158 BOARD OP AGRICULTURE. 



succession. It is generally admitted as a rule of practice 

 that there is, ordinarily, no profit in attempting to grow 

 wheat two years, or, at the furthest, three years in succession 

 on the same soil. It is admitted to be a good plan generally 

 not to grow any crop more than two or three years in succes- 

 sion. Even our natural grasses are included in this rule, al- 

 though in some particular localities they do well indefinitely. 

 We have indeed natural meadows and pastures which are as 

 old as the memory of man and just as good now, for aught 

 that can be seen, as they ever were. But even in the case of 

 natural pastures we know that " circumstances alter cases." 

 Each farm, perhaps, may have some low-lying piece of moist 

 land occasionally flooded by a river, where grass can be cut 

 year after year, year after year. Then we have uplands which 

 must be broken up once in a while ; they get " hide-bound," 

 and the grass runs out. These facts are familiar to you all, 

 and illustrate the broad statement that there are some soils 

 where the same crops can be cultivated for a succession of 

 years and other soils on which rotation is quite indispensable. 

 There are soils where clover has been grown once in three 

 years for a very long period. I have in mind a valley in the 

 Austrian Tyrol — the valley of Saint Martin — where this has 

 been done. No one living can remember the time when this 

 practice was not followed on certain parts of that valley. 

 They have a marl which is regularly put upon the land, and 

 by its use the clover crop continues undiminished from gene- 

 ration to generation. Its growth there is also very luxuriant, 

 the ordinary clover stems being five or six feet in height. 

 This is a very remarkable case of natural clover ground kept 

 unexhausted by a native fertilizer. But the land of Mr. 

 Lawes, adjoining the fields where he raised wheat without in- 

 terruption for twenty-seven years, would not carry clover ex- 

 cept at quite long intervals. Mr. Lawes made a series of 

 experiments on this land, beginning in 1848 and going on un- 

 til 1860, in which he applied stable dung, coleseed cake, su- 

 per phosphate of lime, sulphates of potash, soda, and mag- 

 nesia, sulphate and muriate of ammonia, soot, and fresh 

 burned lime, singly and in various combinations. The fol- 



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