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BULLETIN 1105, U. S. DEPARTMENT OF AGRICULTURE. 



In the 24-inch series, site 1 again seems to have the higher mois- 

 ture content at the beginning of the season. Unlike the 6-inch and 

 12-inch series, which show a sharp decline during June, the 24-inch 

 samples rise steadily through this period. This indicates that com- 

 paratively little moisture was drawn from the lower soil strata dur- 



PiG. 10. — Location of soil sampling points, Table 17. 



ing the early part of the growing season in 1919. Whether this was 

 due to the unusually heavy rainfall in May, or whether it is a normal 

 condition, is not certain. It is known, however, that roots are most 

 numerous above the 2-foot level, and that the soil warms up slowly 

 below the first foot. By the end of August the effect of root action 

 had become apparent even at a depth of 2 feet, as shown by the 





