398 



Artific ial Farmyard Mant're 



Aug . ^ 



ARTIFICIAL FARMYARD MANURE. 



H. B. Hutchinson, Ph.D., and E. H. Kichards, B.Sc, F.I.C. 



Rothamsted Experimental Station. 



As a consequence of the campaign for increased food produc^ 

 tion during the War, and the resulting extension of the area, 

 under cereal crops, it was thought that, even after making 

 allowances for disposal through the usual channels, there might 

 still remain a surplus of straw which could not be utiHsed for feed- 

 ing or for conversion into manure. It was therefore determined to- 

 investigate the possibility of converting straw into manure with- 

 out the intervention of live stock, and a special grant in aid of 

 the investigation was made to the Eothamsted Experimental 

 Station by the late Food Production Department. Apart from 

 war conditions, the possibihty of adding to the supply of organic 

 manure deserves consideration. In the case of market gardens> 

 particularly, the difficulty of obtaining adequate supplies of stable 

 manure is increasing. The investigations described below indi- 

 cate a method by which straw can be converted into a substance 

 having many of the properties of stable manure. Further 

 experiments to test the economic value of the process when 

 conducted on a large scale are in progress at Rothamsted. Ijord 

 Elveden has also generously provided assistance and facilities 

 for experimental work on his Pyrford Estate. 



Of a considerable number of preliminary experiments to secure 

 obvious breakdown and colour changes in fermenting straw, the 

 most promising results were obtained when straw was subjected 

 to the action of a culture of aerobic cellulose-decomposing 

 organisms (e.g., Spirochaeta cytophaga). Further enquiry 

 showed, however, that this effect was not due simply to the 

 provision of an organism capable of breaking down cellu- 

 lose, but rather to the indirect effect of the mineral sub- 

 stances contained in the culture fluid. From this point on, the 

 question of food supply — as distinct from the addition of any 

 particular species of organism — received special attention, and,, 

 as will be seen later, led to results possessing both theoretical 

 and practical importance. 



Without entering into a detailed account of the various stages 

 of the investigation, we may state here that the most essential 

 factors making for the production of well-rotted artificial farm- 

 yard manure are air supply, suitable temperature, and a suitable 

 supply of soluble nitrogen compounds. 



