Loss of Nitrogen in Drainage Waters. 73 



Hence, independently of other adverse effects arising from 

 low temperature and excess of rain, the Rothamsted experi- 

 mental wheat crops of 1879 suffered very considerably from 

 loss of the nitrogen of the manure by drainage. Experi- 

 mental evidence proves that similar loss may arise when 

 animal nitrogenous manures (such as hair, horn shavings, 

 woollen rags, &c.) and vegetable nitrogenous manures (such 

 as rape-cake) are used. Further, the drainage water from 

 the dunged plot in the experimental wheat-field is sometimes 

 found to contain a considerable amount of nitric acid, but 

 always very much less than that collected at the same time 

 from adjoining plots receiving much less nitrogen as manure, 

 but in the form of ammonia-salts or nitrate of soda. Whilst, 

 therefore, it is to be assumed that the loss of the nitrogen 

 of manure by drainage in the season of 1879 was propor- 

 tionally much greater in the experimental wheat-field than 

 in the case of land farmed in the ordinary way, there can 

 nevertheless be no doubt that much of the land of the 

 country at large also suffered loss in the same way. 



