100 CAMPBELL'S SOIL CULTURE MANUAL 



This fact must be kept in mind that, speaking in 

 every-day terms, there is a distinction between fertility 

 and available fertility. Perhaps it is better stated that 

 the only kind of fertility that the farmer cares for is that 

 which is available, and he has little concern for any fer- 

 tility that is supposed to rest within the soil unless he 

 possesses the secret of making it useful in increasing his 

 crop yield. So it is that in speaking of fertility we wish 

 to be understood as referring to available fertility, 



A CONDITION OF THE SOIL. 



Soil fertility is not something that is a part of the soil- 

 A very good soil may have little or no fertility available. 

 It is a thing apart from the soil, to be placed there or to 

 be developed there, through a condition of the soil due 

 to a combination of causes. And it is just to bring about 

 this condition that the farmer tills his land. The pur- 

 pose we have in scientific soil culture is to develop fertility 

 by and through creating within the soil a condition favor- 

 able to this development. The reader will find in this 

 Manual a great deal about the treatment of the soil to 

 conserve the moisture and to give it the proper amount 

 of air, and to guard against drouth, and to keep the soil's 

 physical condition right all looking to development of 

 soil fertility. 



That soil fertility depends a great deal more upon the 

 condition of the soil than has been commonly believed 

 is now coming to be accepted by many of those whose 

 positions entitle them to consideration. Prof. L. H 

 Bailey, of the Cornell University experiment station, a 

 man always fair and always in the front rank, has de- 

 clared that "the texture or physical condition of the soil 

 is nearly always more important than its mere richness in 

 plant food. 77 In explaining why a finely divided, mellow; 



