170 



Manuring of Potatoes - 



and artificials against dung alone. At Garforth the plots 

 which received an application per acre of 4, 8, and 12 cwts. 

 respectively cf a complete artificial manure, along with 12 

 loads (about 9 tons) of dung, furnished, in each instance, a 

 larger crop of potatoes than the plot which received farmyard 

 manure alone ; but a fair money return was obtained only 

 from the use of 4 cwts, of the mixture, for although the 

 heavier dressings aug'mented the crop the extra cost of the 

 artificial manures outweighed the value of the additional 

 yield. Thus it was found that the addition of the first 4 cwts. 

 of artificials to the dung gave an increase of 25 cwts. in the 

 crop, but a further 4 cwts. of artificials returned only an 

 additional 8 cwts. of potatoes, while a still further increase of 

 4 cwts. of artificials (making 1 2 cwts. in all) secured an addition 

 of a further 6 cwts. only in the crop. 



In connection with this point reference may also be made to 

 the results recorded by Professor Patrick Wright. The chief 

 object of the Scotch experiments was to ascertain whether arti- 

 ficial manures could be partially substituted for farmyard 

 manure in the cultivation of the potato crop, and what manures 

 would be most suitable for the purpose. Certain plots were 

 accordingly manured with single dressings of dung alone, at 

 the rate of 20 tons and 10 tons per acre respectively, and the 

 yield from them compared with that obtained from a 

 plot dressed with 10 tons of farmyard manure supplemented 

 with 6J cwt. of a complete artificial manure. The 

 results showed that the substitution of a complete artificial 

 manure for the extra 10 tons of dung in the third case did 

 not succeed in producing quite so large a crop as that 

 obtained from the plot which received 20 tons of farmyard 

 manure alone. The difference was, however, so small as to make 

 it obvious that a slight increase in the artificials would have 

 given a crop as large or larger than that grown on the latter 

 plot, while the yield from the plot which received 10 tons of 

 dung was 28 cwts. per acre short of that furnished b}^ the 

 section dressed with dung and artificials. Moreover, regarded 

 from the points of view ot money returns the Scotch experi- 

 ments are held to have shown clearly that properly propor- 

 tioned dressings of artificial manures are capable of forming 



