DRAINING THE LAND 159 



they are taking them from the place where most able to 

 do good. Drainage provides, therefore, both an entrance 

 into, and, at the same time, an exit out of the soil, for all 

 water that falls as rain. 



The sanitary effect of drainage. Wet soils are sour. 

 They are cold and uninviting. They are attractive nei- 

 ther to plants nor to bacteria. Since these are chiefly 

 interested in the soil, their comfort and their wishes must 

 be obeyed first. When both call for drainage, it 

 should be provided. 



Large tracts of land, now given over to swamps and 

 marshes, and which are in poor sanitary condition, would, 

 if drained, be most useful areas for crop production and 

 highly remunerative returns. 



Not all soils need drainage. You should not think that 

 all soils will be improved by drainage : far from it. Con- 

 sidering the whole area of our country, the total area of 

 land that needs drainage is small. We have vast areas 

 of swamp lands and heavy clay lands, that certainly need 

 drainage. But, on the other hand, many of our agricul- 

 tural lands are naturally drained : they have open sub- 

 soils that readily allow surface soakings to find channels 

 of escape. 



You should be able to determine for yourself where 

 drainage is necessary. What has been said before in this 

 chapter will indicate the type of lands that needs drain- 

 age, and that furnishes a fair diagnosis of drainage cases. 

 If your land needs drainage, by all means provide it. I 

 have known of many instances where a single crop has 

 paid for the entire cost of land drainage. Often soils, 

 more or less worthless, are made highly productive by a 

 thorough system of tiling. 



The kind of drain. We have two forms of drains : open 

 and covered. In case of the former, a simple channel or 



