READY-MIXED FERTILIZER 



107 



or some higher grade. It is suggested that several problems like the 

 preceding be worked in class, either by dwelling long enough on this 

 lesson, or by substituting this class of problems for the usual lesson in 

 arithmetic. 

 ADDITIONAL PROBLEMS : 



(1) What is the commercial value of a ton of complete fertilizer con- 

 taining 8 % available phosphoric acid, 3 % nitrogen, and 3 % potash ? 



(2) How much nitrate of soda, kainit, and 16% phosphate contain 

 the same amounts and kinds of plant-food as the ton of the fertilizer 

 just mentioned? 



(3) What would this mixture cost with acid phosphate at $15, 

 nitrate of soda at $55, and kainit at $14 per ton? 



(4) How much 16% phosphate, cotton-seed meal, and muriate of 

 potash would afford the same number of pounds of each plant-food as 

 one ton of the fertilizer mentioned in first problem ? 



(5) Which should a farmer buy, muriate of potash at $55 per 

 ton, or kainit at $14? What would a pound of potash cost in each? 



(6) Which should a farmer buy, acid phosphate containing 16% 

 available phosphoric acid, costing $14 per ton, or a lower grade con- 

 taining 12%, costing $12 per ton? What does a pound of available 

 phosphoric acid in each cost? 



FIG. 67. NODULES ON A LEGUME, AIDING THE 

 FARMER TO SECURE NITROGEN 



