38 



intrinsic value arising from situation, or other 

 local circumstances. It is commonly found that 

 what is termed exhausted, or worn out land, is 

 only in that condition a few inches deep, such 

 soils having usually been cultivated in a shallow, 

 and imperfect manner ; and below the four or five 

 inches to which the plough has penetrated, there 

 is frequently locked up a considerable store of 

 plant-food. In such cases deeper cultivation, 

 and a more intimate mixing of the soil will some- 

 times, witliout extra appliances, restore its lost 

 fertilit}^ Cultivation, of course, does not create 

 matter, but simplj' changes its mechanical and 

 chemical condition. It frequently happens that 

 soils considered infertile contain a sufficient 

 amount of plant-food in a dormant state, and all 

 that is required to bring it into a condition to 

 enter into the circulation of growing crops is to 

 admit freely air, warmth and moisture by means 

 of deeper cultivation. 



There are, how^ever, too many instances of 

 land being w^orn out by over-cropping, that deep- 

 er tillage alone will not be found sufficient, but 

 extra substances must be applied to the soil be- 

 fore its lost productiveness can be restored, hence 

 the necessit}^ and value of what are termed ma- 

 nures. It is in this department of husbandry 



