CHAPTER VIII 

 Organic Manures 



Need to ascertain their Relative Value. 



Organic manures, including farmyard manure, are 

 of great utility, because in addition to the fertilis- 

 ing substances they contain in a more or less 

 assimilable form, they also give humus, which is 

 indispensable to agriculture and the advantages 

 of which will be shown later. They are therefore 

 very valuable. It is essential, however, to ascertain 

 their relative value before buying them, because 

 some of them really contain very little fertilising 

 matter, and for that reason are scarcely worth the 

 cost of transport. In others the fertilising matter 

 exists in a badly assimilable form. This again 

 lessens their value. Others lose their fertilising 

 matter in storage. There is also a need, perhaps, 

 to take precautions against the possibility of 

 adulteration especially in the higher priced manures, 

 and to get a guarantee of origin or of the form 

 in which the fertilising agent are present, if 

 necessary. 



They are chiefly used m the maufacture of com- 

 pound manures. 



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