6oo 



Journal of Agricultural Research 



Vol. VI, No. 1 6 



EFFECT OF MAGNESIUM AND CALCIUM IN DOLOMITE, MAGNESITE, AND 

 PREPARED CARBONATES UPON WHEAT AND ALFALFA IN SAND (SERIES 

 E AND F) 



Table VI shows the yields of wheat and alfalfa when grown in sand 

 and treated with increasing amounts of magnesium in magnesite. The 

 applications vary between o.i per cent of magnesium and 0.6 per cent 

 of magnesium or 0.35 to 2.1 per cent of megnesite. Chemically pure 

 calcium carbonate was added to make a ratio of calcium to magnesium 

 equal to 5 to 4. The wheat and alfalfa in these two series were grown 

 to maturity, the seeds being ground up with the straw and an analysis 

 of the composite made. 



There was but little seed upon the alfalfa, owing to the fact that it 

 was grown under screens and the fertilization was poor. However, the 

 treatments seemed to cause no injury except where magnesium was 

 applied in the form of the prepared carbonates in pots 104 and 120. 



Table VI. — Yields of wheat and alfalfa {in grams per pot on a water-free basis) in mag- 

 nesite — series E and F 



Treatment. 



Molecular 

 ratio of 

 calcium 

 to mag- 

 nesium. 



Wheat, series E. 



Pot 

 No. 



Tops. 



Alfalfa, series F. 



Pot 



No. 



First 

 crop, 

 tops. 



Second 

 crop, 

 tops. 



Roots. 



None 



Percentage of magnesium in 

 magnesite plus calcium car- 

 bonate : 

 0.1 



Percentage of 



dolomite C3: 



0.6 



magnesium in 



Percentage of magnesium 

 magnesium carbonate 



5 : 4 

 5 : 4 

 5:4 

 5 : 4 

 5 : 4 

 5 : 4 

 5 : 4 

 5 : 4 

 5:4 

 5 : 4 

 5 : 4 

 5:4 



5:5-2 



5:5- 2 



5 : 4 



90 



9 1 

 92 

 93 

 94 



95 

 96 



97 

 98 



99 

 100 

 101 



102 

 103 



104 



7-25 



9.42 

 10.86 



i°5 



105 

 107 

 108 

 109 

 no 

 III 



112 



"3 

 114 



"5 

 Il6 

 117 



Il8 

 119 



6.86 



6-34 



5-72 



5-2 



5-36 



5-8 

 16 



94 



5-9 

 4.66 



3-78 



4-93 

 2. 64 



Table VII shows that the higher treatments have higher contents of 

 calcium and magnesium in the plants. The wheat grown in sand (pot 

 89) shows only 3.3 pounds of calcium and 2.6 pounds of magnesium 

 per ton, as against the pots treated with larger quantities of magnesite 



