FARM IRRIGATION 269 



drought of summer. If the subsoil is filled with 

 water in winter, little summer irrigation may be 

 needed. Winter irrigation is especially useful as 

 an adjunct to dry farming. 



The Time of Day to Irrigate. The best time to 

 irrigate is late in the afternoon, or on a cloudy day, 

 because less water is lost by evaporation; but the 

 more important consideration of convenience usual- 

 ly dictates the time, regardless of the hour. If 

 lieat-loving plants, as corn, are irrigated on a hot, 

 sunny day, the rapid evaporation may cool the soil 

 sufficiently to check growth somewhat. Crops 

 that shade the ground, as fruits and grasses, are not 

 subject to injury in this way. When water is 

 scarce, and can be had only during certain hours, 

 night irrigation is often necessary. This is an 

 economy of water, for less of it is lost by evaporation 

 and the water delivered at night usually costs less 

 than the same amount delivered in the day, but it 

 is difficult to apply it as skilfully. 



Directing the Flow. The flow of the water is 

 directed by a man with a long-handled shovel, 

 with which he keeps certain furrows open or 

 closes them, as needed. It is necessary that the 

 course of the water receive constant attention, for 

 it is likely to collect in the hollows or break the 

 channel. A common mistake in irrigating is to 

 hurry the water, thus increasing the washing of the 

 soil. Let it run so gently that the sides and bottom 

 of the furrows are not washed and the stream runs 

 clear. Too rapid application of water "slickens" 

 or puddles the soil ; let it soak in slowly. If the water 

 runs too slowly, direct more of it into each furrow ; 

 if it runs too fast, reduce the amount that is allowed 

 to enter the furrow. It requires much practice to 

 become really expert in handling water. 



