The Canadian Horticulturist. 275 



SEA- WEED AS A FERTILIZER. 



Sir, — Will you please tell me if sea-weed is a good fertilizer, and, if so, whether for 

 fruit or vegetables ? 



Sea-weed, Vancouver,, B. C. 



Reply by F. T. Shutt, M.A., Chemist, Dominion Experimental Farjfis, Ottaiva. 



3^ 



EA-WEED is essentially a potassic manure, though in a certain 



) degree it may be termed a " complete fertilizer," viz. : one that 



a supplies the three more important constituents of plant 



J^^ growth — nitrogen, phosphoric acid and potash. 



^VX-^ An analysis recently made of a sample of sea-weed (Fucus 



furcatus) obtained from the Atlantic coast, afforded me the 



following figures : — 



Analysis of fresh Sea-weed. 



Water 63 49 



Organic matter, containing nitrogen 27.93 



Ash or mineral matter, containing potash and phos- 

 phoric acid • 8.58 



100.00 



Pounds of fertilizing constituents in one ton of the fresh 

 Sea-weed. 



Nitrogen pounds 9.36 



Phosphoric acid »» 2.18 



Potash t. 40.50 



Sea-weed is a valuable manure both for the potash and nitrogen it contains, and 

 for the ease and rapidity with which, by fermentation, this plant-food is con- 

 verted into soluble and available forms. Its ready decomposition in the soil 

 (except in very wet or very dry seasons) is of great advantage, since the sea- 

 weed requires no previous treatment and its results are obtained in the first crop. 

 Its. application often improves the tilth of soil by supplying decomposing organic 

 matter (humus) and increasing their absorbtive capacity for moisture. 



Seaweed gives best results on an open, porous, sandy, warm soil, and may 

 be applied at the rate of 20-30 tons per acre. For general farm crops it may be 

 supplemented by bone meal and wood-ashes. It may, of course, be used alone 

 for all purposes (though then there is apt to be a deficiency in phosphoric acid) 

 or with barnyard manure.. 



In a light soil it is a responsive though not a permanent fertilizer, since its 

 readily soluble constituents easily leach away. 



