176 



Fertilisers 



[PT. Ill 



vised to mix superphosphate, gypsum, or soil with the 

 heap as "fixers," but recent work is against this view 

 and direct experiment has shown the futihty of these 

 precautions^. Shelter and coinpacting seem the best 

 methods of reducing the loss. 



Nitrogen 



as NH., 



as Amide 



as other 



Nitrogen 



Compounds 



At start 



Kept compact 

 and covered 



Kept loose 

 and covered 



Kept loose 

 and exposed 



Fig. 34. Changes in nitrogen compounds in farmyard manure (cow 

 manure) kept for three months,. January 23 to April 30, 1914. 



The following are general rules for the more efficient 

 conservation of the fertilising constituents of farmyard 

 manure : 



I. Manuremadefrom fatting beasts. If this is made in 

 covered yards it should be left under the beasts until it 



^ In the Ohio experiments, however, gypsum proved effective. 



