IRRIGATION FARMING 243 



a particular kind of grain to obtain the best results is 

 limited to less than three weeks, consequently a man with 

 a large acreage of grain must have his ditches made, and 

 be prepared to apply the water expeditiously, as soon as 

 the time arrives when he thinks it is wise to apply it. It 

 is better not to put water on a grain crop till the 

 stooling process has been completed, otherwise the ap- 

 plication of water might affect the development of the 

 crop at this point. As a rule one irrigation is all that is 

 required, but in extremely dry seasons a second irriga- 

 tion is necessary, if the best results are to be obtained. 

 The method used is to flood irrigate from laterals put in 

 at from forty to seventy yards apart in the field. These 

 may be run lengthwise of the ridges or "hogbacks", or 

 contour ditches may be put in at right angles to the fall 

 of the land. The latter plan is usually preferable. It 

 is better to have the ditches too close together than too 

 far apart. 



195. Potatoes. — It requires more skill and experience 

 to raise potatoes successfully under irrigation than any 

 other crop commonly grown. The secret appears to lie in 

 being able to keep the plants growing vigorously from 

 the beginning with no setbacks, and on the other hand 

 in being able to apply the water so that too sudden 

 growth will not be stimulated at any time. The first 

 irrigation should be very light, and it should not be given 

 until the small potatoes are set and perliaps the size of 

 peas. This stage is usually about the time the first blos- 

 soms appear. If the crop is wet before this time there 

 is danger of the plants setting more potatoes than they 

 will be able to develop to a marketable size. To be sure 

 that the potatoes are not wet too much when the first 

 irrigation is given, it is well to run the water between 



