No. 4.] 



MANURIAL PROBLEMS. 



Ifil 



The great increase of straw in the second cour-se of rota- 

 tion is doubtk^ss attributable in part to the general improve- 

 ment of the soil, but primarily to the increased supply of 

 assimilable nitrogen, — a condition undoubtedly brought 

 about by the clover and the general system of manuring and 

 cropping. 



The results with clover were as follows : — 



First Course of Rotation. 



Second Cotn'se' of Rotation. 



Plot 11, 

 Plot 14, 

 Plot 13, 



The small crop in the year 1895 was readily accounted for 

 by injury to the young plants by drought in 1894. Since 

 clover can assimilate atmospheric nitrogen, an increase of 

 soil nitrogen is of no particular advantage to it except in the 

 earliest stages of its growth. The chief factors determining 

 the success or failure of this crop are the temperature and 

 moisture. The original system of manuring apparently 

 required a change in the amount of potash used for the sake 

 of the clover crop, which led to a special application of 

 potash for this crop. It will be remembered that only 300 

 pounds of muriate of potash were used at first per acre in 

 any case, and then only with the potato crop. It seemed 



* Crop injured by drought during June. During this month the rainfall 

 amounted to but .77 inches ; in June, 1896, it amounted to about 5 inches; and 

 in June, 1897, to 4.43 inches. 



t Crop much injured by severe early drought. 



X Plants destroyed by the drought in 1899, consequently there was no crop. 



