FARM IRRIGATION 267 



out by hand with a mattock, at a cost of 

 $1.50 to $2.50 per acre. Sometimes it may be 

 plowed out in spring. If a railroad rail is dragged 

 over the field several times, in different directions, 

 the brush can be removed more easily. Sometimes 

 the land is flooded for a year to kill the sage- 

 brush. 



It is essential that irrigated land be very smooth 

 so that water will flow readily and evenly. The 

 land is usually first plowed then smoothed with 

 various home-made implements. One of the most 

 common is the "buck scraper" made of two 2-inch 

 planks, 10 inches wide, fastened together and pro- 

 vided with a steel shoe on the lower edge, and with 

 handles for dumping. There are several patented 

 scrapers. The cost of levelling is from $1 to $15 

 per acre. 



FREQUENCY AND TIME OF IRRIGATION 



Water should be applied no more frequently 

 than is absolutely necessary for the welfare of the 

 crop. One great danger in irrigation, especially 

 on fine-grained soils, is that of puddling the surface 

 by frequent copious wettings. Then, too, the 

 more often water is applied the greater is the loss 

 by evaporation and seepage and the greater the 

 labour. Dig down 3 or 4 feet in several places and 

 examine the soil. The condition of the soil and of 

 the crops are reliable guides; irrigate before the 

 subsoil gets very dry and before the crop begins to 

 suffer. Plants indicate the need of water by curling 

 their leaves, or the leaves may turn a darker green 

 than usual, or the lower leaves may turn yellow. 



There is no uniform practice as regards the 

 number of irrigations. It is usually necessary 



