PLANT rKKDlNG. 



11 



Manures or fertilizers may be so compounded as to 

 furnish th€ three important elements in any proportion 

 desired. 



Carriers of nitrogen. Nitrate of soda, sulphate of 

 ammonia and dried blood are commercial forms of fer- 

 tilizing materials that supply nitrogen only. The per cent 

 of nitrogen is shown in the following table : 



Material Per cent Xitrogen 



Nitrate of soda, 16 



Sulphate of ammonia, 20 



Dried blood, 14 



27. How many pounds of nitrogen in a ton of nitrate 

 of soda? 



Process : 2,000 X -16 = 320 



28. How many pounds of nitrogen in a ton of sul- 

 phate of ammonia ? 



29. How many in a ton of dried blood? 



30. When you apply 100 pounds of nitrate of soda to 

 an acre of land, how man\' 

 pounds of actual nitrogen are 

 applied ? 



Process: lUU X -ItJ = 16 



31. How many pounds of 

 actual nitrogen are applied 

 to the soil when a mixture of 

 50 pounds of nitrate of soda 

 and 50 pounds of sulphate of 

 ammonia is used ? 



32. How many pounds of 

 dried blood will be necessary 

 to increase the application to 

 30 pounds? 



With and \VnH>_/L. 1 ■.<.,.,.-. n. 



Wheat was used here as a soil- 

 ing crop. The plot at the left 

 made 4.6 tons to the acre, while 

 the one at the right having had 

 an application of nitrate of soda 

 produced 7 \2 tons. 



