220.921 ha |
| Tucumán | 117.467 ha |
Districts where it is most common
- Rivadavia · Salta
- Vera · Santa Fe
- Robles · Santiago del Estero
- 9 de Julio · Santa Fe
- Pirané · Formosa
- Mayor Luis J. Fontana · Chaco
- San Justo · Córdoba
- Tapenagá · Chaco
- General Obligado · Santa Fe
- General Güemes · Chaco
- Patiño · Formosa
- San Cristóbal · Santa Fe
- Río Seco · Córdoba
- General Alvear · Buenos Aires
- Formosa · Formosa
- Ramón Lista · Formosa
- Libertador General San Martín · Chaco
- Olavarría · Buenos Aires
- Pila · Buenos Aires
- Pilagás · Formosa
It also appears on the detailed maps of: Buenos Aires, Corrientes, Entre Ríos, Santiago del Estero.
How productive it is
Where it is the main soil of the map unit, the productivity index has a median of 10 (very low); half of the units fall between 3 and 14.
Land capability
class IV: 4% · class VI: 10% · class VII: 86%
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
Las Palmas Iv
Buenos Aires
Chelforo · Gowland · Vedia · San Gabriel · Los Mochos · Rancagua · Miñana · Zapiola · La Libertad · Las Heras · Tandileofu · La Paulina · La Emma · Manantiales · General Piran · Faustina · Gelly · San Sebastian · El Destino · Poblet · Amenabar · Azcuenaga · Juncalito · San Isidro · Tuyuti · Las Margaritas · Elena · Coronel Bunge · Tandileufu · Estancia Renana · La Saturna · Los Leones · Huemul · La Guarida del Zorro · Tecua · Estacion Doce de Octubre · Estancia La Margarita · La Limpia · Villa Rossi · Arroyo Juarez
Entre Ríos
Inocencio · Algarrobo · Arroyo Martínez I · Los Mosquitos · Conscripto Bernardi · Arroyo Ormachea · Punta del Monte · Puntas del Monte · Las Flores · El Estribo
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
- Soil Survey Staff. (2014). Claves para la Taxonomía de Suelos, 12.ª edición. USDA - Natural Resources Conservation Service. · Dominio público (USDA)
- INTA · Dominio público (carta 1:500.000)
- INTA - Instituto de Suelos - CIRN. (2023). Cartas de Suelos República Argentina - Provincia de Buenos Aires (2.0) [Data set]. Zenodo. · CC BY 4.0