SALT MARSHES OF EUROPE. 331 



of cultivation. One portion of them is characterized by a 

 calcareous clay ; the other, by a light, sandy soil. The former 

 runs along the coast of the North Sea, beginning on the 

 border of France, and extending to the mouth of the river 

 Scheldt. This belt is from one and one-half to two geo- 

 graphical miles wide, and covers an area of about 250,000 

 acres. The same material which caused the formation of 

 these lands in former days, is at present still accumulating 

 within the small marine inlets in their vicinity. The surface 

 of the soil reaches here but a little above the plane of an 

 average low tide. Extensive sand-bars, supported by well- 

 constructed dikes, exclude the sea-water. Sluice-gates dis- 

 charge the fresh water into the ocean during low tide. 



Stock-fattening, on account of favorable markets, is here 

 still the leading agricultural industry. Wherever the sod has 

 been turned, for a general mixed system of cultivation, most 

 excellent crops, of various kinds, have been raised, — usually 

 without any particular application of manures for a term of 

 from five to six years. , 



The following system of rotation of crops is a very com- 

 mon one in that locality : Barley, or rape ; beans ; wheat ; 

 beans; wheat; clover; potatoes; turnips; oats; winter 

 fallow with manure ; and, about every ten to twelve years, 

 grass for several years. 



In the districts between Courtray and Mastricht, where a 

 light, sandy soil largely predominates, both barn-yard manure 

 and vegetable compost are largely used. 



A system of ditches, containing fresh water, supplies the 

 soil under cultivation with a suitable periodical amount of 

 moisture. The crops are selected, as far as practicable, with 

 reference to an accumulation of organic matter within the 

 cultivated soil. Two crops are usually raised during one 

 season. These lands sell at present frequently from $170 to 

 $180 per acre, which is about ten times their original value. 



The sea-marshes of Schleswig-Holstein contain a great 

 variety of soils, which, as a general rule, are noted for their 

 superior productiveness. The differences in the soil here are 

 mainly clue to a varying relative proportion of but a few min- 

 eral species. Forchhammer, who first carefully studied the 

 salt marshes of his home from a geognostic-agronomic stand- 



