1920.] Farmyard Manure : Its Making and Use. 



445 



comes out quite right, because its valuable constituents are so 

 easily decomposable that they are readily lost. 



Although the dry matter of the urine forms only about 2 per 

 cent, of the actual weight of the dung, it constitutes a much 

 larger proportion of the weight of fertilising materials. A ton of 

 dung contains about 12 to 15 lb. of nitrogen, of which about 4 to 

 9 lb., according to the amount of cake and corn fed, would come 

 from the urine. 



2. Tlie Litter. — Straw is by far the commonest htter, and it 

 forms the chief part, by weight, of farmyard manure. Broadly 

 speaking, one ton of straw makes 4 tons of farmyard manure, 

 but the additional 3 tons is very largely v^•ater, only a ;^mall part 

 being other excretory substances. Of 100 parts cf farmyard 

 manure made in a bullock yard : — 

 75 are water. 



Abi)iU 2 are solid constituents of the liijuid excretions. 



About 8 are constituents of tliu solid cxc;etions. 



About 15 are constituents of the litter. 

 On the basis of bulk, therefore, litter is more impottant than 

 anything else, although not in other respects. It? chief effect 

 is that it forms the humus in the soil, and therefore helps to 

 promote tilth and to improve the water-holding capacity, ijnfor- 

 tunately, its change into humus is expensive to the farmer in 

 that the organisms effecting the change take up valuable nitrogen 

 com^pounds from the urine that ought to have gone to feed the 

 crop. 



The Making of Farmyard Manure — The simplest case is 

 that of manure made from fatting bullocks in stalls or 

 covered yards where the manure is of considerable value, 

 and where pains are commonly taken to preserve it. 

 Of every 100 lb. of nitrogen fed to the animals, about 95 lb. 

 pass into the manure — often about 45 to 60 lb. m the liquid 

 and 50 lb. to 85 lb. in the solid excretions. The 45-60 lb. are in 

 a form highly valuable to the plant. The decomposition process, 

 however, takes rather a heavy toll, in one way or another about 

 15 lb., leaving 30 to 45 lb. in a form really useful to the 

 plant. The nitrogen in the solid, and such of this 15 lb. as is 

 not altogether lost, may at some time become useful to the plant, 

 but it does not count for much : only the 85 to 40 lb. balance 

 can be relied upon to yield any profit. 



When, as often happens, the manure is nuule in open yards, 

 the loss becomes more serious. The minimum loss of 15 per 

 cent, is exceeded, often nuuh exceeded, and, as always, it falls 



