July 17, i 9 i6 Influence of Calcium and Magnesium on Plant Growth 601 



(ico and 101), which show 5.52 pounds of calcium and 10.88 pounds 

 of magnesium. 



Gile and Ageton (5, p. 44) show that many plants such as soybeans, 

 sugar cane, and sunflower have higher lime contents when grown upon 

 calcareous soils and that the increase in lime content tends to decrease 

 the amount of magnesia, iron, and potash. 



Table VII. — Analysis of wheat and alfalfa grown in magnesite — series E and F 



WHEAT STRAW 



ALFALFA HAY 



I°5 



106 and 107. 

 116 and 117. 

 118 and 119. 



105 



106 and 107. 

 116 and 117. 

 118 and 119. 



5 : 9-3 

 5^3-8 

 5 : 4- 2 

 5 : 3-5 



ALFALFA ROOTS 



5:4.8 



5:6 



5:8 



5 : 4. 6 



EFFECT OF MAGNESIUM AND CALCIUM IN CALCAREOUS SOIL, MAGNESITE, 

 DOLOMITE, AND PREPARED CARBONATES UPON WHEAT And ALFALFA 

 (SERIES g and h) 



It can be seen from Table VIII that the ratios of calcium to magne- 

 sium vary from one of 5 to 3.8 to one of 5 to 125 and that in both cases 

 considerable growth occurred. However, in pots 135, 136, 161, and 162, 

 receiving 35 per cent of magnesite and 100 gm. of calcium carbonate, 

 the plants showed a yellow color and some sickness; still, in the case 

 of alfalfa the plants were able to set some seed. The yields in pots 123, 

 124, 149, and 150, which received calcareous soil only, were somewhat 

 less than where sand was mixed with the soil, owing to the soil being 

 decidedly plastic and possessing a less desirable physical condition. 



