186 IRRIGATION PRACTICE 



with six irrigations. Excellent crops of carrots were, how- 

 ever, obtained with four irrigations, and of sugar beets, 

 with only two irrigations. Each district must work out 

 the problem for itself, keeping well in mind that root 

 crops must be made to wait as long as possible for the 

 first irrigation and that thereafter, until early fall, they 

 should receive rather regular irrigations. 



Lucern, or alfalfa, should be watered with reference 

 to the number and times of cuttings. Over the irrigated 

 district three cuttings of lucern are ordinarily obtained 

 annually. The first irrigation should be applied when the 

 crop goes into flower, which is the time of the greatest 

 rate of growth. The next irrigation may be applied just 

 before or after the first cutting. This second irrigation 

 is intended, primarily, for the use of the second crop, and 

 its chief effect is to stimulate the early growth of the 

 second cutting. It matters little whether the crop be irri- 

 gated immediately before or after the cutting. It is pos- 

 sible that an irrigation before cutting permits the water to 

 be distributed more thoroughly in the soil, before the 

 growth of the second cutting begins. On the other hand, 

 the longer the interval between the irrigation and the cut- 

 ting of the first crop, the larger the loss by evaporation. 

 Each cutting of lucern could well receive an irrigation at 

 the time of flowering and another at the time of cutting, 

 excepting the third crop, which is usually cut so late as 

 to require no further irrigation, unless it be the fall irri- 

 gation which is practised for the benefit of next crop. 



Hay crops that yield only one cutting a year should 

 be treated very much as is the first cutting of lucern. 

 The one irrigation should be applied at the time of flow- 

 ering or seed time. If the aftermath is to be used, one or 

 more small applications may be applied throughout the 



