Soil-Group Divisions 85 



and the pedalfers, in the terminology used by Wolfanger ( 1950 ) and 

 shown in Fig. 3.10— or the aridic and the humid soils, in the some- 

 what different classification used by Lyon, Buckman, and Brady 

 (1952). The pedocal division is composed of incompletely leached 

 soils found characteristically in the arid Great Plains of the West. 

 The slight rainfall of these regions does not saturate the soil to a depth 

 sufficient to reach the water table deep in the ground, and lime tends 

 to be deposited in the B horizon. When evaporation from the soil 

 begins, the ground water is drawn upward again toward the surface, 

 carrying some of the solubles with it. The water in this kind of soil 

 has been said to be "hung from the top, like Monday's wash!" The 

 roots of the grasses and shrubs that are characteristic of the pedocal 

 soils absorb the water and the contained salts and also carry them to- 

 ward the surface. Grasses particularly tend to absorb a considerable 

 amount of calcium and to restore this material to the upper layers. 

 This process is aided by the low growth habit of these plants and the 

 great development of rhizomes and other structures near the surface 



PEDOCALS 

 ^^ BUCKERTHS 

 ' M'^'i DARK-BROWNERTHS 

 ^''"' i BROWNERTHS 

 N^ GRAYERTHS 



PEDALFERS 

 ( J GRAY BROWNERTHS 

 ^^ RED-AND-YELLOWERTHS 

 ^^ PRAIRYERTHS 



llllllllll PODZOLS 



lijliljiiil UNDIFFERENTIATED HIGHLANDS 

 |v-:;-:| SANDHILLS 



Fig. 3.10. The soil groups of the United States and their division into Pedocals 

 and Pedalfers. (Modified from Wolfanger, 1950, in Conservation of Natural Re- 

 sources, reprinted with permission of John Wiley and Sons. ) 



