FORTY-FIRST ANNUAL CONVENTION 149 



This principle, however, of going out on to tlie open nicirket 

 and providing ourselves with a commercial fertilizer with which 

 to meet the drain on our soil, does not apply to the element 

 nitrogen, tor the very good reason that the price of commercial 

 nitrogen is so great that the increase in the yield due to its use 

 would not pay its cost under ordinary farming conditions. Be- 

 sides, clover and all other legumes have the power to obtain ni- 

 trogen from the air for us free of charge, so we would not be 

 justified in endeavoring to maintain our supply by use of com- 

 mercial fertilizer regardless of its cost. 



This makes the problem quite complicated, for here w'e 

 have to deal with nature, and nature always has a peculiar habit 

 of making things complex. 



Many practical results have been reached, however, and for 

 these we are indebted in no small way to the Illinois Experiment 

 Station. The tables set forth, as accurately as the present the- 

 ories on the subject will permit, gain or loss of nitrogen under 

 previous rotations and systems of farming. Yields of loo bush- 

 els of corn, loo bushels of oats, 50 bushels of wheat, 4 tons of 

 clover and 8 tons of alfalfa are equally as large as those of the 

 other crops. One may divide the yields of all the crops men- 

 tioned by two, which will make the column of "Lbs. N. required" 

 only half as great, but the column of 'Xbs. N. recovered" will 

 likewise be only half as great, so the same proposition will hold. 



In the first column of the tables will be found the crop re- 

 quirements, and in the second column I have assumed that where 

 the crop or any portion of same was fed, one-fourth of the ni- 

 trogen contained therein has been retained by the animal- body 

 and consequently only three- fourths of the original supply of 

 nitrogen will be returnable to the soil. Though the loss of nitro- 

 gen due to the exposure of manure is frequently of considerable 

 consequence, I have assumed no loss from this source. Under 

 ordinary farming conditions this loss may easily reach 50^^, so 

 it w^ill be well to keep this point in mind, when considering the 

 tabled. 



Gain or loss of Nitrogen under various rotations and sys- 

 tems of farming: 



