16 DEPARTMENT OP AGRICULTURE. 



Example. Formula selected : Strawberries 3-9-12. 



Quantity to be used: 500 Ib. 



Amount of actual nitrogen to be supplied: 3 per cent, of 500 = 15 Ib. 



Amount of actual phosphoric acid : 9 per cent, of 500 = 45 Ib. 



Amount of actual potash to be supplied : 12 per cent, of 500 = 60 Ib. 



If the composition of fertilizers used to supply the three plant foods are : 

 - Nitrate of soda, 15 per cent, nitrogen ; 

 Superphosphate, 16 per cent, available phosphoric acid ; 

 Muriate of potash, 52 per cent, actual potash, 



15 Ib. nitrogen will be supplied by 100 Ib. nitrate of soda. 



45 phosphoric acid supplied by 45/16x100 = 280 Ib. superphosphate. 



60 potash supplied by 60/52 X 100 = 115 Ib. muriate of potash. 



The fertilizer formula for the crops given are compiled for average conditions. 

 On heavy soils well supplied with lime the proportion of the potash may be decreased. 

 On soils that have an excess of vegetable matter the nitrogen proportion may be 

 decreased. If clovers or other legumes are included at short intervals in a crop- 

 rotation the amount of nitrogen that is necessary to apply may be materially 

 decreased. 



The commercial value of fertilizers varies from year to year. This variation 

 must be considered when a fertilizer formula for any crop is selected. For example, 

 the present price of potash is so high that it would probably be wise to reduce the 

 amount of potash in the formulae listed until the price returns to normal. 



Soil conditions are so variable in the Province of British Columbia that it would 

 be unwise to lay down any hard-and-fast formula. Every farmer should attempt 

 to determine the fertilizer formula that suits his particular soil and crop needs. 

 This may 'be done 'by selecting a uniform field and applying different fertilizers and 

 fertilizer mixtures in a manner that the comparative yields resulting therefrom can 

 be easily determined. 



VICTORIA, B.C.: 



Printed by WILLIAM H. CULLIN, Printer to the King's Most Excellent Majesty. 



1921. 



