18 



CANADIAN FARM YEAR BOOK. 



Relative "Supply and Demand" of Seven Elements. 



Essential Plant Pounds in two Pounds in 100 Number of years' 



Food Elements million of the bushels of com supply indicted 

 average crust of (Grain only) 

 the earth 



Phosphorus 2,200 



Potassium 49,200 



Magnesium 48,000 



Calcium 68,000 



Iron 88,600 



Sulphur 2,200 



Nitrogen in air 70 million 



pound over one 

 acre 



100 



700,000 



Two million j>ounds are taken as 

 corresponding to the weight of the 

 soil of the plowed acre of average 

 land to the depth of 6 2-3 inches. 

 Consequently, the table simply gives 

 the amount of plant food contained 

 in an acre of land of plowed sodl, if 

 It represents the average composition 

 of the solid crust of the earth. Corn 

 has been used by Hoplfins in his oal- 

 culatiO'n because it is the most im- 



Barnyard Manure. 



One ton of manure will contain: 

 9 to 15 lbs. of Nitrogen. 

 9 to 15 lbs. of Potash. 

 4 to 9 lbs. of Phosphoric Acid. 



Farmyard manure, in fermenting, 

 should not rise above 30 degrees C. 

 (86 degrees F. ) in temperature; keep 

 cool with liquid manure. Humic and 

 ulmic acids are formed, which unite 

 with and fix the ammonia and potash. 

 Ferrous sulphate added forms am- 

 monic sulphate and ferrous carbonate 

 — bo'th plant foods. Gypsum prevents 

 the waste of nitrogen; and kainit, if 

 added, will fix the ammonia. 

 Green Manures. 

 Plow deep, using jointer and drag 

 chain, if necessary, to bury well. Firm 

 soil after plowing. 



To Calculate Manure Production. 

 Fresh manure is made up of 



poitant crop iu America. It is evi- 

 dent that there is probably no culti- 

 vated soil whose composition is ex- 

 actly the same as the average of the 

 earth's crust, yet the data given in 

 the table serves to show the relative 

 abundance of the elements, and, if 

 some soils are richer, others are cer- 

 tainly poorer, and, further, that there 

 is plant food for many crops, and, in 

 the case of most of the elements, for 

 many h ndreds of crops. 



% dry matter and % water and in 

 order to calculate the manure a cow 

 will make one-half the dry substance 

 in the fodder must be multiplied by 

 four. 



This cut shows water holding capac- 

 ity of a soil. 



