BULLETIN 223] ' [MAY, 1914 



Ontario Department of Agriculture 



ONTARIO AGRICULTURAL COLLEGE 



Fertilizers 



IN RELATION TO SOILS AND CROP PRODUCTION 



By E. Harcourt and A. L. Gibson. 



INTEODUCTIOK 



On our comparatively new lands, and in general farm practice wlie a a 

 judicious rotation of crops is followed, and where grain is fed on the farm and 

 the manure properly cared for, it may not be necessary to use commercial fertilizers ; 

 but where the nature of the crops grown prevents rotation, and where very little 

 farmyard manure is produced, they may be required. More and more each year 

 it is found that the increased cost of production and the consequent need of 

 producing maximum crops, and the growing demands of the larger towns and 

 cities for garden and fruit products of high quality, are causing market gardeners 

 and fruit growers to consider seriously the advisability of using some form of 

 fertilizer. This has created a demand for information concerning these substances 

 which it has not been easy to fill; for experience has shown that the farmer must 

 possess a wide knowledge of plants, soils, and the fertilizers themselves before he 

 can properly use them. 



To intelligently and economically use fertilizers, it is essential that the farmer 

 understands the needs of the crops, their power to gather the essential plant food 

 constituents from the soil, and the purpose of their growth, i.e., whether the 

 object is to produce an immature plant for early market, or whether maturity 

 is required. He must also know something about the available supply of plant 

 food in the soil and the nature of the fertilizer being used. These fertilizers are 

 expensive, and unless they are intelligentiy applied in conjunction with very 

 thorough cultivation they will not give their best results. They cannot take the 

 place of cultivation; for they are food materials, and can only aid the growth 

 of the plant as they are absorbed by the roots, and these cannot develop fully in 

 a poorly cultivated soil. 



Because of the wide variation in the amount of available plant food in soils, 

 the differences in the needs of plants, and the necessity of the farmer gaining 

 some definite information regarding the nature of the fertilizers he is using and 



