1914] Lougliridge: Humus and Nitrogen in Calif ornia Soil Columns 251 



A number of other localities very nearly come into the list 

 as their upper two feet have more than 1 per cent and the third 

 falls a little below. It will be noted that these results are not 

 confined to any particular soil type but that all types from sandy 

 to heavy clay adobe are represented in the list. 



If the humus of the upper three feet be equally distributed 

 through that depth we will find that nine of the columns 

 have each an average of more than 2 per cent of humus in 



Table 44. — Soil Columns Having the Highest Humus Percentages 



In First Foot 



Per cent 



Stockton tule 14.10 



Pomona Cienega 6.26 



Santa Clara adobe 4.43 



Cedarville 4.29 



Arroyo Grande seed- 

 farm 3.78 



Klamath marsh 3.75 



Alturas meadows 3.05 



Gilroy 2.76 



Cedarville meadows.... 2.71 



Yountville 2.64 



Lompoc seed-farm 2.50 



Arroyo Grande 2.50 



Santa Ana adobe 2.42 



Chino moist land 2.31 



Kenwood 2.25 



El Verano adobe 2.14 



Berkeley adobe 2.13 



Farmington 2.04 



Vacaville 1.97 



Santa Eosa 1.95 



AVEEAGE OF UpPEB ThREE 



Feet 



Per cent 



Stockton tule 16.68 



Pomona Cienega 3.67 



Santa Clara adobe 3.63 



Klamath marsh 3.32 



Cedarville 



Gilroy 



Arroyo Grande 



Arroyo Grande seed- 

 farm 



Berkeley adobe 



Yountville 



Cedarville meadows.. 

 Lompoc seed-farm .... 



Alturas meadow 



Kenwood 



El Verano adobe 



Farmington 



Santa Ana adobe 



Eussian Eiver 



Chino 



Glenn , 



2.25 

 2.23 

 2.16 



2.15 

 2.01 

 1.98 

 1.89 

 1.86 

 1.84 

 1.74 

 1.71 

 1.65 

 1.63 

 1.58 

 1.52 

 1.51 



Average of Entire Column 

 OF 10 OR 12 Feet 



Per cent 



Stockton tule 6.81 



Arroyo Grande 1.39 



Santa Clara (10 feet) 1.33 



Pomona Cienega 1.28 



Arroyo Grande seed- 

 farm 1.27 



Gilroy 1.14 



Cedarville (10 feet).... 1.10 



Lompoc seed-farm 



Berkeley 



Eussian Eiver 



Yountville 



Santa Eosa 



El Verano (10 feet).... 



Walnut Creek 



Hayward 



Davis Univ. Farm 



Watsonville 



Chico 



Vacaville 



Glenn 



1.09 



1.04 



1.01 



.95 



.92 

 1.00 

 .80 

 .77 

 .75 

 .74 

 .73 

 .71 

 .69 



the upper three feet, and twenty-five others have an average 

 of more than 1 per cent, all others falling below the 1 per cent. 

 In the distribution of the humus through the entire twelve feet 

 of the columns there are ten which thus give an average of more 

 than 1 per cent for each foot, and twenty-five others whose 

 average is about one-half of 1 per cent. 



