452 



Reading-Course for Farmers. 



Effect of too much zuatcr. 



As is explained in Bulletin 2, water may be present in the soil in 

 such large amounts as to interfere with the growth of the plant. It 

 causes this injury in several ways. In fact, it has some influence on 

 nearly every one of the essential conditions of growth ; and this influence 

 is generally detrimental. 



To understand this point, it must be remembered that water is held 

 in the soil in several ways. If soil is placed in a funnel and water poured 

 upon it and the soil is then permitted to stand for a time, part of the water 

 passes through and out of the soil. But a considerable part of the water is 

 held by the soil by capillarity and it then appears nicely moist. All our 

 common crops are adapted to using this capillary moisture and any other 



Fig. 372. — Clay suil badly in need of tile drainage. Nczi' York. 



form of moisture is injurious to them. They are not adapted to living in 

 it just as a man is not adapted to living in water. If by means of a cork 

 in the funnel this gravity water is retained, it tends to " drown " the roots 

 or limit their development in proportion as the whole mass of soil is 

 saturated. It shuts out the air, locks up plant-food, renders the soil more 

 cold than it would otherwise be, and in addition it renders the soil soft 

 and miry, a condition especially undesirable for the practice of tillage. 



The removal of this surplus water from the soil is termed land or 

 agricultural drainage. 



AT red of drainage in A^e^u York. 



In New York State, millions of acres of land would be benefitted by 

 drainage. In the northern part of the State around Lake Ontario are 

 large areas of clay land, the productiveness of which is greatly reduced 

 because of their flat surface and dense character. In the southern part 



