FERTILIZERS. 



The following table will assist in determining the plant-food values of farm 

 manures : 



NITROGEN MANURES. 



The following table is a list of the commonest nitrogen manures found on the 

 market : 



The first four fertilizers are vegetable products. On account of their value as 

 food for live stock they are not frequently sold as fertilizers. 



From the fifth to the thirteenth are animal by-products. The chief characteristic 

 of the group is that the nitrogen content is very variable. In purchasing the precau- 

 tion should be taken of securing a guaranteed analysis. Their value should be 

 based upon the pounds of nitrogen they contain. The nitrogen in groups 1 and 2 is 

 not so available as the nitrogen in the group of chemical fertilizers. For this reason 

 they should be used when a nitrogen-supply is desired throughout the season. Dried 

 fish-meal is frequently quite rich in phosphoric acid. The content of phosphoric acid 

 varies, depending upon the quantity of bone ground up in its manufacture. If the 

 bone content is low the phosphorie-acid content is low. In the purchase both 

 elements must be considered in estimating the cost. 



The guanos also vary greatly in both nitrogen and phosphoric acid. It is 

 largely a question as to where the guano has been collected that determines its 

 analysis. A guarantee is a safeguard to the purchaser. 



Of the chemical fertilizers, ammonium sulphate and nitrate of soda are the two 

 commonest on the market. Ammonium sulphate is considered the best to apply 



