THE MANURE HEAP 



[CH. 



The yields of hay in cwts per acre were: 



Average of 3 plots for 1900 



Average of 3 plots for each of next 



4 years 1901-4 



Total increase over 5 years from 



applying manure fresh instead of 



rotted 



46-0 



25-5 



41-5 



46-5 



17 



43-7 



5-1 tons 9-0 tons 7-4 tons of potatoes 



control 10 tons manure 10 tons manure 



stored under stored in open 



cover 

 Fig. 6. Effect of storage of farmyard manure on yield of potatoes. (Rothamsted.) 



On light land the long manure may "let in the drought" too 

 much, but this can be obviated by ploughing it in sufficiently 

 early to allow time for decomposition. 



Fixers. It is sometimes suggested that various fixers might be 

 added to the manure heap to help retain the ammonia, but there 

 is no evidence that any of them is of value. The only one for 

 which any advantage has been proved is a layer of earth on the 

 top of the heap; but this is not always practicable. 



Liquid manure. If you are unable to prevent liquid draining 

 away from the farmyard manure then you certainly ought to 

 use it, especialty if the buildings include a tank into which it can 



