44 



FIELD OPERATIONS OF THE BUREAU OF SOILS, 1910. 



valley edge a low terrace usually marks the beginning of the more 

 elevated series previously described. 



In origin this type is wholly alluvial. l)eing the somewhat recent 

 finer material laid down by the two principal west side creeks pre- 

 viously mentioned. It does not appear that wash from the Redding 

 or Tehama series has influenced the type in any marked degree. 

 Great solitary valley oaks dot the surface, remaining members of a 

 heavier growth, and upon uncleared portions they are accompanied 

 by thickets of elder, Avillow, and coffee berry, contrasting strongly 

 in late summer with the barren apjjearance just above the terrace. 

 The rocks yielding the particles forming the Elder silt loam lie far 

 beyond the western limits of the Red Bluff area along the stream 

 sources. 



It is a first-class agricultural soil, being fully utilized at this time, 

 principally in the production of dry-farmed grain. There are also 

 orchards of prunes and ^x^aches covering limited areas near Richfield, 

 together with some alfalfa irrigated by means of water pumped from 

 the gravel beds of Thomas Creek. The type produces heavy yields 

 per acre of wheat and barley under an extensive cropping system, but 

 can not long continue to be simply a grain soil because of its great 

 possibilities. It is one of the best soils of the area, and with irriga- 

 tion is capable of a high degree of intensive cultivation. All the fruits, 

 alfalfa, sugar beets, berries, melons, and truck crops will return 

 profitable yields whenever the soil shall be developed by the applica- 

 tion of water. This is one of the few types of the west side having 

 access to readilj'^ available underground water for irrigation. While 

 the expense of pumping is considerable it is not prohibitive. There 

 :ire some bodies of the type of older deposition lyin.g slightly above 

 the present alluvial plain, but the surface of most of it lies at an 

 elevation easily reached by a moderate lift with centrifugal pumps. 

 Water sufficient for considerable development could be secured in this 

 way from the gravelly beds of Thomas and Elder Creeks for crops 

 not now possible. The type is not suited to intensive cultivation 

 A.ithout irrigation, and while with care trees can be brought to ma- 

 turity the returns are light. Its proper development requires some 

 comprehensive system of irrigation. 



The following table gives the average results of mechanical analyses 

 of the soil of this type: 



McclKiiiicdl ini<il!i'<( .■< (if r]hl( r .v//.' Ininn. 



