134 NATURAL MANURES. VI. 



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

 II. Eock 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 

 comparable as a manure with farm-yard manure, being, how- 

 ever, slightly deficient 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, by Hendrick, appeared in the Trans- 

 actions of the Highland and Agricultural Society of Scotland, 

 Vol. X. (1898). 



The following is a brief summary of the analyses : 



Black wrack. Drift weed. Dulse. 



Collected at Helen sburgh. Stonehaven. Turnberry. Oban. 



Water 70-78% 74-99% 79-00% 78-20% 



Organic matter ... 23-08 ,, 19-15 ,, 14-49 ,, 17*23 ,, 

 Ash ... ... 6-14,, 5-86,, 6.51,, 4-57,, 



Phosphorus pentoxide 0-09,, 0'09 ,, 0-18,, 0-07,, 

 Potash ... ... 1-38,, 0-85,, 1-69,, 1-67,, 



Nitrogen ... ... 0'76,, 0-51,, 0-62,, 0'74,, 



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 case the residue can easily be ground to 

 powder. Sometimes the clot only of blood is employed, the 

 clot being produced either by simple separation by a filter or 

 settling, or by the addition of acid or iron salts to the blood. 



The following table will show the fertilising value of various 

 commercial forms : 



