98 CAMPBELL'S SOIL CULTURE MANUAL 



We have invariably found growth most rapid and the 

 plants most healthful when the soil was fine and firm 

 where the roots were growing, with 'the surface two inches 

 or more loose and open, and ample moisture stored below 

 to a depth of four or more feet, and this so long as there 

 is the required quantity of air and water in that portion 

 beneath the mulch where the principal feeding roots are 

 located. By the aid of heat chemical action is going on 

 and fertility is being made available in large quantities. 

 Now the great point is to keep up this kind of condition, 

 if it can be done through the growing season. Phenom- 

 enal results are sure to come, if there is not too much seed, 

 or some fungus or insect pest at hand. Too much seed 

 is very commonly the cause of a yield below the possible 

 result on soil ideally fitted and especially is this true of 

 oats and wheat. 



