No. 4.] MANURIAL PROBLEMS. 157 



The order of the three-year rotation* is as follows : first 

 year, potatoes ; second year, winter rye ; third year, clover. 

 Three plots are employed, and the crops were introduced in 

 such a way as to have all three continually represented. 

 The winter rye is usually sown in September after the 

 removal of the i)otatoes, and clover seed at the rate of IT) 

 pounds per acre is sown the next spring, preft^rably in March, 

 upon a light snow. The rye can be cut green for fodder or 

 for bedding, or it may be allowed to ripen, as has been done 

 in this instance. Even when the rye is allowed to ripen, a 

 small crop of clover hay is sometimes secured in the same 

 year, provided the season is a wet one ; but if it happens to 

 be extremely dry, there is great danger that the clover will 

 be largely killed the first season. Fortunately, this has 

 occurred but once since the experiment was begun, though 

 at least twice only small crops of clover have been obtained 

 the next year after the remova] of the rye. This was o wing- 

 to droughts at the period when the clover should have been 

 making its chief o-rowth. 



At the outset the following potato formula was used, at 

 first broadcast, but later one-fourth in the drill : — 



Manicres applied per Acre (^Poundf!) . 



Nitrate of soda, . . . . . . .105 



Tankage, 750 



Acid phosphate, t ....... 540 



Fine-ground steamed bone, . . . . .120 



Muriate of jjotash, ...... 300 



After the removal of the potatoes, and before seeding to 

 rye, 360 pounds per acre of fine-ground steamed bone are 

 applied. 



Nitrate of soda at the rate of 120 pounds per acre was at 

 first employed as a spring top-dressing for the rye after it 

 was well tillered. If applied earlier, it promotes greater 



* For a complete description of this experiment for the first two courses of the 

 rotation, see Bulletin No. 74, Rhode Island Agricultural Experiment Station, 

 November, 1900. 



t In some of the years the actual quantity of acid phosphate was changed, 

 but it was always made equivalent to the amount used above, with lo per cent 

 of available phosphoric acid. 



