1907.] The Value of Poultry Manure. 725 



from fowls or ducks. An interesting point is the large amount » 

 of phosphoric acid found in duck manure, which, together with 

 the nitrogen, explains why pastures upon which these birds are 

 kept afterwards produce the finer grasses. The tendency of 

 nitrogen is to stimulate the growth of the grasses, the coarser of 

 which tend to crowd out the finer grasses as well as the clovers ; 

 whilst phosphoric acid promotes growth of the clovers. Practical 

 experience has shown the great value of duck manure in the 

 improvement of pastures. 



; Relative Values. — By comparison of the figures already given 

 as to : quantities produced by A and B, and the values as re- 

 vealed by analysis, it will be seen that in the case of stock 

 at liberty the average value of the manure per fowl is is, id. per 

 annum. Hence, as experience has shown that at least forty 

 birds can be kept on an acre of land without interference with 

 growth of herbage or danger of disease in the birds, and a larger 

 number on arable land, the manure produced, where the land is 

 cropped in rotation, would more than pay the rent during the 

 time of occupation. Where portable houses are used, more 

 especially those without floors, no special care need be taken, as 

 the rnanure will be evenly distributed, but where gathered from 

 permanent buildings it is necessary to preserve it as described 

 below. From the analysis of I. and II. it will be seen that 

 the latter contains very much more moisture, but the air- 

 dried samples differ to a very small extent either in composition 

 or value. 



As might be expected, the value of the manure from birds 

 caged for fattening is high, owing to the nature of the food sup- 

 plied. As these birds are only kept in this way for three weeks, 

 no estimate can be made on the annual basis. In three weeks, 

 as seen above, a fattening fowl produces 5 lb. 8 oz. of moist 

 manure, or of dry matter i lb. 10 oz. On this basis the value 

 of the manure of each bird during the fattening stage of its 

 existence works out at O'pqd., from which it may be estimated 

 that 408 fov/ls undergoing this process will produce a ton of 

 moist manure of the value of £\ 12s. 5d. If to the excreta is 

 added that produced during the growing period, it will be seen 

 that up to the time of killing (sixteen weeks) each bird gives 

 nearly 10 lb. 13 oz. of moist manure ; its value will be r88d.. 



