Lysimeter Experiments 



43 



water of the implanted soil, indicates a disappearance of available nitrogen 

 that may be accounted for by a depression of the process of nitrate 

 formation. 



There is certainly a striking difference in the quantity of available 

 nitrogen in the soil on which these different crops have grown, and 

 apparently this is connected with the growth of the particular kind of 

 plant, since the other conditions were similar. While the data at hand 

 do not supply positive evidence on the subject, they tend to confirm 

 the hypothesis that different kinds of plants have certain characteristic 

 relations to the process of nitrate formation. 



REMOVAL OF CALCIUM 



Calcium was removed in the drainage water to a greater extent than 

 any other of the bases determined, but in the ash of the crops raised 

 calcium was not the constituent removed in largest quantity from the 

 soil. In table 21 is shown the average amount of calcium removed annually 

 from the soil by drainage water and by crops during the five-years 



period : 



TABLE 21. Calcium in Drainage Water and in Crops 

 (Pounds per acre, annual average) 



Effect of plant growth on removal of calcium 



Ihe large removal of calcium in the drainage water of the unplanted 

 soil is very noticeable in table 21. Not only is the quantity of calcium 

 in the drainage water of the unplanted soil greater than that in the planted 



43 



