THe CARBON DIOXIDE OF THE Sort AIR 343 
Per cent 
of COz 
4.6 
4.4 
‘4.2 
4.0 
3.8 
3 6 
3.4 
3.2 
3.0 
2.8 Villét or7 
2.4 
2.94% 
2.0 ® Wee é 
1.8 N jo% CO S01/ 
1.6 Ny 
1.4). 
11674 NN 
1.078 NO CTOL O”7 | 
0.8 N P21G/2 C O,.50// 
0.6 
0.4 
fvo coo Ov7 
0.2 ow CO, 50// 
wy) 
DA 
July August 
Fic. 58. RELATION BETWEEN THE AMOUNTS OF CARBON DIOXIDE IN AIR FROM CROPPED 
AND FROM UNCROPPED DUNKIRK CLAY LOAM HAVING HIGH AND LOW INITIAL CONTENTS 
OF CARBON DIOXIDE, RESPECTIVELY 
Per cent 
of CO2 
4.8 
SIMet croo, /WE——_— 
OAP COP, (P/F vee evene 
wWNWwWWwHnwwr PP 
D2KDOWNR AD WDONKROD 
ce 
SP esorvoe® 
4 3 2 c) 0 a 74 3 4 
Weeks before heading - Weeks after heading 
Fic. 59. RELATION BETWEEN THE AMOUNTS OF CARBON DIOXIDE IN AIR FROM DUN- 
KIRK CLAY LOAM CROPPED TO OATS AND MILLET, RESPECTIVELY, BEFORE AND AFTER 
THE CROPS HEADED 
