518 



The Storage of Far my or d Manure 



mat together into a kind of thatch which, had it been perfect, would no 

 doubt have shielded the rest of the heap. But in its imperfect state 

 it allowed rain to get in, much of which flowed away again as a stream 

 of black liquid. This, of course, complicates the matter, and it is not 

 surprising that the exposed heaps do not show the relationship between 

 temperature and losses that are exhibited in the sheltered heaps. The 

 temperature of these exposed heaps did not rise so high as that of the 

 covered heaps excepting in one case, but the loss of dry matter was con- 

 siderably higher. The total loss of nitrogen compounds, however, did not 

 follow in the same way, and was sometimes no more than in the sheltered 

 heaps in spite of the difference in loss of dry matter : this was particu- 

 larly the case with the bullock manure during the first three months 

 of storage. The loss of ammonia was usually much greater, excepting 

 only in two cases, while the loss of other nitrogen compounds was some- 

 times actually less. This is shown in Table III, other results obtained 

 with mixed manure are given in Fig. 4. 



Table III. Ejfect of shelter on the amount of loss from decomposing 



farmyard manure. 



Cow manure stored loosely for 



3 months 



Re-made and left 

 for 3 months 



Highest temperature 

 Loss of dry matter 

 Loss of nitrogen 

 Of which :— NH, 



Exposed 

 21° 

 21 

 25 

 15 

 9 



Covered 



16° 



7 



7-5 

 8-4 

 + 0-7 



other compounds 



Bullock manure. 



Compact 3 mths Compact 9 mths 



Exposed 

 29° 

 28 

 13 

 3 

 12 



Covered 

 32° 

 26 

 30 

 8-5 

 23-5 



Loose 3 mths 



Loose 9 mths 



Exposed Covered Exposed Covered Exposed Covered Exposed Covered 



Highest temperature ... 40° 51° 40° 51° 55° 71° 55° 71° 



Loss of dry matter ... 39 30 60 47-5 41 35 60 45 



Loss of nitrogen 28 26 50 42 27 26 51 32 



Of which i—NHj 16 11 17 15 16 16 17 19 



amide Nil 1 3 3 Nil Nil 4 Nil 



other compounds 12 14 30 24 11 10 30 13 



In these tables the original dry matter is put = 100 as also is the original nitrogen. 



There is evidence here of two opposing factors : the rain washes 

 out soluble matter, but it also keeps down the temperature and thereby 

 reduces decomposition of the nitrogen compounds and loss of ammonia 



