COMPOSITION OF SOILS. 15 



crop of fruit can be grown unless the soil itself, or the 

 manure which is applied, contains nitrogen. 



That substances rich in nitrogen increase the verdure, 

 darken the foliage-colour, and generally promote and 

 prolong the growth of the trees is a recognised fact. 



Lime is found in all fertile soils, and, indeed, it enters 

 into the composition of every kind of plant and animal. 

 And experience teaches us that it forms a very neces- 

 sary element in all successful fruit growing, and more 

 especially in the production of stone fruit. In its more 

 common form it tends to strengthen the stem and woody 

 portion of the tree, generally shortens the period of 

 growth, and hastens the time of ripening. 



Hence we find that retentive clays that contain little or 

 no lime in their composition extend the period of growth 

 and ripening, with the result that some of the strong 

 growing varieties do not properly mature their wood or 

 ripen their fruit, and are most easily affected by frost. 



On the other hand, in a shallow, moderately light soil, 

 say from fifteen to twenty inches deep, which rests upon 

 a subsoil of chalk, marl, or loose rock, the growth of a 

 fruit tree will be moderate, the shoots short and sturdy, 

 and the fruit well ripened. 



A careful examination of the most successful vinej'ards 

 and fruit orchards on the Continent will show that the 

 greater part of the soil consists of argil-calcareous or 

 argillaceous gravel. 



The vineyards of the Rhine are all planted upon thin 

 soils, with rocky foundations, bnt sparingly covered with 

 soil. 



COMPOSITION OF SOILS. 



The following particulars as to the constituents of Cali- 

 fornian soils may be of interest. 



