LIMING OF SOILS FROM A PHYSIOLOGICAL STANDPOINT. 17 
effect, according to the law of mass. The writer noted, for example, 
among other observations, that certain alge, such as Spirogyra, died 
in five days in a solution of 1 per 1,000 magnesium nitrate, while they 
remained alive for a number of weeks in this solution when 0.3 per 
1,000 calcium nitrate was added. Of course, magnesium in form of 
sarbonate or phosphate in the soil would act injuriously in much less 
degree than the soluble magnesium nitrate, or sulphate; but nevertheless 
injury will show in time. 
How much, however, the result is influenced by the degree of fine- 
ness of these compounds may be judged from the observation of 
Ulbricht’ that a large amount of the commercial precipitated basic 
magnesium carbonate acts much more injuriously than finely powdered 
magnesite, and that slaked lime in excess diminished the yield in 
lupin more than an excess of powdered marl. This author also 
described cases in whicha rich manuring with lime depressed the yield, 
and further observed that a proper liming will remedy the evil effect 
of magnesium chlorid. 
Also Atterberg (1892) observed injurious effects of large applica- 
tions of magnesia upon oats on marsh soil and the prevention of this 
injury by liming. But previous to these authors E. Wolff* had 
observed on the one hand an injurious effect of burnt magnesia, and 
on the other the depression of the yield by a too excessive liming. 
Heinrich observed a decrease of the crop of the yellow lupin of 36 
per cent after adding as much as 0.5 per cent gypsum to the soil 
(quoted by Ulbricht, |. c.) and Uibricht observed by adding only 0.011 
per cent gypsum, a gain of 10.6 per cent of the lupin crop, and 21.5 
per cent of the buckwheat crop, while with red clover and with 
timothy a gain of only 1.5 per cent was noted. 
The crop of the yellow lupin was further considerably decreased in 
the experiments of Ulbricht by the application of 500 and 1,000 kilo- 
grams of lime to the morgen (1.6 acres). Also burnt magnesian lime- 
stone with 40 per cent magnesia had an injurious effect not only for 
lupin but for barley and vetch when applied in the amount of 500 
kilograms to the morgen. A diminution of the lime one-half and of 
magnesia one-fourth, or an appropriate mixture of pure limestone with 
magnesian limestone, might have resulted in a favorable harvest. 
Lime and magnesia can exert their indispensable nutritive functions 
only in a certain dependence upon each other. Hence a certain ratio 
between these two nutrients will produce the most favorable results,’ 
while a great excess of the one in the finest portion of the soil will 
lead to starvation and of the other to poisonous phenomena. 
1Landw. Vers. Stat., Vol. LIT, p. 383 (1899). The basic properties of precipitated 
magnesium carbonate and of slaked lime are soon destroyed by the carbonic acid 
dissolved in the water of the soil. 
* Grundlagen des Ackerbaues, 2d ed., p. 598. 
* This ratio will differ somewhat with different crops. 
4784 No. 1—01--—2 
