SOIL SUEVEY OF THE RED BLUFF AEEA, CALIFORNIA. 



39 



was formed from other types. Intermittent streams have accumu- 

 lated this type by gradual wash, and it grades rather imperceptibly 

 into some of the other types of the same elevation. 



About 50 i^er cent of this inextensive soil is devoted to pears, figs, 

 peaches, and alfalfa, the remainder being grazing land. A little 

 irrigation is practiced by pumping, and results give evidence of a 

 natural fertility and adaptation to irrigated crops of the region. 

 "With more extensive watering its whole area will be found capable 

 of intensive development. Alfalfa and practically all the fruits of 

 the area are possible. Pears maj^ be found very well adapted to 

 this soil. It can not be made to produce maximum yields without 

 irrigation and the profits derived from it at present are meager. 

 Only small quantities of water are available for pumping, and its 

 development will depend upon irrigation with water drawn from 

 distant sources. 



The following table gives the results of a mechanical analysis of 

 the soil of this type '. 



Mechanical analyfiis of Mayicood siliii clay loam. 



KIKKWOOD SILTY CLAY ADODE. 



The Kirkwood silty clay adobe consists of a dark-gray to almost 

 black silty claj' or heavj^ silt}" clay loam of smooth, very sticky texture. 

 It at all times possesses an adobe structure, cracking into huge blocks, 

 which are subsequently checked and subdivided into small cubes or 

 angular fragments. The type is puddled and miry when wet and 

 exceedingly hard and compact when dry, rendering it a soil of poor 

 tilth and refractory character. It is usually 6 feet deep. The subsoil 

 is occasionally a lighter textured, slightly more friable clay loam, 

 but not of sufficient thickness to modify the soil. A small content of 

 waterworn gravel is occasionally found. In some places the cemented 

 clay, sand, and fine gravel of the contiguous Corning gravelly loam 

 underlies the type at depths below 5i inches. 



This type occupies several relatively small bodies partially sur- 

 rounded by or closely associated with the Corning gravelly loam. 

 Its surface is level to gently sloping, and the areas are quite dis- 

 tinctly separated from the Corning gravelly loam by terraces or steep 

 banks. The surface drainage is rather good, despite the fact that the 

 type often receives run-off from the higher soils. A water-logged 



