[sHUTT] PRESIDENTIAL ADDRESS 9 
market gardeners and green-house workers have found them very 
valuable. There is a great future for research work in connection 
with the biology of the soil. 
Following the determination of the chemical constituents of 
plants and the establishment of the sources from which they are 
drawn, came the use of chemical plant foods, the so-called commercial 
fertilizers. Laboratory and field work showed that of the thirteen or 
so chemical elements entering into the composition of vegetable 
structures, three only—nitrogen, phosphoric acid and potash—need 
be considered in practical agriculture. Of the others, save occasion- 
ally lime, the soil and the air might always be depended upon to fur- 
nish an ample supply for crop needs. Out of this knowledge, the 
result of scientific research, has grown the use of fertilizers to increase 
crop production. The first of these was superphosphate, advocated 
and manufactured by Lawes in the earlier years of his investigations 
at Rothamsted. We, in Canada, have as yet done little towards as- 
certaining the place that fertilizers can take in economic methods of 
soil management, but yearly we are adding to our store of knowledge 
in this direction. Though we believe and teach that adherence to a 
rational system for the upkeep of fertility, the keeping of livestock, 
a proper rotation and correct methods of soil cultivation will 
make the farmer largely independent of these artificial and expensive 
forms of plant food, we also believe that with increased land values and 
increasing prices of labour on the one hand, and of agricultural prod- 
ucts on the other, intensive rather than extensive farming will be prac- 
tised, and with this change will come the wider and better use of fer- 
tilizers. That this use may be made with a fair expectancy of a profit- 
able return we are now experimenting widely on various types of soils 
and with many classes of crops. 
So far we have spoken of research work in connection with the 
requirements of crops; we might similarly indicate the nature of 
investigations to determine the requirements in the animal economy; 
the digestibility of the nutrients in cattle feeds are for the most part 
well established and this knowledge with that of the requirements of 
the animal for its maintenance, growth and reproduction have enabled 
the agricultural chemist to formulate ‘“‘balanced rations’’—the pro- 
portions most economic of protein, fat and carbohydrates—for main- 
tenance, for animals expending energy in doing work, for flesh pro- 
duction, for milk production, etc. Although the farmer can not 
understand the methods by which all this knowledge has been obtained, 
he has learnt the significance of the terms protein, fat and carbohy- 
drates, that feeding stuffs differ in their composition, in their digesti- 
bility and hence in their nutritive value, and all this information he can 
