ing the actual content of Nitrogen, phosphoric acid, and p£^ ts for 



potash by the trade value for these constituents in mixed 



fertilizers, we find that there is an actual difference of 22 7 

 nearly $14 in their commercial values, whereas the diff- 

 erence in price made by the manufacturer is only $5. 



The fertilizer materials in the higher priced fertiliz- 

 ers are about thirty-three per cent, cheaper than those 

 in the lower priced article. 



As a general rule the more concentrated the form 

 of fertilizing materials in commercial fertilizers, or the 

 higher the grade of unmixed raw materials purchased 

 by the farmer for home mixing, the greater will be the 

 saving in actual cost. 



The higher the grade of materials the less will be 

 the expense for freight, mixing, and spreading upon the 

 land. 



There are these decided advantages about the mix- 

 ing of materials at home, viz., each raw material can 

 be separately examined, and if there is any cause for 

 suspecting inferior forms of Nitrogen, phosphoric acid, 

 or potash, samples may be sent to the State Experiment 

 Station for analysis. The detection of error or fraud 

 is more certain and much easier in unmixed raw 

 materials than in mixed fertilizers. Another important 

 advantage of home-mixing is the opportunity afforded 

 the intelligent farmer to adapt the composition of a 

 fertilizer to the special soil requirements of his land and 

 to the wants of the crop to be grown. And, lastly, home 

 mixtures have, as a rule, proved to be much cheaper 

 than ready-made fertilizers. However, the economy of 

 home-mixing should in every instance be determined by 

 actual calculation. 



Nitrogen, phosphoric acid, and potash, as we have 

 already seen, are necessary for the complete develop- 

 ment of farm crops, and are the constituents most likely 

 to be deficient in cultivated soils; different crops have 

 different capacities for consuming these plant foods, so 

 that when no increase in crop production follows a 

 rational application of one, two, or all three of these 

 constituents the soil evidently contains them in suffi- 

 cient stores to develop crops to limitations fixed by 

 season and existing climatic conditions. By a careful 



