Farmyard Manure. 



[JUNE, 



Table VII. — Composition of Farmyard Manure made at 

 Rothamsted from Roots and Hay only, or from Roots and 



Hay with Cake. 







Year. 



Dry Matter. | 



Total 

 Nitrogen. 



Nitrogen as 

 Ammonia. 



Nitrogen as 

 Amides. 



Insoluble 

 Nitrogen. 











Per 



Per 



Per 



Per 



Per 









cent. 



cent. 



cent. 



cent. 



cent. 





Roots and hay only 



1904 



23*6 



o'577 



0*046 



0*067 



0*464 



Made into mixen 



Cake fed 





24-0 



0716 



0*079 



0-096 



o-54i 



and stored. 



Roots and hay only 



1905 



29-5 



0*462 



0-040 



0*047 



o-375 



Made into mixen 



Cake fed 



31-3 



0-698 



0-182 



0*055 



0*461 



and stored. 



Roots and hay only 



1906 



22*0 



0-466 



0'022 



0*033 



0*411 





Cake fed 



>> 



24'3 



0-690 



0-097 



0*049 



o'544 





Roots and hay only 



1907 



25-3 



0-589 



0-I25 



0-053 



0*411 



Not stored. 



Cake fed ... 



" 



25-5 



0-815 



0-377- 



0*033 



0-405 





Table VI I a. — Crop Returns from the above Manures. 





Year of 

 Application. 



Second 

 Year. 



Third 

 Year. 



Mean of 2. 



Mean of 4. 



Mean of 3. 



: Unmanured plot 



16 tons per acre root and hay dung ... 

 ,, ,, cake-fed dung 



Per cent. 

 100 

 132 

 I*? 



Per cent. 

 100 

 136 

 140 



Per cent. 

 100 ; 



117 : 



121 



It will be seen that the cake-fed dung is always considerably 

 richer in nitrogen, the average percentage being 0-73 as 

 against 0*523, a superiority of nearly 40 per cent. Moreover, 

 the extra nitrogen in the cake-fed dung is mostly in the 

 highly available forms, the ammonia, urea and amido corn- 

 pounds which represent the digestible nitrogen of the cake ; 

 the insoluble nitrogen in the cake-fed dung is only 0*488 

 as against 0*415 in the dung made from roots and hay, 

 a superiority of less than 18 per cent. That the superiority of 

 the cake-fed dung as regards the soluble nitrogen compounds 

 is not even more pronounced is due to the change back from 

 ammonia into proteins effected by bacteria during storage ; 

 in 1907 when the dung was sampled as it left the yard both 

 lots had practically the same proportion of insoluble nitrogen 

 and both possessed an exceptional amount of ammonia which, 



