CH. xii] Consumption of FertUisers 217 



Nitrate of soda should go on as a top dressing after 

 the crop is up. 



Sulphate of ammonia should go on just before the 

 crop is up except in the case of wheat and winter oats, 

 when it may be added as a top dressing in spring. 



Superphosphate, potassic fertilisers and slag can go 

 on whenever convenient but should be applied not later 

 than early spring. 



Labour may be saved by mixing the fertilisers when 

 two or more are to be drilled in or distributed, but the 

 following should not be mixed by the farmer: 



Basic slag, lime or chalk with sulphate of ammonia. 



Dissolved bones with nitrate of soda. 



The following can be mixed if they are applied with- 

 out delay : 



Superphosphate with nitrate of soda ; dissolved bones 

 with potash manures; basic slag with kainit. 



All artificial manures have to be stored in a dry place 

 and mixed on a hard dry floor. 



Fig. 40 shows the amounts of artificial manures pro- 

 duced annually before the Avar in all countries of the 

 world. The quantities used in the United Kingdom were 

 about one-tenth of these values : they were as follows : 



Estimated pre-war Estimated 



consumption in annual value 



United Kingdom pre-war prices 



tons per annum 

 Farmyard manure 



Nitrate of soda 

 Sulphate of ammonia . . 

 Cyanamide (nitrolim) and nitrate of lime 

 Superphosphate 

 Basic slag- 

 Guano ... 

 Bones . . 

 Others ... 



Total 



^ No good estimate can be made of the amount of guano, bones, and 

 other materials used as fertilisers. 



