VI. 



MANURING AND GENERAL MANURES 



125 



Sea-weed, which is plentiful on some coasts, forms a cheap and 

 valuable manure. It has one great advantage its rapidity of decom- 

 position, which causes it to be a quick-acting manure. Its composition 

 may be gathered from the following analyses : 



I. Mixed weed from the Orkney Islands (Anderson). 



II. Rock -weed, American (Storer). 



III. Various varieties of Fucus (Marchand). 



IV. Mixed weed (American). 



From the above analyses it will be seen that sea- weed is compar- 

 able as a manure with farm-yard manure, being, however, slightly de- 

 ficient in phosphates. It has the advantage over farm -yard manure of 

 being more easily fermented and quite free from the seeds of weeds, 

 which are often abundant in the latter product. 



An account of sea-weed as a manure, giving analyses of many 

 specimens of different varieties and the relative values of it and other 

 manures, was given by Hendrick. 1 



The following is a brief summary of the analyses : 



In the field experiments it was found that sea-weed gave with 

 potatoes, quite as good results as an equal weight of farm-yard manure 

 and that the application of superphosphate further increased the crop, 

 confirming the statement just made that sea- weed is an excellent 

 organic general manure, though deficient in phosphates. 



Dried blood from slaughter-houses is occasionally used as a manure. 

 Sometimes the blood is simply evaporated at a steam heat, in which 



1 Transactions of the Highland and Agricultural Society of Scotland, Vol. X 

 (1898). 



