FAVOURABLE ACTION OF CLOVER AND TUENIPS. 97 



has been taken, may possibly give as fine a succeeding 

 cereal crop as a field of equal extent in which the lu- 

 pines have been ploughed in. 



All these observations tend to show the great im- 

 portance of the mechanical conditions which impart fer- 

 tility to a soil not originally deficient in the means of 

 nourishing plants ; and that a comparatively poorer but 

 well-tilled soil, if its physical condition is more favour- 

 able for the activity and developement of the roots, 

 may yield a better harvest than richer land. In like 

 manner, it often happens that the cultivation of a bulb- 

 ous plant renders the ground better suited for a follow- 

 ing cereal, and that a winter crop succeeding a green 

 forage plant, turns out all the better, the richer the 

 previous green forage crop has been, or rather the roots 

 left by it. 



Clover and turnips act favourably upon a succeed- 

 ing winter crop, as their long hardy roots move the 

 subsoil, which is inaccessible to the plough, and open 

 it for the roots of wheat. Here the favourable influ- 

 ence upon the physical condition of the soil far out- 

 weighs, for the wheat-plant, the injurious effect of the 

 decrease in the quantity of the chemical conditions re- 

 sulting from the previous turnip and clover erops. 

 Facts of this nature have but too often misled practical 

 agriculturists to surmise that the physical condition is 

 everything, and that a thorough working and pulver- 

 isation of the soil will suffice to command a good crop. 

 These views, however, have always been refuted by 

 time ; and all we can consider established is this, that 

 for a series of years the restoration of a proper physical 

 condition in the soil is as important for the productive- 

 ness of many fields as manuring, and often more so. 



The influence of a proper physical condition of the 

 soil upon the produce can hardly be more convincingly 

 proved than by the facts which agriculture has derived 

 from the drainage of land, under which we comprise 

 the removal of the subsoil water to a greater depth, and 

 the quicker withdrawal from the arable soil of the por- 

 tion circulating in it. A great many fields unsuited, 



