19 



MAGNESIUM SALTS AS FERTILISERS. 

 I^'ield experiments made in 1922 with magnesium sulphate in- 

 dicate that while apparently ineffective in ordinary conditions 

 (apart from the potash-starved plots at Rothamsted) , it has, in 

 certain farming conditions, a considerable fertilising value : — 



EFFECT OF MAGNESIUM SULPHATE ON THE YIELD OF POTATOES 

 RECEIVING POTASSIUM SULPHATE. 



(a) Sulplialf of potash used in complete manure. 



(b) Muriate of potash used in complete manure. 



We cannot at present explain this result, but the experiment 

 is being repeated. 



ARTIFICIAL FARMYARD MANURE. 



This material is now being made at a number of centres and on 

 a large .scale. Some 2,000 tons of straw, in lots varying up to 

 80 tons in quantity, have now been treated under the direction of 

 Messrs. E. H. Richards and R. L. Amoore on different farms in 

 the country — mostly in the Eastern Counties. The material has 

 been considerably improved by the introduction of phosphates, but 

 there remain difficulties connected with the wetting of the straw. 

 The product is not yet up to a good sample of true farmyard 

 manure, but it is being steadily improved, and the 1922 results are 

 distinctly promising. The following is a large scale test made by 

 the Chelmsford Institute with potatoes on an Essex farm :-^ 



It is also shown that this artificial farmyard manure does not 

 lose nitrogen on exposure to weather, while heaps of natural farm.- 

 yard manure under similar conditions lost as much as 10% to 30%. 



The development of practical applications of this kind involves 

 an immense amount of detailed work and a business organisation 

 differing entirely from that of an experimental station. Artificial 



