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University of California Publications in Agricultural Sciences [Vol. 1 



In the following table we have placed the names of the twenty 

 localities which have as much as 1.95 per cent in the surface 

 foot, and the twenty which rank highest in averages of the upper 

 three feet and in the entire column of ten or twelve feet. 



Composite Columns op Agricultural Regions 



In the following table are given the averages of each of the 

 agricultural regions embracing all of the 109 columns represent- 

 ing the state at large, taken from thirty-seven counties. The tule 

 marshes of Stockton, Pomona, and Klamath are placed in a 

 column by themselves. In some of the individual columns that 

 form the composite for each region either a depth of twelve feet 

 was not secured or the humus itself was not found to that depth. 



The marsh lands are naturally richest in humus because of 

 the large amount of decaying vegetable matter they hold. But 

 next to these we find that the Coast Range valleys have the 

 highest amount in the surface foot, the upper three feet, and in 

 the entire column respectively. The lava-bed valley and meadow 

 lands are but little above the Sacramento Valley in amount of 

 humus, while the San Joaquin Valley falls behind Southern 

 California. The "desert" plains naturally are lowest of the 

 eight groups, but it is interesting to note that in the quite even 

 distribution throughout the column there is a larger amount in. 

 the lower six feet than is found in the lower six feet of either 

 the San Joaquin Valley or the lava-bed valleys. 



In the foothill and lava-bed valleys the upper two feet hold 

 one-half of the total humus; in the desert lands one-half of the 

 humus is distributed through the upper five feet of soil, while in 

 each of the other columns the upper three feet holds one-half of 

 the humus. 



The first foot of the desert lands contains but about one-eighth 

 of the total amount of humus of the column; that of the Coast 

 Range valleys and the marshes, a little more than one-fifth ; while 

 in the other regions the upper foot holds from one-third to one- 

 fourth of the total amount found in the respective columns. 



On glancing at the table the attention is first called to the 

 depth of twelve feet to which humus reaches in all of the com- 



