38 



T. Lyttleton Lyon and James A. Bizzell 



jected when it was placed in the tanks in 1909. In 1914 the nitrogen 

 showed a tendency to fall below its usual ratio to the flow of drainage 

 water. It is difficult to trace this to any weather conditions obtaining 

 that year, as neither the rainfall nor the temperature was abnormal during 

 the months when nitrate formation might be expected to be active. 

 It is possible that with the settling of the soil in the tanks and the 

 diminished aeration, there is j. tendency for the process of nitrate formation 

 to be less active. This can be confirmed or refuted only as the experi- 

 ments are continued. 





t9/o 



/9/3 



/^/■<t 



-//o ?C 

 -/oo ^ 



-70 f 

 -60 \ 



Fig. 9. relation of yearly flow of drainage water to yearly removal of 



nitrogen in drainage water, tank 8 



The most noticeable factor in determining the quantity of nitrogen 

 in the drainage water is the presence or absence of plants on the soil. 

 The unplanted tanks average seventeen times as much nitrogen in the 

 yearly flow as do the planted tanks. Absorption of nitrogen by the 

 growing plants may be assumed to account in large measure for the 

 difference. 



Effect of ime on removal of nitrogen 



The application of lime apparently has not increased the amount of 

 nitrogen in the drainage water. Comparing tanks 4 and 8, of which 

 neither was cropped but the latter was limed, it is seen that there was 

 more nitrogen removed from the unUmed soil during the five years than 



38 



