120 NATURE AND PROPERTIES OF SOILS 



63. The humus content of soils is of course lower than 

 the organic matter contained in them. It likewise varies 

 according to climate and region, not only in amount, but also 

 in composition. The following data from Hilgard * and 

 Alway 2 illustrate these points : 



Table XXVI 



the composition of california arid and humid soils, 

 (hilgard) 



Table XXVII 



COMPARATIVE COMPOSITION OF SEMI-ARID (WAUNETA) AND HUMID 

 (WEEPING WATER) LOESS SOILS OF NEBRASKA. ( ALWAY ) 



1 Hilgard, E. W., Soils, pp. 136-137; New York, 1911. For further 

 data regarding Hilgard 's conclusions see: Alway, F. J., and Bishop, 

 E. S., Nitrogen Content of the Humus of Arid Soils; Jour. Agr. Ecs., 

 Vol. 5, No. 20, pp. 909-916, Feb., 1916. 



2 Alway, F. J., et al., The Loess Soils of the Nebraska Portion of the 

 Transition Eegion: I. Eygroscopicity, Nitrogen and Organic Carbon; 

 Soil Sci., Vol. I, No. 3, pp. 197-238, Mar., 1916. II. Humus, Humus-Ni- 

 trogen and Color; Soil Sci., Vol. I, No. 3, pp. 239-258, Mar., 1916. 



