FERTILIZING AND FERTILIZERS 



other things, is going to branch out and become a real 

 scientific agriculturist who wants to know everything? 

 And then besides, who can know too much, even though 

 he is but a beginner? 



It is only recently comparatively, that investigators 

 have been led to believe that plants give off certain 

 organic substances during the processes of growth 

 which, accumulating in the soil, are harmful to the 

 successive growth of plants of the same kind. This 

 may be the reason, or one of the reasons, why the bene- 

 fits of crop rotation are so marked : the soil is freed from 

 the toxic matter emanating from one species in the 

 three or four years during which other crops are 

 grown upon it. Sometimes not often to be sure, 

 but sometimes poor and sterile soil may be poor 

 and sterile because thus poisoned. 



But that is a big subject and such a condition 

 will hardly occur in even a very advanced beginner's 

 garden. So one need not to go into the matter at 

 first. However, remember it if later experience ever 

 brings you the baffling problem of a soil that con- 

 sistently and obstinately produces only failure under 

 every kind of manipulation. There are such soils 

 that will not yield nourishment enough to sustain plant 

 life but happily they are being studied and experi- 

 mented on until the reasons for their sulkiness stand 

 small chance of remaining secret much longer. And 

 every State Agricultural Experiment Station is ready 

 to give anyone who may ask all the information which 

 they have acquired on the subject or to go farther 



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