1914] Loughridge: Huvius and Nitrogen in California Soil Columns 209 



Columns of the red slate soil were taken from Palermo, Butte 

 County, and from the former experiment station tract near 

 Jackson, Amador County; also from a bluff near Newcastle, 

 Placer County, taken by Mr. Paul H. Steude of Newcastle. 



The red clay soils of Jackson and Palermo are quite similar 

 in the amount of humus in the first foot, but the former is the 

 richer below that. The clay is quite close and compact, and this 

 has prevented the development of roots to the extent permitted 

 by the looser gravelly granitic soil of Newcastle, in which there 

 is more humus. The general average of humus in the first foot 

 is 1.12 per cent ; that of thirty-one soils of the foothills previously 

 examined is 1.05 per cent, although it is found to be higher in 

 the valleys farther up in the mountains, in the regions of 

 Auburn, Grass Valley, Nevada City, and Placerville, than near 

 the Sacramento Valley. In percentage summation the general 

 average of the upper three feet of the columns is .80 per cent. 



The humus in each of the Palermo and Jackson soils is very 

 poor in nitrogen, not only in the upper three feet but in the 

 entire column ; and the nitrogen of the respective soils is also 

 below the normal. On the other hand, the humus in the soil 

 from Newcastle is far richer in nitrogen, there being as much 

 as 8.8 per cent in the humus of each foot of the twelve-foot 

 column. The soil itself contains 0.10 per cent in the upper three 

 feet, which is much above the normal, and is equivalent to about 

 4000 pounds for each foot in depth per acre. 



SOIL COLUMNS OF THE COAST EANGE VALLEYS 



The Coast Range of mountains, reaching from the Oregon 

 state line south to the Mexican border, has but few agricultural 

 possibilities except in the many valleys enclosed between the 

 mountain ridges. The country north of I\Iendocino County is 

 especially rugged and the valleys are few, but southward there 

 are many valleys that present splendid agricultural attractions, 

 and we have endeavored to have the soils of the largest and most 

 important ones represented in the columns of this series. Of 

 course, it must be understood that in each valley there are a 

 number of soil variations and gradations from the hills to the 

 lower valley center, and that the column has been selected to 



