17 



CHLORIDES AND SULPHATES AS FERTILISERS. 



Farmers now have the choice of muriate or sulphate of 

 potash : and they can also have the choice of muriate or sulphate 

 of ammonia. The experiments with potassic fertilisers are de- 

 scribed under M Potatoes." Our experience with the muriate of 

 ammonia is that it is less effective than the sulphate for potatoes 

 but more effective for barley. The difference depends on the 

 rainfall during the months of March, April and May and becomes 

 less as the rainfall increases. The average of all the results at 

 Rothamsted has been as follows : — 



1924 



Effectiveness of muriate when that of 



Sulphate = 100 Corn ... 



Potatoes 

 Rainfall — March, April and May (inches) 



104 



100 



8-95 



*Crop almost failed ; 2 tons per acre only. 



The chloride of ammonia has had a remarkable effect on the 

 grain of barley as is described below. 



BARLEY. 



During the past three years an extended investigation into 

 the effect of manures on the yield and quality of barley has been 

 carried out at Rothamsted and on certain good barley farms in 

 various parts of the country, the work being done in connection 

 with the Research Scheme of the Institute of Brewing. The 

 variety grown is Plumage Archer, and seed from one and the 

 same field was used at all the centres. 



The results show a considerable degree of concordance among 

 themselves, but they differ in several important respects from 

 the current teachings of agricultural science. It is usually recom- 

 mended that the manuring for barley should be mainly phosphatic, 

 nitrogen being given only after a corn crop and potash but rarely. 

 Out of 30 different tests this recommendation would have involved 

 loss of money in no less than 26. The actual yields are given 

 on p. 114; the average reduction in yield in bushels per acre, 

 consequent on the omission of each fertiliser during the three 

 years 1922, 1923 and 1924, has been :— 



(The figures in brackets are increases and not decreases.) 



