20 BULLETIN 721. U. S. DEPARTMENT OF AGRICULTURE. 
lem of water supply should be considered carefully before any large 
sum 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 frequently 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 
