138 



Irrigation and Drainage 



again May 5, in order to. discover whether in that time 

 progressive changes would take place. Between the 

 first and last date there had been a total rainfall of 5.33 

 inches, making conditions very favorable indeed to 

 obliterate the effects of the subsoiling in a short time. 

 The changes which these rains, together with the fitting 

 and planting of the ground, produced, are shown in the 

 table below: 



-April 8- 



First ft.. 

 Second ft 

 Third ft.. 

 Fourth ft. 



Subsoiled 



PER CENT 

 19.58 



19.01 

 17.39 

 16.79 



Not 



subsoiled Difference Subsoiled 



PER CENT PER CENT PER CENT 



April 16 v 



Not 

 subsoiled Difference 



22.04 

 17.61 

 17.06 

 16.20 



2.46 

 +1.40 

 + .33 

 4- .59 



20.80 

 18.62 

 16.48 

 16.11 



PER CENT 



22.88 

 18.97 

 16.70 

 16.50 



PER CENT 

 2.08 



.3f) 



.22 



.39 



It will be seen that the difference between the water 

 in the soil under the two treatments becomes less each 

 time the samples are taken, and that on May 5 the dif- 

 ference between them had nearly disappeared. But it 

 should be observed that this close agreement at the last 

 time may be more apparent than real, on account of the 

 fact that a rain of 1.3 inches had fallen on May 1, and 

 it is possible that time enough had not yet elapsed to 

 allow an equilibrium to be established. 



