43 



The aXtemat© iaov®iB©nt of the water urpward ana doiraward 

 perhaps explains the sudden increase of soluble nitrogen 

 noted at times iate in the season. Where rain occurs after 

 an accumulation on the surface of nitrates derived either 

 from the soix or from an artificial application, the nitrates 

 bi^ntpath th© surface wixl increasa. Probably if the soil 

 siflmple includ^i-s the surface eoil, ruoh sti<^</eya, fluctuations 

 would not occur. There lis, however, another possibility 

 in a high rate of nitrification du© to a good moisture and 

 te^erature condition. If the plants should cease to use 

 soluble nitrogen sone time previous to taking the soil eample, 

 there would b© an additional cause for an increase of this 

 constituent. 



