Field Irrigation by Flooding 347 



of the regular plowing for the crops, and permitted 

 to extend through a number of years, thus making 

 the expense of fitting the ground for irrigation 

 mainly that of fitting the land for crops. By this 

 plan the field would be plowed in lands in one direc- 

 tion, with the back furrows always in the same place, 

 until the desired height is attained ; then these back 

 furrows would be crossed to form the other sides of 

 the checks, plowing in the same manner. 



In case the checks are large, 'the land between 

 the ridges may be subdivided and plowed in the 

 ordinary way, letting the back furrows and dead 

 furrows alternate in position with the seasons, in the 

 usual manner. There will be some finishing work 

 required, especially where the check ridges cross one 

 another. 



It is not, of course, necessary that the flooding 

 checks shall be square. If the field has a consider- 

 able fall in one direction and little or none in the 

 other, the checks may be made much longer in the 

 nearly level direction, and thus reduce the labor and 

 inequalities in the field. 



In cases where the slopes are more or less undu- 

 lating, the check ridges which are horizontal will 

 necessarily follow the course of contour lines, and 

 may neither cross the others at right angles nor be 

 parallel with one another, but they may still be 

 formed in the same manner. 



When it comes to flooding, the water may be 

 taken from the head distributary and sent down first 

 one tier of checks and then another, dropping the 



