TIME OF IRRIGATION 185 



planted in well-saturated soil. The first irrigation should 

 be postponed, for the reasons already given, until the 

 plants really show need of water. From the time of the 

 first irrigation, water must be applied to these long- 

 growing crops at regular intervals throughout the grow- 

 ing season. Sugar beets, carrots, corn and like crops, 

 planted usually in May, need the greater quantity of 

 water in July and first half of August. From the first of 

 September and during autumn, little, if any, water should 

 be applied, even if the harvest does nob occur until October 

 or November. Sugar beets are seldom benefited by irri- 

 gation after the first of September. 



Under the conditions of the inter-mountain coun- 

 try and on deep clayey or loamy soils, 5 inches of water is a 

 fairly large single application. An irrigation of this 

 degree every two or three weeks throughout the season, 

 from the time of the first irrigation until the first week in 

 September, is quite sufficient to maintain the soil in a 

 first-class condition for the needs of beets and other long- 

 season crops. Usually, a much smaller quantity of water 

 at each irrigation will suffice to produce a bountiful har- 

 vest of root crops. It is doubtful, however, if more than 

 three weeks should elapse between irrigations, where 

 water is fairly abundant, for if the soil dries out too much 

 the plant may be injured permanently. When 15 acre- 

 inches are applied throughout the season it is well to 

 apply them hi four or five irrigations. The deeper the 

 soil, and the more thorough the surface-cultivation, the 

 fewer need be the applications. During the hot season, they 

 will naturally be closer together than in the early or late 

 summer. In one series of experiments, the highest yield 

 of carrots, a long-season crop, was obtained with seven 

 irrigations; the highest yield of sugar beets was obtained 



