300 Practical Farming 



SOME GENERAL CONCLUSIONS ABOUT FERTILIZERS 



The mixtures on the market known as commercial fer- 

 tiHzers are of use in furnishing in a concentrated form the 

 three elements that are most generally deficient in old 

 cultivated soils, nitrogen, phosphorus, and potassium. 

 These are furnished in combination with other matters, 

 since the pure elements cannot be used. 



The notion that some have formed that the commercial 

 fertiUzers are merely stimulants, has arisen from the in- 

 judicious way in which they have been used merely to get 

 a httle more sale crop from the soil by adding a dribble of 

 the fertiUzer, which is all taken up by the crop and the soil 

 further drawn upon so that the soil is left poorer than 

 before. Where Hberally used to increase the growth of 

 the renovating and nitrogen-storing crops of the legume 

 nature, these fertiUzers can be used for the increase of the 

 fertihty of the soil. 



Lime and plaster, the sulphate of lime, are more in the 

 nature of stimulants, since they serve to unlock plant food 

 already in the soil so that plants can use them, and they 

 bring about changes in the mechanical texture of the soil, 

 and are active in the promotion of the nitrification of 

 organic matter in the soil, and thus enable the plants to 

 get the nitrogen in an available form. Their office in the 

 soil is as reagents rather than fertiUzers. 



An application of fertilizers to every crop grown may 

 show an apparent profit, but an accurate account with the 

 crops win show that such a course is wasteful and ex- 

 pensive, and that the true use of the commercial fertiUzers 

 is to keep up the store of phosphoric acid and potash in 



