246 



Bulletin 247. 



Wheat was then grown by the basket method in so called good and poor 

 soil and in good soil to which sufficient nitrate of soda was added to give 

 it the same water-soluble nitrogen as the poor soil : 



Table XIV Gives the Green Weight in Grams of 30 Wheat Plants by Basket 

 Method Under Each of the Various Treatments, as Determined by 

 Reid. 



Check 



320 P 



80 K 



160 N 



320 P + 160 N 



160 N+ 80 K 



320 N+ 80 K+320 P 

 Average 



Whatever else may be said of these figures, it must be admitted that 

 when the water-soluble nitrogen was made equal, the growth of wheat 

 seedlings was equal, while where the amount of water-soluble nitrogen 

 was unequal the growth was unequal. 



It is just as easy for me to believe that the cause was a direct one 

 as an indirect one. 



The question still remains unsettled, however, as to why- these spots 

 of soil refused to grow crops, in the one case mangel wurzels and cab- 

 bages and in the other case timothy. Was it due to the excess of water- 

 soluble nitrogen or did the fact that crops failed to grow and thus failed 

 to consume the water-soluble nitrogen, cause it to accumulate in the 

 soil ? Were the water-soluble salts the cause or the result of such failure ? 

 I think the latter is probable and that, therefore, the cause for the 

 failure of these areas to grow the crops mentioned is yet unsolved. 



The temporary fluctuating character of water-soluble nitrogen. 



I shall now proceed to detail some experiments showing the tempor- 

 ary character of water-soluble nitrogen and the influence of vegetation. 

 In his investigations last winter, Clark extracted the water-soluble salts 

 from the good and poor cabbage soils by the stirring of a quantity of 



