FARMERS' INSTITUTES. 19 



There are three elements in the soil upon which the chemist looks with 

 special attention — potash, phosphorus and nitrogen. This combination 

 constitutes the banking basis to sustain the green banks with which 

 nature clothes our fruitful fields — the currency of vegetable and animal 

 life, without which world-wide bankruptcy — famine — would blot out 

 all forms of life. 



DISCUSSION. 



Q. Does the fertility get away throvigh the tile when the land is drained? , 



Dr. Kedzie: But very little. As the water containing the plant food percolates 

 through the upper two or three feet of the soil it loses the soluble salts, which become 

 insoluble and remain in the ground. Naturally, if there be an excess of soluble food, 

 especially nitrates, there is quite certain to be some considerable loss. However, the old 

 idea that tile would leach the soil is now entirely exploded. 



Q. Do .you think the tile drains will help in maintaining or increasing fertility? 



Mr. Kedzie: In some ways, yes. They remove the water which excludes the air 

 necessary to make plant food already existing in the soil available. This insoluble 

 plant food is made soluble by bacteria very largely. These bacteria cannot live where 

 there is an excess of water. The drains by removing this excess of water therefore very 

 directly aid the increase of immediately available plant food. 



Q. Will humus not be lost where tile drains are put in? 



Dr. Kedzie; While humus is not itself directly available as plant food it serves an 

 indispensable purpose in retaining in the soil valuable elements of fertility in such shape 

 as to become available to plants when they need them most. For instance, the water- 

 holding capacity of the soil depends not alone upon the fineness of the soil particles, 

 but upon the amount of humus which the soil contains. Humus is vegetable and 

 animal matter slowly decaying. In very coarse soils this material decays too rapidly 

 to form humus. In undrained soils it may decay too slo^^iy or its decomposition may 

 result in products absolutely harmful to plant growth. In the latter case drainage 

 will actually aid the formation of humus. 



Q. Do oxide of iron, humus and clay hold nitrogen? 



Dr. Kedzie: No. Niti'ogen may be washed away from them. The best good to the 

 greatest number always comes in the proper balance of opposing forces. Were not a 

 large proportion of the nitrogen Avashed away from our soils health would suffer. 

 Where too much is washed away the fertility of the soil suffers. 



THE SOIL AS THE BACTERIOLOGIST SEES IT. 



PROF. C. E. MAKSHALL, AGRICULTURAL COLLEGE. 



The bacteriologist always has in view two distinct purposes when 

 he begins a complete analysis of the soil. One is the relation of the 

 soil to hygiene, in which he considers the dissemination of disease-pro- 

 ducing bacteria, such as the germs of typhoid fever, lockjaw, quarter 

 evil, anthrax, hog cholera, etc. The other is the relation of the soil to 

 the changes wrought by bacteria among its constituents. The latter 

 is evidently intended for our theme today. 



Before attempting to study bacteria in their actions as carried on in 

 the soil, let us make a cursory review of what they are capable of doing 

 in general. A keener appreciation of what they can accomplish in the 

 soil will be gained. 



