158 • BOARD OF AGRICULTURE. [JclH., 



Other source. Next to this comes nitrogen in nitrate of soda. 

 Owing to the availability of nitrogen in nitrate of soda and 

 to the facility with which it can be mixed with other fertilizer 

 without deterioration, it is probable that for general use nitrate 

 of soda will maintain its lead as a source of nitrogen as plant 

 food. 



In considering this problem the question arises is there not 

 some practical source from which the farmer may reduce 

 gradually the amount of nitrogen purchased as a fertilizer 

 from year to year until finally he will be required to purchase 

 only potash and phosphoric acid. When we compare the 

 prices of these other fertilizers with nitrate of soda, we see 

 that potash can be purchased for 4^-2 cents a pound, that 

 available phosphoric acid can be purchased for about 5 cents 

 per pound. These prices, compared with the cost of a pound 

 of nitrogen would naturally tend to bring about the use of 

 fertilizers relatively rich in potash and phosphoric acid and 

 should lead us to seek home sources of nitrogen. 



It may not be out of place to discuss briefly here the home 

 sources of nitrogen and means by which the nitrogen may be 

 preserved and used in actual farm practice. It is well known 

 that by the growth of legumes as a cover crop we can capture 

 some of the nitrogen of the air and incorporate it in the plants' 

 structure and that these plants in decaying give up their 

 nitrogen to succeeding plants. This fact has been known for 

 years, and attention has been called to it so many times that 

 it would seem almost unnecessary even to mention it again, 

 and yet as a matter of fact the growth of legumes is not nearly 

 so general as it should be. The practice has become so general 

 of purchasing the nitrogen from commercial fertilizers and 

 paying the bill after the crop is harvested that nothing except 

 the rise in price of nitrogen from commercial sources will lead 

 our farmers generally to consider the home supply of nitrogen. 

 Many will hesitate to pay $8 or $9 per bushel for clover seed. 

 even though as a result of the use of that clover seed nitrogen 

 to the value of $100 or more may be secured. 



Farm manure as a source of nitrogen is worthy of most 

 serious consideration. Where large amounts of concentrated 

 foods are used as in this state, the manure is especially rich 

 in nitrogen. This element, however, is so elusive that as the 

 manure pile is ordinarily handled, much of this nitrogen is lost 



