THE DRAINAGE OF FARM SOILS 195 



drained for at least four feet below the surface. 

 Some of the most poorly drained farm soils are 

 on slopes. They are usually clayey and may 

 have springs oozing from them. In other words, 

 a slope is an aid to good drainage, but the 

 nature of the soil and its elevation with refer- 

 ence to surrounding land are far more important 

 factors. 



WHEN IT WILL PAY TO DRAIN LAND 



Not all land that would be greatly benefited by 

 being drained will it pay to drain. It is a question of 

 economics as well as of securing maximum pro- 

 ductiveness. It might be more practicable, for 

 example, to put a certain field of hard and rather 

 wet soil into grass, which usually grows fairly well 

 under these conditions, or at least better than most 

 other farm crops, than to go to the expense of 

 draining it for corn, cotton or rye. Trie more 

 exacting the crop, as regards an equable supply 

 of moisture, the more likely is it that it will pay 

 to drain the land. Likewise the higher the value 

 of land, and the more intense the culture, the 

 greater are the arguments for drainage. 



Again, it might pay to drain land used for 

 special crops which nave a high value per acre, as 

 market-garden crops, when it would not pay to 

 drain this land if it were planted to staple crops, 

 which have a lower value per acre. Furthermore, 

 it might not pay to drain a certain field if the far- 

 mer has plenty of other land which is better drained, 

 and land is cheap. Much also depends upon the 

 kind of soil, and the difference between its present 

 value and its value after being drained. The same 

 system of drainage may add $10 per acre to the 



