SOIL SURVEY OF THE RED BLUFF AREA, CALIFORNLA.. 27 



structure than the average. At about 3G inches the soil grades into 

 heds of reworked gravelly material or rests directly upon cemented 

 beds of sandy clay and waterworn gravel similar to those underlying 

 the typical Corning loam, but of a more friable nature. It is ex- 

 tremely variable in its subsoil. The surface soil is usually similar 

 to the soils of the Tehama series, and where erosion or deposition of 

 later stream-borne material has completely changed the surface the 

 type throughout the 6-foot section approaches the soils of the Tehama 

 series, but the subsoil in general is generally of Corning material. 



The sandy phase. Corning loam, usually carries a scattered growth 

 of upland oaks and a sparse growth of grass. It is not farmed. 

 Portions of it once produced grain in small quantities, but this crop 

 has been abandoned. It is not adapted to dry farming methods, and 

 some attempts to grow fruit upon it without irrigation have been 

 failures. Water for irrigation is not to be secured by pumping. 

 "\'\lien the type is irrigated it will be found to possess much the same 

 possibilities as the typical Corning loam. The shallow-rooted fruit 

 crops and berries will prevail to the exclusion of alfalfa, prunes, and 

 apricots, if best results are to be secured. The greater part of it will 

 bear the expense of irrigation and will warrant a moderate valuation. 



CORNING GRAVELLY LOAM. 



The Corning gravelly loam consists of a light-red or yellowish-red 

 loam of medium texture, often carrying <]uantities of coarse sand and 

 varying proportions of small angular or waterworn gravel. This 

 coarse material is similar to that carried by the Bedding loam. The 

 type is boggy when wet and quite compactly structured when dry, 

 though easily tilled with proper moisture conditions. At from 12 to 

 20 inches the surface soil is underlain by a deep-red compact, hea^^ 

 clay or clay loam, practically free from gravel. This subsoil becomes 

 very hard and much cracked when exposed. It is in turn underlain 

 at a depth from 24 to 48 inches by very compact semicemented layers 

 of fine waterworn gravel, clay, or beds of yellow smooth-textured silt. 



While the above description represents the typical soil column there 

 are considerable departures from it in different parts of the area. 

 Occasionally the gravelly loam with its heavy subsoil rests upon 

 a w^ell-defined hardpan layer, making the type quite similar to the 

 Eedding loam. Again the clay subsoil itself occurs in a partially 

 cemented state, being only slowly penetrated by water. Normally the 

 type does not have a distinct hardpan layer, but subsoil conditions 

 are unfavorable. The partially cemented gravel, silt, or clay usually 

 found at from 2 to 4 feet below the surface is impenetrable to plant 

 roots, and blasting would yield small relief. An average depth of 



