Jan. is, 1921 Concentration of Potassium in Orthoclase Solutions 6 1 7 



Table I. — Relative availability of potassium in orthoclase solutions and in potassium- 



chlorid solutions 



Culture 

 No. 



ia 

 2a 

 3a 

 4a 



ib 

 2b 

 3b 

 4b 



5b 

 6b 

 ic 



2C 



3C 



4C 



5C 



id 

 2d 



3d 



4d 



5d 



6d 

 yd 

 8d 



9 d 



Culture solution. 



Control (distilled water) 



Control with CaSo, 



Orthoclase (solid phase present) 

 Orthoclase with CaSo 4 (solid 



phases present) 



Control 



Control with CaSo 4 



Orthoclase (solid phase present) 

 Orthoclase with CaSo 4 (solid 



phases present) 



KC1 



KC1 with CaSo, 



Control 



Orthoclase (solid phase present) 

 Orthoclase with CaSo 4 (solid 



phases present) 



Orthoclase with CaC0 3 (solid 



phases present) 



Orthoclase with 50 p. p. m. 



N0 3 and 50 p. p. m. P,0 5 



Control 



Control with CaSo, 



Orthoclase (solid phase present), 



changed daily 



Orthoclase and CaSo 4 (solid 



phases present), changed 



daily 



Orthoclase (solid phase) and 4 



p. p.m. K,0 as KC1, changed 



daily 



KC1 



KC1 with CaSo 4 



Orthoclase and KC1, changed 



once 



Orthoclase, not changed 



KsOin 

 solution. 



P. p. m. 

 O 

 O 

 2 tO 9 



2 tO 9 



to 

 to 



to 

 to 

 to 



Dry weight 

 of plants. 



to «9 



O 



o 

 to 9 



2 to 9 



6 to 13 

 4 



4 



6 to 13 

 2 to 9 



Gm. 



i- Si 



i-53 

 i-54 



1.58 

 1.36 



i-34 



i-43 



i-45 

 i-5° 

 1. 40 

 3.68 

 3-96 



3.68 



3-92 



3- 6 4 

 4.08 

 4.48 



4-3° 



4- 5° 



4- 5° 

 4-45 

 4.85 



4. 20 

 4. 10 



K20in 

 100 plants. 



Gm. 



o. 0295 

 . 0281 

 . 0284 



. 0272 



•036S 

 .0368 

 . 0366 



.0372 

 .0783 

 .0860 

 .0310 

 .0302 



•0345 



•0341 



.0341 

 .0368 



•0395 

 •0457 



041 1 



'. 0978 

 .0947 

 . IOIO 



.0683 



K2O in- 

 crease over 

 control. 



Per cent. 



O 



- 4 



- 3 



i.S 



+ 



+ 2 

 + 114 

 + 136 



+ 11 



+ 10 



+ 10 

 o 



+ 7 



+ 33 



+ 11 



+ 166 

 + 157 

 + 175 



+ 86 



+ 5 



AVAILABILITY OF POTASSIUM IN ORTHOCLASE SOLUTIONS NOT IN- 

 CREASED BY LIME OR GYPSUM 



The application of lime and gypsum to orthoclase-bearing soils has 

 been considered by some workers as a means of increasing the availability 

 of the potassium in such soils. The authors 1 found in an earlier investi- 

 gation that the addition of lime or gypsum to orthoclase solutions con- 

 taining the solid phase did not increase the concentration of the potas- 

 sium in the solution. The data presented in Table I show that these 

 substances also had no effect on the availability of the potassium in the 

 orthoclase solution. 



1 Briggs, Lyman J., and Breazeale, J. F. availability of potash in certain orthoclase-bearing 

 soils as affected by lime or gypsum. In Jour. Agr. Research, v. 8, no. i, p. 21-28. 1917. 



