Food for ]\[o. I has a commercial value of less than ^24, while No. 



^"^^ 2 has a commercial value of nearly ^37 per ton; or in No. i 



170 we are asked ^1.50 per 100 pounds for a fertilizer worth 



about $1.16, and in No. 2 we are asked ^1.75 per 100 pounds 



for a fertilizer worth ^1.85. 



The fertilizer materials in the higher priced fertilizers 

 are about thirty-three per cent, cheaper than those in the 

 lower priced article. 



As a general rule the more concentrated the form of fertiliz- 

 ing 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 mixing 

 of materials at home, viz., each raw material can be sepa- 

 rately 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 require- 

 ments 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 deter- 

 mined by actual calculation. 



Nitrogen, phosphoric acid, and potash, as we have 

 already seen, are necessary for the complete development 

 of farm crops, and are the constituents most likely to be defi- 

 cient in cultivated soils; different crops have different capac- 

 ities 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 sufficient stores to develop crops to limita- 

 tions fixed by season and existing climatic conditions. By 

 a careful study of the capacities of different crops for using 

 Nitrogen, phosphoric acid, and potash, we may, within rea- 

 sonable limits, approximate the quantities, which, under 

 average conditions of crop, soil, and season, should be 



