EXPERIMENTAL STUDY. 53 
The more soluble forms of magnesia, as nitrate and sulphate, are in 
excess more injurious to plants than the less soluble as carbonate, 
while the more soluble forms of lime as sulphate and nitrate are 
more efficient in overcoming the noxious effects of magnesia than less 
soluble forms as carbonate. 
In applying fertilizers containing magnesia, as in the crude potash 
salts, liming should be carried on in conjunction unless the soil is 
known to contain an excess of lime. Where the lime content of the 
soil is about equal to or less than the magnesia content, lime in a 
finely divided form, as sulphate, should be supplied with the fertilizer 
in an amount in excess of the magnesia present in the latter. 
In liming soils the amount of lime and magnesia should be first 
determined in both the soil and the material applied. In this way 
only can the process be intelligently carried out and the best ratio 
between the two bases for the promotion of the growth of crops be 
maintained. 
O 
