158 AGRICULTURE 





Where farmyard manure is not available, 

 cases become more numerous where potash 

 will justify its inclusion in an artificial dress- 

 ing, and yet even under these circumstances 

 and assuming that the land is grazed by 

 stock during autumn and winter potash 

 will often be found to have very little effect. 

 One of the most conclusive experiments 

 bearing upon this point is that which has 

 been going on for fifteen years at the Nor- 

 thumberland Experimental Farm near 

 Morpeth. Two sets of plots on that farm 

 are separated by a highway ; and on one 

 side are the rotation experiments, which 

 demonstrate in the most convincing manner 

 that without farmyard manure a turnip crop 

 practically cannot be grown in the absence of 

 potash. On the other side of the road are 

 the permanent grass plots, where not only 

 does the addition of potash to phosphates, 

 with or without nitrogen, produce no increase 

 in the hay, but its tendency on the whole is 

 markedly in the direction of reducing the 

 yield. The reduction of yield as a result of 

 using potash is specially striking where this 

 substance is used alone or in the presence of 

 nitrogen only. On these plots it is only 

 when potash is added to phosphates, without 

 nitrogen, that a small increase in the yield of 



