lO 



Journal of Agricultural Research 



Vol. XIII, No. I 



fixed by the total external surface area of the soil particles, the individual 

 pore spaces being so large as to prevent the water films about the particles 

 from consolidating sufficiently to fill appreciably the interstices. 



Table III. — Water content before and after irrigation, the moisture equivalent, and the 

 pore space of the soils of typical alfalfa farms in Sacramento Valley, California, 1914. 

 Averages for each foot of soil to a depth of gfeet « 



[Results expressed in acre-inches per acre-foot of soil) 



SILT-LOAM SOILS HAVING FINE SANDY-LOAM SUBSOILS^ 



SILT-LOAM SOILS « 



See Table II for the number of times each of the above fields was irrigated, the average quantities of 

 water applied, and the total amounts of water retained by the soil. 

 b These data are presented graphically in figure 2. 

 « From 7 to 9 feet average of only 8 borings. 

 i Upper 6 feet. 



« These data are presented graphically in figure 3. 

 / Upper 9 feet, less first and sixth. 



SILT-LOAM SOILS 



In Table III and figure 3 are presented results of moisture determina- 

 tions upon three tracts classed as silt-loam soils which are based upon 

 138 6-foot and 36 9-foot borings, making a total of 1,152 moisture deter- 

 minations. The results for the upper 6 feet of soil as presented in figure 3 



