20 



Therefore when the ammonia has been nitrified, and the 

 resulting nitric acid has combined with carbonate of lime 

 to form nitrate of lime, the nitrogen is then subject to 

 serious loss by drainage after every fall of rain that occurs, 



INFLUENCE OF CLIMATE AND SEASON ON THE EFFECT 

 OF SULPHATE. 



The many conditions affecting nitrification, and the in- 

 fluence which the rate of nitrification must obviously have 

 on the waste of nitrogen applied as sulphate of ammonia, 

 suggest that some seasons and climates must be more suit- 

 able for this manure than others. In this connection, it is 

 interesting to compare sulphate of ammonia and nitrate of 

 soda. The former is rather the less soluble, and requires to 

 undergo nitrification before it is liable to be washed out of 

 the soil. Nitrate, on the other hand, is always subject to 

 loss by drainage. Therefore we find in practice that sul- 

 phate of ammonia usually gives better results than nitrate 

 of soda in a wet season, but in a dry one it is likely to 

 remain inert in the soil, and therefore to have a relatively 

 w r orse effect. As will be shown later on, in the latter case 

 part of the unused manure may be recovered in subsequent 

 crops. 



Wet climates and wet seasons are therefore favourable to 

 sulphate of ammonia; dry climates and seasons, to nitrate 

 of soda. An example of this with regard to season is 

 afforded by the Woburn wheat experiments. The follow- 

 ing table shows the produce per acre of corn and straw in 

 each year in which the rainfall of the growing season (April 

 to September) was 2 inches or more either above or below 

 the average. * 



TABLE VIII. 



* Voelcker, 

 Vol. IX., T.S. 



Journal of the Royal Agricultural Society of England," 



