30 



T. Lyttleton Lyon and James A. Bizzell 

 TABLE 7 (continued) 



Date 



Plat 711 



Plat 720 



Plat 728 



Plat 729 



Un- 

 planted 



Planted 



Un- 

 pl anted 



Planted 



Un- 

 planted 



Planted 



Un- 

 planted 



Planted 



July (continued) 

 9 





"2l'0 



26'4 



"23'6 



"23^0 

 ' 2l'3 



23.4 

 "23;4 



26^4 

 "22^6 



" 2L9 

 26.7 



"23^3 



22.6 

 "24;2 

 "26^8 

 "24^2 



23'l 

 25.6 



"22^4 



23'4 



"25^0 



31^7 



24^6 



"23^8 

 "24^0 



"2L7 



"23^8 



3L9 



"24^3 



"23^1 

 "24^6 



» 

 "28^2 



"23;0 



"27^2 



20.0 



"2L7 

 "22^1 





11 







13 



26 1 



16 



24.5 





18 





20 







21 





22 6 



23 



24 



28.0 





25 





. 



27 





26 7 



29 



24.5 





30 





31 







August 

 3 





19 6 



5 



6 



21.0 





8 







11 







12 





21 3 



14 



18 



23.4 





19 







20 





21.7 









It is seen from these tables that, while there is considerable range in 

 the maximum and minimum moisture contents of these plats, the changes 

 are not rapid; at least, the drying-out process is slow, and it is the drying 

 that causes aeration in soil. Furthermore, it is quite apparent that on 

 the maize soil, in which nitrification is most active, the changes in the 

 moisture content of the cropped soil do not differ greatly from those 

 on the uncropped soil on the same dates. It is also very evident that 

 the changes in the moisture content continue throughout the summer, 

 and should therefore induce nitrate formation during the ripening stage 

 of the crop growth as well as in the early stages; while Table 2 shows that 

 nitrate production is greater on the planted soil only during the earlier 

 stages of growth. 



