604 



Journal of Agricultural Research 



Vol. VI, No. 16 



of growth was only 42 days. This is due chiefly to the extensive de- 

 velopment of roots, making it possible to utilize more of the small quan- 

 tities of calcium and magnesium remaining in the extracted sand, for in 

 the other pots where these two elements were added such striking differ- 

 ences do not occur in the different crops. 



To each pot receiving 15 alfalfa seeds, 0.19 mgm. of calcium and 0.32 

 mgm. of magnesium were added in the seed, and for the three crops 

 164.5 mgm. of calcium and 90.72 mgm. of magnesium were removed. 

 This indicates to what extent the plants may attack relatively insoluble 

 compounds. 



Table X. — Analysis of alfalfa grown in soil, dolomite, andmagnesiie — series H 

 ALFALFA, FIRST CROP 



Pot No. 



147 and 148 

 149 and 150 

 151 and 152 

 155 and 156 

 157 and 158 

 159 and 160 

 161 and 162 

 163 



Substance added. 



Calcium. 



3. OI4 



5-78 

 2.897 



•73 2 

 1-44 

 .666 

 .666 

 3.47 



Magnesi- 

 um. 



O. 016 

 2. 64 

 I.328 



•344 

 2. o 

 6.0 

 10. o 



12. 7 



Composition of plants. 



Mom. 

 II. 2 

 98.4I 



136. O 



I27.8 



9 2 - 5 

 23.8 

 76.7 

 34-2 



Per cent. 

 O.382 

 I.382 



I-43 2 



1.28 



. 922 



. 426 



1.05 



.66 



Magnesium. 



Per cent. 



0. 198 



• 373 

 •357 



• 346 

 •744 

 •936 



1. 148 



■(>33 



Molecular 

 ratio of 

 calcium 

 to mag- 

 nesium. 



5 : 4-3 



5: 2.2 



5- 2 



5: 2. 2 



5: 6.8 



5:18.3 



5: 9-i 



5: 8 



ALFALFA, SECOND CROP 



147 



149 and 150 

 151 and 152 

 155 and 156 

 157 and 158 

 159 and 160 

 161 and 162 

 163 



5:5 

 5:2.2 



5:2.5 

 5:3-7 

 5:5-4 



5:8.5 

 5:6 



5:5.5 



ALFALFA, THIRD CROP 



147 



149 and 150 

 151 and 152 

 155 and 152 

 157 and 158 

 159 and 160 

 161 and 162 

 163 



5:3. 

 5:2. 

 5:1. 

 5:2. 

 5:4 

 5:7 

 5:9. 

 5:4. 



