410 THE MANGOLD-WURZEL CROP. 



tion of clay to give a moderate tenacity to the mass, and 

 to secure to the growing plant not only the mineral sub- 

 stances required for its structural development, but also 

 the amount of moisture necessary to sustain its functions 

 in a vigorous state during the whole period of its growth. 



Clay, we know, possesses these properties to a greater 

 degree than any of the other soil constituents; it usually 

 contains sulphates, phosphates, and potash; it possesses 

 the power of abstracting ammonia from the atmosphere, 

 and also of absorbing and retaining moisture all points 

 of direct importance to plant development, which is always 

 more or less affected in proportion to their absence or 

 presence in the soil. These necessary conditions are met 

 with probably to the least extent in the soils of the chalk 

 (upper) formation. They are generally shallow, deficient 

 in clay, and deficient in moisture; and consequently are 

 those least suited for mangold, which is rarely seen in 

 chalk districts presenting the same vigorous growth as it 

 exhibits elsewhere. 



The different habit of growth of the Long and of 

 the Globe varieties gives an opportunity of selecting 

 the most suitable for cultivation, according to the class of 

 soils in which they are to be grown. The Globe varie- 

 ties are those best suited for the strong clay loams 'or 

 for shallow soils ; the Long varieties for soils of medium 

 strength, or of greater depth. The first, perfecting their 

 bulk chiefly above the surface, are more readily lifted at 

 harvest from the stronger soils than the Long Red, which, 

 in such soils, owing to the fleshy brittleness of the roots, 

 are very apt to break off a portion of their lower end in 

 the ground; while the habit of growth of the Globe keeps 

 their roots nearer to the surface, and thus fits them for 

 cultivation in shallower soils than those of the Long varie- 

 ties, whose characteristic is to penetrate and develope them- 

 selves deep in the ground. Possessing this suitability, 



