The document discusses black soils in Argentina and Uruguay. It provides information on the area covered by black soils in both countries, their agricultural and socioeconomic importance, and main degradation threats. It notes that black soils cover over 94 million hectares in Argentina, representing 34% of the country's area. In Uruguay, mollisols and vertisols occupy 30% of the country's 17.6 million hectared land area. The document also outlines increases in cropped areas and crop production in both countries in recent decades, but notes yield gaps remain and threats like erosion, salinization, and soil organic matter losses need addressed.

1. Global Symposium on Soil Organic
Carbon (GSOC17)
Co-organized by FAO, GSP/ITPS, IPCC,
UNCCD/SPI and WMO
GSOC17 - Launch of the International Network of Black Soils
Miguel A. Taboada, INTA and CONICET, Argentina
Fernando García Phéchac, La República University
Area covered by black soils in Argentina and Uruguay

2. • Area covered by black soils in Argentina
• Soil use and socio-economic importance
• Main degradation threats
• Crop yields and yield gaps

3. Loess soils
in temperate and
subtropical areas
Mollisols
mainly in
temperate areas
15 defined ecoregions

4. AREA COVERED BY BLACK SOILS IN ARGENTINA
Area covered by black soils: 94.832.922 ha . 34%
% of the Cartographic Unit
Area covered by Mollisols: 91.712.192 ha. 33%
Area Covered by Vertisols: 3.120.730 has. 1%
Soil GIS of Argentina, scale 1:2.500.000. Godagnone
and de la Fuente. Institute of Soils. INTA. 2017

5. Uruguayan Soils
• Ecosystem: Grasslands (still 65% of the country surface: 17 Mha)
• Topography: Rolling Plains and Low hills
• Soils: Mollisols and Vertisols Map Units occupy 30%.

6. • AREA: 176 215 km² (17.6 Mha) .
• Population:
• People: 3.400.000
• Cattle (Bovine): 12.000.000
• Sheeps: 6.500.000
• Cropped Area: 1.800.000 ha
• Forested Area: 1.000.000 ha
• Other “Traditional”
Export Products:

7. Typic Argiudoll (US Soil Taxonomy)
Argillic Phaeozem (FAO Soil System)
(Photo taken in the Rolling Pampa)

8. Soils of the Inland or Sandy Pampa
Thapto-argic Hapludoll (US Soil Taxonomy)
Sandy Holocenic deposit
Buried or thapto sol from the Pleistocene

9. Two-fold increase in cropped area (16 a 34 millon hectares)
0.0
5,000.0
10,000.0
15,000.0
20,000.0
25,000.0
30,000.0
35,000.0
40,000.0
thousandhectares/yr
peanut
paddy rice
sunflower
soybean
sorghum
maize
wheat

10. Crop production x 4 (30 to 117 millon tons grains)
0.0
20,000.0
40,000.0
60,000.0
80,000.0
100,000.0
120,000.0
140,000.0thousandtons/yr
peanut
paddy
rice
sunflo
wer
soybea
n
sorghu
m
maize

11. SOM contents under pristine and agricultural soil use of Mollisols in Argentina

12. Main threats on productive soils of Argentina:
• Water and wind erosion and land-sliding affecting up to 118
million hectares
• Soil salinization and sodification (300 thousand hectares in
irrigation areas)
• SOM losses and decreasing soil C stocks
• Soil compaction and decreased topsoil structural quality)
• Waterlogging and ponding
• Unbalanced and depleted nutrient stocks (N, P, S)
• Biodiversity losses caused by deforestation, grassland
dissapearence, and wetland
degradation.

13. Crop yield gaps under
rainfed cropping: 22%
y 69%.
Mean yield gap:
Wheat: 41%
Maize: 41%
Soybean: 32%
Aramburu Merlos et al. Field
Crops Research 184 (2015)
145–154

14. Thanks!