AQUATIC PRODUCTS AS FERTILIZERS. 277 



those just thrown up by a storm, rather than those which have lain 

 on the beach for a considerable time. 



The large content of potash makes sea plants, particularly rock- 

 weeds, especially favorable to the growth of clover. Storer refers to 

 the abundant natural growth of red clover upon the tract of country 

 back of Rye Beach, Maine, which has been manured with these plants 

 since the settlement of the country. Seaweeds are also excellent for 

 wheat, and are used for parsnips, turnips, and to some extent for 

 potatoes, although it is claimed that they impart a somewhat unpleas- 

 ant flavor to the last-named. The general opinion in this country is 

 that potatoes grown with seaweeds are much less liable to be affected 

 by scab than those grown with barnyard manure, but they are less 

 mealy and of inferior flavor. « Seaweeds have been strongly recom- 

 mended for tobacco-culture, but owing to their effect on the quality 

 of the leaf, they are not much used for this purpose. They are also 

 highly recommended for cauliflower and cabbages. They act very 

 quickly, and the effect of their ai3plication is confined largely to the 

 season in which they are used, having little action upon the second 

 and succeeding crops. 



Owing to their small content of fertilizing materials and the large 

 amount of moisture, aquatic plants are usually rather exi^ensive for 

 fertilizer if long cartage is required, at least 4 tons of water being 

 transported for every ton of dry material. This limits their value to 

 the immediate vicinity of the beaches, and they are rarely used on 

 land more than 10 or 12 miles from the coast. 



However, the manurial value of seaweeds must not be regarded 

 merelj" from the point of view of the fertilizing agencies which they 

 contain. They have a mechanical action on the soil, tending to make 

 it friable and binding its constituents together; but the manufacture 

 of soil is rather expensive where there is so much good land avail- 

 able as in this country. They have an advantage over barnyard 

 manure in the freedom from seeds of land weeds. Formerly it was 

 considered desirable to apply the material in the form of a compost 

 with lime or gypsum, but experience of recent years indicates that it 

 does not pay as a rule to compost them, except possibly in case of 

 eelgrass and also rockweeds, to be applied as a summer or autumn 

 top-dressing for grass land.^ The usual practice in applying them is 

 to plow the seaweeds into the soil or to spread them upon the land as 

 a top-dressing, the plants being in either case in as fresh a state as 

 practicable. They also tend to prevent the crops from suffering from 

 summer droughts, grass fields dressed with seaweeds frequently 

 remaining green when adjacent fields are suffering. 



So important is the crop of seaweeds in the Channel Islands that 

 special laws are enforced to govern their collection and distribution. 

 The cutting of weeds from the rocks is restricted to certain seasons 

 comprising about four or five weeks each year. Those cast up on the 



"See Bulletin No. 31 of Rhode Island Agricultural Experiment Station, p. 20. i> Ibid p. 8. 



