190 THE BOOK OF CORN 



the soil. In a slightly sandy loam, the work is accom- 

 plished in a brief period, but more and more time is 

 required as the soil grows finer in texture or more 

 clayey in composition. The first irrigation is some- 

 times performed by running small furrows near the 

 corn rows. In such cases the soil is not all made wet 

 and less water is required. 



Frequency of Application — The frequency of irri- 

 gation depends principally upon the capacity of the soil 

 and subsoil for holding water, the depth to which roots 

 may penetrate, and the attention given to keeping up 

 soil mulch and freeing the land of weeds. The method 

 of preparing the soil for planting, that is, the depth of 

 plowing and thoroughness in pulverizing, and the quan- 

 tity of water applied at each irrigation, will also affect 

 the frequency. A sandy loam with a gravelly subsoil 

 is very much less retentive of water and will, hence, re- 

 quire more frequent irrigation than a slightly clay loam 

 with a medium clay subsoil. The frequency is also 

 affected by the number of windy days and the regu- 

 larity of the sunshine. The more cloudy days and the 

 less wind, the more slow the evaporation and the less 

 frequent the irrigation. 



As the corn advances in growth and shades the 

 ground more and more, the evaporation is retarded 

 and there is a longer interval between the times of 

 applying the water. While enough moisture should 

 be kept in the ground for rapid growth, there is no time 

 that an abundant supply of water is more needed or 

 will have better effect than during the period covering 

 the time from the appearance of the silk and tassel until 

 the ears are formed, filled, and fully grown 



Time to Apply — If the soil contains a medium 

 amount of moisture at the time of planting, and it is 

 carefully conserved, there will be no need of irrigating 

 until the corn is well started. It is better to irrigate 



