22 BULLETIN 995, U. S. DEPARTMENT OE AGRICULTURE. 
beets, and should be allowed to flow until the soil is thoroughly wet. 
The head of water which is used in furrow irrigation must not be too 
large, as shown in Plate III, figure 2. The size of the head must be 
governed by the slope of the land, by the nature of the soil, and by 
the number of furrows that can be irrigated at one time. 
Leveling.— In order that irrigation may be properly done the field 
must be carefully leveled, as shown in Plate V, figure 2. This is 
frequently a limiting factor on many fields and occasionally in an 
entire community. The lack of success in at least one sugar-beet 
area is due primarily to the failure of the growers to level the ground 
properly. It usually requires several years to level a field properly 
for furrow irrigation, for the reason that the depressions that are 
filled during the first effort to level the field will usually settle and 
still leave slight depressions, while the higher points from which 
the soil was removed to make the fills do not settle, and an uneven- 
ness results. If the leveling process is repeated for two or three years 
the ground generally becomes sufficiently level to admit of furrow 
irrigation. If the ground is very uneven the Fresno scraper may 
often be used to good advantage. In some localities the surface of 
the soil is by nature sufficiently level to admit of proper irrigation. 
In other sections the slopes are sufficiently long and the -source of 
the water supply so high that it can be carried to the highest point 
and distributed over large areas without the expense of leveling the 
ground. In the process of leveling, the better surface soil is removed 
from the high point and carried to the depression. It is then neces- 
sary to improve the areas from which the better soil has been re- 
moved, either by the use of stable manure or a leguminous crop. 
Sometimes several years are required to make a leveled field uniform 
in fertility as well as in firmness of surface. 
A very coarse soil, especially if it has a porous subsoil, is irri- 
gated with great difficulty, and frequently much time and money 
are wasted in leveling such lands, as they are not adapted to the 
growing of sugar beets or other intensively cultivated crops. 
DRAINAGE. 
Drainage has an important bearing upon sugar-beet growing in 
general, as well as upon the production of other farm crops. Large 
areas of land that are now too wet to be cultivated could be put under 
tillage and would produce good crops if properly drained. Other 
large areas now under cultivation are in many instances becoming 
water-logged, especially in the irrigated sections, and will soon be 
unfit for crop production unless they are drained. In some instances 
the further expansion of the sugar-beet acreage is limited to the 
bringing in of areas through drainage. 
