Lecture 4 



79 



Movement and Distribution 



(c) nutrients were available only during a 12 hour 

 dark period in each 24 hours. During periods of ex- 

 clusion of nutrients, the roots were immersed in dis- 

 tilled water. 



The plants were grown in a greenhouse for three- 

 week periods according to this plan, in both summer 



30 



SO 



a; 



!s;«o 



<n 



a 

 < so 



S 



d 



5 40 



z 



530 

 o 



'20 



10 



WINTER 



1-1 



L 



i 



SALT SUPPLY (UNAERATtO) 



.Ig H.RS,,fj)(;Ht 



12 HRS. DM 



SUMMER 



■-1 



I 



Co 



i 



30 



20 



10 



l 

 rTO 



60 



-40 

 30 



a> 



10 



pq. 



ASH 



ORGANIC 0"'' 

 MATTER WEIGKT 



Textfigure 21. — Total amounts of nutri- 

 ents under several conditions as explained in 

 text. These plants called "unaerated" actually 

 had access to considerable oxygen, but did not 

 receive forced aeration. The general conclu- 

 sions are similar for other sets receiving such 

 forced aeration. (From Beoyer and Hoag- 

 land) . 



and winter seasons. They made excellent growth with 

 all three modes of supplying nutrient salts. The data 

 of these experiments provided evidence that with re- 

 spect to the ions studied (K, Ca, Mg, H2PO4, NO3) 

 their intake by the plant over a 12 hour interval was 

 nearly the same during a dark period, with relatively 

 small water absorption by the plants, as during a 



