SOILS OF THE NORTHERN PART OF THE VALLEY. 13 



diate types having some characteristics of the San Luis series and 

 some of the Rio Grande series. 



These intermediate types are light-brown or chocolate-brown to 

 dark grayish brown in color and generally a heavy loam to clay 

 loam in texture, with but little gravel. At Swede Corners, near the 

 mountain foot slope, 6 miles south of Saguache, the prevailing soil 

 is a light-brown, friable sandy loam, retentive of moisture, and 

 underlain by a grayish-brown or chocolate-brown compact clay loam. 

 It is well suited to irrigation and the production of vegetables and 

 staple farm crops. In the district north of the various branches of 

 Saguache Creek and below the " mesas," as the alluvial fans and 

 foot slopes are locally termed, the mixing of material washed from 

 the hills with the heavier lake and stream sediment of the valley 

 floor has given rise to chocolate-brown, dark-brown, or gray soils, 

 generally of heavy clay loam texture, becoming lighter in color and 

 texture below the first foot, but usually extending with but little 

 change to depths greater than 3 feet. The surface is here slightly 

 sloping or flat and drainage is deficient. The soils generally support 

 a heavy growth of the usual desert shrubs, but barren areas sometimes 

 showing surface incrustation of alkali salts occur in the more poorly 

 drained localities. 



Samples collected in sec. 2, T. 44 N., R. 9 E., in the margin of a 

 wet, barren depression, contained slightly more than 1 per cent of 

 alkali salts in the soil and subsoil, an amount in excess of that which 

 can be withstood by ordinary farm crops. Additional samples col- 

 lected in sec. 30, T. 44 N., R. 10 E., on soil of similar character, were 

 found to carry 3.61 per cent of total salts in the first 18 inches and 

 2.45 per cent in the subsoil to 3 feet. The soils of this district are 

 tenacious heavy clay loams. When dry they frequently assume a 

 peculiar granular condition, giving them a porous, mealy structure. 

 They are at present not extensively utilized except for grazing, and 

 without irrigation and drainage are not generally suitable for the 

 production of crops. With irrigation and artificial drainage, which 

 favor the removal of excess alkali salts, they would be available for 

 alfalfa, grasses, grains, and some of the hardier vegetables adapted 

 to heavy soils. 



While drained by no permanent stream, the northern part of the 

 valley is traversed by a large number of creeks carrying considerable 

 quantities of water after heavy rainfall on the mountain slopes. Of 

 these Saguache Creek is the largest and of most constant flow. Upon 

 reaching the valley many of these streams divide into a network of 

 channels covering extensive areas which, during floor periods, are 

 subject to overflow. The most of the tributary waters pass into the 

 subsoils, and with those of the Rio Grande and other streams lying 

 to the south become the source of supply for the artesian basin cover- 



