Rural School Leaflet. 



707 



you have a fertilizer anal3zing two per cent, of nitrogen, eight per cent, 

 phosphoric acid, and ten per cent, potash, i. e., a 2:8:10 fertilizer. 



Problem j. — What materials and how much of each would be needed 

 to make a fertilizer that would analyze 3:7:12? 



At the College of Agriculture, two tons of manure that had been 

 weighed and analyzed, were left exposed from April 25 to September 22, 

 with the following results: 



April 2 5 Sept. 22 



Pounds Pounds 



Total weight 4>ooo 1,730 



Nitrogen 19-60 7.72 



Phosphoric acid 14.80 7.79 



Potash 36 8.65 



717 



No treatment 



3S20 lbs. hay per acre 



716 

 160 lbs. nitrate soda 

 320 lbs. acid phosphate 

 5820 lbs. hay per acre 



715 

 160 lbs. nitrate soda 

 5590 lbs. hay per acre 



Fir,. 41. — Nitrate of soda greatly increases the yield of tiiiiotliy hay on the 

 College of Agriculture farms. Bulletin 241. 



Problem 4. — What was the value of the nitrogen, phosphoric acid, and 

 potash in the above table on April 25 and on September 22? Use the 

 values found in Problem i. How much was lost? There are two ways 

 to prevent most of these losses — the manure may be hauled and spread 

 on the land every few days, or it may be kept in a covered shed. 



A good fertilizer for timothy hay on the College farms has been found 

 to be one containing 200 pounds of nitrate of soda, 100 pounds of acid 

 phosphate and 50 pounds of muriate of potash per acre. 



Problem 5. — How much would this cost per acre? 



Problem 6. — What percentage of nitrogen, potash anrl phosphoric acid 

 would this fertilizer contain? 



