20 BULLETIN 121. U. S. DEPARTMENT OF AGRICULTURE. 



lem of water supply should be considered carefully before any large 

 sirni of money is expended in the erection of a mill in any locality 

 in which irrigation is necessary. 



If the water supply in a given area will insure the growing of 

 only 5,000 acres of sugar beets annually under proper crop rotation 

 and under other conditions favorable to sugar-beet culture, it would 

 not be advisable to build a mill having a capacity greater than 500 

 tons per day. It frequentlj^ happens that a large part of the water 

 used for irrigating purposes is wasted either by badly constructed 

 ditches or by improper methods of irrigating. Ditches are im- 

 properly constructed when they allow an excessive amount of seep- 

 age or when they are so easily clogged that they overflow. Under 

 the methods in practice it is sometimes impossible to avoid using 

 water on certain fields when it is really not needed. Occasionally 

 the water is turned on from the reservoir or the community pumping 

 plant is put in operation before the water is actually needed by any 

 of the growers. Much can be done to delay the first irrigation and 

 to extend the time between irrigations by proper preparation of the 

 seed bed and by proper cultivation. In most irrigated areas the 

 actual water supply is limited, and in order to meet the crop re- 

 quirements as nearly as practicable there should be no waste of water 

 beyond the unavoidable losses due to seepage and evaporation. 



Methods of irrigation. — There are two general methods of irrigat- 

 ing sugar beets, namely, by flooding, as shown in Plate III, figure 2, 

 and by the furrow method, as shown in Plate I, figure 2. The first is 

 generally detrimental to sugar-beet production and is wasteful of 

 water. In flooding the entire surface of the field, more water is 

 used than would be used by the furrow method. There is a much 

 larger surface for evaporation. The air supply is cut off from the 

 beet roots, and as soon as the ground begins to dry after a flood irri- 

 gation the surface frequently forms a crust, which further cuts off 

 the air supply, promotes evaporation, and incases the beet plants in 

 such a way that it is very difficult to cultivate or otherwise work the 

 plants without doing some damage. It is argued that flood irrigation 

 is necessary in certain sections where the slope of the land is slight, 

 but it is seldom the case that the slope is not sufficient to enable the 

 careful irrigator to use the furrow method, especially if proper lat- 

 erals and cross ditches are used. In using the furrow method of 

 irrigation a furrow is made between the rows of beets or between 

 each alternate row and the next, as shown in Plate I, figure 2, and 

 frequently this furrow is smoothed or sledded out by an implement, 

 as shown in Plate V, figure 1, which is drawn lengthwise through 

 the furrow, leaving its surface smooth and well adapted to carrying 

 the water. The water should be turned into these furrows and 

 should be confined to them entirely, without flooding the surface 



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