THE ADAPTATION OF THE PLANT TO THE SOIL. 



13 



On the size of the particles, whether fine ones or coarse ones pre- 

 dominate, depend such fundamental facts as how the soil will work, 

 whether light or heavy, how soon will it he fit to work after rain, 

 whether it will be cold and late or warm and early, its drought-resisting 

 power, &c. The size of the particles making up the soil regulates, 

 in fact, the water supply, and that is the biggest factor in producing 

 a crop. If we now put together the mechanical analyses of all the 

 soils on which fruit is found to grow successfully we shall find great 

 similarity of type, whatever may have been the geological origin of the 

 soil. For example. Table IV. shows the analyses of such a series, in 

 which it will be seen that the good fruit soils all contain more than 

 12 but less than 17 per cent, of the very fine material which an 

 analyst calls clay, and which does more than anything else to form 

 the character of the soil. In all the soils, again, we find sand and silt, 

 generally to the extent of from 60 to 70 per cent, of the whole, but as a^ 

 rule there is not much coarse sand present. By way of contrast the 

 analyses of two or three other soils are added. At one end of the 

 scale come soils so light that they are only suited to strawberries or 

 nursery stock which is not required to stand more than two or three 

 years in the same place. On the heavy soils, at the other end of the 

 scale, only occasional apple orchards occur, and are so unhealthy that 

 they would be commercially unprofitable. Thus, by the consideration 

 of such a map and of a long series of analyses of the soils in the district 

 covered by the map it becomes possible to formulate the mechanical 

 composition of what we may call a fruit soil, and again by the analysis 

 of any unknown soil to decide whether it is fit for fruit-growing or not, 

 provided the other conditions of exposure and elevation are suitable. 



Table IV. 



Mechanical Analysis of Fruit Soils. 



Formation 



Bagshot 

 Sand 



Thanet 

 Sand 



Thanet 

 Sand 



Brick 

 Earth 



Lower 

 Green- 

 sand 



Chalk 



Clay 

 with 

 Flints 



Hast- 

 ings 

 Beds 



Weald 

 Clay 



Locality 



Wis ley 



Swanley 



Selling 



Wick- 

 ham 



East 

 Farleigh 



Minster 



Molash 



Rolven- 

 den 



Sutton 

 Valence 





Only 

 Nursery 

 Stock 



Straw- 

 berries 



Mixed 

 Fruit 



Mixed 

 Fruit 



Mixed 

 Fruit 



Mixed 

 Fruit 



Cherries, 

 Apples 



Apples, 

 Black 

 Currants 



Apples, 

 Bad* 



Fine gravel 

 Coarse sand 

 Fine sand . 

 Silt . 

 Fine silt 

 Clay . 



0-1 

 18-1 

 70-1 



3- 8 



4- 1 

 3-8 



1-3 

 10-9 

 62-3 

 14-2 

 5-4 

 5-9 



0-8 



5- 3 

 60-3 

 15-4 



6- 2 

 12-0 



0-4 

 0-9 

 32-4 

 46-7 

 8-4 

 11-2 



2-7 

 10-9 

 35-3 

 22-8 

 12-9 

 15-4 



0-7 



9-7 

 38-3 

 27-9 , 



7-4 

 160 



1-4 

 1-6 

 39-2 

 29-2 

 11-9 

 16-7 



0-4 

 0-7 

 27-3 

 33-3 

 21-9 

 16-4 



2-3 

 4-4 

 12-5 

 15*1 

 25-9 

 39-8 



* This soil is really too heavy for fruit, though apple orchards are found upon it. 



When we turn to other crops we find similar correlation between 

 their distribution and the mechanical composition of the soil. The maps 

 (figs. 9, 10, 11) and Tables V. VI. VII. show this in the case of hops 

 and barley and potatos. A plant which is grown on such a scale must 



