No. 7. DEPARTMENT OF AGRICULTURE. 483 



success in the production of crops. He must not be content to main- 

 tain the soil in its present state of fertility, but should, if possible, 

 add to the fertility already at hand and thereby increase the pro- 

 ductive power of the soil. 



One of the well recognized means of bringing about this result — of 

 increasing the productive power of the soil — is that of tile draining: 

 The presence of free water is decidedly harmful to most plants, espe- 

 cially if allowed to stagnate near the surface. When the level of 

 free water is near the surface of the ground, great benefit is almost 

 certain to result from some system of underdrainage. So far as we 

 are aware, none of our agricultural plants will send their roots 

 below the water level ; but by means of drains we can lower the water 

 table and so increase the depth to which plant roots may feed. By 

 lowering the level of the free water in the soil we not only increase 

 the amount of root pasturage but open the way for the admission and 

 circulation of air in the soil spaces; a condition absolutely essen- 

 tial to root development. 



The admission of air to soils also assists in hastening the decay of 

 organic matter and in the production of nitrates. A soil charged with 

 surplus water is always cold, and the influence of drains in warming 

 the soil is very decided, especially in the spring. More heat is re- 

 quired to raise the temperature of a given weight of water one 

 degree than is necessary to cause the same increase in temperature 

 in an equal weight of soil. Hence a soil surcharged with water re- 

 mains cold in the spring much longer than well drained soils because 

 the heat from the sun which should go toward warming up the soil 

 is absorbed by the evaporation of moisture. The entire time allotted 

 to this paper might well be devoted to a discussion of this question 

 of drainage, but there are other factors to be mentioned relating to 

 the maintenance of soil fertility, so that we may not linger longer 

 on this phase of the question. But just in passing permit me to 

 urge upon you the importance of thorough drainage. In my judg- 

 ment it is the first and most important question to be considered in 

 establishing a permanent and profitable system of husbandry. 



TILLAGE 



Tillage includes all the operations of plowing and preparing the 

 ground for the reception of the seed and the subsequent cultivating 

 of the soil. Good tillage is one of the most efficient means of assist- 

 ing nature in rendering plant food available. The first effect of 

 tillage is to improve the texture of the soil in the mere mechanical 

 sense; that is, to make it fine and mellow so that the roots of plants 

 may readily pass through it, and that air and water may be more 

 readily admitted; thereby improving the conditions for root de- 

 velopment and for the multiplication of beneficial organisms. Some 

 soils are so stiff and heavy that neither roots nor water can easily 

 penetrate them; others are so loose and open that they have very 

 little capacity for retaining moisture. In either case tillage is 

 highly beneficial, especially if accompanied by the incorporation with 

 the soil of liberal quantities of organic matter. Surface cultivation 

 and the establishment of a dust mulch is especially desirable during 

 periods of drought at any time during the growing season. 



Man has not yet reached the point where he can regulate the 

 amount of rainfall which falls upon the earth ; but by proper tillage 



