104 



SOILS AND FERTILIZERS 



is astonishing. The loss from the cropped soil is moderate, 

 but from the unplanted soil it is excessive. The loss of sulfur 

 is decreased by cropping, and much increased by fertilizing 

 with sulfate of potash. 



The loss of lime and nitrogen in the uncropped soil as 

 compared with the one that was cropped is greater than 

 the quantity that would have been removed by ordinary 

 crops. Consequently there is an actual saving of these 

 plant-food materials when crops are produced. 



122. Effect of fertilizers on loss of plant-food materials 

 in drainage. — We have seen that the effect of sulfate of 

 potash was to increase the loss of lime, magnesia and sulfur. 

 In general, the result of fertilizer applications is similar to 

 that shown above. This is borne out by experiments con- 

 ducted at the Rothamsted Experimental Station in which 

 drainage was collected from plats treated with different 

 fertilizers. The total flow of drainage water from these 

 plats was not measured, but the composition of the water 

 indicates the effect of the fertilizers. 



Table 25. — Composition of Drainage Water from Wheat 

 Plats, Rothamsted Experiment Station 



