So far as potatoes and mangolds are concerned, results vary somewhat. The 

 potato harvest shews a slight improvement both from a potassic dressing and from 

 a nitrogenous dressing, as against no manure; but here again the full advantage of 

 the potash could not be derived in the presence of insufficient nitrogen, and 

 contrariwise the action of the nitrogenous fertiliser was hampered considerably by 

 the absence of an adequate store of soluble potash. Only where potash and 

 nitrogen were applied together, was a really distinct improvement to be observed. 

 The effect of potash on the crops is easily seen from the photographs, the foliage 

 being of a much lighter shade where potash has been applied, and the green a 

 much yellower one. Best of all perhaps is this brought out by the plot which 

 received potash alone. The complete manured, the potash-nitrogen, and the 

 potash-phosphoric acid plot illustrations are, however, also very characteristic, and 

 especially so if placed alongside those of the dark-green foliaged nitrogen and 

 phosphoric acid plots. 



The experimental field, which is rich in potash shews, that in the case of mangolds, 

 the demand of which for large quantities of potash is now an accepted fact, 

 the influence of nitrogenous manuring exceeds by far, the influence of potash 

 manurmg. 



From this we may readily infer, that the powers of mangolds for obtaining potash 

 from the soil are much greater than those of potatoes; for whereas in the case 

 of mangolds, practically the full yield is obtained where a nitrogenous fertiliser 



- 45 — 



