PLANTING AND CULTIVATING II9 



down this row of stakes before setting the wire stake, 

 a straight cross check can be secured. 



CULTIVATION 



The reasons for cultivation are: I, to destroy 

 weeds ; 2, conserve soil moisture; and 3, aerate the soil. 

 Of these the most important is the conservation of soil 

 moisture. If the ground is not stirred it bakes, cracks 

 open and the evaporation of moisture goes on very 

 rapidly. By stirring the soil through frequent cultiva- 

 tion, thus keeping a loose mulch on the surface, 

 capilliarity is broken up and the moisture retained. 

 The moisture can be used by plants for growth which 

 would otherwise be lost in the atmosphere. 



Conservation of Soil Moisture — The Wisconsin 

 experiment station has determined the amount of water 

 necessary to pass through the corn plant in order to 

 mature the plant. This station states that there is not 

 enough moisture in the soils of the cornfields of the 

 United States to mature the largest possible crop. This 

 moisture, taken up by the corn roots, passes through 

 the plant, carrying dissolved plant food which the 

 plants abstract and use in their process of growth, and 

 is given off to the atmosphere through the stomates of 

 the leaves. 



These pores of the corn leaves have a regulating 

 influence upon the amount of water given off to the 

 atmosphere. During dry, hot weather they open wide 

 as a bent spring or bow, and transpiration goes on very 

 rapidly. This tends to cool the temperature of the 

 plant as the perspiring of human beings tends to regu- 

 late the temperature of the body. So that the water 

 has not only the function of taking food into the plant, 

 but also the important matter of regulating the tem- 

 perature of the plant. 



