288 THE TURNIP CROP. 



able of being grown, the turnip cannot, of course, be so 

 readily placed between two straw crops; its cultivation, 

 however, can be so arranged as to place it between two 

 crops belonging to different orders, and having different 

 food requirements from the soils, and different habits of 

 growth to itself. This is best secured by taking turnips 

 after oats and following them by beans. The deep and 

 careful tillage the root crop receives, the cleaning opportu- 

 nities it affords, and the large quantity of rich nitrogenous 

 manure it leaves behind, are all excellent preparatives, 

 which rarely fail to tell beneficially upon the succeeding 

 bean crop. In all cases, and with all crops, it should be 

 remembered as a rule that the longer interval we can 

 arrange between their cultivation on the same soil, the 

 greater the chances of freedom from disease and insect 

 ravages. Therefore, we should always bear in mind the 

 desirability of substituting, whenever we can, other crops 

 having the same economic uses and value, but different 

 habits and growth requirements. The importance of this 

 rule is as marked in regard to turnips as to any other crop, 

 as will be seen presently when we come to discuss the dis- 

 eases to which the plant is liable. Fortunately, we have 

 at hand a good substitute for turnips in the shape of man- 

 gold, which possesses equal value to the farmer, and indeed 

 offers many advantages for sharing with the latter one- 

 half of the root-acreage of our farms. If this plan were 

 generally carried out, it would act beneficially on both 

 crops, as it would at once double the length of time (inter- 

 val) between the recurrence of the same crop on the same 

 field, and thus materially lessen the chances of injury, 

 whether from disease, insect attacks, or climatal influences. 

 At the same time, the labour arrangements of the farm 

 would be rather relieved and benefited by it, as the man- 

 gold crop is got in earlier than the turnip ; and although 

 stored away in the same manner and at an earlier period, 



