68 T. LytTrLeton Lyon AnD JAMES A. BizzELUL 
REMOVAL OF MAGNESIUM 
Magnesium was removed in much smaller quantity than was calcium, 
both in the drainage water and in the crops. In both ways the removal 
was less from the Volusia soil than from the Dunkirk, altho the removal 
of calcium was greater. 
Effect of plant growth on removal of magnesium 
The effect of plant growth on the removal of magnesium is brought out 
by table 20. It will be seen that there is a greater loss of magnesium in 
TABLE 20. AverRAGE ANNUAL REMOVAL OF MAGNESIUM FROM PLANTED AND FROM 
UNPLANTED TANKS 
(In pounds per acre) 
Magnesium removed in 
; Total 
Soil : 
Tanks t magnesium 
reatment De 
rainage Grops removed 
water 
LSE Se costae eee ee Planted. c.-:. 30.6 3.5 34.1 
AEST G2 hla siesta ee mee: fore) ce Barents eee A5 <4)'\" oo eee 45.4 
Magnesium conserved by cropping\55 =... asc-.02 5s oe ke oe eee 11.3 
the drainage water of the uncropped soil than in both the drainage and 
the crops of the planted soil. The large quantity of magnesium leached 
from the bare soil is apparently caused mainly by the solvent action of 
the nitric acid, as was the case with calcium. 
Not only is the total removal of magnesium greater from the bare than © 
from the planted soil, but its concentration is greater in the water from | 
the uncropped soil, as may be seen from table 21: 
