Field Experiments with Fertilizers. 329 



was far ahead of the other fertilizers. This result may be due in 

 part to the useful bacteria possibly in the manure, or to the effect 

 of the manure on the physical qualities of the soil, such as its tex- 

 ture, its temperature, etc. 



Many other illustrations might be given of the value to the farmer 

 of this kind of experimentation, but lack of space forbids. 



Injury caused by fertilizers. — As already stated in this bul- 

 lel,in, not all the experiments were entirely successful. In some 

 cases the plats were too small, in others not enough care was taken 

 in mixing the fertilizers thoroughly with the soil ; the result was 

 either a partial injury to the crop, or killing it completely. Such 

 injurious effects were especially noticeable with the muriate of pot- 

 ash and nitrate of soda. The superphosphate did not seem to cause 

 any damage even when applied very close to the plant or in large 

 quantities, even at the rate of two tons per acre, as in some cases by 

 mistake. Superphosphate may therefore be used very carelessly 

 without doing any harm, while great care must be exercised in the 

 application of nitrate of soda or muriate of potash. 



Does it pay to use commercial fertilizers ? — This question 



is frequently asked by farmers, but it is a question that can be 



answered only by the questioners themselves. They, only, know what 



the purchased fertilizers cost them ; they, only, can know or they 



ought to know what increase of crop is yielded by the fertilizers 



applied, and how much money they have received for such increase. 



As a rule, they know only wiiat they have paid for the fertilizers, 



and how many bushels or tons of their crops they have harvested ; 



but they do not know how many bushels or tons are to be credited 



to the fertilizers, for they do not know how much the soil will yield 



without any fertilizer, or with stable manure. Neither do they know 



what the stable manure has cost them. Furthermore, since as a rule 



they use complete fertilizers, containing all three of the plant-foods, 



nitrogen compounds, potash and phosphate, therefore they do not 



know whether any increase in crop is due to the action of all three 



of the plant-foods, or to two of them, or to one only. In the case 



of several of the series of experiments that have been carried out 



under the supervision of this Station, it has been conclusively shown 



