284 GROUND RAPE-CAKE. 



Increase of produce over the xmmanured field (see p. 190). 



Here, again, we see, as in the case of farm-yard 

 manure, guano, and bone-dust, that on no one field did 

 the effect of the rape-cake bear any visible proportion or 

 relation to the quantity used. 



1000 Ihs. of ground rape-cake gave increase of produce 



These experiments are interesting in reference to the 

 effect of the nitrogen supphed in the manure. A com- 

 parison of the increase of produce obtained at Ober- 

 bobritzscb, severally by guano and ground rape-cake, 

 gives the following result in this respect : — 



