CHAPTER XVI 



BACTERIOLOGICAL AND ENZYME CHEMISTRY IN 

 RELATION TO AGRICULTURE 



It is becoming increasingly necessary for the scientific agri- 

 culturist to be well acquainted with the chemical changes 

 induced by bacteria and by enzymes. The economical use of 

 farmyard manure is better understood by a knowledge of the 

 character of fermentation which it undergoes, both spontane- 

 ously and in contact with the soil, before it is fitted for the 

 food of plants. The conditions of fertihty of soils, including 

 the maintenance of a sufficient proportion of nitrogen, are 

 intimately related to the bacterial life of the soil. 



For a right understanding of the conditions of growth of 

 plants, careful study is required of the changes brought about 

 by enzyme action in the various organs of the plant, particu- 

 larly in the seed and leaves. 



Important enzyme changes also occur in the preparation 

 of special fodder or silage for stock. 



Finally, for successful dairy work, especially the abiUty to 

 maintain a constant quahty in butter and cheese, a knowledge 

 of bacteriological chemistry is now almost essential. In the 

 following pages these aspects of the subject will be briefly 

 dealt with in order. 



Farmyard Manure. — Stable manure is of course a 

 complex mixture of substances, and the possible fermentations 

 which it may undergo are very various. When the animals 



