602 



Journal of Agricultural Research 



Vol. VI, No. 16 



Plate LXXXIV shows the difference between some of the treatments 

 in series G. Observe the small growth of the wheat in the pot receiving 

 6 per cent of magnesium in magnesite. This is due to the physical con- 

 dition caused by applying the magnesite in a finely ground form, which 

 caused a setting that resembled cement, whereas in the pot with 10 per 

 cent of magnesium almost twice as much magnesite was applied, but 

 in a coarser form. For the ratios in these pots see Table VIII. 



Plate LXXXIV shows alfalfa growing under similar treatments. 



. Yields of wheat and alfalfa (in grams per pot on water-fr 

 dolomite, and magnesite series G and H 



basis) in soil, 



One of the most noticeable facts brought out in these series is the great 

 sensitiveness of the plants to small quantities of calcium and magnesium, 

 also their ability to utilize relatively insoluble forms of these two ma- 

 terials. In pots 121 and 122, Table IX, and pots 147 and 148, Table X, 

 the plants were grown in extracted sand receiving no calcium and mag- 

 nesium and were able to obtain considerable quantities that had not been 

 removed by the acid extractions. The alfalfa was even able to mature 

 a few seeds. 



