AGKICULTUBAL SURVEY OF SOUTH AMERICA 
17 
Approximately one-third of the Republic is too dry for crops with- 
out irrigation. In a large part of the Pampa region the rainfall varies 
widely from the average in some years ; that is, it is either very much 
greater or very much less than tne average, so that in the very dry 
years the crops burn up and in the very wet years they are damaged by 
excessive rainfall. For example, San Vincente, in the Province of 
Buenos Aires, with an average rainfall of 32 inches, had only about 
13 inches in 1910 but more than 70 inches in 1914. Parana, in the 
Province of Entre Rios, with an average rainfall of 33 inches, had less 
than 5 inches in 1910 and more than 60 inches in 1914. In many of the 
drier regions practically no rain falls during the winter months of June, 
July, and August. In periods of prolonged droughts, livestock losses 
are likely to be exceptionally heavy. 
HUMIDITY 
As a general rule, the humidity is high along the coast and in the 
northeastern part of Argentina, but is very low in the interior and 
extreme west. The high humidity at Buenos Aires makes the heat 
oppressive and the cold penetrating. 
SOILS 
Throughout the great cereal region of Argentina there is a deep 
black loam prairie soil, becoming more and more sandy and lighter 
in the west. The whole of this area is almost free from stones, except 
north of La Plata River and east of the Parana where there are out- 
croppings of rock and clay. To the north of this region, through the 
Chaco country especially, the soil is similar in character, a dark 
sandy loam, becoming more sandy in the west. Outside of these two 
regions there are alternating areas of loam, clay silt, sand, gravel, and 
rock. Throughout most of Argentina the soil is alkaline, and 
especially in the semiarid areas where there are accumulations of 
salts on or in the surface layers. Within 200 miles of Buenos Aires 
to the west are many shifting sand dunes which make soil binders 
necessary. In Argentina the soils are classified as shown in Table 3. 3 
Table 3. — Argentina soils 
Clay 
Sand 
Silt 
Humus 
Ideal soil 
Clay soil 
Clay sand 
Clay loam 
Clay humus. . 
Sandy 
Sandy clay... 
Sandy loam.. 
Sandy humus 
Loam soil 
Humiferous.- 
Per cent 
20 to 30 
More than 40 
More than 30 
More than 30 
More than 30 
Less than 10 
10 to 20 
Less than 10 
Less than 10 
Less than 10 
Less than 10 
Per cent 
50 to 
Less than 
50 to 
Less than 
Less than 
More than 
More than 
More than 
More than 
50 to 
Less thaD 
Per cent 
5 to 10 
Less than 5 
Less than 5 
5 to 10 
Less than 5 
Less than 5 
Less than 5 
5 to 10 
Less than 5 
More than 10 
Less than 5 
Per cent 
5 to 10 
5 to 10 
5 to 10 
5 to 10 
More than 10 
5 to 10 
5 to 10 
5 to 10 
More than 10 
5 to 10 
More than 30 
3 Girola, C. D. Investigation agricola en la Republiea Argentina. Buenos Aires, Compafii'a Sud- 
Americana de billetes de banco, 1904. Republiea Argentina. Anales del Ministerio de agricultura. 
Section agricultura; botanica y agronomia. Agronomia. t. I, n 1. 
83919°— 26 2 
