14 SOILS OP THE SAN LUIS VALLEY, COLORADO. 



ing the valley. At times these waters become charged with sediment. 

 Owing to the agencies favoring wide distribution and deposition 

 afforded by the network of streams of slight gradient, this material 

 has been deposited superficially over extensive areas, giving rise to 

 several types of soil related to the Rio Grande series. 



Much of the territory in the vicinity of Moffat and Saguache con- 

 sists of soils of this character. Deficient slope and the absence of any 

 efficient natural drainage outlet, with the nearly constant water 

 supply afforded by Saguache Creek, has here developed extensive 

 areas suited for the production of native hay. Poor drainage has also 

 caused the accumulation of alkali over wide areas and the saturation 

 of the subsoils of the lower districts. Owing to these conditions, the 

 soils are often adapted only for native grasses for hay or grazing. 

 The soils are usually dark in color, well supplied with organic matter, 

 friable under cultivation, arid retentive of moisture, and when ade- 

 quately irrigated and drained they will be adapted to the produc- 

 tion of the grains, grasses, potatoes, and truck crops. Samples 

 taken in sec. 3, T. 43 N., R. 9 E., in an area used for wild hay 

 west of Moffat, show a dark-gray, friable sandy loam soil, extending 

 to a depth of 24 inches, underlain by a heavier sticky loam. Both soil 

 and subsoil carry a small quantity of alkali salts, which have only 

 locally become sufficiently concentrated to cause injury to crops, the 

 excess of salts having here been removed by periodical flooding. 



West of this section, in the Warner neighborhood, drainage condi- 

 tions show improvement, the soil being a dark heavy loam, generally 

 free from alkali and excellently adapted to the production of root 

 crops, hardy vegetables, and general farm crops. In the vicinity 

 of Saguache the prevailing soils occurring along Saguache Creek 

 consist of dark-colored to black loams and heavy loams, carrying a 

 large quantity of organic matter, friable, productive, and frequently 

 underlain by sands and gravels at less than 3 feet. They are some- 

 times subject to overflow or poor drainage and to local accumulation 

 of alkali salts. 



In the districts covered by recent alluvial stream deposits in the 

 extreme northwestern part of the valley occur limited areas of dark 

 loam of a more silty character than is typical of the larger soil 

 areas of the valley. This soil is friable, easily tilled, and of excellent 

 moisture-retaining properties. It is usually well drained and free 

 from alkali, well situated for irrigation, and ranks as one of the 

 most promising soils of the entire valley. One area of particularly 

 desirable character and location occurs in the vicinity of Mirage. 



Near the northern extremity of the valley trough, where it is crossed 

 by San Luis Creek, the soils are dark-gray to black in color, usually 

 heavy loam or clay loam in texture, and carry a large quantity of 

 organic matter. When in a favorable condition as regards moisture 



