24 



month and presuiacibiy lh» NO should have been also, Was 



3 



th6r« an increan© in NO^ ^^.^ shown in th-^ table which 

 cauB&d 6 greater consumption of HPO^.? And HPO. being the 

 lusB diffusible, ie it improbable that for a short period 

 it wiiS the limiting factor rath'sr than N0„ ? In general 

 the ^IP04 decreases with th€i depth, but would not s-tjera to b© 

 a limiting fiactor except possibly in August. 



The results (Pu. Soils 26, 47) On the PoccosaTz. soil 

 show a decided faxi in NO3 in the surfae-? four feet, not- 

 withstandm'? an increase in aoistur® as show^i in Tabl« Xl> 



Table X/ : Moisture and NO3 Content in Poccosan Soil 



Whdra Corn was Growing, 



Date Moisture NOg WPO4 

 % pp 4 HJ pp. 4 in 



May 30 1823 65.34 36.94 



Aug. 27 2065 11. ^ 14.20 



In a wood«^d tract of large trees on Goldsboro compact 

 sandy loam, thr NO- lowers vt»ry much mor^ rapidly than the 



o 



moisturw m ^ach of thfe surface four feet of soil (Eu. 

 Soils 26, 45). The fourth foot, just referred to above, 

 is drained as completely of its NO^ ^^ ^v,^ eurf^c© foot. 

 The difference to which the roots penetrate, perhapa at least 

 is a factor in causing tli* variation. The HPO4 is much 



