

ROOT-CROPS. 27 



only a larger proportion of edible root, but that root contains 

 a larger proportion of solid matter or food-material. 



As with the Norfolk white, however, so also with the Composi- 

 Swedish turnip, the leaf contains a much higher percentage tion . °f , 

 of dry substance than the root, and the dry substance of the Yeavesqf 

 leaf contains a much higher percentage of both nitrogen and Swedes . 

 total mineral matter than does the dry substance of the root, 'turrdps. * 



The lower division of the table shows, when compared 

 with the corresponding particulars relating to the Norfolk 

 white turnip, that with the Swedish turnip there was, with 

 the highest manuring, fully one and a-half time as much dry 

 substance per acre in the root — that is, one and a-half time as 

 much food produced per acre as with the common turnip. 



Further, there is a quite insignificant amount of matter 

 accumulated and remaining in the leaf, for the most part only 

 serving as manure again. 



Of the nitrogen, again, there is, under all conditions of 

 manuring, even those giving the greatest luxuriance, a very 

 small proportion remaining in the leaf. The same is the case 

 with the total mineral matter. 



The question obviously suggests itself, If the Swedish tur- Superiority 

 nip has all these advantages over the numerous varieties of °f Swedes - 

 the so-called common turnip, why are these ever grown ? 

 why not always the Swedish turnip ? 



In the first place, soil and season have to be taken into why other 

 account. Then the economy of the farm requires that de- vaneties 



• j • i i i i i i i i ii .are grown. 



scriptions should be selected that can not only be sown in 

 due succession, but which will mature at different periods, so 

 as to supply food for stock in due succession, and also fre- 

 quently to get the crop early off the land, to leave it free for 

 some other crop. Again, a comparatively large proportion of 

 leaf serves as protection against frost while the crop is still 

 in the field ; and the storing qualities of the root have to be 

 considered in connection with the character of the seasons of 

 the locality. For example, on the light soils of Norfolk, 

 which are very favourable for the development of root, and 

 but little for that of leaf, and where the roots can be largely 

 consumed by sheep on the land without injury to its me- 

 chanical condition, the Swedish turnip is the predominant 

 root. In the north-east and east of Scotland, on the other 

 hand, several varieties of yellow common turnips are grown 

 in much larger proportion, and a large amount of leaf is not 

 recognised as a disadvantage. And here it may be observed Production 

 that, the higher the nitrogenous manuring, and the heavier ^T' 

 the soil, the greater is the tendency to produce a large amount leaf. 

 of leaf. Further, as a rule the larger the amount of leaf re- 

 maining vigorous at the time the crop is taken up, the less 



