lO 



The Botanical Survey of Nebraska 



Considerable fluctuation in water content in the first foot of 

 soil during July at this station is explained by frequent local 

 showers. The effect of such precipitation is, however, seldom 

 felt by the lower soil layers. 



Figure 4. Soil moisture at 0-6 in, 6-12 in., and 12-24 in. at the sumac 

 station, Lincoln, 1917. 



Figure 4 indicates the soil moisture conditions which prevailed 

 in the sumac thicket on the prairie during the season of 1917- 

 The most significant fact revealed by these graphs is that there 

 was no available moisture in the upper two feet of the soil for 

 considerable periods during the latter part of the growing season 

 and that there was considerable fluctuation of the water content 



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