BENEFITS AND PROFITS OF DRAINAGE. 21 g 



drained sandy loam and an undrained black marsh 

 soil, both of them bare and level. 



Date. 



Apnl 24 



!* 25 

 " 26 

 " 27 



Temp, of 



Air 



Temp of 



Drained 



Soil. 



60.5° F. 

 64.0'= F. 

 45.0^ F. 

 53.0° F. 



66.50° F. 

 70.00° F. 

 50.00° F. 

 55.00° F. 



Temp, of 



Undramed 



Soil. 



54 00° F. 

 58,00° F. 

 44-00° F. 

 50.75° F. 



Differences. 



12 



12 



6 



4 



50° F. 

 00° F. 

 00° F. 

 25° F. 



The above observations are upon unlike soils, but the 

 range of differences in temperature between a drained 

 and undrained soil from which the surface-water has 

 been removed may be taken at from 5 to 10 degrees. 



Drainage Prevents a Large Waste of Fertility 

 by Surface WasMng. — The object of all drainage 

 should be to remove all surplus water through the soil, 

 not over it, thereby preventing loss by washing away 

 the fine soil particles which constitute its richest part. 

 The drained soil acts as a filter to arrest all the fertility 

 which may be held in suspension by the water to be 

 removed. 



Increases the Depth of Soil. — A drained soil be- 

 comes renovated — opened up, so to speak, to the full 

 depth to which it is drained. An additional field is 

 opened up for the use of plant-roots, giving them a 

 larger range from which to obtain both food and 

 moisture. 



A Drained Soil Resists Drought* — With reference 

 to the value of drainage for enabling soils to resist the 

 inroads of drought, experience confirms what we might 

 expect would be true from the general effects which 

 drainage has upon the soil. The additional fineness of 



