556 The Storage of Farmyard Manure 



was no change in total nitrogen as compared with compacted heaps. 

 In general the effect of compacting is to delay rather than prevent 

 decomposition. By leaving it exposed to the weather we lost an 

 additional 8 % of dry matter, 33 % of ammonia in two experiments 

 and 10 % in another, and 21 % of total nitrogen in two experiments, 

 and 2 % in two others, as compared with sheltered heaps. Field 

 experiments showed that the crop producing power of the manure 

 was considerably lowered by exposure and that even a slight shelter 

 was beneficial^. 



It appears then that the heap is at best an imperfect method of 

 storage, but that its defects are lessened by keeping it compact 

 and sheltered, where it will neither be washed by rain nor suffer 

 too much loss on drying, and in particular by avoiding summer 

 storage. 



It is difficult to suggest any alteration in method of clamping that 

 would be a further improvement ; the best practical men have probably 

 developed the method as far as its fundamental imperfections allow, 

 and the only hope of further advancement seems to be in the wholly 

 fresh direction we suggest, — to set up some pit or tank where absolute 

 anaerobic conditions can be attained, and where the temperature can 

 be kept at 26° C. or thereabouts. This has been successfully done 

 for silage, the old stack silo having given place to the air-tight concrete 

 structure, and it may yet be accomplished for manure. 



2. Manure thrown out daily. From the start the conditions here 

 are aerobic, which, as we have seen, involve marked losses of dry 

 matter, of ammonia, and to a less extent of total nitrogen as well, 

 and these are aggravated when the heaps are thrown out in the open 

 and exposed to the washing of the rain and the drying effects of 

 the sun. 



Much can be done to improve matters by carrying the manure into 

 a shelter, such as the Cheshire dungstead, a structure like a small Dutch 

 barn surrounded on three sides by a low wall, the fourth being open to 

 allow the cart to back in, and compact the manure. The Oxford 

 manure house does not allow the manure to be so readily compacted. 

 It is probable that the dungstead could be improved in some details, 

 but at the best it still retains some of the imperfections of the clamp. 



We think the best prospect of dealing with manure from dairy cows 

 is to aim straight away at storage in a pit or tank ; but as no practicable 



^ Journ. Roy. Agric. Soc. 1917, 77, 1-3.5. 



