196 SOILS 



value of a poor soil, and $100 per acre to the value 

 of rich soil. 



These, and other points in farm economics, 

 should decide the practicability of draining land, 

 after the need for draining it has been clearly 

 proved. There is much farm land now producing 

 indifferent crops, and the owners do not even sus- 

 pect that its mediocrity is due to poor drainage. 

 The first cost of draining land is large and the 

 returns from the outlay are not immediate; they 

 are distributed over many years. It may be 

 several years before the drains have paid for them- 

 selves. This fact is responsible for much of the 

 hesitancy among farmers about undertaking an 

 improvement that they readily admit is needed. 

 They hate to "bury their money," or to put into 

 the soil and out of sight an improvement the 

 operation of which they cannot watch. The same 

 argument, however, might be raised against the 

 use of a fertiliser; the operation of neither can be 

 watched, but the effects of both are readily seen. 

 There is a deepening interest in farm drainage 

 as land increases in value and as it becomes 

 correspondingly necessary to make plants comfort- 

 able, so that they may be grown at the lowest 

 possible cost of production. 



EFFECT OF DRAINING ON THE SOIL 



The direct benefits of draining land have al- 

 ready been pointed out in the chapters on the nature 

 of the soil and on soil water. The most important 

 result is that it makes the soil warmer. A wet 

 soil is cold, chiefly because the water in it is con- 

 stantly evaporating, and evaporation is a cooling 

 process. To illustrate this: If the bulb of one 



