248 



Bulletin 247. 



soluble nitrogen may in the course of a month recover a sufficient concen- 

 tration of water-soluble nitrogen to grow cabbages successfully, assuming 

 the soil to contain a sufficient quantity of total nitrogen, ; and second that 

 a plant may under favorable conditions consume nearly all the water- 

 soluble nitrogen, so that crops on two soils having contained unlike 

 quantities of water-soluble nitrogen may grow unequally, consuming un- 

 like quantities and thus leaving the soil with like quantities of water- 

 soluble nitrogen. A statement of the soluble nitrogen in the two soils 

 just after they have raised, say, in one case six bushels of wheat and 

 in another case 30 bushels of wheat would, therefore, be as misleading 

 as to try to judge the contents of a man's stomach from the food remain- 

 ing on the table after a meal. Of what use can water-soluble nitrogen 



Fig. 85. — Cabbages grown on leached and unleached soils, i, Good soil unleached; 2, 

 " poor " soil unleached; 3, good soil leached; 4, poor soil leached. Soils in 

 bushels 2 and 4 contained high percentages of water-soluble nitrogen, while in 

 bushels I and 3 they contained low percentages. 



be to plants unless they use it? A man cannot expect to grow fat unless 

 he eats the food placed before him. If he eats it, the food will no longer 

 be on the table. 



Influence of nitrate of soda on water-soluble nitrogen ivhen applied to 

 timothy. 



To show that this is not theory as applied to plant growth under 

 field conditions the following experiment is here presented : 



To Plat 725 and 728 of our regular timothy fertilizer series were 

 applied on 17th of April, 320 lbs. nitrate of soda, 80 lbs. muriate of 

 potash and 320 lbs. acid phosphate. On May 8th, 320 lbs. of nitrate of 

 soda were also applied to plat 728. On May 31 and on July 11 the 

 latter being the date of harvesting, samples of soil were taken by Clark 



