^ 



San Luis Series and Associated Soils. 153 



1 i 3 4 



Soil (4) 51 . 32 10 8 



Acres. 

 San Luis Valley, Colo 136, 960 



San Luis sandy loam. — A coarse, gravelly, reddish-brown loam 

 from 18 inches to 3 feet deep, resting on a subsoil of almost pure 

 gravel and sand, which extends to indeterminate depths. Near 

 the mountains the surface soil is shallower, more sticky, and the 

 gravel larger and more waterworn. Heavier phases of the soil 

 are known locally as "adobfe." Occupies imperceptibly sloping 

 plains, the surface of which is broken by many knolls and ridges 

 from 8 inches to not more than 2 feet in height. Soil is a lacus- 

 trine deposit. Near the mountains the soil is well drained and 

 free from alkali. Lower areas are alkaline. Nearly all the culti- 

 vated areas are sown to cereals and pease. Well adapted to these 

 crops, and also to potatoes and truck crops. 



12 3 4 



Soil (3) 35 31 20 13 



Subsoil (1) 8 34 52 6 



Acres. 

 San Luis Valley. Colo 196, 992 



San Luis loam. — A plastic and sticky, reddish-brown loam, con- 

 taining some gravel, 24 to 36 inches deep, resting on a subsoil of 

 sand or sandy loam, beneath which occurs sand and gravel. The 

 surface is level and uniform and well adapted to irrigation. La- 

 custrine deposit formed by further breaking down of materials of 

 Pan Luis sandy loam. Contains more or less alkali, and is not at 

 present cultivated. AVhen irrigated, produces a good crop of wild 

 hay. Would be well adapted to the grain crops. 



12 3 4 



Soil (1) 15 39 12 34 



Acres. 

 San Luis Valley, Colo 9, 088 



Rio Grande sandy loam. — Dark-brown to black, friable, easily 

 cultivated sandy loam, with an average depth of about 2 feet, 

 resting on a l)e(l of gravelly sand. Occurs as narrow strips along 

 river. The surface is generally level. The drainage usually poor. 

 Potatoes succeed very well, and the production of these and nati\ e 

 pasturage are about the only uses made of the soil. 



