70 



60 



50 



40 



30 



20 



10 



- 



1 D I 



X 



T — 







.y"^^ ^ 









y^ cy 







—^^ 



^ 







^^7 



^ 







>>^ 



^ 







^r^ 



^ 







^r 



^ 







^r 



■^ A^ 





" 



^^ 



y ^^ fT" 



— 





/ ^O' 



^^^-^^^^Cf^ 







V/ -" /y- 



^^""^ ^^^ 







^r / ^^^ 



^^ 







/ -S^^"' 



^ 





















- 



I^V/^^ 





. 



v 





No Aeration 





) 



/£/ O Na^ 



Aeration 





-[■ 



LfOt 





- 



t 



y A K^ 



No Aeration 





1 



5 D K^ 



1 1 1 



Aeration 



_J_ 



16 



20 



24 



Figure 28. 



8 12 



Hours 



Experiment 3. Effect of aeration on net loss of 

 sodium or potassium from roots during exposure 



to 0.5-mM NH4CI. 



54 



