500 SOILS: PBOFEBTIJSS AND MANAGEMENT 



nitrates and leached from the soil in sufficient quantities to 

 entail a very decided loss of nitrogen. There is not likely 

 to be so large a loss of nitrogen from ammonium salts as 

 from nitrates, and, as would naturally be expected, there is 

 greater loss of nitrogen when these salts are used alone than 

 when they are combined with other fertilizing ingredients. 

 HalF has estimated the loss of nitrogen from certain 

 drained plats at the Rothamsted Experiment Station. 

 This estimate is based on the concentration of the drain- 

 age from the different plats, of which there was no record 

 of total flow, but for which the measurements of flow from 

 the lysimeter draining 60 inches of soil were taken and the 

 total loss of nitrates was calculated on this basis. Esti- 

 mated in this way the effects of several different methods 

 of manuring are shown in the accompanying table : — 



Pounds to the Acee of Nitric Nitrogen in Drainage Water 



Treatment 



Unmanured 



Mineral fertilizers only 



Minerals + 400 pounds ammonium 

 salts 



Minerals + 550 pounds nitrate of 

 soda 



Minerals + 400 pounds ammonium 

 salts applied in autumn .... 



400 pounds ammonium salts alone . 



400 pounds ammonium salts + sul- 

 phate of potash 



Estimated drainage in inches . 



1879-80 



Sprmg 

 sowing 



to 

 harvest 



1.7 

 1.6 



18.3 

 45.0 



9.6 

 42.9 



19.0 



11,1 



Harvest 



to 

 spring 

 sowing 



10.8 

 13.3 



12.6 



15.6 



59.9 

 14.3 



16 4 



4.7 



1880-81 



Sprmg 

 sowing 



to 

 harvest 



0.6 

 0.7 



4.3 



15.0 



3.4 



7.4 



3.7 



1.8 



Harvest 



to 

 spring 

 sowing 



17.1 



17.7 



41.0 



74.9 

 35.2 



18.8 



^Hall, A. D. The Book of the Rothamsted ExperimentSj 

 p. 235. New York, 1905, 



