EFFECT OF THE NITROGEN IN THE MANURE. 285 



The one field at Oberbobritzscli received in the ground 

 rape-cake nearly double the quantity of nitrogen that the 

 other got in the guano, and the difference in the produce 

 of the two is in the highest decree strikinsr. 

 In the two experiments — 



The effect of the nitrogen in the guano was, accordingly, 

 in the cereals four times, in the potatoes twelve times, 

 and in the clover seven times, greater than that of the 

 nitrogen in the rape-cake. 



Upon comparing the increase of produce with the 

 amount of phosphoric acid in the two manures, we find 

 that this increase appears to bear some proportion, though 

 yet by no means a definite one, to the amount of phos- 

 phoric acid severally contained in them. 



Tlie general results of the experiments made, in a four 

 years' rotation, on four different fields at Cunnersdorf, 

 Miiusegast, Kotitz, and Oberbobritzsch, may be summed 

 up as follows : — 



The 48 harvests from the unmanured plots and from 

 those manured severally with bone-dust, guano, and 

 ground rape-cake, gave in rye grain and straw, in potatoes, 

 in oats grain and straw, and in clover, by manuring with — 



