Commercial Fertilizers . 1695 



At the time of sowing alfalfa recently, I used on an acre, 100 



pounds of nitrate of soda, 500 pounds of acid phosphate and 50 



pounds of potash. The percentage of the above mixture would be 



b(^- 



Per cent. 



Nitrogen 2 . 30 



Phosphoric acid 10.77 



Potasli 3 . 84 



The problem is solved as follows: 



Pounds Per cent. Pounds 



Nitrate of soda 100 15 15 



Phosphoric acid 500 14 70 



Potash 50 50 25 



Total 650 



We have here a mixture of 650 pounds of material containing 15 



pounds of nitrogen, 70 pounds of phosphoric acid and 25 pounds 



of potash. Divide the amount of each element by the total amount 



of the mixture and we have the per cent, of each. 



Pounds Pounds of material Per cent. 



Nitrogen 15 divided by 650 equals 2 . 30 



Phosphoric acid 70 divided by 650 equals 10. 77 



Potash 25 divided by 650 equals 3 . 84 



By this simple process the percentage of each element in any 

 mixture may be found provided the analysis of the materials is 

 given. 



When ready mixed fertilizers are used the farmer will, as a rule, 

 get more for his dollar if he purchases high-grade, readily avail- 

 able materials and uses less an acre, than if he buys the low-grade 

 goods and uses relatively more. Much of the nitrogen in low-grade 

 fertilizers is from sources which renders it very slowly available, 

 also each ton contains more filler or worthless material, than does 

 the high-grade goods. The price paid does not determine whether 

 a fertilizer is high or low-grade. Phosphoric acid in the form of 

 14 per cent, acid phosphate, which can be purchased for $12 to $14 

 a ton, is a high-grade fertilizer if it is all the soil needs for the 

 growing of the crop. 



My observation and experience lead me to believe that, where 

 lime or acid phosphate are used in fairly liberal quantities, for 

 most of the soils in New York State — especially the clay soils 

 — the purchase of more than a small amount of potash is not 

 economical, and in many cases no return is given for the expen- 

 diture. 



