9Q THE SOIL. 



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 influence upon the 

 physical condition of the soil far outweighs, for the wheat- 

 plant, the injurious effect of the decrease in the quantity 

 of the chemical conditions resulting from the previous 

 turnip and clover crops. 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 pulverisation 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 productiveness 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 fi'om 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 portion circulating 

 in it. A great many fields unsuited, by their constant 

 humidity, for the cultivation of cereal plants and the 

 superior kinds of forage grasses, have been reclaimed by 

 drainage, and made fit to produce food for man and beast. 

 Wlien the farmer, by means of drainage, keeps within 

 bounds the amount of water in his fields, he controls its 

 injurious influence at all seasons ; and by the speedier 

 removal of the water, which soaks the earth and destroys 

 its porosity, a path is opened for the au" to reacli the 

 deeper layers of the ground, and to exercise upon these 

 the same beneficial influence as upon the surface soil. 



In winter, the earth at a depth of 3 or 4 feet is warmer 



