THE BEET-SUGAR INDUSTRY IN 1920. 21 
in any locality in which irrigation is necessary to grow satisfactory 
crops of beets. 
If the water supply in a given area will insure the growing of 
only 5,0Q0 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 capachVy 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 improperly 
constructed when they allow an excessive amount of seepage 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 requirements as nearly as 
practicable there should be no Avaste of water beyond the unavoid- 
able 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 
method 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 frequently as the ground begins to dry after a 
flood irrigation the surface 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 fre- 
quently this furrow is smooth 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, should be 
confined to them entirely without flooding the surface around the 
