METHOD OF IRRIGATION 



213 



throughout the length of the furrow is very difficult. On 

 sandy soils, especially, the upper end of the furrow 

 absorbs so much water that little is left for the lower end. 

 In fact, when the furrow is long, it frequently happens 

 that the water disappears before the lower end is reached. 

 The best way to overcome this difficulty is probably to 

 shorten the furrows, and to have a series of temporary 

 supply ditches for each series of furrows. 



Finally, the soil is benefited by being occasionally 

 covered with water. The Utah work showed that, with 

 a given quantity of water, as large yields were invariably 

 obtained when the water was applied by flooding as by 

 furrowing, in spite of the greater loss by evaporation 



FIG. 54. Zigzag furrows to insure uniform distribution over soil. 



