crops and thereby have greater profits. This information 

 is best obtained first hand through experience and ob- 

 servation from the use of various fertilizer constituents 

 on particular crops. A demand for special grades of 

 fertilizers would be quickly met by the manufacturers. 

 The writers have reason to believe that for certain crops 

 most of the increased yield is produced by some one fer- 

 tilizer constituent, Under such conditions the cost of the 

 ineffective constituents is such as to wipe out or reduce 

 the profits that might otherwise be obtained. There are 

 now on the market many fertilizers for special crops. The 

 fact that a fertilizer is a "Special for Potatoes" by name 

 may offer no recommendation or argument for its pur- 

 chase for that purpose. The same material may be of- 

 fered, under a different name, for corn or some other crop. 

 Also the consumer should not lose sight of the fact that 

 potato fertilizers vary widely in their compositions. It is 

 well enough to keep the name of the brand in mind, but 

 it is of much more importance to scrutinize the guarantee 

 and at the same time bear in mind the needs of the crop 

 and soil in the light of experience and observations. 



Nitrogen is the most important fertilizer constituent 

 and unfortunately the most expensive. Most of our New 

 Hampshire soils are relatively poor in organic matter and 

 therefore deficient in the amount of nitrogen which can 

 be made available for crops. In many localities cultiva- 

 tion of the soil has been neglected and bacterial action has 

 become limited. Because of these conditions fertilizers 

 rich in nitrogen are generally more effective than others. 

 On the other hand, our soils are very rich in potash. It 

 so happens that potash is the least expensive of the fer- 

 tilizer constituents and for some crops the least effective 

 when used as a fertilizer. Under some conditions where 

 cultivation is good the returns from the use of potash 

 fertilizers are very slight. Because of these conditions 

 and facts the writers wish to point out the necessity of 



