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T. Lyttleton Lyon and James A. Bizzell 



On the whole there appears to be no evidence that the application of 

 lime has increased the formation of nitrates in this soil in the tanks, altho 

 it may have done so in the corresponding plats in the field. 



Effect of plant growth on nitrogen removal in drainage water 



The total removal of nitrogen from the tanks used in these experiments 

 is rather large. It is seen by tables 17 and 18 that from planted soil 

 much more nitrogen is removed in the crops than in the drainage water. 

 There seems to be a close margin between the quantity of nitrates pro- 

 duced and the quantity absorbed by the crop. When soil is cropped 

 the loss of nitrogen in the drainage water is usually not great. On the 

 other hand, when land is continually kept free of vegetation there is 

 a very heavy loss of nitrogen in the drainage water, amounting usually 

 to more than the nitrogen removed in the crop and in the drainage water 

 combined on cropped land. This is seen by table 19, which shows that 



TABLE 19. Nitrogen in Crops plus Drainage Water of Planted Tanks, and in 

 Drainage Water Alone of Unplanted Tanks 



the average loss of nitrogen in the drainage water from the unplanted 

 tanks 2, 4, and 8 averaged 460 pounds per acre for the five-years 

 period, while the removal of nitrogen in both drainage and crops from 

 the planted tanks 1, 3, 5, 6, 7, 9, 10, 11, and 12 averaged 362 pounds 

 per acre. 



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