206 INTRODUCTION TO GENERAL SCIENCE 



d. 1606 : 48-50. How Water is Held in the Soil. 



e. 1607 : 129-133. How Water is Held in the Soil Soil Ca- 



pacity. 



/. 1608 : 43-45. Kinds of Moisture. 

 g. 1611 : 41-45. How Water is Held in the Soil. 

 h. 1612 : 40-43. Three Forms in which Water Exists in the 



Soil. Water-holding Capacity. 



148. To INCREASE THE MOISTURE-HOLDING CAPACITY 



TILLING 



The two aims of the farmer are to obtain as large an amount 

 of water as possible, and to conserve this water. If the soil 

 is left in its natural condition, a large percentage of the water 

 will run off, little being absorbed. To increase the capacity 

 of the soil for holding moisture, it should be loosened, and left 

 rough to prevent this surface water from running off, and the 

 amount of humus, which will be described later (Section 153), 

 should be increased. The idea is to render the soil as porous 

 as possible, so that the water may be absorbed rapidly. 

 Underdrainage takes a large amount of water away from the 

 soil, yet it leaves the soil porous, thereby increasing its 

 capillarity, and the water level, or, as it is called, the water 

 table, is maintained more nearly at the proper depth, than 

 without underdrainage. Under these conditions the soil 

 causes the water to rise from the water table, and there is 

 more water available for the plants. Any tilling, or cultivat- 

 ing of the land, which breaks up the soil into finer particles, 

 increases its moisture-holding capacity. 



By tilling of the soil is meant any artificial changing of the 

 surface of the ground, to prepare it for planting, or to aid in 

 the growth of the plants. The removal of weeds also comes 

 under this heading, since they deprive the soil of plant food, 

 which is thus lost. It is only in modern times that the ad- 



