1024 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



In order to examine the results obtained on the continuously undunged 

 plots, it is necessary to state separately the average results obtained during 

 the first five years and during the last three years, as the dressings on the 

 undunged land have been increased during the last three years. The 

 results obtained in the case of these plots are shown in the following 

 table : — 



JERUSALEM ARTICHOKES. 







Average wei 



glit of roots 





Annual cost 



or tubers 



per acre 



Annual manuring per acre. 



of manure 













per acre 



Five years 

 (1894-1898) 



Three years 

 (1899-1901) 





£ s. d. 



tons cwt. 



tons cwt. 



50 loads (25 tons) London Dung (applied to 









previous crop) ....... 



25 loads (12^ tons) London Dung (applied to 



nil 



10 2 



13 12 











nil 



7 12 



11 9 



No Dung to previous crop ; Phosphates (no 









Potash) and 4 cwt. Nitrate of Soda (applied to 











2 15 0 



7 10 





Ditto, ditto (with Potash) 



3 5 0 



9 18 





No Dung to previous crop ; Phosphates (no 









Potash) and 8 cwt. Nitrate of Soda (applied to 











4 15 0 





8 9 



Ditto, ditto (with Potash) 



5 5 0 



- 



11 7 



The results, on the whole, appear to indicate that, if the market 

 gardener has been extravagant enough to use as much as 50 loads of 

 dung per acre for any other crop, and wishes subsequently to grow 

 Jerusalem Artichokes, he had better plant them there without further 

 manuring, since on land thus manured chemical fertilisers have not, on 

 the average of our experiments, produced any material increase in yield. 

 The results obtained in 1900, it is true, showed an advantage from the 

 usual chemical fertilisers, but the increase was not sufficient to affect the 

 average of years. 



The general results of our manuring experiments, however, as will be 

 seen over and over again in the course of this report, indicate that heavy 

 dunging of this kind is, for most crops, wasteful and unprofitable, and 

 that a much lighter dressing of dung, supplemented by chemical fertilisers, 

 is the best application ; and when land is farmed on this principle it would 

 appear that the most economical crops of Artichokes are raised by a simple 

 dressing of phosphates (say 4 to 6 cwt. of superphosphate) with 1 cwt. of 

 sulphate of potash (or 4 cwt. of kainit) per acre, with a top dressing of 

 2 cwt. of nitrate of soda per acre. 



When, however, we have to deal with land that has not been previously 

 dunged, the nitrate of soda may be increased to 4 cwt. per acre. 



The effect of potash on this crop is remarkable. On the average of 

 eight years, the use of potash has produced an increase in the weight of 

 tubers per acre amounting to nearly a ton in one series of plots, and to 

 nearly three-quarters of a ton on another series, even on the dunged land. 

 On the plots on which no dung has been applied during the whole of the 

 series of experiments, the use or omission of potash has made a difference 



